Pro-inflammatory interactions of streptolysin O toxin with human neutrophils in vitro

The recent global resurgence of severe infections caused by the Group A streptococcus (GAS) pathogen, Streptococcus pyogenes, has focused attention on this microbial pathogen, which produces an array of virulence factors, such as the pore-forming toxin, streptolysin O (SOT). Importantly, the interactions of SOT with human neutrophils (PMN), are not well understood. The current study was designed to investigate the effects of pretreatment of isolated human PMN with purified SOT on several pro-inflammatory activities, including generation of reactive oxygen species (ROS), degranulation (elastase release), influx of extracellular calcium (Ca2+) and release of extracellular DNA (NETosis), using chemiluminescence, spectrophotometric and fluorimetric procedures, respectively. Exposure of PMN to SOT alone caused modest production of ROS and elastase release, while pretreatment with the toxin caused significant augmentation of chemoattractant (fMLP)-activated ROS generation and release of elastase by activated PMN. These effects of treatment of PMN with SOT were associated with both a marked and sustained elevation of cytosolic Ca2+concentrations and significant increases in the concentrations of extracellular DNA, indicative of NETosis. The current study has identified a potential role for SOT in augmenting the Ca2+-dependent pro-inflammatory interactions of PMN, which, if operative in a clinical setting, may contribute to hyper-activation of PMN and GAS-mediated tissue injury.

Transforming growth factor-β1 and soluble co-inhibitory immune checkpoints as putative drivers of immune suppression in patients with basal cell carcinoma

The current study compared the levels and possible associations between systemic soluble immune checkpoints (sICPs, n = 17) and a group of humoral modulators of immune suppressor cells (n = 7) in a cohort of patients with basal cell carcinoma (BCC, n = 40) and a group of healthy control subjects (n = 20). The seven humoral modulators of immunosuppressor cells were represented by the enzymes, arginase 1 and fibroblast activation protein (FAP), the chemokine, RANTES (CCL5) and the cytokines, interleukin-10 and transforming growth factor-β1 (TGF-β1), as well as the M2-type macrophage markers, soluble CD163 (sCD163) and sCD206. The plasma levels of six co-inhibitory sICPs, sCTLA-4, sLAG-3, sPD-1, sPD-L1, sTIM-3 and sPD-L2 were significantly elevated in the cohort of BCC patients (p<0.001-p<0.00001), while that of sBTLA was significantly decreased (p<0.006). Of the co-stimulatory sICPs, sCD27 and sGITR were significantly increased (p<0.0002 and p<0.0538) in the cohort of BCC patients, while the others were essentially comparable with those of the control participants; of the dual active sICPs, sHVEM was significantly elevated (p<0.00001) and TLR2 comparable with the control group. A correlation heat map revealed selective, strong associations of TGF-β1 with seven co-stimulatory (z = 0.618468-0.768131) and four co-inhibitory (z = 0.674040-0.808365) sICPs, as well as with sTLR2 (z = 0.696431). Notwithstanding the association of BCC with selective elevations in the levels of a large group of co-inhibitory sICPs, our novel findings also imply the probable involvement of TGF-β1 in driving immunosuppression in this malignancy, possibly via activation of regulatory T cells. Notably, these abnormalities were present in patients with either newly diagnosed or recurrent disease.

Filgrastim biosimilar (EP2006): A review of 15 years' post-approval evidence

Filgrastim is approved for several indications, including reduction of the incidence and duration of chemotherapy-induced neutropenia and for stem cell mobilization. The filgrastim biosimilar, EP2006, has been available in Europe since 2009, and in the United States since 2015. In this time, preclinical and clinical data used to support the approval of EP2006 have been published. These data established the biosimilarity of EP2006 to reference filgrastim in terms of structure, pharmacokinetics, pharmacodynamics, efficacy, safety, and immunogenicity. Additional real-world evidence studies have also demonstrated equivalent efficacy and safety of EP2006 compared with reference filgrastim, both in the reduction of neutropenia and in stem cell mobilization in clinical practice. This review summarizes these preclinical, clinical, and real-world data, as well as the available cost-effectiveness data, for EP2006 since its approval 15 years ago.

Cigarette Smoking as a Risk Factor for Tuberculosis in Adults: Epidemiology and Aspects of Disease Pathogenesis

It has been noted by the World Health Organisation that cases of tuberculosis in 2022 globally numbered 10.6 million, resulting in 1.3 million deaths, such that TB is one of the infectious diseases causing the greatest morbidity and mortality worldwide. Since as early as 1918, there has been an ongoing debate as to the relationship between cigarette smoking and TB. However, numerous epidemiological studies, as well as meta-analyses, have indicated that both active and passive smoking are independent risk factors for TB infection, development of reactivation TB, progression of primary TB, increased severity of cavitary disease, and death from TB, among several other considerations. With this considerable body of evidence confirming the association between smoking and TB, it is not surprising that TB control programmes represent a key potential preventative intervention. In addition to coverage of the epidemiology of TB and its compelling causative link with smoking, the current review is also focused on evidence derived from clinical- and laboratory-based studies of disease pathogenesis, most prominently the protective anti-mycobacterial mechanisms of the alveolar macrophage, the primary intracellular refuge of M. tuberculosis. This section of the review is followed by an overview of the major strategies utilised by the pathogen to subvert these antimicrobial mechanisms in the airway, which are intensified by the suppressive effects of smoke inhalation on alveolar macrophage function. Finally, consideration is given to a somewhat under-explored, pro-infective activity of cigarette smoking, namely augmentation of antibiotic resistance due to direct effects of smoke per se on the pathogen. These include biofilm formation, induction of cellular efflux pumps, which eliminate both smoke-derived toxicants and antibiotics, as well as gene modifications that underpin antibiotic resistance.

Intergenerational effects of ionizing radiation: review of recent studies from human data (2018-2021)

PURPOSE

The purpose of this paper was to conduct a review of the studies published between 2018 and 2022 to investigate radiation-related effects in the offspring of human individuals exposed to ionizing radiation.

METHODS

The search identified 807 publications, from which 9 studies were selected for detailed analysis to examine for effects in children whose parents were exposed to various types and doses of radiation.

RESULTS

The review does not yield substantial evidence supporting intergenerational effects of radiation exposure in humans. However, caution is required when interpreting the results due to limitations in the majority of the published articles.

CONCLUSION

This review, covering the period 2018-2022, serves as an extension of the previous systematic review conducted by Stephens et al. (2024), which encompassed the years 1988-2018. Together, these two papers offer a comprehensive overview of the available evidence regarding the intergenerational effects of parental pre-conceptional exposure to ionizing radiation. Overall, the findings do not provide strong evidence supporting a significant association between adverse (or other) outcomes in unexposed children and parental preconception radiation exposure.

Glucocorticoids with or without fludrocortisone in septic shock: a narrative review from a biochemical and molecular perspective

Two randomised controlled trials have reported a reduction in mortality when adjunctive hydrocortisone is administered in combination with fludrocortisone compared with placebo in septic shock. A third trial did not support this finding when hydrocortisone administered in combination with fludrocortisone was compared with hydrocortisone alone. The underlying mechanisms for this mortality benefit remain poorly understood. We review the clinical implications and potential mechanisms derived from laboratory and clinical data underlying the beneficial role of adjunctive fludrocortisone with hydrocortisone supplementation in septic shock. Factors including distinct biological effects of glucocorticoids and mineralocorticoids, tissue-specific and mineralocorticoid receptor-independent effects of mineralocorticoids, and differences in downstream signalling pathways between mineralocorticoid and glucocorticoid binding at the mineralocorticoid receptor could contribute to this interaction. Furthermore, pharmacokinetic and pharmacodynamic disparities exist between aldosterone and its synthetic counterpart fludrocortisone, potentially influencing their effects. Pending publication of well-designed, randomised controlled trials, a molecular perspective offers valuable insights and guidance to help inform clinical strategies.

Emerging markers of cancer cachexia and their relationship to sarcopenia

PURPOSE

Emerging biomarkers of cancer cachexia and their roles in sarcopenia and prognosis are poorly understood. Baseline assessments of anthropometrics, sarcopenia, cachexia status and biomarkers of cachexia were measured in patients with advanced cancer and healthy controls. Thereafter, relationships of the biomarkers with cachexia and sarcopenia were explored.

METHODS

A prospective case-control design was used, including 40 patients with advanced cancer and 40 gender, age-matched controls. Bioelectrical impedance [skeletal muscle index (SMI)] and hand dynamometry [hand grip strength (HGS)] assessed sarcopenia and a validated tool classified cancer cachexia. Albumin, lymphocyte and platelet counts, haemoglobin, C-reactive protein (CRP), pro-inflammatory cytokines/chemokines and citrullinated histone H3 (H3Cit) were measured.

RESULTS

Patients had significantly lower SMI (6.67 kg/m2 versus 7.67 kg/m2, p =  < 0.01) and HGS (24.42 kg versus 29.62 kg) compared to controls, with 43% being sarcopenic. Significant differences were found for albumin, lymphocyte and platelet counts, haemoglobin, CRP, and tumour necrosis factor α (TNFα), (p < 0.01). Interleukin (IL)-6 (p < 0.04), IL-8 (p = 0.02), neutrophil/lymphocyte ratio (NLR), p = 0.02, platelet/lymphocyte (PLR) ratio, p < 0.01 and systemic immune inflammatory index (SII), p < 0.01 differed significantly. No difference was observed for CXC motif chemokine ligand 5 [CXCL5 or epithelial neutrophil-activating peptide 78 (ENA78)] or H3Cit. Albumin and haemoglobin correlated negatively with total protein, skeletal muscle mass and SMI (all p < 0.01). The presence of sarcopenia associated significantly with albumin, haemoglobin and CRP.

CONCLUSION

Significant relationships and differences of haemoglobin, CRP and albumin supports future use of these biomarkers in cancer cachexia. CXCL5 and H3Cit as valuable biomarkers in cancer cachexia remains to be defined.

A prospective, real-world, multinational study of febrile neutropenia (FN) occurrence in oncology patients receiving chemotherapy with intermediate risk of FN: a MASCC Neutropenia, Infection, and Myelosuppression Study Group initiative

PURPOSE

Limited knowledge is available on the incidence of febrile neutropenia (FN) in intermediate-risk patients and the rationale for use of granulocyte colony-stimulating factor (G-CSF) in these patients. We aimed to estimate the rate at which patients associated with intermediate risk (10-20%) of FN would develop ≥ 1 episode of FN with a commonly used chemotherapy regimen in clinical practice.

METHODS

This prospective, real-world, observational, multinational, multicenter study (December 2016-October 2019) recruited patients with solid tumors or Hodgkin's/non-Hodgkin's lymphoma. Patients receiving chemotherapy with intermediate risk of FN, but not G-CSF as primary prophylaxis were included and observed for the duration of the chemotherapy (≤ 6 cycles and ≤ 30 days after the last chemotherapy administration).

RESULTS

In total, 364 patients (median age, 56 years) with 1601 cycles of chemotherapy were included in the analysis. The incidence of FN was 5% in cycle 1, 3% in cycles 2-3, and 1% in cycles 4-6. The rate of patients with ≥ 1 episode of FN was 9%, and 59% of FN events were reported during cycle 1. The rate of grade 4 neutropenia in cycle 1 was 11%, and 15% of patients experienced ≥ 1 episode of grade 4 neutropenia.

