Radiomics Analysis of Contrast-Enhanced Breast MRI for Optimized Modelling of Virtual Prognostic Biomarkers in Breast Cancer

Objective

Breast cancer clinical stage and nodal status are the most clinically significant drivers of patient management, in combination with other pathological biomarkers, such as estrogen receptor (ER), progesterone receptor or human epidermal growth factor receptor 2 (HER2) receptor status and tumor grade. Accurate prediction of such parameters can help avoid unnecessary intervention, including unnecessary surgery. The objective was to investigate the role of magnetic resonance imaging (MRI) radiomics for yielding virtual prognostic biomarkers (ER, HER2 expression, tumor grade, molecular subtype, and T-stage).

Materials and Methods

Patients with primary invasive breast cancer who underwent dynamic contrast-enhanced (DCE) breast MRI between July 2013 and July 2016 in a single center were retrospectively reviewed. Age, N-stage, grade, ER and HER2 status, and Ki-67 (%) were recorded. DCE images were segmented and Haralick texture features were extracted. The Bootstrap Lasso feature selection method was used to select a small subset of optimal texture features. Classification of the performance of the final model was assessed with the area under the receiver operating characteristic curve (AUC).

Results

Median age of patients (n = 209) was 49 (21-79) years. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of the model for differentiating N0 vs N1-N3 was: 71%, 79%, 76%, 74%, 75% [AUC = 0.78 (95% confidence interval (CI) 0.72-0.85)], N0-N1 vs N2-N3 was 81%, 59%, 24%, 95%, 62% [AUC = 0.74 (95% CI 0.63-0.85)], distinguishing HER2(+) from HER2(-) was 79%, 48%, 34%, 87%, 56% [AUC = 0.64 (95% CI 0.54-0.73)], high nuclear grade (grade 2-3) vs low grade (grades 1) was 56%, 88%, 96%, 29%, 61% [AUC = 0.71 (95% CI 0.63-0.80)]; and for ER (+) vs ER(-) status the [AUC=0.67 (95% CI 0.59-0.76)]. Radiomics performance in distinguishing triple-negative vs other molecular subtypes was [0.60 (95% CI 0.49-0.71)], and Luminal A [0.66 (95% CI 0.56-0.76)].

Conclusion

Quantitative radiomics using MRI contrast texture shows promise in identifying aggressive high grade, node positive triple negative breast cancer, and correlated well with higher nuclear grades, higher T-stages, and N-positive stages.

Skeletal stability of inter-molar mandibular distraction osteogenesis in growing patients

INTRODUCTION

The aim of this retrospective study was to firstly assess the stability of surgical advancement using inter-molar mandibular distraction osteogenesis (IMDO) and secondly to assess the impact of the surgical intervention on subsequent mandibular growth in patients with residual growth.

METHODS

The sample consisted of 17 (13F and 4M) consecutively treated patients who underwent IMDO and orthodontic treatment. Cephalometric analysis was performed at three time points: T0 prior to distraction; T1 post-distraction immediately prior to surgical removal of the distractors; and T2 following completion of orthodontic treatment when the final lateral cephalogram was taken (0.86-4.37 years after T1). Statistical comparison of lower facial height, mandibular length, growth, condylar position and anterior mandibular rotation was performed.

RESULTS

No association was found between changes in any of the cephalometric measurements and the length of the follow-up interval. The anterior mandibular segment underwent clockwise rotation during distraction and recovered to near its pre-distraction angulation during remodelling. An increase in the lower facial height of 1.88 ± 2.81mm also occurred during distraction (T0-T1) and was maintained during the follow-up period (T1-T2). Post-distraction (T1-T2) growth of lower facial height (p value 0.872) and mandibular length (p value 0.251) showed no association when compared to an untreated control group and an overall reduction in growth was reported.

CONCLUSIONS

IMDO was highly stable within a follow-up period of 2.3 ± 0.9 years; however, growth appears to have been inhibited.

A mixed-methods evaluation of the impacts of an online Carer wellbeing and connection program

Objective

To evaluate a facilitated, 90-min session, delivered for four weeks, Online Carer Wellbeing and Connection Program in Victoria, Australia.

Methods

One hundred and three carers took part in the evaluation. Eighty-six completed both pre- and post-program surveys evaluating program impacts on psychological distress, perceived loneliness, and social support. Qualitative interviews were conducted (n = 76) post-program for experiential data.

Findings

Paired samples t-tests showed significant decreases between pre- and post-program for psychological distress (M = 25.10, SD = 7.08; M = 22.00, SD = 6.57; t(85) = 4.88, p = 0.000), perceived loneliness (M = 6.69, SD = 1.89; M = 6.14, SD = 1.76; t(85) = 3.45, p = 0.000) and perceived social support (M = 8.31, SD = 2.48; M = 8.83, SD = 2.21; t(85) = -2.54, p = 0.013). Thematic analysis identified positive experiences and the mechanisms of action (or the ingredients for program success) as: 1. Delivery by a trained facilitator; 2. Provision of respite for person being cared for during meetings; 3. Technical assistance; 4. Online modality; 5. Inclusivity; 6. Diversity of experience; 7. Shared understanding; 8. Safety; 9. Emotional release; 10. Reflection, and; 11. Self-care practices.

Innovation

A model illustrating the mechanisms of action based on the findings of the mixed-methods evaluation is presented to support wider implementation and translation.

Conclusion

The online program effectively reduced psychological distress and loneliness and improved carer wellbeing.

The impact of preoperative sarcopenia on postoperative ileus following colorectal cancer surgery

PURPOSE

Sarcopenia is associated with poor short- and long-term patient outcomes following colorectal surgery. Despite postoperative ileus (POI) being a major complication following colorectal surgery, the predictive value of sarcopenia for POI is unclear. We assessed the association between sarcopenia and POI in patients with colorectal cancer.

METHODS

Elective colorectal cancer surgery patients were retrospectively included (2018-2022). The cross-sectional psoas area was calculated using preoperative staging imaging at the level of the 3rd lumbar vertebrae. Sarcopenia was determined using gender-specific cut-offs. The primary outcome POI was defined as not achieving GI-2 by day 4. Demographics, operative characteristics, and complications were compared via univariate and multivariate analyses.

RESULTS

Of 297 patients, 67 (22.6%) were sarcopenic. Patients with sarcopenia were older (median 74 (IQR 67-82) vs. 69 (58-76) years, p < 0.001) and had lower body mass index (median 24.4 (IQR 22.2-28.6) vs. 28.8 (24.9-31.9) kg/m2, p < 0.001). POI was significantly more prevalent in patients with sarcopenia (41.8% vs. 26.5%, p = 0.016). Overall rate of complications (85.1% vs. 68.3%, p = 0.007), Calvien-Dindo grade > 3 (13.4% vs. 10.0%, p = 0.026) and length of stay were increased in patients with sarcopenia (median 7 (IQR 5-12) vs. 6 (4-8) days, p = 0.013). Anastomotic leak rate was higher in patients with sarcopenia although the difference was not statistically significant (7.5% vs. 2.6%, p = 0.064). Multivariate analysis demonstrated sarcopenia (OR 2.0, 95% CI 1.1-3.8), male sex (OR 1.9, 95% CI 1.0-3.5), postoperative hypokalemia (OR 3.2, 95% CI 1.6-6.5) and increased opioid use (OR 2.4, 95% CI 1.3-4.3) were predictive of POI.

CONCLUSION

Sarcopenia demonstrates an association with POI. Future research towards truly identifying the predictive value of sarcopenia for postoperative complications could improve informed consent and operative planning for surgical patients.

A co-design living labs philosophy of practice for end-to-end research design to translation with people with lived-experience of mental ill-health and carer/family and kinship groups

There is increased recognition that people with lived-experience of mental ill-health ought to be centred in research design, implementation and translation, and quality improvement and program evaluation of services. There is also an increased focus on ways to ensure that co-design processes can be led by people with lived-experience of mental ill-health. Despite this, there remains limited explanation of the physical, social, human, and economic infrastructure needed to create and sustain such models in research and service settings. This is particularly pertinent for all health service sectors (across mental and physical health and social services) but more so across tertiary education settings where research generation occurs for implementation and translation activities with policy and services. The Co-Design Living Labs program was established in 2017 as an example of a community-based embedded approach to bring people living with trauma and mental ill-health and carers/family and kinship group members together with university-based researchers to drive end-to-end research design to translation in mental healthcare and research sectors. The program's current membership is near to 2000 people. This study traces the evolution of the program in the context of the living labs tradition of open innovation. It overviews the philosophy of practice for working with people with lived-experience and carer/family and kinship group members-togetherness by design. Togetherness by design centres on an ethical relation of being-for that moves beyond unethical and transactional approaches of being-aside and being-with, as articulated by sociologist Zygmunt Bauman. The retrospective outlines how an initial researcher-driven model can evolve and transform to become one where people with lived-experience of mental ill-health and carer/family kinship group members hold clear decision-making roles, share in power to enact change, and move into co-researcher roles within research teams. Eight mechanisms are presented in the context of an explanatory theoretical model of change for co-design and coproduction, which are used to frame research co-design activities and provide space for continuous learning and evolution of the Co-Design Living Labs program.