CONCLUSIONS

Overall, the incidence of FN was low, with a high incidence in cycle 1 and a decrease in the subsequent cycles. These results provide the real FN risk for common chemotherapy regimens in patients generally excluded from clinical trials. Prophylactic G-CSF in intermediate-risk patients could be considered as per clinician's judgement.

Subcutaneous panniculitis-like T-cell lymphoma in two unrelated individuals with BENTA disease

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare primary cutaneous non-Hodgkin lymphoma involving CD8+ T cells, the genetic underpinnings of which remain incompletely understood. Here we report two unrelated patients with B cell Expansion with NF-κB and T cell Anergy (BENTA) disease and a novel presentation of SPTCL. Patient 1 presented early in life with recurrent infections and B cell lymphocytosis, linked to a novel gain-of-function (GOF) CARD11 mutation (p.Lys238del). He developed SPTCL-like lesions and membranoproliferative glomerulonephritis by age 2, treated successfully with cyclosporine. Patient 2 presented at 13 months with splenomegaly, lymphadenopathy, and SPTCL with evidence of hemophagocytic lymphohistiocytosis. Genetic analysis revealed two in cis germline GOF CARD11 variants (p.Glu121Asp/p.Gly126Ser). Autologous bone marrow transplant resulted in SPTCL remission despite persistent B cell lymphocytosis. These cases illuminate an unusual pathological manifestation for BENTA disease, suggesting that CARD11 GOF mutations can manifest in cutaneous CD4+and CD8+ T cell malignancies.

Comparison of platelet-and endothelial-associated biomarkers of disease activity in people hospitalized with Covid-19 with and without HIV co-infection

Introduction

SARS-CoV-2 elicits a hyper-inflammatory response that contributes to increased morbidity and mortality in patients with COVID-19. In the case of HIV infection, despite effective anti-retroviral therapy, people living with HIV (PLWH) experience chronic systemic immune activation, which renders them particularly vulnerable to the life-threatening pulmonary, cardiovascular and other complications of SARS-CoV-2 co-infection. The focus of the study was a comparison of the concentrations of systemic indicators o\f innate immune dysfunction in SARS-CoV-2-PCR-positive patients (n=174) admitted with COVID-19, 37 of whom were co-infected with HIV.

Methods

Participants were recruited from May 2020 to November 2021. Biomarkers included platelet-associated cytokines, chemokines, and growth factors (IL-1β, IL-6, IL-8, MIP-1α, RANTES, PDGF-BB, TGF-β1 and TNF-α) and endothelial associated markers (IL-1β, IL-1Ra, ICAM-1 and VEGF).

Results

PLWH were significantly younger (p=0.002) and more likely to be female (p=0.001); median CD4+ T-cell count was 256 (IQR 115 -388) cells/μL and the median HIV viral load (VL) was 20 (IQR 20 -12,980) copies/mL. Fractional inspired oxygen (FiO2) was high in both groups, but higher in patients without HIV infection (p=0.0165), reflecting a greater need for oxygen supplementation. With the exception of PDGF-BB, the levels of all the biomarkers of innate immune activation were increased in SARS-CoV-2/HIV-co-infected and SARS-CoV-2/HIV-uninfected sub-groups relative to those of a control group of healthy participants. The magnitudes of the increases in the levels of these biomarkers were comparable between the SARS-CoV-2 -infected sub-groups, the one exception being RANTES, which was significantly higher in the sub-group without HIV. After adjusting for age, sex, and diabetes in the multivariable model, only the association between HIV status and VEGF was statistically significant (p=0.034). VEGF was significantly higher in PLWH with a CD4+ T-cell count >200 cells/μL (p=0.040) and those with a suppressed VL (p=0.0077).

Discussion

These findings suggest that HIV co-infection is not associated with increased intensity of the systemic innate inflammatory response during SARS-CoV-2 co-infection, which may underpin the equivalent durations of hospital stay, outcome and mortality rates in the SARS-CoV-2/HIV-infected and -uninfected sub-groups investigated in the current study. The apparent association of increased levels of plasma VEGF with SARS-CoV-2/HIV co-infection does, however, merit further investigation.

Pro-Tumorigenic and Thrombotic Activities of Platelets in Lung Cancer

Aside from their key protective roles in hemostasis and innate immunity, platelets are now recognized as having multifaceted, adverse roles in the pathogenesis, progression and outcome of many types of human malignancy. The most consistent and compelling evidence in this context has been derived from the notable association of elevated circulating platelet counts with the onset and prognosis of various human malignancies, particularly lung cancer, which represents the primary focus of the current review. Key topics include an overview of the association of lung cancer with the circulating platelet count, as well as the mechanisms of platelet-mediated, pro-tumorigenic immunosuppression, particularly the role of transforming growth factor beta 1. These issues are followed by a discussion regarding the pro-tumorigenic role of platelet-derived microparticles (PMPs), the most abundant type of microparticles (MPs) in human blood. In this context, the presence of increased levels of PMPs in the blood of lung cancer patients has been associated with tumor growth, invasion, angiogenesis and metastasis, which correlate with disease progression and decreased survival times. The final section of the review addresses, firstly, the role of cancer-related platelet activation and thrombosis in the pathogenesis of secondary cardiovascular disorders and the associated mortality, particularly in lung cancer, which is second only to disease progression; secondly, the review addresses the potential role of antiplatelet agents in the adjunctive therapy of cancer.

The Global Burden of Community-Acquired Pneumonia in Adults, Encompassing Invasive Pneumococcal Disease and the Prevalence of Its Associated Cardiovascular Events, with a Focus on Pneumolysin and Macrolide Antibiotics in Pathogenesis and Therapy

Despite innovative advances in anti-infective therapies and vaccine development technologies, community-acquired pneumonia (CAP) remains the most persistent cause of infection-related mortality globally. Confronting the ongoing threat posed by Streptococcus pneumoniae (the pneumococcus), the most common bacterial cause of CAP, particularly to the non-immune elderly, remains challenging due to the propensity of the elderly to develop invasive pneumococcal disease (IPD), together with the predilection of the pathogen for the heart. The resultant development of often fatal cardiovascular events (CVEs), particularly during the first seven days of acute infection, is now recognized as a relatively common complication of IPD. The current review represents an update on the prevalence and types of CVEs associated with acute bacterial CAP, particularly IPD. In addition, it is focused on recent insights into the involvement of the pneumococcal pore-forming toxin, pneumolysin (Ply), in subverting host immune defenses, particularly the protective functions of the alveolar macrophage during early-stage disease. This, in turn, enables extra-pulmonary dissemination of the pathogen, leading to cardiac invasion, cardiotoxicity and myocardial dysfunction. The review concludes with an overview of the current status of macrolide antibiotics in the treatment of bacterial CAP in general, as well as severe pneumococcal CAP, including a consideration of the mechanisms by which these agents inhibit the production of Ply by macrolide-resistant strains of the pathogen.

Comparison of the effects of electronic cigarette vapours and tobacco smoke extracts on human neutrophils in vitro

Background

Electronic cigarettes (ECs) are electronic aerosol delivery systems composed of nicotine and various chemicals, which are widely used to facilitate smoking cessation. Although ECs are considered safer than cigarettes, they do, however, contain chemical toxicants, some of which may interact with cells of the host's innate immune system of which neutrophils constitute a key component.

Methods

The current study was designed to compare the effects of aqueous EC aerosol extracts (ECEs; with or without nicotine) with those of cigarette smoke extract (CSE) on neutrophil and platelet reactivity in vitro. Neutrophil reactivity is characterised by the generation of reactive oxygen species (ROS), degranulation (elastase release) and the release of extracellular DNA (neutrophil extracellular trap (NET) formation: NETosis), which were measured using chemiluminescence, spectrophotometric and microscopic procedures, respectively. Platelet reactivity was measured according to the magnitude of upregulated expression of the adhesion molecule CD62P on activated cells using a flow cytometric procedure.

Results

Exposure of neutrophils to either ECEs or CSE caused a significant inhibition of ROS generation and elastase release by N-formyl-l-methionyl-l-leucyl-l-phenylalanine (1 µM)-activated neutrophils. Pre-treatment of neutrophils with CSE also resulted in a marked attenuation of phorbol 12-myristate 13-acetate (6.25 nM)-mediated release of extracellular DNA, which was unaffected by the ECEs. Similarly, CSE, but not the ECEs, inhibited the expression of CD62P by platelets activated with ADP (100 µM).

Conclusions

These observations suggest that ECE aerosols may inhibit some of the immuno-protective activities of neutrophils such as ROS production and elastase release by activated cells, the effect of which was not enhanced by inclusion of nicotine. The inhibitory effects of CSE were significantly more pronounced than those of ECEs, especially so for suppression of NET formation and platelet activation. If operative in vivo, these harmful immunosuppressive effects of ECEs may compromise intrinsic pulmonary antimicrobial defence mechanisms, albeit less so than cigarette smoke.

Dysregulation of systemic soluble immune checkpoints in early breast cancer is attenuated following administration of neoadjuvant chemotherapy and is associated with recovery of CD27, CD28, CD40, CD80, ICOS and GITR and substantially increased levels of PD-L1, LAG-3 and TIM-3

Neoadjuvant chemotherapy (NAC) may alter the immune landscape of patients with early breast cancer (BC), potentially setting the scene for more effective implementation of checkpoint-targeted immunotherapy. This issue has been investigated in the current study in which alterations in the plasma concentrations of 16 soluble co-stimulatory and co-inhibitory, immune checkpoints were measured sequentially in a cohort of newly diagnosed, early BC patients (n=72), pre-treatment, post-NAC and post-surgery using a Multiplex® bead array platform. Relative to a group of healthy control subjects (n=45), the median pre-treatment levels of five co-stimulatory (CD27, CD40, GITRL, ICOS, GITR) and three co-inhibitory (TIM-3, CTLA-4, PD-L1) soluble checkpoints were significantly lower in the BC patients vs. controls (p&lt;0.021-p&lt;0.0001; and p&lt;0.008-p&lt;0.00001, respectively). Following NAC, the plasma levels of six soluble co-stimulatory checkpoints (CD28, CD40, ICOS, CD27, CD80, GITR), all involved in activation of CD8+ cytotoxic T cells, were significantly increased (p&lt;0.04-p&lt;0.00001), comparable with control values and remained at these levels post-surgery. Of the soluble co-inhibitory checkpoints, three (LAG-3, PD-L1, TIM-3) increased significantly post-NAC, reaching levels significantly greater than those of the control group. PD-1 remained unchanged, while BTLA and CTLA-4 decreased significantly (p&lt;0.03 and p&lt;0.00001, respectively). Normalization of soluble co-stimulatory immune checkpoints is seemingly indicative of reversal of systemic immune dysregulation following administration of NAC in early BC, while recovery of immune homeostasis may explain the increased levels of several negative checkpoint proteins, albeit with the exceptions of CTLA-4 and PD-1. Although a pathological complete response (pCR) was documented in 61% of patients (mostly triple-negative BC), surprisingly, none of the soluble immune checkpoints correlated with the pCR, either pre-treatment or post-NAC. Nevertheless, in the case of the co-stimulatory ICMs, these novel findings are indicative of the immune-restorative potential of NAC in early BC, while in the case of the co-inhibitory ICMs, elevated levels of soluble PD-L1, LAG-3 and TIM-3 post-NAC underscore the augmentative immunotherapeutic promise of targeting these molecules, either individually or in combination, as a strategy, which may contribute to the improved management of early BC.

1354 USING REALIST PROGRAMME THEORY TO DESIGN A NEW INTERVENTION FOR IMPROVING RECOVERY AFTER DELIRIUM

Introduction

People who recover poorly after delirium are likely to require an increased level of care. It is presently unknown whether interventions to improve recovery after delirium are effective and cost-effective. This research aimed to develop a programme theory to inform the design of an intervention to improve recovery after delirium.

Method

A rapid realist review of literature was conducted to develop an initial programme theory. Following this, a qualitative investigation of the perceived rehabilitation needs of older people who have experienced delirium during a hospital stay was conducted via semi-structured interviews with 41 key stakeholders (older people (5), carers (12), and healthcare professionals (24)). Data were analysed using a realist approach to identify what works, for whom, and in what context. This was deductively informed by the initial programme theory while also employing an inductive analysis to identify novel insights. Through an iterative, retroductive process, context-mechanism-outcome configurations (CMOCs) were coded to reflect stakeholders’ views to refine the programme theory.

Results

The initial programme theory highlighted the importance of cognitive and physical rehabilitation and emotional support as key domains of recovery. New CMOCs included optimisation of good medical care to manage delirium and monitoring and management of underlying medical conditions to promote recovery. Others included developing educational resources and support networks for older people and their carers to aid sense-making, and encouraging social interaction to reduce isolation and empower independent functioning. These recovery elements should be addressed in a person-centred manner that is tailored to individual needs and preferences, engages carers, integrates intervention goals into daily functioning, and ensures continuity of care.

Conclusion

A refined programme theory was developed and is currently being used to design a manualised intervention to improve recovery after delirium. The acceptability of the intervention will be tested in a multi-centre, single-arm feasibility study.

Pro-Inflammatory Interactions of Dolutegravir with Human Neutrophils in an In Vitro Study

There is increasing awareness of an association between the uptake of the HIV integrase inhibitor, dolutegravir, in first-line antiretroviral regimens with unusual weight gain and development of the metabolic syndrome, particularly in African women. Although seemingly unexplored, the development of systemic inflammation linked to the putative pro-inflammatory activity of dolutegravir represents a plausible pathophysiological mechanism of this unusual weight gain. This possibility was explored in the current study undertaken to investigate the effects of dolutegravir (2.5−20 μg/mL) on several pro-inflammatory activities of neutrophils isolated from the blood of healthy, adult humans. These activities included the generation of reactive oxygen species (ROS), degranulation (elastase release) and alterations in the concentrations of cytosolic Ca2+ using chemiluminescence, spectrophotometric and fluorimetric procedures, respectively. Exposure of neutrophils to dolutegravir alone resulted in the abrupt, dose-related, and significant (p < 0.0039−p < 0.0022) generation of ROS that was attenuated by the inclusion of the Ca2+-chelating agent, EGTA, or inhibitors of NADPH oxidase (diphenyleneiodonium chloride, DPI), phospholipase C (U733122), myeloperoxidase (sodium azide) and phosphoinositol-3-kinase (wortmannin). In addition, exposure to dolutegravir augmented the release of elastase by stimulus-activated neutrophils. These pro-inflammatory effects of dolutegravir on neutrophils were associated with significant, rapid, and sustained increases in the concentrations of cytosolic Ca2+ that appeared to originate from the extracellular compartment, seemingly consistent with an ionophore-like property of dolutegravir. These findings are preliminary and necessitate verification in the clinical setting of HIV infection. Nevertheless, given the complex link between inflammation and obesity, these pro-inflammatory interactions of dolutegravir with neutrophils may contribute to unexplained weight gain, possibly via the development of insulin resistance.

Dolutegravir potentiates platelet activation by a calcium-dependent, ionophore-like mechanism

Dolutegravir is a highly potent HIV integrase strand transfer inhibitor that is recommended for first-line anti-retroviral treatment in all major treatment guidelines. A recent study has shown that people taking this class of anti-retroviral treatment have a substantially higher risk of early-onset cardiovascular disease, a condition shown previously to be associated with increased platelet reactivity. To date, few studies have explored the effects of dolutegravir on platelet activation. Accordingly, the current study was undertaken with the primary objective of investigating the effects of dolutegravir on the reactivity of human platelets in vitro. Platelet-rich plasma, isolated platelets, or buffy coat cell suspensions prepared from the blood of healthy adults were treated with dolutegravir (2.5-10 µg/ml), followed by activation with adenosine 5'-diphosphate (ADP), thrombin, or a thromboxane A₂ receptor agonist U46619. Expression of platelet CD62P (P-selectin), formation of heterotypic neutrophil:platelet aggregates, and calcium (Ca²⁺) fluxes were measured using flow cytometry and fluorescence spectrometry, respectively. Dolutegravir caused dose-related potentiation of ADP-, thrombin- and U46619-activated expression of CD62P by platelets, as well as a significant increases in formation of neutrophil:platelet aggregates. These effects were paralleled by a spontaneous, receptor-independent elevation in cytosolic Ca²⁺ that appears to underpin the mechanism by which the antiretroviral agent augments the responsiveness of these cells to ADP, thrombin and U46619. The most likely mechanism of dolutegravir-mediated increases in platelet cytosolic Ca²⁺ relates to a combination of lipophilicity and divalent/trivalent metal-binding and/or chelating properties of the anti-retroviral agent. These properties are likely to confer ionophore-type activities on dolutegravir that would promote movement of Ca²⁺ across the plasma membrane, delivering the cation to the cytosol where it would augment Ca²⁺-dependent intracellular signaling mechanisms. These effects of dolutegravir may lead to hyper-activation of platelets which, if operative in vivo, may contribute to an increased risk for cardiometabolic co-morbidities.

The remarkable history of pneumococcal vaccination: an ongoing challenge

Although it varies with age and geographical distribution, the global burden of infection with Streptococcus pneumoniae (pneumococcus) remains considerable. The elderly, and younger adults with comorbid conditions, are at particularly high risk of pneumococcal infection, and this risk will increase as the population ages. Vaccination should be the backbone of our current strategies to deal with this infection.

Main body: This manuscript reviews the history of the development of pneumococcal vaccines, and the impact of different vaccines and vaccination strategies over the past 111 years. It documents the early years of vaccine development in the gold mines of South Africa, when vaccination with killed pneumococci was shown to be effective, even before the recognition that different pneumococci were antigenically distinct. The development of type-specific vaccines, still with whole killed pneumococci, showed a high degree of efficacy. The identification of the importance of the pneumococcal capsule heralded the era of vaccination with capsular polysaccharides, although with the advent of penicillin, interest in pneumococcal vaccine development waned. The efforts of Austrian and his colleagues, who documented that despite penicillin therapy, patients still died from pneumococcal infection in the first 96 h, ultimately led to the licensing first of a 14-valent pneumococcal polysaccharide in 1977 followed by the 23-valent pneumococcal polysaccharide in 1983. The principal problem with these, as with other polysaccharide vaccines, was that that they failed to immunize infants and toddlers, who were at highest risk for pneumococcal disease. This was overcome by chemical linking or conjugation of the polysaccharide molecules to an immunogenic carrier protein. Thus began the era of pneumococcal conjugate vaccine (PCV), starting with PCV7, progressing to PCV10 and PCV13, and, most recently, PCV15 and PCV20. However, these vaccines remain serotype specific, posing the challenge of new serotypes replacing vaccine types. Current research addresses serotype-independent vaccines which, so far, has been a challenging and elusive endeavor.

Conclusion: While there has been enormous progress in the development of pneumococcal vaccines during the past century, attempts to develop a vaccine that will retain its efficacy for most pneumococcal serotypes are ongoing.

O003 Radiation-related chromosomal aberrations observed in high volume endovascular operators performing X-ray guided surgery

Introduction

The biological effects of chronic, low dose radiation, to which operators performing fluoroscopy-guided procedures are exposed, are unknown. We have previously demonstrated acute DNA damage/repair in lymphocytes from operators performing fluoroscopy-guided endovascular aneurysm repair (EVAR), but these markers normalised after 24 hours and did not inform on the residual accumulated effects of chronic radiation exposure. In the present study cytogenetic techniques were used to examine for chromosomal aberrations in endovascular operators.

Methods

Peripheral blood lymphocytes were isolated from high volume endovascular operators performing EVAR and age-matched radiation naïve general surgeons as controls. Giemsa staining was used to visualise the full complement of chromosomes and all dicentrics, where 2 centromeres are present in a single chromosome, were identified. The genome was analysed for abnormal exchanges of genetic material between chromosomes using multiplex fluorescence in situ hybridisation (mFISH).

Results

Lymphocytes from 18 operators (12 exposed, 6 controls) were analysed. A higher frequency of dicentric chromosomes were found in exposed operators compared with controls (0.0011 vs 0.0004, respectively, P=0.002) after examining 54,000 lymphocytes. Twice as many complex chromosome rearrangements were seen in endovascular operators compared with controls (0.48% vs 0.24%). Aneuploidy, the abnormal loss of chromosomes, was more frequent in endovascular operators with a median difference of 0.35 per chromosome (P=0.004).

Conclusion

We have found a higher frequency of chromosomal aberrations in endovascular operators compared with radiation naïve colleagues. This justifies further individual biological profiling for genomic instability and personalised radiation risk assessment.

Take-home message

Radiation-related DNA damage occurs in endovascular operators despite current radiation protection measures. Biological dosimetry could be a useful tool, allowing personalised risk assessment.

P-422 A retrospective cohort study on the usefulness of Endometrial Receptivity Analysis (ERA) prior to a gestational carriers’ (GC) first euploid frozen embryo transfer (FET)

Study question

Does determination of endometrial receptivity by ERA improve the outcome of FET for GC prior to their first FET using a euploid embryo?

Summary answer

GC with ERA prior to FET had 92.3% implantation and 84.6% live birth rate (LBR) compared to 81.5% implantation rate and 72.2% LBR without ERA.

What is known already

The endometrial window of implantation is approximately 24 hours wide with a complex interaction of autocrine, paracrine and endocrine factors. Successful embryo implantation involves a 3-step process of apposition, adhesion and invasion of an embryo into a receptive endometrium. The ERA was developed using the expression profile of 248 genes using Next Generation Sequencing to determine if the endometrium is receptive, early receptive, late receptive, pre-receptive or post-receptive to objectively determine the optimal timing of progesterone exposure prior to embryo transfer. Some studies have shown statistically significant improvements in live birth rates while other studies have shown no difference.

Study design, size, duration

A retrospective cohort study compared the implantation and live birth rates of 26 GC who chose to have a personalized embryo transfer using their ERA profile vs. 54 GC who used our standard FET protocol without an ERA prior to their first euploid FET. All GC having their first FET from January 2018 – December 2020 were included.

Participants/materials, setting, methods

A single private practice fertility clinic performed 80 euploid FET cycles on first-time GC from January 2018 – December 2020. All intended parents were offered the opportunity to complete an ERA for their GC prior to their first FET cycle. Implantation and live birth rates were calculated for all FET cycles using a GC for the first time with associated p – values.