Metabolomics 2022 workshop report: state of QA/QC best practices in LC-MS-based untargeted metabolomics, informed through mQACC community engagement initiatives

INTRODUCTION

The Metabolomics Quality Assurance and Quality Control Consortium (mQACC) organized a workshop during the Metabolomics 2022 conference.

OBJECTIVES

The goal of the workshop was to disseminate recent findings from mQACC community-engagement efforts and to solicit feedback about a living guidance document of QA/QC best practices for untargeted LC-MS metabolomics.

METHODS

Four QC-related topics were presented.

RESULTS

During the discussion, participants expressed the need for detailed guidance on a broad range of QA/QC-related topics accompanied by use-cases.

CONCLUSIONS

Ongoing efforts will continue to identify, catalog, harmonize, and disseminate QA/QC best practices, including outreach activities, to establish and continually update QA/QC guidelines.

A scoping review of cardiovascular risk factor screening rates in general or family practice attendees living with severe mental ill-health

BACKGROUND

Primary care is essential to address the unmet physical health needs of people with severe mental ill-health. Continued poor cardiovascular health demands improved screening and preventive care. No previous reviews have examined primary care cardiovascular screening rates for people living with severe mental ill-health; termed in the literature "severe mental illness".

METHODS

A scoping review following Joanna Briggs Institute methodology was conducted. Cardiovascular risk factor screening rates in adults with severe mental ill-health were examined in general or family practices (as the main delivery sites of primary care). Literature published between 2001 and 2023 was searched using electronic databases including Medline, Embase, Web of Science, PsychINFO and CINAHL. Two reviewers independently screened titles and abstracts and conducted a full-text review. The term "severe mental illness" was applied as the term applied in the literature over the past decades. Study information, participant details and cardiovascular risk factor screening rates for people with 'severe mental illness' were extracted and synthesised.

RESULTS

Thirteen studies were included. Nine studies were from the United Kingdom and one each from Canada, Spain, New Zealand and the Netherlands. The general and/or family practice cardiovascular disease screening rates varied considerably across studies, ranging from 0 % to 75 % for people grouped within the term "severe mental illness". Lipids and blood pressure were the most screened risk factors.

CONCLUSIONS

Cardiovascular disease screening rates in primary care settings for adults living with severe mental ill-health varied considerably. Tailored and targeted cardiovascular risk screening will enable more comprehensive preventive care to improve heart health outcomes and address this urgent health inequity.

Enhancing survivorship and growth of juvenile Montipora capitata using the Hawaiian collector urchin Tripneustes gratilla

The biodiversity of coral reef habitats is rapidly declining due to the effects of anthropogenic climate change, prompting the use of active restoration as a mitigation strategy. Sexual propagation can maintain or enhance genetic diversity in restoration of these ecosystems, but these approaches suffer from a range of inefficiencies in rearing and husbandry. Algal overgrowth of juveniles is a major bottleneck in the production of sexually propagated corals that may be alleviated by co-culture with herbivores. We reared juvenile Montipora capitata alongside juvenile native Hawaiian collector urchins, Tripneustes gratilla, for 15 weeks and documented significant ecological benefits of co-culture. Urchin treatments significantly increased the survivorship of coral aggregates (14%) and individual settlers (24%). We also documented a significant increase in coral growth in the presence of urchins. These results demonstrate the utility of microherbivory in promoting coral growth and survivorship in ex situ conditions, providing valuable insight for restoration pipelines of native Hawaiian coral species.

Genetically diverse mouse models of SARS-CoV-2 infection reproduce clinical variation in type I interferon and cytokine responses in COVID-19

Inflammation in response to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection drives severity of coronavirus disease 2019 (COVID-19) and is influenced by host genetics. To understand mechanisms of inflammation, animal models that reflect genetic diversity and clinical outcomes observed in humans are needed. We report a mouse panel comprising the genetically diverse Collaborative Cross (CC) founder strains crossed to human ACE2 transgenic mice (K18-hACE2) that confers susceptibility to SARS-CoV-2. Infection of CC x K18-hACE2 resulted in a spectrum of survival, viral replication kinetics, and immune profiles. Importantly, in contrast to the K18-hACE2 model, early type I interferon (IFN-I) and regulated proinflammatory responses were required for control of SARS-CoV-2 replication in PWK x K18-hACE2 mice that were highly resistant to disease. Thus, virus dynamics and inflammation observed in COVID-19 can be modeled in diverse mouse strains that provide a genetically tractable platform for understanding anti-coronavirus immunity.

Cyanoacrylate glue reactions: A systematic review, cases, and proposed mechanisms

OBJECTIVE

Cyanoacrylate glue closure was first used in humans 10 years ago to treat venous reflux of the axial veins. Studies have since shown its clinical efficacy in vein closure. However, great need exists to elucidate further the types of specific adverse reactions that cyanoacrylate glue can cause for better patient selection and to minimize these events. In the present study, we systematically reviewed the literature to identify the types of reported reactions. In addition, we explored the pathophysiology contributing to these reactions and proposed the mechanistic pathway with inclusion of actual cases.

METHODS

We searched the literature for reports of reactions following cyanoacrylate glue use in patients with venous diseases between 2012 and 2022. The search was performed using MeSH (medical subject headings) terms. The terms included cyanoacrylate, venous insufficiency, chronic venous disorder, varicose veins, vein varicosities, venous ulcer, venous wound, CEAP (clinical, etiologic, anatomic, pathophysiologic), vein, adverse events, phlebitis, hypersensitivity, foreign body granuloma, giant cell, endovenous glue-induced thrombosis, and allergy. The search was limited to the literature reported in English. These studies were evaluated for the type of product used and the reactions noted. A systematic review, in accordance with the PRISMA (preferred reporting items for systematic reviews and meta-analyses) method, was performed. Covidence software (Melbourne, VC, Australia) was used for full-text screening and data extraction. Two reviewers reviewed the data, and the content expert served as the tiebreaker.

RESULTS

We identified 102, of which, 37 reported on cyanoacrylate use other than in the context of chronic venous diseases and were excluded. Fifty-five reports were determined appropriate for data extraction. The adverse reactions to cyanoacrylate glue were phlebitis, hypersensitivity, foreign body granuloma, and endovenous glue-induced thrombosis.

CONCLUSIONS

Although cyanoacrylate glue closure for venous reflux is generally a safe and clinically effective treatment choice for patients with symptomatic chronic venous disease and axial reflux, some adverse events could be specific to the properties of the cyanoacrylate product. We propose mechanisms for how such reactions can occur based on histologic changes, published reports, and case examples; however, further exploration is necessary to confirm these theories.

Comparative outcomes and risk analysis after cone repair or tricuspid valve replacement for Ebstein's anomaly

Objective

Ebstein's anomaly is a rare congenital heart malformation for which surgical and medical management are still controversial. The cone repair has transformed surgical outcomes in many of these patients. We aimed to present our results on the outcomes of patients with Ebstein's anomaly who underwent a cone repair or tricuspid valve replacement.

Methods

A total of 85 patients who underwent a cone repair (mean age, 16.5 years) or tricuspid valve replacement (mean age, 40.8 years) between 2006 and 2021 were included. Univariate, multivariate, and Kaplan-Meier analyses were used to evaluate operative and long-term outcomes.

Results

Residual/recurrent greater than mild-to-moderate tricuspid regurgitation at discharge was higher after cone repair compared with tricuspid valve replacement (36% vs 5%; P = .010). However, at last follow-up, the risk of greater than mild-to-moderate tricuspid regurgitation was not different between groups (35% in the cone group vs 37% in the tricuspid valve replacement group; P = .786). The tricuspid valve replacement group had a higher risk of tricuspid valve reoperation (37% vs 9%; P = .005) and tricuspid stenosis (21% vs 0%; P = .002) compared with the cone repair group. Kaplan-Meier freedom from reintervention was 97%, 91%, and 91% at 2, 4, and 6 years after cone repair, respectively, and 84%, 74%, and 68% at 2, 4, and 6 years after tricuspid valve replacement, respectively (P = .0191). At last follow-up, right ventricular function was significantly worse from baseline in the tricuspid valve replacement group (P = .0294). There were no statistical differences between age-stratified cohorts or surgeon volume in the cone repair group.

Conclusions

The cone procedure offers excellent results, with stable tricuspid valve function and low reintervention and death rates at last follow-up. The rate of greater than mild-to-moderate residual tricuspid regurgitation at discharge was higher after cone repair compared with tricuspid valve replacement, but this did not expose the patient to a higher risk of reoperation or death at last follow-up. Tricuspid valve replacement was associated with a significantly higher risk of tricuspid valve reoperation and tricuspid valve stenosis, and worse right ventricular function at last follow-up.

The gut microbiota and metabolome are associated with diminished COVID-19 vaccine-induced antibody responses in immunosuppressed inflammatory bowel disease patients

BACKGROUND

Patients with inflammatory bowel disease (IBD) treated with anti-TNF therapy exhibit attenuated humoral immune responses to vaccination against SARS-CoV-2. The gut microbiota and its functional metabolic output, which are perturbed in IBD, play an important role in shaping host immune responses. We explored whether the gut microbiota and metabolome could explain variation in anti-SARS-CoV-2 vaccination responses in immunosuppressed IBD patients.

METHODS

Faecal and serum samples were prospectively collected from infliximab-treated patients with IBD in the CLARITY-IBD study undergoing vaccination against SARS-CoV-2. Antibody responses were measured following two doses of either ChAdOx1 nCoV-19 or BNT162b2 vaccine. Patients were classified as having responses above or below the geometric mean of the wider CLARITY-IBD cohort. 16S rRNA gene amplicon sequencing, nuclear magnetic resonance (NMR) spectroscopy and bile acid profiling with ultra-high-performance liquid chromatography mass spectrometry (UHPLC-MS) were performed on faecal samples. Univariate, multivariable and correlation analyses were performed to determine gut microbial and metabolomic predictors of response to vaccination.

FINDINGS

Forty-three infliximab-treated patients with IBD were recruited (30 Crohn's disease, 12 ulcerative colitis, 1 IBD-unclassified; 26 with concomitant thiopurine therapy). Eight patients had evidence of prior SARS-CoV-2 infection. Seventeen patients (39.5%) had a serological response below the geometric mean. Gut microbiota diversity was lower in below average responders (p = 0.037). Bilophila abundance was associated with better serological response, while Streptococcus was associated with poorer response. The faecal metabolome was distinct between above and below average responders (OPLS-DA R²X 0.25, R²Y 0.26, Q² 0.15; CV-ANOVA p = 0.038). Trimethylamine, isobutyrate and omega-muricholic acid were associated with better response, while succinate, phenylalanine, taurolithocholate and taurodeoxycholate were associated with poorer response.

INTERPRETATION

Our data suggest that there is an association between the gut microbiota and variable serological response to vaccination against SARS-CoV-2 in immunocompromised patients. Microbial metabolites including trimethylamine may be important in mitigating anti-TNF-induced attenuation of the immune response.

FUNDING

JLA is the recipient of an NIHR Academic Clinical Lectureship (CL-2019-21-502), funded by Imperial College London and The Joyce and Norman Freed Charitable Trust. BHM is the recipient of an NIHR Academic Clinical Lectureship (CL-2019-21-002). The Division of Digestive Diseases at Imperial College London receives financial and infrastructure support from the NIHR Imperial Biomedical Research Centre (BRC) based at Imperial College Healthcare NHS Trust and Imperial College London. Metabolomics studies were performed at the MRC-NIHR National Phenome Centre at Imperial College London; this work was supported by the Medical Research Council (MRC), the National Institute of Health Research (NIHR) (grant number MC_PC_12025) and infrastructure support was provided by the NIHR Imperial Biomedical Research Centre (BRC). The NIHR Exeter Clinical Research Facility is a partnership between the University of Exeter Medical School College of Medicine and Health, and Royal Devon and Exeter NHS Foundation Trust. This project is supported by the National Institute for Health Research (NIHR) Exeter Clinical Research Facility. The views expressed are those of the authors and not necessarily those of the NIHR or the UK Department of Health and Social Care.

Faecal metabolite deficit, gut inflammation and diet in Parkinson's disease: Integrative analysis indicates inflammatory response syndrome

BACKGROUND

Gut-brain axis is widely implicated in the pathophysiology of Parkinson's disease (PD). We take an integrated approach to considering the gut as a target for disease-modifying intervention, using continuous measurements of disease facets irrespective of diagnostic divide.

METHODS

We characterised 77 participants with diagnosed-PD, 113 without, by dietary/exogenous substance intake, faecal metabolome, intestinal inflammation, serum cytokines/chemokines, clinical phenotype including colonic transit time. Complete-linkage hierarchical cluster analysis of metabolites discriminant for PD-status was performed.

RESULTS

Longer colonic transit was linked to deficits in faecal short-chain-fatty acids outside PD, to a 'tryptophan-containing metabolite cluster' overall. Phenotypic cluster analysis aggregated colonic transit with brady/hypokinesia, tremor, sleep disorder and dysosmia, each individually associated with tryptophan-cluster deficit. Overall, a faster pulse was associated with deficits in a metabolite cluster including benzoic acid and an imidazole-ring compound (anti-fungals) and vitamin B3 (anti-inflammatory) and with higher serum CCL20 (chemotactic for lymphocytes/dendritic cells towards mucosal epithelium). The faster pulse in PD was irrespective of postural hypotension. The benzoic acid-cluster deficit was linked to (well-recognised) lower caffeine and alcohol intakes, tryptophan-cluster deficit to higher maltose intake. Free-sugar intake was increased in PD, maltose intake being 63% higher (p = .001). Faecal calprotectin was 44% (95% CI 5%, 98%) greater in PD [p = .001, adjusted for proton-pump inhibitors (p = .001)], with 16% of PD-probands exceeding a cut-point for clinically significant inflammation compatible with inflammatory bowel disease. Higher maltose intake was associated with exceeding this calprotectin cut-point.

CONCLUSIONS

Emerging picture is of (i) clinical phenotype being described by deficits in microbial metabolites essential to gut health; (ii) intestinal inflammation; (iii) a systemic inflammatory response syndrome.

SARS-CoV-2 Omicron BA.1 and BA.2 are attenuated in rhesus macaques as compared to Delta

Since the emergence of SARS-CoV-2, five different variants of concern (VOCs) have been identified: Alpha, Beta, Gamma, Delta, and Omicron. Because of confounding factors in the human population, such as preexisting immunity, comparing severity of disease caused by different VOCs is challenging. Here, we investigate disease progression in the rhesus macaque model upon inoculation with the Delta, Omicron BA.1, and Omicron BA.2 VOCs. Disease severity in rhesus macaques inoculated with Omicron BA.1 or BA.2 was lower than those inoculated with Delta and resulted in significantly lower viral loads in nasal swabs, bronchial cytology brush samples, and lung tissue in rhesus macaques. Cytokines and chemokines were up-regulated in nasosorption samples of Delta animals compared to Omicron BA.1 and BA.2 animals. Overall, these data suggest that, in rhesus macaques, Omicron replicates to lower levels than the Delta VOC, resulting in reduced clinical disease.

Interventions to support the mental health and well-being of front-line healthcare workers in hospitals during pandemics: an evidence review and synthesis

OBJECTIVE

Pandemics negatively impact healthcare workers' (HCW's) mental health and well-being causing additional feelings of anxiety, depression, moral distress and post-traumatic stress. A comprehensive review and evidence synthesis of HCW's mental health and well-being interventions through pandemics reporting mental health outcomes was conducted addressing two questions: (1) What mental health support interventions have been reported in recent pandemics, and have they been effective in improving the mental health and well-being of HCWs? (2) Have any mobile apps been designed and implemented to support HCWs' mental health and well-being during pandemics?

DESIGN

A narrative evidence synthesis was conducted using Cochrane criteria for synthesising and presenting findings when systematic review and pooling data for statistical analysis are not suitable due to the heterogeneity of the studies.

DATA SOURCES

Evidence summary resources, bibliographic databases, grey literature sources, clinical trial registries and protocol registries were searched.