Main results and the role of chance

GC were 22 – 38 years old with a mean age of 30 and a history of 2.4 previous spontaneous births prior to their first FET. GC who used a standard FET protocol with 5 days of progesterone (P + 5) exposure before FET had an implantation rate of 81.5% and a live birth rate of 72.2%, compared to an implantation rate of 92.3% and a live birth rate of 84.6% for GC who used a personalized embryo transfer protocol based on their ERA profile (p = 0.17). 19.2% of GC had a receptive endometrial profile using P + 5, 26.9% of GC were pre-receptive needing P + 5.5 and 53.8% needed P + 6. No GC were found to have a post-receptive endometrial profile (P + 4 or P + 4.5). Our retrospective cohort study was not powered to find a statistically significant difference, though our data trended towards an improvement in both implantation and live birth rates by over 10% if a GC were to complete an ERA prior to her first FET.

Limitations, reasons for caution

Implantation and live birth rates for the clinic during the study period were 75% and 68% respectively using euploid embryos. Our high baseline implantation and live birth rates, coupled with low numbers of patients included in this study, may make these results less generalizable to the IVF population at large.

Wider implications of the findings

It is controversial to recommend an ERA to a good prognosis patient such as a GC without a prior unsuccessful euploid FET. These results should prompt further study to confirm our findings with a larger prospective randomized controlled trial of gestational carriers using ERA profiles prior to their first FET.

Trial registration number

N/A

P-458 Testosterone treatment induces changes in stromal collagen and elastin content of the ovaries of transgender men

Study question

Does gender-affirming testosterone therapy alter the composition of the extra-cellular matrix (ECM) within the ovarian stroma and subsequently affect follicle activation in vivo

Summary answer

Ovarian stroma of trans men is more collagenous and less elastic, indicating fibrotic change. This may affect in vivo follicle growth activation

What is known already

Changes in the ovarian stroma have been demonstrated in the ovaries of transgender men taking testosterone, including thickening of the tunica albuginea, stromal cell hyperplasia and stromal cell luteinisation. Ovaries of trans men also have increased cortical stiffness. These changes are similar to those seen in female patients with PCOS and in physiological ovarian aging, which has been attributed to accumulation of collagen in the ECM. Increasing stiffness of the supportive follicular microenvironment has been shown to reduce follicle growth activation in vitro

Study design, size, duration

Whole ovaries were obtained from transgender men (mean age 27.6 ± 1.7 years, n = 8) with informed consent at oophorectomy. All patients had received 1000mg testosterone undecanoate intramuscularly at 12-16 week intervals for a minimum of 18 months pre-operatively (range 18 months-10 years). Cortical tissue was dissected into small fragments (≈1x1x0.5mm) and fixed for histological and immunohistochemical analysis. Testosterone-treated ovaries were compared to cortical biopsies from age-matched healthy women obtained at caesarean section (mean age 31.8±1.5, n = 8).

Participants/materials, setting, methods

Follicle number, classification of developmental stage, non-growing follicle density (NGFD) and stromal cell density were evaluated by histological analysis of ovarian cortical tissue. Sections were stained with Picrosirius red (PSR) to analyse total collagen content using brightfield microscopy. Polarised light was also used to analyse the collagen birefringence, which allows quantification of collagen fibre thickness into thick, medium or thin. Total elastin content was evaluated using immunofluorescence.

Main results and the role of chance

4526 follicles were analysed. Transgender ovary showed a higher proportion of non-growing follicles found compared to control (93.9±1.2% vs 84.6±1.5% p &lt; 0.05): the proportions of primary (4.7±0.9% vs 10.6±1.5%, p = 0.2) and secondary (1.4±0.4% vs 4.6±0.7%, p = 0.1) follicles tended to be lower. Stromal cell density was significantly higher in transgender ovarian cortex than control (2.5±0.1 x106cells/mm3 vs 1.7±0.1 x106cells/mm3), indicating stromal cell hyperplasia. Combined data from control and transgender groups showed a positive correlation between NGFD and stromal density (r = 0.64, p = 0.01).

Transgender ovary had a higher total collagen content (77.2±1.2%) compared to control (31.3±3.3%, p &lt; 0.005). Analysis of collagen birefringence showed that transgender ovaries had similar quantities of thick collagen fibres (0.014±0.005 vs 0.010±0.009, p = 0.1), more medium thickness collagen fibres (45.1±6.6%vs 14.4±4.9%, p &lt; 0.05) and fewer thinner fibres (41.5±9.6% vs 27.7±2.8%, p = 0.08) than control. The total elastin content in transgender ovaries was lower than control (1.3±0.1% vs 3.6±0.6%, p &lt; 0.005) and subsequently, the collagen/elastin ratio was significantly higher (63.1±7.9 vs 10±1.3, p &lt; 0.005).

Limitations, reasons for caution

The impact of these findings on in vivo follicle growth are unclear. The effect of duration of testosterone treatment has not investigated.

Wider implications of the findings

More collagenous, less elastic ovarian stroma in trans men indicates fibrotic change; these findings are similar to women with PCOS and with reproductive ageing. These stromal changes may alter follicle growth activation and may contribute value to our understanding of the regulation of follicle function in a range of conditions.

Trial registration number

nil

P-698 Pituitary functioning gonadotroph adenomas (FGA)-induced ovarian hyperstimulation syndrome (OHSS): results from tertiary neuroendocrine centres in the UK

Study question

There are no published series of OHSS due to FGA. What FGA features should clinicians look for during OHSS, and what treatments are effective?

Summary answer

FGA tumour size is always &gt;10mm. Other pituitary hormones may be deficient. Surgical resection of FGA is an effective treatment for OHSS.

What is known already

Pituitary adenomas affect 1:1000 adults and are classified as functioning or non-functioning. Non-functioning pituitary adenomas do not secrete hormones, but most commonly stain histologically gonadotroph cells. Functional pituitary adenomas secrete hormones such as prolactin causing prolactinoma. However, it is rare for a pituitary tumour to cause clinical features of excessive gonadotrophins (functioning gonadotroph adenoma; FGA).

Single case reports, but no case series, have been published on the presentation of FGA-induced OHSS in women.

Surgical excision of adenomas has been reported to cause remission of symptoms, though systematic data are lacking owing to rarity of these tumours.

Study design, size, duration

National case series from tertiary neuroendocrine units in England, Wales and Scotland.

Participants/materials, setting, methods

Eight high-volume pituitary endocrine tertiary units within England, Wales and Scotland audited their records for any cases of FGA-induced OHSS; only seven patients have been identified to date. In all cases, there had been no recent exposure to assisted reproductive technologies (ART) or drugs known to induce OHSS including gonadotrophins or selective oestrogen receptor modulators (SERMS).

Main results and the role of chance

Seven cases of FGA were identified with mean age 31.6 years (range 16-48) at diagnosis. Two-of-seven women presented acutely unwell with abdominal pain, distention and palpable mass requiring oophorectomy for ovarian torsion/ruptured ovarian cyst. The remaining five women presented with abdominal pain (n = 2), thyrotoxicosis (n = 1), menstrual irregularities/galactorrhoea (n = 1) and visual disturbances (n = 1). All women experienced intermittent pelvic pain during medical attendance. Pelvic ultrasound demonstrated enlarged multiseptated ovaries (volume ranging 27-442cm3). Ascites was noted in one woman. Six women had visual field defects due to optic chiasm compression on formal assessment. Median FSH was 26.10 u/L (8.3-33), but LH was &lt;2.5 u/L in all cases. Estradiol (E2) far exceeded the reference range in 5/7 women (2990 to &gt; 18000pmol/L);E2 was at the upper limit of normal in the remaining 2/7 women (960-1450pmol/L). Hyperprolactinaemia, hyperthyroidism and other pituitary hormones deficiency were noted in 6/7, 1/7 and 4/7 women respectively. All FGAs were macroadenomas with diameters ranging 16-48mm. Two patients were administered a somatostatin analogue prior to surgery, but FSH, E2 and tumour size did not change. Transsphenoidal surgery was performed in 6/7 women, and always improved symptomatic and biochemical features of OHSS; however, residual FGA tumour was present post-operatively in all cases studied.

Limitations, reasons for caution

It is possible that some ‘non-functioning’ gonadotroph adenomas cause subclinical problems including menstrual irregularity and mild OHSS which were never diagnosed.

We have insufficient data to determine the prognosis for future pregnancy after FGA-induced OHSS.

This study utilised historical case-notes, so some data is missing.

Wider implications of the findings

The ‘spontaneous’ presentation of OHSS may be confusing for clinicians. We report that FGA is an important cause of spontaneous OHSS which has well-defined biochemical and radiological characteristics, which may be treated effectively in the short-to-medium with pituitary surgery. Results of this study may provide greater awareness of FGA-induced OHSS.

Trial registration number

N/A

P-456 Differential distribution of the extracellular matrix components within the human ovarian cortex and remodelling during in vitro culture

Study question

How is the extracellular matrix (ECM) network distributed within the human ovarian cortex, and how does in vitro culture alter its structure?

Summary answer

The ECM composition varies in the different layers of the ovarian cortex and is further remodelled during in vitro culture.

What is known already

The ovarian ECM is the scaffold within which follicles and stromal cells are organised. Its composition and structural properties constantly evolve to accommodate follicle development and expansion. Culturing primordial follicles within ovarian strips enables to reproduce the exact composition and stiffness of the native ECM. Yet, tissue preparation, which involves mechanical loosening, induces modifications in the ECM network and alters cell-cell contact, leading to spontaneous follicle activation. Characterising the native ovarian cortical ECM and its dynamic changes during culture will help decipher its role during folliculogenesis and improve both in vitro activation (IVA) and in vitro growth (IVG) systems.

Study design, size, duration

Fresh ovarian cortical biopsies were obtained from 6 women aged 28–38 years (mean ± SD: 32.7 ± 4.1 years) at elective caesarean section. Biopsies were cut into fragments of ∼4 × 1×0.5 mm and cultured for 0, 2, 4 or 6 days.

Participants/materials, setting, methods

Stromal cell density as well as the percentage of ECM-related protein (collagen, elastin, fibronectin, laminin) positive area in the entire cortex were quantified at each time point using histological and immunohistological analysis. Collagen and elastin contents were further quantified within each layer of the human ovarian cortex, namely the outer cortex, the mid-cortex, and the cortex-medulla junction regions.

Main results and the role of chance

Collagen content of the cortical ECM decreased from 55.5% ± 1.7% positive area at day 0 (D0) to 42.3% ± 1.1% at D6 (p = 0.001), and elastin increased from 1.1% ± 0.2% at D0 to 1.9% ± 0.1% at D6 (p = 0.001). Fibronectin and laminin remained stable. This suggests tissue loosening during culture, in accordance with the decreased stromal cell density from 3.6x106 ± 0.6 to 2.8x106 ± 0.3 cells/mm3 at D2 (p = 0.033) with no subsequent change. Moreover, collagen and elastin distribution were uneven throughout the cortex and during culture. Collagen deposition was maximal at the outer cortex and the lowest at the mid-cortex (69.4% ± 1.6% vs 53.8% ± 1.5% positive area, p &lt; 0.001), and decreased from D0 to D2 (65.2% ± 2.0% vs 60.6% ± 2.2%, p = 0.033) then stabilised. Elastin showed the converse distribution, being most concentrated at the cortex-medulla junction (3.7% ± 0.3% vs 0.9% ± 0.2% in the outer cortex, p &lt; 0.001), and peaked at D6 compared to D0 (3.1% ± 0.3% vs 1.3% ± 0.2%, p &lt; 0.001). These data indicate a distinct phenotype of the ovarian cortical ECM depending on both its region and the culture period. Further characterisation of the differences in ECM architecture is ongoing.

Limitations, reasons for caution

Ovarian cortical biopsies were obtained from pregnant women undergoing caesarean sections. As such, the data obtained may not accurately reflect the ECM distribution of non-pregnant women.

Wider implications of the findings

Clarifying the composition and architecture signature of the ovarian cortical ECM will not only provide a foundation for further exploration of ovarian microenvironments, but also be of importance for understanding of ECM-follicle interactions maintaining the primordial pool and early growth stages leading to improvements in IVA and IVG.

Trial registration number

not applicable

P-424 Endometrial receptivity as determined by Endometrial Receptivity Analysis (ERA) can change after a successful live birth from a frozen embryo transfer (FET)

Study question

Endometrial receptivity as determined by Endometrial Receptivity Analysis (ERA) can change after a successful live birth from a frozen a frozen embryo transfer (FET)

Summary answer

27 of 33 patients with a previous live birth from FET had an altered endometrial receptivity profile by ERA after a subsequent unsuccessful FET.

What is known already

The endometrial window of implantation is approximately 24 hours wide with a complex interaction of autocrine, paracrine, and endocrine factors. Successful embryo implantation involves a 3-step process of apposition, adhesion, and invasion of an embryo into a receptive endometrium. The ERA was developed using the expression profile of 248 genes using Next Generation Sequencing to determine if the endometrium is receptive, early receptive, late receptive, pre-receptive or post-receptive to objectively determine the optimal timing of progesterone exposure prior to embryo transfer. Some studies have shown statistically significant improvements in live birth rates while other studies have shown no difference.

Study design, size, duration

Case series of 33 patients with successful live birth following euploid FET using 5 days of progesterone (P + 5) with subsequent unsuccessful FET using the same protocol from January 2018 – December 2020. 27 of 33 patients who repeated their ERA were found to be non-receptive using P + 5. The new ERA profile results were used for their next FET. Implantation and live birth rates were calculated.

Participants/materials, setting, methods

A single private practice fertility clinic performed 340 ERA cycles from January 2018 – December 2020 with 276 subsequent FET cycles. An observational study of 33 patients with a previous live birth using P + 5 elected to repeat their ERA cycle after an unsuccessful FET. Implantation and live birth rates were calculated for their subsequent FET after completing the repeat ERA.

Main results and the role of chance

Repeat ERA result for patients with a previous live birth using P + 5 revealed that 6 patients still needed P + 5 (18.2%) for a receptive endometrial profile, 8 patients (24.2%) needed an extra 12 hours (P + 5.5), 18 patients (54.5%) needed an extra 24 hours (P + 6) and only one patient (3.0%) needed an extra 48 hours (P + 7). No patient that repeated their ERA after a previous live birth had a post-receptive profile (P + 4 or P + 4.5) and one patient had successful live births after using 3 different ERA profiles (P + 5, P + 6 and P + 7). All patients except one had repeat ERA results that were pre-receptive with only one patient changing from P + 6 to P + 5. FET cycles using P + 5 and P + 7 had a 100% implantation and pregnancy rate, while patients using P + 5.5 had the lowest implantation rate (62.5%) and live birth rate (37.5%). Patients with an ERA profile of P + 6 had an implantation rate of 94.1% and live birth rate of 88.2%. The small number of patients in this case series make a type I error possible because of the low number of patients in each ERA profile category with insufficient power to reach statistical significance.

Limitations, reasons for caution

Implantation rate for the clinic during the study period was 75% and live birth rate of 68% using euploid embryos. Our high baseline implantation and live birth rates, coupled with low numbers of patients in this observational study, make these results less generalizable to the IVF population at large.

Wider implications of the findings

It is widely accepted that ERA results are reproducible and do not change during a woman’s reproductive life. These results suggest that some women may have an altered window of receptivity after both successful and unsuccessful FET cycles. It may be reasonable to repeat ERA cycles for carefully selected patients.

Trial registration number

N/A

Systemic Immune Dysregulation in Early Breast Cancer Is Associated With Decreased Plasma Levels of Both Soluble Co-Inhibitory and Co-Stimulatory Immune Checkpoint Molecules

Breast cancer cells exploit the up-regulation or down-regulation of immune checkpoint proteins to evade anti-tumor immune responses. To explore the possible involvement of this mechanism in promoting systemic immunosuppression, the pre-treatment levels of soluble co-inhibitory and co-stimulatory immune checkpoint molecules, as well as those of cytokines, chemokines, and growth factors were measured in 98 newly diagnosed breast cancer patients and compared with those of 45 healthy controls using multiplex bead array and ELISA technologies. Plasma concentrations of the co-stimulatory immune checkpoints, GITR, GITRL, CD27, CD28, CD40, CD80, CD86 and ICOS, as well as the co-inhibitory molecules, PD-L1, CTLA-4 and TIM-3, were all significantly lower in early breast cancer patients compared to healthy controls, as were those of HVEM and sTLR-2, whereas the plasma concentrations of CX3CL1 (fractalkine), CCL5 (RANTES) and those of the growth factors, M-CSF, FGF-21 and GDF-15 were significantly increased. However, when analyzed according to the patients’ breast cancer characteristics, these being triple negative breast cancer (TNBC) vs. non-TNBC, tumor size, stage, nodal status and age, no significant differences were detected between the plasma levels of the various immune checkpoint molecules, cytokines, chemokines and growth factors. Additionally, none of these biomarkers correlated with pathological complete response. This study has identified low plasma levels of soluble co-stimulatory and co-inhibitory immune checkpoint molecules in newly diagnosed, non-metastatic breast cancer patients compared to healthy controls, which is a novel finding seemingly consistent with a state of systemic immune dysregulation. Plausible mechanisms include an association with elevated levels of M-CSF and CCL5, implicating the involvement of immune suppressor cells of the M2-macrophage/monocyte phenotype as possible drivers of this state of systemic immune quiescence/dysregulation.

Dysregulation of immune checkpoint proteins in patients with newly diagnosed early breast cancer

3044

Background: Checkpoint proteins regulate the immune system. Breast cancer (BC) cells can up-regulate or down-regulate these proteins to evade anti-tumor immune responses. Soluble forms of immune checkpoint molecules (ICMs) can be measured in human plasma. The study aimed to measure the systemic levels of a series of co-stimulatory and co-inhibitory ICMs at diagnosis, post-neo-adjuvant chemotherapy (NAC) and post-surgery in newly- diagnosed BC patients (pts) relative to those of a healthy control group. Methods: Soluble ICMs were measured using multiplex bead array technology in plasma from 72 BC pts and 45 healthy controls. Data was prospectively obtained and levels compared between pre-treatment, post-NAC, and post-surgery using non-parametric tests (Mann-Whitney & Kruskal-Wallis). Results: Pre-treatment levels of the soluble stimulatory molecules viz. GITR (p<0.0001), GITRL (p< 0.020), CD27 (p< 0.024), CD40 (p< 0.021), ICOS (p< 0.009), as well as the inhibitory molecules PD-L1 (p< 0.0001), CTLA-4 (p< 0.005), TIM-3 (p< 0.0004), HVEM (p< 0.0004) were significantly lower in early BC pts compared to controls. Post-treatment, there were significant increases in most ICM levels (Table), with the exception of CTLA-4, which decreased significantly following treatment. On the other hand, pre-treatment plasma concentrations of CCL5 (RANTES) (84.22 vs. 48.72 pg/mL, p<0.0001), M-CSF (84.41 vs 13.34 pg/mL, p<0.0001), FGF-21 (24.36 vs. 8.64 pg/mL, p<0.001) and GDF-15 (806.82 vs. 430.03 pg/mL, p<0.0001) were significantly increased in the breast cancer pts compared to healthy controls. A pathological complete response (pCR) was documented in 65% of pts (mostly TNBC). There were no correlations between pre-treatment ICM levels, CCL5, M-CSF, FGF-21 and GDF-15 and pCR. Conclusions: We identified low levels of stimulatory and inhibitory ICMs in newly-diagnosed, non-metastatic BC pts compared to healthy controls. Following treatment, with the exception of CTLA-4, most of these pre-treatment abnormalities of systemic ICM levels corrected. NAC is associated with upregulation of sPD-L1 and most other ICMs. These results indicate that early BC is associated with down-regulation of soluble stimulatory and inhibitory ICMs. Newly-diagnosed early BC pts appear to have generalized immune-suppression independent of subtype and stage. To our knowledge, this is the first study to describe the effect of treatment on systemic ICMs in early BC pts. [Table: see text]

CIRMI—a new term for a concept worthy of further exploration: a narrative review

Background and Objective

Methods

Key Content and Findings

Conclusions

Systemic levels of the soluble co-inhibitory immune checkpoints, CTLA-4, LAG-3, PD-1/PD-L1, and TIM-3 are markedly increased in basal cell carcinoma

3043

Background: Although co-inhibitory immune checkpoint proteins are primarily involved in promoting inhibitory cell-cell interactions in adaptive immunity, especially tumor immunity, the soluble cell-free variants of these molecules are also detectable in the circulation of cancer patients where they retain immunosuppressive activity. Nevertheless, little is known about the systemic levels of these soluble co-inhibitory immune checkpoints in patients with various subtypes of basal cell carcinoma (BCC), which is the most invasive and treatment-resistant type of this most commonly occurring malignancy. Methods: In the current study, we have measured the systemic concentrations of five prominent co-inhibitory immune checkpoints, namely CTLA-4, LAG-3, PD-1/PD-L1 and TIM-3, as well as those of C-reactive protein (CRP) and vitamin D (VD), in a cohort of patients (n = 40) with BCC, relative to those of a group of control participants (n = 20), using the combination of multiplex bead array, laser nephelometry and ELISA technologies, respectively. Results: The median systemic concentrations of CRP and VD were comparable between the two groups; however, those of all five immune checkpoints were significantly elevated ( P= 0.0184 - P£0.00001), with those of CTLA-4 and PD-1 being highly correlated (r = 0.87; P< 0.00001). Conclusions: This seemingly novel finding not only identifies the existence of significant systemic immunosuppression in BCC, but also underscores the therapeutic promise of immune checkpoint targeted therapy, as well as the potential of these proteins to serve as prognostic/predictive biomarkers in BCC.

Assessment of the efficacy of clofazimine alone and in combination with primary agents against Mycobacterium tuberculosis in vitro

OBJECTIVES

The chemotherapeutic regimens of drug-susceptible (DS)-tuberculosis (TB) patients comprise four primary anti-TB drugs; rifampicin (RMP), isoniazid (INH), ethambutol (EMB) and pyrazinamide (PZA), administered for six-to-nine months. These drug regimens target the various microbial populations that include actively-replicating (AR), slow-replicating (SR) and non-replicating (NR) organisms. Clofazimine (CFZ) has showed benefit in shortening DS-TB treatment in vivo from six to four months when used in combination with this regimen in murine models of experimental infection. However, its antimicrobial efficacy when used in combination with the primary drugs against the various microbial populations of Mycobacterium tuberculosis has not been demonstrated.

METHODS

In the current in vitro study, the inhibitory and bactericidal activities of CFZ in combination with the primary anti-TB drugs, RMP, INH and EMB against the AR and SR organisms in planktonic and biofilm-forming cultures, respectively, were evaluated by fractional inhibitory concentration index (FICI) and fractional bactericidal concentration index (FBCI) determinations, using the Loewe Additivity Model.