ELIGIBILITY CRITERIA

Subject heading terms and keywords covering three key concepts were searched: SARS-CoV-2 coronavirus (or similar infectious diseases) epidemics, health workforce and mental health support interventions. Searches were limited to English-language items published from 1 January 2000 to 14 June 2022. No publication-type limit was used.

DATA EXTRACTION AND SYNTHESIS

Two authors determined eligibility and extracted data from identified manuscripts. Data was synthesised into tables and refined by coauthors.

RESULTS

2694 studies were identified and 27 papers were included. Interventions were directed at individuals and/or organisations and most were COVID-19 focused. Interventions had some positive impacts on HCW's mental health and well-being, but variable study quality, low sample sizes and lack of control conditions were limitations. Two mobile apps were identified with mixed outcomes.

CONCLUSION

HCW interventions were rapidly designed and implemented with few comprehensively described or evaluated. Tailored interventions that respond to HCWs' needs using experience co-design for mental health and well-being are required with process and outcome evaluation.

SARS-CoV-2 Omicron BA.1 and BA.2 are attenuated in rhesus macaques as compared to Delta.. [PMID: 35971544 PMCID: PMC9377356 DOI: 10.1101/2022.08.01.502390]

Since the emergence of SARS-CoV-2, five different variants of concern (VOCs) have been identified: Alpha, Beta, Gamma, Delta, and Omicron. Due to confounding factors in the human population, such as pre-existing immunity, comparing severity of disease caused by different VOCs is challenging. Here, we investigate disease progression in the rhesus macaque model upon inoculation with the Delta, Omicron BA.1, and Omicron BA.2 VOCs. Disease severity in rhesus macaques inoculated with Omicron BA.1 or BA.2 was lower than those inoculated with Delta and resulted in significantly lower viral loads in nasal swabs, bronchial cytology brush samples, and lung tissue in rhesus macaques. Cytokines and chemokines were upregulated in nasosorption samples of Delta animals compared to Omicron BA.1 and BA.2 animals. Overall, these data suggests that in rhesus macaques, Omicron replicates to lower levels than the Delta VOC, resulting in reduced clinical disease.

Relevance of necroptosis in the hearts subjected to acute versus chronic ischemia/reperfusion injury

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): Slovak Research and Development Agency

Medical Research Council Grant

Necroptosis, a necrosis-like programmed cell death modality dependent on the activity of receptor-interacting protein kinase 3 (RIP3) and mixed lineage domain kinase domain-like pseudokinase (MLKL), plays a prominent role in mediating myocardial ischemia/reperfusion injury. However, the extent to which necroptosis contributes to such damage under short and long reperfusion has not been evaluated in detail. In Wistar rat hearts, subjected to global 30-min ischemia followed by an acute 10-min reperfusion period, with compromised cardiac function, no changes in the protein expression of the main necroptotic markers (pThr231/Ser232-RIP3, MLKL) were found. Likewise, the non-canonical pathways of necroptosis involving Ca2+/calmodulin dependent protein kinase II–mitochondrial permeability transition pore (CaMKII–mPTP) or phosphoglycerate mutase 5–dynamin-related protein 1 (PGAM5–Drp1) axes were unlikely affected by such short reperfusion. In contrast, hearts subjected to global 30-min ischemia followed by a prolonged 40-min reperfusion period exhibited worsened hemodynamic parameters what was accompanied by the increased levels of RIP3, pSer229-RIP3 and MLKL. Moreover, this reperfusion period induced MLKL translocation to the plasma membrane, indicating necroptosis execution with resultant very likely cell disruption. Similarly, activated necroptosis, evidenced by the higher levels of proteins of the canonical pathway, has been suggested to contribute to the pathogenesis of post-infarction heart failure (30-min ischemia, 42-day reperfusion). Collectively, these findings suggest that short reperfusion seems to be insufficient to induce necroptosis in the heart and the molecular mechanisms being activated during the longer reperfusion phase are needed to promote necroptotic cell dying. Therefore, inhibition of necroptosis might represent a cardioprotective strategy in the settings of chronic, but not acute myocardial ischemia/reperfusion injury.

POS0145 CLINICAL RESPONSE TO RITUXIMAB IS ASSOCIATED WITH PREVENTION OF B-CELL DRIVEN SALIVARY GLAND INFLAMMATION AND EPITHELIAL RESTORATION AS REVEALED BY MOLECULAR PATHOLOGY: RESULTS FROM THE TRACTISS TRIAL IN PRIMARY SJOGREN’S SYNDROME

Background

The TRial for Anti-B-Cell Therapy In patients with pSS (TRACTISS) is the largest multi-centre, placebo-controlled, phase-III trial with the administration of 2 cycles of Rituximab (RTX) or placebo at week 0 and 24, with trial clinical endpoints at week 48. Despite the primary endpoints (30% reduction in fatigue or oral dryness) were not met, RTX treated patients showed an improvement in secondary endpoints, such as unstimulated whole salivary flow (UWSF), and salivary gland (SG) total ultrasound score1,2. Additionally, recent post-hoc analysis of TRACTISS using novel CRESS composite endpoints3, highlighted a significantly increased response rate in the RTX vs placebo arm.

Objectives

To perform the first longitudinal analysis of matched transcriptomic and histological data of SG biopsies of pSS patients treated with RTX vs placebo at 3 time points, over 48 weeks, from the TRACTISS cohort, in order to identify mechanisms of response/resistance to B cell depletion.

Methods

29 pSS patients randomised to RTX or placebo arm consented for labial SG biopsies at week 0, 16 and 48. Patients received two 1000mg cycles of RTX or placebo at week 0 and 24. SG focus score, inflammatory aggregate area fraction, B-cells (CD20+), T-cells (CD3+), follicular dendritic cells (FDCs) (CD21+) and plasma cells (CD138+) density were assessed using quantitative digital image analysis. RNA sequencing with deconvolution and pathway analysis was performed to identify genes signatures and consensus gene modules as biomarkers of disease evolution and response/resistance to therapy.

Results

Placebo-treated SGs showed worsening of SG inflammation highlighted by the increment of aggregate size, B-cell density, development of new FDC networks, and a higher ectopic GC prevalence over 48 weeks, compared to RTX-treated patients. No difference in focus score, total T-cell and plasma cell infiltration was observed. RTX downregulated genes involved in immune cell recruitment and inflammatory aggregate organisation (e.g. CXCL13, CCR7 and PDCD1). Gene signature-based analysis of 35 immune cell types using XCell highlighted how RTX blocked class-switched and memory-B-cells accumulation in SGs over 48 weeks. Pathway analyses confirmed the downregulation of leukocyte migration, MHC-II antigen presentation, and T-cell co-stimulation immunological pathways, such as the CD40 receptor complex pathway. Among RTX-treated patients, only CRESS-responders demonstrated prevention of worsening B cell-driven molecular pathology signatures over time and a significant improvement in UWSF, in parallel with the upregulation of molecular pathways associated to SG restoration of the glandular epithelium. None of the above effects were observed at week 16 after the first RTX cycle.

Conclusion

Two RTX infusions repeated at week 24 exerted beneficial effects on labial SG inflammatory infiltration in pSS by downregulating genes involved in immune cell recruitment, activation and organisation in ectopic GCs. Conversely, all the above parameters showed significant evolution in placebo treated patients over 48 weeks demonstrating progression of SG immunopathology. Clinical responders to RTX based on CRESS response criteria were characterised by preservation of exocrine function which appear driven by SG epithelial restoration.

References

[1]Fisher, B. A. et al. Effect of rituximab on a salivary gland ultrasound score in primary Sjögren’s syndrome: results of the TRACTISS randomised double-blind multicentre substudy. Ann. Rheum. Dis.77, 412–416 (2018).

[2]Bowman, S. J. et al. Randomized Controlled Trial of Rituximab and Cost-Effectiveness Analysis in Treating Fatigue and Oral Dryness in Primary Sjögren’s Syndrome. Arthritis Rheumatol.69, 1440–1450 (2017).

[3]Arends, S. et al. Composite of Relevant Endpoints for Sjögren’s Syndrome (CRESS): development and validation of a novel outcome measure. Lancet Rheumatol.3, e553–e562 (2021).