RESULTS

In planktonic cultures, CFZ demonstrated synergistic growth inhibitory activity in combination with RMP and INH individually and collectively. With respect to bactericidal activity, CFZ exhibited synergistic activity only in a two-drug combination with RMP. However, in biofilm-forming cultures, all CFZ-containing anti-TB drug combinations exhibited synergistic inhibitory and bactericidal effects, particularly in combination with RIF and INH.

CONCLUSION

Clofazimine exhibited synergistic effects in combination with primary anti-TB drugs against both planktonic and biofilm-forming cultures, showing potential benefit in augmenting treatment outcome when used during standard TB chemotherapy.

Elevated Levels of Soluble CTLA-4, PD-1, PD-L1, LAG-3 and TIM-3 and Systemic Inflammatory Stress as Potential Contributors to Immune Suppression and Generalized Tumorigenesis in a Cohort of South African Xeroderma Pigmentosum Patients

Xeroderma Pigmentosum (XP), an autosomal recessive disorder characterized by ultraviolet radiation-induced abnormalities of DNA excision and repair pathways is associated with early development of cutaneous cancers. Intracellular oxidative stress has also been proposed as a contributor to the occurrence of skin cancers. However, little is known about the possible augmentative contributions of chronic inflammation, immune suppression and oxidative stress to the pathogenesis of malignancies associated with other subtypes of XP. This has been addressed in the current study, focused on the measurement of systemic biomarkers of inflammation, immune dysfunction and oxidative damage in XP patients, consisting of XP-C, XP-D and XP-E cases, including those XP-C cases who had already developed multiple skin malignancies. The inflammatory biomarker profile measured in XP patients and healthy control subjects included the cytokines, interleukins (ILs)-2, -4, -6, -10, interferon-γ (IFN- γ) and tumor-necrosis factor-α (TNF-α), the acute phase reactant, C-reactive protein (CRP), and cotinine (as an objective indicator of smoking status). Immune suppression was detected according to the levels of five soluble inhibitory immune checkpoint proteins (CTLA-4, PD-1, PD-L1, LAG-3 and TIM-3), as well as those of vitamin D, while oxidative stress was determined according to the circulating levels of the DNA adduct, 8-hydroxy-2-deoxyguanosine (8-OH-dG). These various biomarkers were measured in plasma using immunofluorimetric, nephelometric and ELISA procedures. Significant elevations in IL-6 (P<0.01) and TNF-α (P<0.0001), but none of the other cytokines, as well as increased levels of all five soluble inhibitory immune checkpoints (P=0.032-P=0.0001) were detected in the plasma of the XP patients. C-reactive protein and vitamin D were increased and decreased, respectively (both P<0.0001), while only one participant had an elevated level of plasma cotinine. Surprisingly, the levels of 8-OH-dG were significantly (P=0.0001) lower in the group of XP patients relative to a group of healthy control subjects. The findings of increased levels of pro-inflammatory cytokines and, in particular, those of the soluble immune checkpoints, in the setting of decreased vitamin D and moderately elevated levels of CRP in XP patients suggest a possible secondary role of ongoing, inflammatory stress and immune suppression in the pathogenesis of XP-associated malignancies.

Abstract P4-04-11: Dysregulation of immune checkpoint proteins in newly- diagnosed early breast cancer patients

Background: Checkpoint proteins regulate the immune system. Breast cancer (BC) cells can up-regulate or down-regulate these proteins to evade anti-tumor immune responses. Soluble forms of immune checkpoint molecules (ICMs) can be measured in human plasma. The study aimed to measure the systemic levels of a series of positive and negative ICMs at diagnosis, post-neo-adjuvant chemotherapy (NAC) and post-surgery in newly- diagnosed BC patients (pts) relative to those of a healthy control group. Method: Soluble ICMs were measured using Multiplex® bead array technology in plasma from 72 BC patients and 45 healthy controls. Data was prospectively obtained and levels compared between pre-treatment, post-NAC, and post-surgery using non-parametric tests (Mann-Whitney & Kruskal-Wallis). Results: Pre-treatment, soluble stimulatory molecules viz. GITR (p&lt;0.0000), GITRL (p&lt; 0.0199), CD27 (p&lt; 0.0243), CD40 (p&lt; 0.0209), ICOS (p&lt; 0.0087), as well as the inhibitory molecules PD-L1 (p&lt; 0.0000), CTLA-4 (p&lt; 0.005), TIM-3 (p&lt; 0.0004), HVEM (p&lt; 0.0004) levels were significantly lower in early BC pts compared to controls. Post treatment, there were significant increases in most ICM levels (Table 1), with the exception of CTLA-4 which decreased significantly following treatment. A pCR was documented in 65% of patients (mostly TNBC). There was no correlation between pre-treatment ICM levels and pCR. Conclusion: We identified low levels of stimulatory and inhibitory ICMs in newly-diagnosed, non-metastatic BC patients compared to healthy controls. Following treatment, with the exception of CTLA-4, most of these pre-treatment abnormalities of systemic ICM levels corrected. NAC is associated with upregulation of sPD-L1 and most other ICMs. These results indicate that early BC is associated with down-regulation of soluble stimulatory and inhibitory ICMs. Newly-diagnosed early BC patients appear to have generalized immune-suppression independent of subtype and stage. To our knowledge, this is the first study to describe the effect of treatment on systemic ICMs in early BC patients.

Table 1.The effect of treatment on soluble, systemic ICMsICMControlDiagnosis (Group A)Post-NAC (Group B)Post-surgery (Group C) Group A vs Group BComparing pre-treatment levels vs post-treatment levelsMedian (pg/ml)p-valueBTLA18147130229987127770,0366CD8023291678304836110,0000CD8614297115859922124390,2789CTLA-4261815665986870,0000LAG31504161312754648805001330,0000PD-L133421647479452150,0000PD-1149171230513350150760,8888TIM350473897997596150,0000CD2745773342535154270,0000CD28461353291444277500580,0415CD4019771523203020540,0002GITR37971497403544340,0000GITRL71515886533959270,4938ICOS265061512326586297460,0001HVEM22901865404739500,0000TLR2304772683133837370420,0257

Citation Format: Bernardo Leon Rapoport, Helen C Steel, Carol Ann Benn, Simon Nayler, Teresa Smit, Liezl Heyman, Annette Theron, Nomsa Hlatswayo, Luyanda Kwofie, Pieter Meyer, Ronald Anderson. Dysregulation of immune checkpoint proteins in newly- diagnosed early breast cancer patients [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P4-04-11.

Emerging Role of Platelet-Endothelium Interactions in the Pathogenesis of Severe SARS-CoV-2 Infection-Associated Myocardial Injury

Cardiovascular dysfunction and disease are common and frequently fatal complications of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Indeed, from early on during the SARS-CoV-2 virus pandemic it was recognized that cardiac complications may occur, even in patients with no underlying cardiac disorders, as part of the acute infection, and that these were associated with more severe disease and increased morbidity and mortality. The most common cardiac complication is acute cardiac injury, defined by significant elevation of cardiac troponins. The potential mechanisms of cardiovascular complications include direct viral myocardial injury, systemic inflammation induced by the virus, sepsis, arrhythmia, myocardial oxygen supply-demand mismatch, electrolyte abnormalities, and hypercoagulability. This review is focused on the prevalence, risk factors and clinical course of COVID-19-related myocardial injury, as well as on current data with regard to disease pathogenesis, specifically the interaction of platelets with the vascular endothelium. The latter section includes consideration of the role of SARS-CoV-2 proteins in triggering development of a generalized endotheliitis that, in turn, drives intense activation of platelets. Most prominently, SARS-CoV-2–induced endotheliitis involves interaction of the viral spike protein with endothelial angiotensin-converting enzyme 2 (ACE2) together with alternative mechanisms that involve the nucleocapsid and viroporin. In addition, the mechanisms by which activated platelets intensify endothelial activation and dysfunction, seemingly driven by release of the platelet-derived calcium-binding proteins, SA100A8 and SA100A9, are described. These events create a SARS-CoV-2–driven cycle of intravascular inflammation and coagulation, which contributes significantly to a poor clinical outcome in patients with severe disease.

Fate and transport in environmental quality

Changes in pollutant concentrations in environmental media occur both from pollutant transport in water or air and from local processes, such as adsorption, degradation, precipitation, straining, and so on. The terms "fate and transport" and "transport and fate" reflect the coupling of moving with the carrier media and biogeochemical processes describing local transformations or interactions. The Journal of Environmental Quality (JEQ) was one of the first to publish papers on fate and transport (F&T). This paper is a minireview written to commemorate the 50th anniversary of JEQ and show how the research interests, methodology, and public attention have been reflected in fate and transport publications in JEQ during the last 40 years. We report the statistics showing how the representation of different pollutant groups in papers changed with time. Major focus areas have included the effect of solution composition on F&T and concurrent F&T, the role of organic matter, and the relative role of different F&T pathways. The role of temporal and spatial heterogeneity has been studied at different scales. The value of long-term F&T studies and developments in modeling as the F&T research approach was amply demonstrated. Fate and transport studies have been an essential part of conservation measure evaluation and comparison and ecological risk assessment. For 50 years, JEQ has delivered new insights, methods, and applications related to F&T science. The importance of its service to society is recognized, and we look forward to new generations of F&T researchers presenting their contributions in JEQ.

Pulmonary Toxicities Associated With the Use of Immune Checkpoint Inhibitors: An Update From the Immuno-Oncology Subgroup of the Neutropenia, Infection & Myelosuppression Study Group of the Multinational Association for Supportive Care in Cancer

The development of immune checkpoint inhibitors (ICIs) has revolutionized cancer treatment, with agents such as nivolumab, pembrolizumab, and cemiplimab targeting programmed cell death protein-1 (PD-1) and durvalumab, avelumab, and atezolizumab targeting PD-ligand 1 (PD-L1). Ipilimumab targets cytotoxic T lymphocyte-associated antigen-4 (CTLA-4). These inhibitors have shown remarkable efficacy in melanoma, lung cancer, urothelial cancer, and a variety of solid tumors, either as single agents or in combination with other anticancer modalities. Additional indications are continuing to evolve. Checkpoint inhibitors are associated with less toxicity when compared to chemotherapy. These agents enhance the antitumor immune response and produce side- effects known as immune-related adverse events (irAEs). Although the incidence of immune checkpoint inhibitor pneumonitis (ICI-Pneumonitis) is relatively low, this complication is likely to cause the delay or cessation of immunotherapy and, in severe cases, may be associated with treatment-related mortality. The primary mechanism of ICI-Pneumonitis remains unclear, but it is believed to be associated with the immune dysregulation caused by ICIs. The development of irAEs may be related to increased T cell activity against cross-antigens expressed in tumor and normal tissues. Treatment with ICIs is associated with an increased number of activated alveolar T cells and reduced activity of the anti-inflammatory Treg phenotype, leading to dysregulation of T cell activity. This review discusses the pathogenesis of alveolar pneumonitis and the incidence, diagnosis, and clinical management of pulmonary toxicity, as well as the pulmonary complications of ICIs, either as monotherapy or in combination with other anticancer modalities, such as thoracic radiotherapy.

P–720 Prevalence of Female Infertility in the UK Armed Forces

Study question

What is the prevalence of female infertility among UK military personnel and does it differ from the Metropolitan Police Service (MPS) and civilian populations?

Summary answer

Prevalence of self-reported infertility was higher in servicewomen (31.7%) and female MPS officers (36.3%) than in civilian women (24.4%).

What is known already

Arduous employment is associated with numerous potential occupational hazards and behaviours that may be relevant to fertility. These include physical and psychological stress, smoking, alcohol drinking and other lifestyle factors. A preliminarily report in 2016 indicated that UK servicewomen over 30 years of age were more likely to present with fertility problems compared with reported civilian infertility data for age-matched women. Few previous studies have compared infertility prevalence of servicewomen with civilians, and none have compared infertility prevalence with other occupations.

Study design, size, duration

A cross-sectional study was undertaken in 2019 to determine prevalence of infertility. All eligible UK servicewomen (14,650) and MPS officers (8,262) aged 18–60 years were invited to participate with sisters of participants recruited as controls using a snowball technique. Data including pregnancy history, time to each pregnancy and self-reported infertility risk-factors were collected using an online questionnaire. We estimated a sample of 4898 servicewomen would give a precision of 1% around infertility prevalence estimates.

Participants/materials, setting, methods

The questionnaire was developed, piloted and adapted for electronic distribution. The occupational groups were invited by email to complete the questionnaire on three occasions. Prevalence of infertility was defined as the proportion of women at risk of pregnancy who had not become pregnant within 12 months. Only women with pregnancy outcomes, or fully tested for fertility (12 months or more of exposure), were included in the denominator.

Main results and the role of chance

Participants included 4806 (33%) women serving in the UK Armed Forces, 1237 (15%) female MPS officers and 435 (estimated 8%) non-military, non-MPS sisters (biological, half, step or adopted) of both groups. 98.4% of responses were complete. Prevalence of self-reported 12-month infertility was 31.7% (95% CI 29.9–33.5) in servicewomen, 36.3% (95% CI 33.1–39.7) in MPS officers and 24.4% (95% CI 19.6–29.8) in civilian women. Age, history of polycystic ovary syndrome, endometriosis, fibroids, tubal and pelvic surgery, hysterectomy and a short General Health Questionnaire (GHQ 12) score of &gt; 4 (suggesting a minor psychiatric disorder) were associated with infertility and adjusted for in logistic regression models to estimate odds ratios. The adjusted odds ratio (aOR) of infertility in servicewomen was 1.0 (95% CI 0.8–1.2) compared with MPS officers and 1.5 (95% CI 1.1–2.0) in both servicewomen and MPS officers compared with sisters.

Limitations, reasons for caution

The major limitation is the low response rate, particularly in the two control groups, potentially resulting in response bias. Prevalence of infertility could have been further over-estimated if fertile women are more likely to have left the military or MPS. There is scope for residual confounding.

Wider implications of the findings: Further analyses will explore the key risk factors to identify what aspects of these occupations contribute to infertility and which may be modifiable. Future cohort studies would be helpful to extend the understanding of the influence of occupation on infertility.

Trial registration number

Not applicable

P–758 The efficacy, safety and proven security of microSecure vitrification offers “peace of mind” and reliability during a global pandemic

Study question

Under deadly pandemic conditions involving the novel SARS-CoV–2 corona virus, could biopsied blastocysts be safely cryopreserved, stored and utilized for subsequent warming cycles?

Summary answer

Blastocysts were securely stored, effectively warmed and safely transferred to yield normal pregnancy outcomes under uncertain laboratory conditions subject to unprecedented policy changes.

What is known already

By April 2020, every IVF lab worldwide was implementing deep cleaning/disinfecting procedures in their laboratory and patient-contact areas, thorough hand-washing policies and mandatory PPE to reduce the chance of contact transmission and spread of the potentially deadly SARS-CoV–2 coronavirus. Furthermore, we know that safeguards like oil overlay culture dishes and pipetting dilution factors provide insurance against possible contamination. However, knowing that the trophectoderm of blastocysts possessed the ACE–2 binding receptor, potential concern existed regarding the continuation of laser zona opening and biopsy procedures that could possibly expose cryopreserved embryos to the coronavirus in liquid nitrogen storage (vapor or liquid).

Study design, size, duration

Between March 8 and December 22, 2020, 508 patients performed FET cycles involving the use of single (n = 490) or dual (n = 18) euploid microSecure vitrified blastocysts. In this retrospective analysis, we compared clinical pregnancy outcomes to a 5 year dataset (2015–2019) encompassing 2768 single and 272 dual embryo transfer FET cycles. All blastocysts were vitrified using a closed microSecure system and Innovative Cryoenterprise (ICE; NJ, USA) non-DMSO, glycerol-EG solutions. Differences were assessed by Chi-square analysis (p < 0.05).

Participants/materials, setting, methods

Deep cleaning was performed with Simple Green Pro3+ Virucide in non-lab areas (e.g., ET rooms, waiting room) and 6% H2O2 & OoSafe solutions to disinfect lab surfaces and equipment. Group embryo cultures were performed in MCO–5M humidified incubators under low oxygen tri-gas conditions with varying CO2 levels (5.3–6.0%; pH = 7.3–7.35) using 25µl droplets of LifeGlobal medium+7.5%LGPS+1%sodium hyaluronate, before changing to 10µl droplet/GPS dishes post-biopsy. FET cycles involved 4-step sucrose dilutions and transvaginal ultrasound-guided embryo transfers.

Main results and the role of chance

While ICSI fertilization rates were unchanged in 2020 (79.4% 2PN vs 77.3%), blastocyst utilization rates tended to be slightly lower than past years (56.4% vs 59.9%) but within an acceptable range. Of 529 blastocysts warmed, 527 (99.7%) survived completely for transfer, being comparable to the 99.4% experienced over 5 years. Furthermore, there was no differences detected in single embryo transfer pregnancy outcomes. The implantation and ongoing clinical pregnancy/live birth rates were 69% and 66.53% compared to 70.4% and 65.1%, respectively. Under pandemic conditions we did not observe an increase in biochemical pregnancies (10.3%) nor spontaneous miscarriage rates (7.8%). Although it is possible that our rigorous disinfection practices could have attributed to lower blastocyst production, the viability of those embryos was not compromised. Importantly, we were able to feel comfortable performing micromanipulation and cryopreservation procedures throughout the year knowing that we were effectively eliminating possible vertical transmission of coronavirus to an exposed trophectoderm layer in cryostorage by applying mircoSecure vitrification. Post-FET clinical check-ups revealed no patient reporting any fever or other Covid–19 symptoms in the weeks following their transfers. We are fortunate to say that our Lab staff, physicians and patients have remained healthy throughout 2020.

Limitations, reasons for caution

Blastocyst survival and viability are independent of possible viral exposure. Previously, the risk of disease transmission via liquid nitrogen or vapor exposure was considered highly unlikely (Pomeroy et al., 2010), but that was at a time when embryos were primarily zona-enclosed. Today’s ART standards have us re-evaluating safer approaches.

Wider implications of the findings: We have effectively mitigated avoiding performing zona opening procedures by employing our standard practice of aseptic, closed vitrification. In combination with standard preventative measures (PPE, hand hygiene, distance awareness) and routine deep cleaning practices, we sustained a contamination-free environment and healthy patients, capable of sustaining high levels of pregnancy success.

Trial registration number

Not applicable

P–437 The ovaries of transgender men indicate effects of high dose testosterone on the primordial and early growing follicle pool

Study question

Does high-dose testosterone therapy affect the stage distribution, morphological health and DNA damage repair capacity of human ovarian follicles and their survival in vitro?

Summary answer

Testosterone exposure is associated with reduced follicle growth activation, reduced follicle health and increased DNA damage: these further deteriorate after six days of culture. What is known already: Androgens have diverse actions within the ovary, however, there is a lack of information regarding the long-term effects of high-dose testosterone on ovarian function and reproductive potential. Cumulus-oocyte complexes recovered from transgender men have been successfully matured in-vitro but little is known regarding the impact of this gender affirming endocrine therapy on the primordial follicle pool. Study design, size, duration: Whole ovaries were obtained from four transgender men aged 25–36 years with informed consent at oophorectomy. All patients had received 1000mg testosterone undecanoate intramuscularly at 12–16 week intervals for a minimum of 4 years pre-operatively. Cortical tissues were dissected into small pieces (≈1x1x0.5mm) and either immediately fixed for histological analysis or cultured for 6 days. Testosterone-treated ovaries were compared to cortical biopsies from age-matched healthy women obtained at caesarean section (n = 4, age 26–36). Participants/materials, setting, methods: Follicle number, classification of developmental stage and morphology were evaluated by histological analysis of ovarian cortical tissue from day 0 and 6 days post culture. Immunohistochemical analysis included γH2AX as a marker of DNA damage, and meiotic recombination 11 (MRE11), ataxia telangiectasia mutated (ATM) and Rad51 as DNA repair proteins. A total of 3802 follicles from testosterone exposed and 878 from control ovaries were analysed. Main results and the role of chance: At day 0 (D0), transgender tissue had a higher proportion of non-growing follicles (92.7±1.7%) compared to control (85.4±6.2%, p &lt; 0.05) but a lower proportion of morphologically healthy follicles (non-growing 59%, primary 61%, secondary 36%; vs 83%, 75%, 80% in controls, all p &lt; 0.005). After 6 days in culture, the proportion of growing follicles increased (51.3% vs 46.5%) but follicle health further declined (all stages p &lt; 0.005).

DNA damage was assessed by expression of γH2AX. At D0, the proportion of oocytes showing DNA damage was significantly higher in transgender non-growing follicles (48.1±12.5%, vs 12.3±0.25%, p &lt; 0.005). After culture, γH2AX expression increased in both transgender (p &lt; 0.005) and controls (p &lt; 0.005) but remained higher in transgender oocytes (non-growing 72.2%, primary 71.7% vs 27.3%, 46.2%, all p &lt; 0.05). At D0, there was no difference in expression of DNA repair enzymes ATM and RAD51 between transgender and control oocytes, and increased expression of MRE11 in control non-growing follicles (p &lt; 0.05). Post-culture, there was a significant increase in ATM expression in transgender non-growing oocytes compared to control (98.5% vs 77.8%, p &lt; 0.05) and a less marked decline in RAD51 expression(p &lt; 0.05). The expression of MRE–11 in control non-growing oocytes dramatically declined (100% to 58.2%, p &lt; 0.05), unlike in transgender tissue where expression was comparable to D0.

Limitations, reasons for caution

A large number of follicles have been analysed, but only from a small number of ovaries. DNA damage at D0 and after 6 days of culture may not reflect DNA damage and repair capacity at later stages of follicle growth. The effect of duration of testosterone treatment was not investigated.

Wider implications of the findings: These data indicate that high circulating concentrations of testosterone have previously unrecognised effects on the primordial and small-growing follicles of the ovary. These results may have implications for transgender men receiving gender-affirming therapy prior to considering pregnancy or fertility preservation measures.

Trial registration number

n/a

P-437 The ovaries of transgender men indicate effects of high dose testosterone on the primordial and early growing follicle pool

Study question

Does high-dose testosterone therapy affect the stage distribution, morphological health and DNA damage repair capacity of human ovarian follicles and their survival in vitro?

Summary answer

Testosterone exposure is associated with reduced follicle growth activation, reduced follicle health and increased DNA damage: these further deteriorate after six days of culture. 