Disclosure of Interests

None declared

OP0085 CELL LINEAGE-SPECIFIC TRANSCRIPT DECONVOLUTION OF SYNOVIAL BIOPSIES FROM THE R4RA TRIAL IDENTIFIES CELL POPULATIONS ASSOCIATED WITH RESPONSE TO RITUXIMAB AND TOCILIZUMAB

Background

The R4RA trial, the first biopsy-based randomised trial in TNF-i inadequate responder patients with Rheumatoid Arthritis, showed that molecular stratification of RA synovial tissue was associated with clinical response, demonstrating that, in patients with low/absent B-cell lineage signature in synovial-tissue, tocilizumab is superior to rituximab1.

Objectives

Here, we aimed to perform cell-transcript deconvolution of pre-and post-treatment synovial biopsies from the R4RA trial.

Methods

A total of 164 patients underwent pre-treatment synovial biopsy (US-guided or arthroscopic) prior to randomization 1:1 to rituximab (83) or tocilizumab (81). 65 patients had a repeat biopsy at 16 weeks when clinical response was assessed using Clinical Disease Activity Index (CDAI) 50% improvement. RNA extracted from a minimum of 6 synovial samples/patient underwent RNA-sequencing and the abundance of tissue-infiltrating immune and stromal cell populations was estimated using the Microenvironment Cell Populations-counter (MCP-counter) method (Figure 1a).

Results

At baseline, while synovial semiquantitative immunohistochemistry scores did not differ between CDAI50% responders and non-responders, both for rituximab and tocilizumab, MCP-counter analysis showed significantly higher CD8 T-cells in responders to rituximab and higher macrophage-monocytes and myeloid dendritic cells (mDC) in responders to tocilizumab (Figure 1b). Moreover, when patients were classified according to MCP-counter scores, B-cell poor patients (MCP-counter B cell score <median value) showed significantly higher response rates to tocilizumab, while no difference was found in B-cell rich patients (Figure 1c). In contrast, macrophage and myeloid dendritic cell (mDC) rich individuals showed higher responses to tocilizumab (Figure 1d). Combined scores for lymphoid and myeloid cells demonstrated that patients poor in B-cells but rich in macrophages/mDC had a significantly higher response to tocilizumab (77% responders to tocilizumab vs 14% responders to rituximab, p=0.017, OR 16.48, 95%CI 1.29-1000.5) (Figure 1e). By analysing disease activity over time from baseline to week 16, we found a statistically significant interaction effect between treatments and time in B-cell poor (p=0.003), T-cell poor (p=0.022), mDC rich (p=0.029) and B-cell poor/Macrophages-mDC rich patients (p=0.006) (Figure 1f-g-h). Finally, by applying MCP-counter on matched pre-and post-treatment biopsies, rituximab-treated patients showed a significant reduction of B-cells, T-cells and monocyte/macrophages, while tocilizumab-treated patients showed a significant reduction of monocyte/macrophages, T-cells, but also neutrophils, myeloid dendritic cells and, interestingly, an increase in fibroblast signature (Figure 1i).

Conclusion

In silico deconvolution of the synovial tissue identify pre-treatment lymphoid cell lineages associated with response to rituximab and myeloid cells for tocilizumab. The longitudinal analysis of matched pre- and post-treatment synovial biopsies indicated that both medications have an effect on synovial immune cells, but tocilizumab can also affect stromal cells.

References

[1]Humby et al. Rituximab versus tocilizumab in anti-TNF inadequate responder patients with rheumatoid arthritis (R4RA): 16-week outcomes of a stratified, biopsy-driven, multicentre, open-label, phase 4 randomised controlled trial Lancet. 2021 Jan 23;397(10271):305-317. doi: 10.1016/S0140-6736(20)32341-2.

Acknowledgements

We would like to thank all patients and the R4RA recruiting centres and principal investigators http://www.r4ra-nihr.whri.qmul.ac.uk/recruiting_centres.php We would also like to acknowledge the UK National Institute of Health Research for funding the R4RA trial (grant reference: 11/100/76) and Versus Arthritis for providing infrastructure support through the Experimental Arthritis Treatment Centre (grant number: 20022).

Disclosure of Interests

None declared.

OP0077 SYNOVIAL RNA-SEQ ANALYSIS OF THE R4RA TRIAL IDENTIFIES SIGNATURES OF TREATMENT RESISTANCE AND REFRACTORY STATE IN RHEUMATOID ARTHRITIS

Background

Although up to 5-20% of rheumatoid arthritis (RA) patients do not respond to all current medications including biologic therapies, relatively little is known about the underlying pathogenic mechanisms driving non-response. In the first biopsy-driven randomized clinical trial in RA (R4RA)1, patients, in whom synthetic-DMARDs and at least one anti-TNF drug were not effective, were randomised 1:1 to rituximab (RTX) or tocilizumab (TOC) with a balanced stratification based on their synovial B-cell rich/poor signature, and response was assessed at 16 weeks. Non-responders were subsequently allowed to switch to the alternative drug with 48-week follow-up.

Objectives

Investigate mechanisms of response and non-response to RTX and TOC through deep molecular (RNA-Sequencing) profiling of synovial tissue.

Methods

RNA-Seq from baseline synovial tissue biopsies of patients who received RTX (n=88) or TOC (n=94) at any point in the trial was analysed for differentially expressed genes and associated modules between responders and non-responders. Response was defined as 50% improvement in clinical disease activity index (CDAI) score. Patients who had received both drugs during the trial were subdivided into RTX only responders (pro-RTX, n=9), TOC only responders (pro-TOC, n=12) and refractory patients (no response to both RTX & TOC, n=32) and analysed for differential gene expression and performed gene module analysis.

Results

6625 genes were significantly differentially expressed between RTX responders compared to non-responders, with a predominance of antigen presentation as well as T- and B-cell genes being associated with response, while non-response was linked to fibroblast associated genes. Comparison between TOC responders and non-responders identified fewer (85) differentially expressed genes, however lymphocyte and immunoglobulin genes were also high in the synovial tissue of TOC responders similar to RTX responders, while non-responder genes and modules also included a fibroblast signature.

The cross-over study design enabled comparison of rituximab-specific responders (pro-RTX), tocilizumab-specific responders (pro-TOC) and refractory patients (non-responders to both RTX & TOC, n=32) in a 3-way analysis (see Figure 1). This identified 1980 genes upregulated both in pro-RTX and pro-TOC patients, 175 genes exclusive to the pro-RTX group and 306 to the pro-TOC group, while 1277 genes were exclusive to the refractory group. While leukocyte modules and genes dominated RTX & TOC response, the refractory state was strongly associated with fibroblast genes and modules. We confirmed the observed expansion of fibroblasts from the RNA-Seq data by immunohistochemistry showing the presence of DKK3+ sublining fibroblasts in refractory rather than responder patients.

Conclusion

We provide novel insights into the cellular and molecular pathways underpinning multi-biologic resistance that define a refractory RA phenotype, characterised by a stromal/fibroblast signature.

References

[1]Humby, F., et al. Lancet (2021)

Acknowledgements

We would like to thank all patients and the R4RA recruiting centres and principal investigators http://www.r4ra-nihr.whri.qmul.ac.uk/recruiting_centres.php We would also like to acknowledge the UK National Institute of Health Research for funding the R4RA trial (grant reference: 11/100/76) and Versus Arthritis for providing infrastructure support through the Experimental Arthritis Treatment Centre (grant number: 20022).

Disclosure of Interests

None declared.

POS0138 RHEUMATOID SYNOVIAL FIBROBLASTS DISPLAY IMPRINTED MEMORY OF THEIR SYNOVIAL ENDOTYPE WHICH CAN BE PLASTICALLY MODULATED BY B-CELLS CROSSTALK

Background

Despite advances in the treatment of Rheumatoid Arthritis (RA), synthetics and biologicals drugs are ineffective in ~40% of patients. The origin of this refractoriness is unclear, but several clues point at the synovial microenvironment (SE) and the relative cellular heterogeneity between patients. We previously described the existence of different RA endotypes such as the lympho-myeloid, LM, which is B-cell rich and the fibroid-paucimmune, FPI, which is devoid of B-cells. While there is clear evidence that the crosstalk between stromal and immune cells in rheumatoid joints is critical for the perpetuation of chronic inflammation and autoimmunity, it is currently unknown whether transcriptional signatures identified in synovial fibroblasts (SFs) derived from different RA endotypes are driven by “imprinted” properties of the SFs or are shaped by the interaction with infiltrating immune cells in the RA joints.

Objectives

I) to identify “imprinted” vs “inducible” RASFs signatures trough the comparison of freshly isolated SFs and primary established SFs cultures obtained from LM vs FPI RA synovial biopsies and ii) to investigate the identified RASF signature as predictive biomarkers of disease evolution and of response to conventional and biological DMARDs.

Methods

We performed flowcytometry and single cell RNA sequencing (sc-RNAseq) on SFs obtained from LM and FPI biopsies, in isolation or in co-culture with RA B cells. Next, supernatant has been screened trough Multiplex and ELISA. Furthermore, we compared our results to publicly available sc-RNAseq datasets on freshly isolated SFs and to our bulk-RNAseq data from clinical trials patients.

Results

Hierarchical clustering from sc-RNAseq transcriptional profiling of LM vs FPI RASF - after several cell passages - identified profoundly different gene signatures: whereby LM-RASF were characterised by genes involved in inflammation, proteoglycan formation and integrin binding, FPI-RASF were defined by genes related to collagen biosynthesis. Comparing the above signatures with those of freshly isolated RASF we identified both imprinted (i.e. maintained through several in vitro passages) and inducible (i.e. loss after long term culture) gene signatures. Notably, RA B-cells co-cultured with FPI-RASF profoundly altered the FPI-RASF transcriptional profile including the ex-novo expression of gene signatures typical of LM-RASF. Consensus gene modules constructed on LM vs FPI RASF imprinted gene signatures could be tracked in longitudinal whole tissue bulk RNA-seq data obtained from both early arthritis and established RA and were associated with synovial pathotype-specific histological and clinical features. Finally, modulation of FPI-RASF related genes following B-cell depletion identified poor responders to Rituximab in the R4RA randomised clinical trial.

Conclusion

Our work demonstrates that RASFs from different endotypes display imprinted memory of their original synovial tissue when maintained in culture over several months. We also demonstrated that imprinted memory typical of RASF isolated from B-cell rich LM synovial tissues can be dynamically modulated in FPI RASF following crosstalk with RA B cells. Finally, consensus gene modules based on FPI vs LM RASF-gene signatures were able inform on response/resistance to targeted biologic therapies.

References

[1]Lewis, M. J. et al. Molecular Portraits of Early Rheumatoid Arthritis Identify Clinical and Treatment Response Phenotypes. Cell Rep (2019)

[2]Humby, F. et al. Synovial cellular and molecular signatures stratify clinical response to csDMARD therapy and predict radiographic progression in early rheumatoid arthritis patients. Ann Rheum Dis (2019)

[3]Zhang, F. et al. Defining inflammatory cell states in rheumatoid arthritis joint synovial tissues by integrating single-cell transcriptomics and mass cytometry. Nat Immunol (2019)

[4]Humby, F. et al. Rituximab versus tocilizumab in anti-TNF inadequate responder patients with rheumatoid arthritis (R4RA). Lancet (2021)

Disclosure of Interests

None declared

POS0441 IN-DEPTH ANALYSIS OF Axl AND MerTK EXPRESSION PATTERNS AND REGULATION BY BIOLOGIC TREATMENTS IN RHEUMATOID ARTHRITIS

Background

Tyrosine kinases receptors MerTK and Axl have been implicated in the pathogenesis of several autoimmune diseases. Despite sharing significant structural homology and having common ligands, Axl and MerTK have distinct features and biological functions [1]. A growing body of evidence suggests that both Axl and MerTK play a crucial role in Rheumatoid Arthritis (RA) pathogenesis and progression and may be exploited as novel therapeutic targets [2]. However, numerous unanswered questions remain to be addressed.

Objectives:

i.To define common and distinct gene-partners of Axl/MerTK and quantify their expression in RA synovial tissue.

ii.To assess the co-expression of Axl/MerTK by synovial cells.

iii.To outline the longitudinal variation in Axl/MerTK expression upon treatment intervention.

Methods

Synovial tissue samples were collected by US-guided synovial biopsy from: i. Patients with early (<12 months) RA DMARDs/steroid-naïve [n=87]; and ii. RA patients who failed the first-line biologic with TNF-inhibitors (TNFi) before and 16 weeks after receiving either Rituximab (RTX) or Tocilizumab (TOC) [n=164] [3]. Gene expression was obtained by bulk RNAseq performed on an Illumina HiSeq2500 platform. Axl-/MerTK-modules were defined using STRING networks and the module expression determined by the mean z-score of regularized log transformed expression for all genes in the set. Axl, MerTK, CD55, CD90, CD68 protein expression was analysed by multiplex immunofluorescence staining.

Results

Using STRING network analysis, we defined an Axl- and a MerTK-module composed of 31 predicted gene-partners of either Axl or MerTK. Thirteen genes were common to both modules and included the ligands Gas6 and ProteinS, and EGFR. Conversely, eighteen genes were uniquely present in the Axl-module (e.g., PIK3-family, IGF1R, IFNAR1 and STAT3) or the MerTK-module (e.g., Galectin3 and TULP, recently discovered MerTK ligands, FCGR1A/CD64, PTPN1and MEGF10). Axl/MerTK-modules quantified in the early-arthritis treatment-naïve RNAseq dataset showed a significant negative correlation with the synovitis score (Axl r=−0.33, p=0.0032; MerTK r=-0.33, p=0.003). At protein level, CD68+macrophages of the Lining showed notable heterogeneity between patients: they could express either Axl or MerTK alone, or co-express both. Axl was also present in most CD55+ Lining Fibroblast-Like-Cells (FLS) but not by CD90+ Sublining FLS while MerTK, as expected, was restricted to macrophages, including intra-aggregate tingible-body-macrophages.

To define how Axl and MerTK vary depending on disease stage and treatment exposure, we quantified their gene expression in active RA patients inadequately responding to TNFi, prior and 16 weeks after starting second-line biologic (RTX or TOC) [3]. Differently from the early-arthritis cohort, MerTK was significantly up-regulated in synovia characterised by higher degree of tissue inflammation (lympho-myeloid > diffuse-myeloid > pauci-immune, p<0.0001) and significantly positively correlated with several cytokines’ genes such as TNF, IL-6, CCL8 and IL-10. MerTK expression was dependent on clinical response to RTX but not TOC as assessed by EULAR response (DAS28CRP, good vs none/mod, FDRresp 0.048). Conversely, Axl expression significantly increased upon IL-6 blockade by TOC independently of the clinical response (FDRtime 0.016).

Conclusion

Our data further corroborate that Axl and MerTK constitute a dynamic axis influenced by the synovial tissue inflammatory features, the disease stage, the exposure and the response to targeted treatment and the blockade of critical inflammatory pathways over time. A better understanding of the individual features of these tyrosine kinases as well as their interaction would be beneficial to define novel treatment approaches.

References

[1]Zagórska A, et al. Nat Immunol. 2014 Oct;15(10):920-8

[2]Kemble S, Croft AP. Front Immunol. 2021 Sep 3;12:715894

[3]Humby F et al. Lancet. 2021 Jan 23;397(10271):305-317

Acknowledgements

Versus Arthritis.

Disclosure of Interests

None declared.

POS0431 PDGF-BB, TNF-α, AND LT-β REGULATE FOLLICULAR DENDRITIC CELL DEVELOPMENT IN THE RHEUMATOID SYNOVIUM

Background

Follicular dendritic cells (FDCs) fundamentally contribute to the formation of synovial ectopic lymphoid-like structures in rheumatoid arthritis (RA) which is associated with poor clinical prognosis. Despite this critical role in RA pathogenesis, FDC development in the RA synovium has not been fully elucidated.

Objectives

To investigate the role of TNF-α/LT-β and PDGF-BB in the ontogeny of RA synovial FDCs and the differentiation of lymphoid and fibroid RA synovitis.

Methods

RA Synovial tissues were obtained from the Pathobiology of Early Arthritis Cohort (PEAC) of the Centre for Experimental Medicine and Rheumatology of Queen Mary University of London. RNA-Seq analysis and confocal imaging of early and late FDC differentiation markers were carried out and the stromal cell subsets were sorted by flow cytometry. The stromal cell subsets were treated with TNF-α/LT-β and/or PDGF-BB and the expression of FDC differentiation genes was assessed by qPCR. Germinal centre reactions were setup in vitro using TNF-α/LT-β activated stromal cells, and antibody production by naive human B cells stimulated with anti IgM was measured by ELISA.