What is known already

Androgens have diverse actions within the ovary, however, there is a lack of information regarding the long-term effects of high-dose testosterone on ovarian function and reproductive potential. Cumulus-oocyte complexes recovered from transgender men have been successfully matured in-vitro but little is known regarding the impact of this gender affirming endocrine therapy on the primordial follicle pool

Study design, size, duration

Whole ovaries were obtained from four transgender men aged 25-36 years with informed consent at oophorectomy. All patients had received 1000mg testosterone undecanoate intramuscularly at 12-16 week intervals for a minimum of 4 years pre-operatively. Cortical tissues were dissected into small pieces (≈1x1x0.5mm) and either immediately fixed for histological analysis or cultured for 6 days. Testosterone-treated ovaries were compared to cortical biopsies from age-matched healthy women obtained at caesarean section (n = 4, age 26-36). 

Participants/materials, setting, methods

Follicle number, classification of developmental stage and morphology were evaluated by histological analysis of ovarian cortical tissue from day 0 and 6 days post culture. Immunohistochemical analysis included γH2AX as a marker of DNA damage, and meiotic recombination 11 (MRE11), ataxia telangiectasia mutated (ATM) and Rad51 as DNA repair proteins. A total of 3802 follicles from testosterone exposed and 878 from control ovaries were analysed. 

Main results and the role of chance

At day 0 (D0), transgender tissue had a higher proportion of non-growing follicles (92.7±1.7%) compared to control (85.4±6.2%, p &lt; 0.05) but a lower proportion of morphologically healthy follicles (non-growing 59%, primary 61%, secondary 36%; vs 83%, 75%, 80% in controls, all p &lt; 0.005). After 6 days in culture, the proportion of growing follicles increased (51.3% vs 46.5%) but follicle health further declined (all stages p &lt; 0.005).

DNA damage was assessed by expression of γH2AX. At D0, the proportion of oocytes showing DNA damage was significantly higher in transgender non-growing follicles (48.1±12.5%, vs 12.3±0.25%, p &lt; 0.005). After culture, γH2AX expression increased in both transgender (p &lt; 0.005) and controls (p &lt; 0.005) but remained higher in transgender oocytes (non-growing 72.2%, primary 71.7% vs 27.3%, 46.2%, all p &lt; 0.05). 

At D0, there was no difference in expression of DNA repair enzymes ATM and RAD51 between transgender and control oocytes, and increased expression of MRE11 in control non-growing follicles (p &lt; 0.05). Post-culture, there was a significant increase in ATM expression in transgender non-growing oocytes compared to control (98.5% vs 77.8%, p &lt; 0.05) and a less marked decline in RAD51 expression(p &lt; 0.05). The expression of MRE-11 in control non-growing oocytes dramatically declined (100% to 58.2%, p &lt; 0.05), unlike in transgender tissue where expression was comparable to D0.

Limitations, reasons for caution

A large number of follicles have been analysed, but only from a small number of ovaries. DNA damage at D0 and after 6 days of culture may not reflect DNA damage and repair capacity at later stages of follicle growth. The effect of duration of testosterone treatment was not investigated.

Wider implications of the findings

These data indicate that high circulating concentrations of testosterone have previously unrecognised effects on the primordial and small-growing follicles of the ovary. These results may have implications for transgender men receiving gender-affirming therapy prior to considering pregnancy or fertility preservation measures. 

Trial registration number

n/a

Role of the kdpDE Regulatory Operon of Mycobacterium tuberculosis in Modulating Bacterial Growth in vitro

Bacteria use K⁺-uptake transporters differentially for adaptation in varying growth conditions. In Mycobacterium tuberculosis, two K⁺-uptake systems, the Trk comprising the CeoB and CeoC proteins and the Kdp consisting of the two-component system (TCS), KdpDE and KdpFABC, have been characterized, but their selective utilization during bacterial growth has not been completely explored. In the current study, the roles of the M. tuberculosis KdpDE regulatory system alone and in association with the Trk transporters in bacterial growth were investigated by evaluating the growth of M. tuberculosis KdpDE-deletion and KdpDE/Trk (KT)-double knockout mutant strains in planktonic culture under standard growth conditions. The KT-double knockout mutant strain was first constructed using homologous recombination procedures and was evaluated together with the KdpDE-deletion mutant and the wild-type (WT) strains with respect to their rates of growth, K⁺-uptake efficiencies, and K⁺-transporter gene expression during planktonic growth. During growth at optimal K⁺ concentrations and pH levels, selective deletion of the TCS KdpDE (KdpDE-deletion mutant) led to attenuation of bacterial growth and an increase in bacterial K⁺-uptake efficiency, as well as dysregulated expression of the kdpFABC and trk genes. Deletion of both the KdpDE and the Trk systems (KT-double knockout) also led to severely attenuated bacterial growth, as well as an increase in bacterial K⁺-uptake efficiency. These results demonstrate that the KdpDE regulatory system plays a key role during bacterial growth by regulating K⁺ uptake via modulation of the expression and activities of both the KdpFABC and Trk systems and is important for bacterial growth possibly by preventing cytoplasmic K⁺ overload.

Supportive care for new cancer therapies

PURPOSE OF REVIEW

The past decade has witnessed unprecedented delivery to the clinical arena of a range of novel, innovative, and effective targeted anticancer therapies. These include immunotherapies, most prominently immune checkpoint inhibitors, as well as agents that target growth factors and cancer-related mutations. Many of these new cancer therapies are, however, associated with an array of toxicities, necessitating insight and vigilance on the part of attending physicians to achieve high-quality supportive care alongside toxicity management. In this review, we consider some of the key supportive care issues in toxicity management.

RECENT FINDINGS

Although both supportive care and targeted therapies have brought significant benefits to cancer care, the management of novel cancer therapy toxicities is nevertheless often complex. This is due in large part to the fact that target organs differ widely, particularly in the case of checkpoint inhibitors, with minor dermatological disorders being most common, while others, such as pneumonitis, are more severe and potentially life threatening. Accordingly, efficient management of these immune-related adverse events requires collaboration between multiple medical specialists.

SUMMARY

Supportive care is a key component in the management of new cancer therapy toxicities and needs to be incorporated into treatment pathways.

Frontiers in Pharmacology: Review Manuscript Targeting of the Neutrophil as an Adjunctive Strategy in Non-Small Cell Lung Cancer

Lung cancer remains the leading cause of cancer mortality in the United States, with non-small cell lung cancer (NSCLC) accounting for around 85% of cases. Of particular concern is the poor responsiveness of this malignancy to therapy, resulting in a very low 5-year survival rate (17.4%) and a prominent tendency to progress to metastatic disease. A number of very recent studies, both pre-clinical and clinical, have implicated the neutrophil in both the pathogenesis and unsatisfactory response to therapy of NSCLC. In this context, movement of neutrophils into the tumor microenvironment (TME) is a common feature of NSCLC. Indeed neutrophils are the dominant type of immune cell in the NSCLC TME, creating a highly immunosuppressive milieu that is not only conducive to tumor growth and spread, but also represents a significant obstacle to the success of anti-tumor therapy, especially novel immunotherapies. The clinically relevant adverse impact of a neutrophil predominance both systemically and in the TME of patients with NSCLC is underscored by the negative prognostic value of both a persistent neutrophilia and, in particular, a high (≥5) neutrophil:lymphocyte ratio. On a more positive note, however, recognition of the involvement of the neutrophil in both the pathophysiology of NSCLC and treatment failure has enabled identification of neutrophil-targeted strategies that have the potential to serve as adjuncts to standard anti-cancer therapies, including immunotherapy. These strategies together with a consideration of the immunosuppressive, pro-tumorigenic properties of the neutrophil represent the major thrusts of this review.

Evaluation of three different laboratory methods to detect preformed human leukocyte antigen antibodies in a South African kidney transplant population

Background

Anti-human leukocyte antigen antibodies (anti-HLA) play a crucial role in graft. Detection of anti-HLA, both pre- and post-transplant is a crucial investigation in clinical organ transplantation.

Objectives

Three methodologies for the detection of lymphocytotoxic antibodies were compared to establish which of these is best suited to optimise pre-transplant donor-recipient matching.

Methods

Serum samples from 15 renal transplant patients were tested for the presence of anti-HLA by i) cytotoxic-dependent cross-match (CDCXM), ii) flow cytometric cross-match (FCXM) and iii) Luminex-based donor specific antibody cross-match (DSAXM) method, Confirmatory tests for the presence of preformed HLA antibodies were tested using Luminex methodology.

Results

Two (13%) of the 15 patients had positive HLA Class I antibodies (Ab) using all 3 methods. An additional 2 HLA Class I Ab were identified with FCXM/CDCXM. DSAXM identified 1 HLA Class I positive, not indicated by CDCXM/FCXM.

High HLA Class II positivity (40%), identified by CDCXM, while DSAXM and FCXM identified two and one patients, respectively. CDCXM produced 4 false-positive results confirmed by lymphocyte single antigen (LSA) assay.

Conclusions

The DSAXM method appears to add value in pre-transplantation screening to identify pre-sensitised patients that may not reject the donor graft due to the absence of donor-specific antibodies.

Dysregulation of soluble immune checkpoint proteins in newly-diagnosed early breast cancer patients

556

Background: Checkpoint proteins regulate the immune system. Breast cancer (BC) cells exploit the up-regulation or down-regulation of these proteins to evade anti-tumor immune responses. Soluble forms of immune checkpoint molecules (ICM) can be measured in human plasma, however their biological and clinical significance remains essentially unknown. The aim of the present analysis was to measure the pre-treatment ICM in newly- diagnosed BC patients (pts) and compare them to healthy controls. Methods: Soluble forms of ICM, as well as cytokines and chemokines, were measured using Multiplex bead array and ELISA technologies. Plasma samples from 98 BC pts and 45 healthy controls were analyzed for each protein. Data was prospectively obtained. Measured levels were compared between BC pts and healthy controls using a non-parametric test (Mann-Whitney). P-values below 0.05 were considered statistically significant. Results: Soluble stimulatory molecules GITR (p < 0,000002), GITRL (p < 0,007), CD27 (p < 0,002), CD28 (p < 0,003), CD40 (p < 0,003), CD80 (p < 0,009), ICOS (p < 0,0006), as well as inhibitory molecules PD-L1 (p < 0.0000001), CTLA-4 (p < 0,005), TIM-3 (p < 0,00006), HVEM (p < 0,00002) TLR-2 (p < 0,05), levels were significantly lower in early BC pts compared to healthy controls. When analyzed according to BC characteristics (TNBC vs. non-TNBC, tumor size, stage, nodal status and age) no significant difference was detected between the soluble levels of these ICM between the different subsets. Additionally, serum CXCL5 (p < 0,000001), CCL23 (p < 0,04), IL-16 (p < 0,00005), interferon-α (p < 0,03) and IL1-RA (p < 0,03) were significantly lower compared to healthy controls. Serum CX3CL1 or fractalkine (p < 0,024465) was significantly higher compared with healthy controls. Serum interferon-γ (p < 0,2), IL-6 (p < 0.6) and IL-2 (p < 0.6) levels were not significantly different between the BC pts and the healthy controls. Conclusions: We identified low levels of both the stimulatory and inhibitory immune checkpoint molecules, in newly-diagnosed, non-metastatic BC pts compared to healthy controls. These results indicate that early BC is associated with a down-regulation of both soluble stimulatory and inhibitory immune-checkpoint pathways. Newly-diagnosed early BC pts have a generalized immune-suppression independent of subtype (TNBC vs non-TNBC) and stage, which, to our knowledge, is the first study to describe soluble immune checkpoints in early BC pts.