Results

Our results indicate that PDGF-BB induces the FDC marker CNA.42+ on NG2+/αSMA+ type-1 pericytes, stimulates THY-1 and αSMA gene expression, and strongly correlates with fibroid synovitis using RNA-Seq analysis. On the other hand, TNF-α/LT-β downregulate PDGFR-β, THY-1, αSMA; induce CD21, FcɣRIIB expression, and significantly correlate with lymphoid synovial pathotype. Ultrastructural examination of antigen trapping on TNF-α/LT-β-activated RA synovial fibroblasts (RASFs) showed periodically retained surface antigens and these fibroblasts were able to induce T cell independent B cell activation in in vitro germinal centre reactions. The transition from an early PDGFR-β+ pre FDCs to a late TNF-α/LT-β-responsive mature FDCs is promoted by PDGF-BB. PDGF-BB induces TNF-αR expression in RASFs and facilitates B cell recruitment via pericyte CXCL13 expression and stromal cell migration.

Conclusion

To the best of our knowledge, this is the first report describing the crosstalks between PDGF-BB and TNF-α/LT-β in FDC development in the rheumatoid synovium and its association with the evolution of lymphoid and fibroid synovitis. Selective targeting of this interplay could inhibit FDC differentiation and potentially ameliorate RA in clinically severe and drug-resistant patients.

Disclosure of Interests

None declared.

OP0109 EXPRESSION QUANTITATIVE TRAIT LOCI IN EARLY TREATMENT-NAÏVE RHEUMATOID ARTHRITIS

Background

To date more than 100 genetic loci have been associated with rheumatoid arthritis (RA), particularly in the human leukocyte antigen (HLA) region. Our understanding of the functional consequences of genetic variation in RA causality, however, is limited and it has been shown that a substantial portion of complex disease risk alleles modify gene expression in a cell-specific manner [1]. The Pathobiology of Early Arthritis Cohort (PEAC) is a longitudinal study looking at treatment-naiv̈e RA patients with genotyped data as well as both synovial and blood RNA-sequenced biopsies prior to treatment with disease modifying anti-rheumatic drugs (DMARDs).

Objectives

To explore expression quantitative trait loci (eQTL) in synovium and blood within PEAC and characterise the effects of genetic variation on gene expression measured by RNA-sequencing. A further goal was to investigate the role of these variants in RA disease severity and response variables.

Methods

Genotypes were generated by Illumina Human CoreExome-24 version 1-0 array in 118 RA patients. Single nucleotide polymorphisms (SNPs) in the HLA region were imputed using HLA-TAPAS. A candidate gene study was performed on variants within the HLA region using Plink v2.0. Synovial (n=85) and blood (n=51) RNA-sequenced samples then underwent cis-eQTL analysis (loci within ±5x105Mb of the variant) based on linear regression models with the matrixeQTL R package using PEER [2] and PCA eigenvectors as covariates. Differences in eQTL between tissues were determined using a linear interaction term.

Results

The candidate gene study determined several amino acids around HLA-DRB1 acting as markers for seropositivity, which replicated findings by Raychaudhuri et. al. [3]. Using eQTL analysis, around 33,000 synovial SNPs were found with genome-wide significance (p ≤ 5x10-8) and around 29,000 in blood. This corresponded to 279 unique significant genes in synovium and 417 in blood (Figure 1). There were 100 genes common to both synovium and blood, including PSORS1C3, HLA-DRB9 and ERAP2, which have known associations with autoimmune diseases and inflammatory arthritis. Notably, 92 genes showed significantly different patterns of QTL expression between synovial tissue and blood (p ≤ 5x10-8). eQTL data also confirmed the triad of genetic variants significantly driving tissue gene expression of HLA-DPB2, while both HLA-DPB2 SNPs and HLA-DPB2 RNA-sequencing synovial expression correlated highly with erythrocyte sedimentation rate (ESR).

Figure 1.

Manhattan plots for cis-expression quantitative trait loci (eQTL) analysis performed on 85 synovial samples (top) and 51 blood samples (middle). Tissue interaction eQTL (bottom) show significant differences between tissues (p ≤ 5x10-8).

Conclusion

The high significance of genes in the HLA region in both tissues is in-keeping with the strong association between HLA and susceptibility to RA, as well as other autoimmune diseases. Most notably variants linked to HLA-DPB2 synovial expression were found to be a marker for disease severity through ESR association. Additionally, the significant differences between eQTL in blood and synovium highlight the need to explore functional consequences of genetic associations in the diseased tissue directly.

References

[1]Thalayasingam et. al. (2018). CD4+ and B lymphocyte expression quantitative traits at rheumatoid arthritis risk loci in patients with untreated early arthritis: implications for causal gene identification. Arthritis & Rheumatology, 70(3), 361-370.

[2]Stegle et al. (2012). Using probabilistic estimation of expression residuals (PEER) to obtain increased power and interpretability of gene expression analyses. Nature protocols, 7(3), 500-507.

[3]Raychaudhuri et al. (2012). Five amino acids in three HLA proteins explain most of the association between MHC and seropositive rheumatoid arthritis. Nature genetics, 44(3), 291-296.

Disclosure of Interests

None declared

Genetically diverse mouse models of SARS-CoV-2 infection reproduce clinical variation and cytokine responses in COVID-19

Inflammation in response to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection drives severity of coronavirus disease 2019 (COVID-19), with effective versus dysregulated responses influenced by host genetics. To understand mechanisms of inflammation, animal models that reflect genetic diversity and clinical outcomes observed in humans are needed. We report a mouse panel comprising the diverse genetic backgrounds of the Collaborative Cross founder strains crossed to K18-hACE2 transgenic mice that confers high susceptibility to SARS-CoV-2. Infection of CC x K18-hACE2 F1 progeny resulted in a spectrum of weight loss, survival, viral replication kinetics, histopathology, and cytokine profiles, some of which were sex-specific. Importantly, survival was associated with early type I interferon (IFN) expression and a phased proinflammatory response distinct from mice with severe disease. Thus, dynamics of inflammatory responses observed in COVID-19 can be modeled in diverse mouse strains that provide a genetically tractable platform for understanding antiviral immunity and evaluating countermeasures.

ONE SENTENCE SUMMARY

Genetically diverse mice display a broad spectrum of clinically relevant responses to SARS-CoV-2 infection, reflecting variability in COVID-19 disease.

Impact of solid-liquid interfacial thermodynamics on phase-change memory RESET scaling

A model of the RESET melting process in conventional phase-change memory (PCM) devices is constructed in which the Gibbs-Thomson (GT) effect, representing local equilibrium at the solid-liquid interface, is included as an interfacial condition for the electro-thermal model of the PCM device. A comparison is made between the GT model and a commonly used model in which the interfacial temperature is fixed at the bulk melting temperature of the PCM material. The model is applied to conventional PCM designs in which a dome-shaped liquid/amorphous region is formed. Two families of solutions are computed representing steady state liquid regions, distinguished by their thermodynamic aspects. There is a family of solutions representing a hypothetical liquid nucleation process, and a family of larger steady-state liquid solutions representing the limit of the melting process. These 'melting limits' enable calculation of minima in voltage and corresponding current required for the RESET process. In this PCM configuration, the GT effect constrains the equilibrium solid-liquid interface temperature to remain above the bulk melting temperature during melting. The magnitude of this temperature difference increases with decreasing device size scale, thus requiring an increase in the required voltage and current needed for RESET compared to the case in which the interface temperature is approximated by the bulk melting temperature. This increase becomes substantial for active device dimensions in the <20 nm range. The impact of this phenomena on PCM device design is discussed.

Abstract TP169: Post-Neonatal Stroke In Children With Critical Congenital Heart Defects

Background: Critical congenital heart defects (CCHD) are a subset of mostly cyanotic lesions that require intervention within the first days to weeks of life for survival. For children born with CCHD, the neonatal period is considered the time of highest risk for brain injury as abnormalities in fetal circulation can lead to vulnerabilities in cerebral perfusion prior to corrective cardiac procedures. The prevalence and timing of cerebrovascular events associated with CCHD after the neonatal period is less clear.

Methods: We performed a cross-sectional analysis using the National Inpatient Sample database from 2012-2018. We included all children aged 1-18 years hospitalized with either ischemic stroke (IS), intracerebral hemorrhage (ICH), or subarachnoid hemorrhage (SAH). We created multivariable linear and logistic regression models to assess differences in age at stroke onset and mortality after stroke.

Results: We identified 4,647 pediatric strokes, 162 (3.5%) of which were associated with CCHD. Adjusting for demographic and clinical covariates, the median age at time of stroke was lower in CCHD patients across all stroke subtypes (Figure). Children with CCHD experienced a higher proportion of IS compared to children without CCHD (75.3% vs 49.5%, P<0.001); and a lower proportion of ICH and SAH (10.5% vs 25.7% and 14.2% vs 24.9%; both P = 0.002). In-hospital mortality for the entire sample following stroke was 10.4% for IS, 14.5% for ICH, and 13.4% for SAH. Adjusting for demographics and confounders, presence of CCHD doubled the odds of death following stroke (OR 2.05; 95% CI 1.35-3.11).

Conclusion: Beyond the first year of life, children with CCHD have earlier age at stroke onset and higher post-stroke mortality compared to children without CCHD. Continued vigilance and monitoring of potential neurological complications is warranted in children with CCHD.

The role of wind in controlling the connectivity of blue mussels (Mytilus edulis L.) populations

BACKGROUND

Larval connectivity between distinct benthic populations is essential for their persistence. Although connectivity is difficult to measure in situ, it can be predicted via models that simulate biophysical interactions between larval behaviour and ocean currents. The blue mussel (Mytilus Edulis L.) is widespread throughout the northern hemisphere and extensively commercialised worldwide. In the Irish Sea, this industry represents ~ 50% of Welsh shellfisheries, where cultivation is mainly based on wild spat. However, the main sources and amount of spat varied interannually (1100 tonnes harvest in 2014 against zero in 2018). The aim of this study is to characterise the structure and dynamics of the blue mussel metapopulation within the northern part of the Irish Sea.

METHODS

We develop a Lagrangian particle tracking model, driven by a high-resolution (from 30 to 5000 m) validated unstructured coastal hydrodynamic model of the Irish Sea, to simulate spatial and temporal variability of larval dispersal and connectivity between distinct mussel populations and potential settlement areas.

RESULTS

Our results showed that: (1) larvae positioned near the surface were strongly influenced by wind-driven currents suggesting that connectivity networks had the potential to span hundreds of kilometres; (2) in contrast, larvae positioned deeper in the water column were driven by tidal currents, producing intricate spatial patterns of connectivity between mussel beds over tens of kilometres that were consistent over time.

CONCLUSIONS

Dispersal of mussel larvae in the tidally energetic Irish Sea during the April-May spawning season is potentially driven by wind-driven surface currents, as confirmed by fisherman observations of inter-annual variability in wild spat collection. These results have important implications for metapopulation dynamics within the context of climate change and sustainable shellfisheries management (i.e. gain and loss of populations and harvest areas according to wind conditions).

Nurturing attachments group: A virtual group intervention for adults caring for traumatised children in the context of COVID-19

Background: Evidence indicates that the more traditional and behavioural parenting strategies are ineffective when parenting a child who has experienced developmental trauma. Recognising the need to parent with an attachment focus, the current paper evaluates the effectiveness of running the [Enfys] Nurturing Attachments Group, virtually, within the context of the COVID-19 pandemic. Method: A pilot feasibility study evaluated eight bespoke groups. Consenting professionals and co-professionals completed the Brief Parental Self-Efficacy Scale (BFSS), Care Questionnaire (CQ) and the Parental Reflective Functioning Questionnaire (PRFQ). Results: One hundred forty individuals attended the groups, with 51 (36%) completing both pre-and post-measures. The results provide evidence that professionals and co-professionals reported statistically significant positive increases on both the BPSS (d = .55) and CQ (d = .62). For the PRFQ, the results showed a statistically significant decrease on the Pre-mentalising sub scale, a non-significant mid-range score for Certainty about Mental States and a non-significant increase for Parental Interest and Curiosity in Mental States. Conclusion: The study has demonstrated initial viability of effectively facilitating the [Enfys] Nurturing Attachments Group, virtually. Importantly, it has also shown that the group can be run with professionals alongside co-professionals.

A review of the UK and British Channel Islands practical tidal stream energy resource

This review provides a critical, multi-faceted assessment of the practical contribution tidal stream energy can make to the UK and British Channel Islands future energy mix. Evidence is presented that broadly supports the latest national-scale practical resource estimate, of 34 TWh/year, equivalent to 11% of the UK's current annual electricity demand. The size of the practical resource depends in part on the economic competitiveness of projects. In the UK, 124 MW of prospective tidal stream capacity is currently eligible to bid for subsidy support (MeyGen 1C, 80 MW; PTEC, 30 MW; and Morlais, 14 MW). It is estimated that the installation of this 124 MW would serve to drive down the levelized cost of energy (LCoE), through learning, from its current level of around 240   £ / MWh to below 150   £ / MWh , based on a mid-range technology learning rate of 17%. Doing so would make tidal stream cost competitive with technologies such as combined cycle gas turbines, biomass and anaerobic digestion. Installing this 124 MW by 2031 would put tidal stream on a trajectory to install the estimated 11.5 GW needed to generate 34 TWh/year by 2050. The cyclic, predictable nature of tidal stream power shows potential to provide additional, whole-system cost benefits. These include reductions in balancing expenditure that are not considered in conventional LCoE estimates. The practical resource is also dependent on environmental constraints. To date, no collisions between animals and turbines have been detected, and only small changes in habitat have been measured. The impacts of large arrays on stratification and predator-prey interaction are projected to be an order of magnitude less than those from climate change, highlighting opportunities for risk retirement. Ongoing field measurements will be important as arrays scale up, given the uncertainty in some environmental and ecological impact models. Based on the findings presented in this review, we recommend that an updated national-scale practical resource study is undertaken that implements high-fidelity, site-specific modelling, with improved model validation from the wide range of field measurements that are now available from the major sites. Quantifying the sensitivity of the practical resource to constraints will be important to establish opportunities for constraint retirement. Quantification of whole-system benefits is necessary to fully understand the value of tidal stream in the energy system.

Areas of global importance for conserving terrestrial biodiversity, carbon and water

To meet the ambitious objectives of biodiversity and climate conventions, the international community requires clarity on how these objectives can be operationalized spatially and how multiple targets can be pursued concurrently. To support goal setting and the implementation of international strategies and action plans, spatial guidance is needed to identify which land areas have the potential to generate the greatest synergies between conserving biodiversity and nature's contributions to people. Here we present results from a joint optimization that minimizes the number of threatened species, maximizes carbon retention and water quality regulation, and ranks terrestrial conservation priorities globally. We found that selecting the top-ranked 30% and 50% of terrestrial land area would conserve respectively 60.7% and 85.3% of the estimated total carbon stock and 66% and 89.8% of all clean water, in addition to meeting conservation targets for 57.9% and 79% of all species considered. Our data and prioritization further suggest that adequately conserving all species considered (vertebrates and plants) would require giving conservation attention to ~70% of the terrestrial land surface. If priority was given to biodiversity only, managing 30% of optimally located land area for conservation may be sufficient to meet conservation targets for 81.3% of the terrestrial plant and vertebrate species considered. Our results provide a global assessment of where land could be optimally managed for conservation. We discuss how such a spatial prioritization framework can support the implementation of the biodiversity and climate conventions.

Mitophagy antagonism by ZIKV reveals Ajuba as a regulator of PINK1 signaling, PKR-dependent inflammation, and viral invasion of tissues

Dysregulated inflammation dominated by chemokine expression is a key feature of disease following infection with the globally important human pathogens Zika virus (ZIKV) and dengue virus, but a mechanistic understanding of how pro-inflammatory responses are initiated is lacking. Mitophagy is a quality-control mechanism that regulates innate immune signaling and cytokine production through selective degradation of damaged mitochondria. Here, we demonstrate that ZIKV nonstructural protein 5 (NS5) antagonizes mitophagy by binding to the host protein Ajuba and preventing its translocation to depolarized mitochondria where it is required for PINK1 activation and downstream signaling. Consequent mitophagy suppression amplifies the production of pro-inflammatory chemokines through protein kinase R (PKR) sensing of mitochondrial RNA. In Ajuba^-/- mice, ZIKV induces early expression of pro-inflammatory chemokines associated with significantly enhanced dissemination to tissues. This work identifies Ajuba as a critical regulator of mitophagy and demonstrates a role for mitophagy in limiting systemic inflammation following infection by globally important human viruses.

Morbidity among Israeli backpack travelers to tropical areas

BACKGROUND

Travelers to tropical areas may be susceptible to illness or injuries. This study aims to assess morbidity among travelers during their travel and compare those who became ill or were injured with those who did not.

METHODS

This prospective study included 400 travelers who were counselled by a physician in pre-travel clinics in central Israel between 2017 and 2018. Participants were interviewed within a month after their return regarding morbidity during travel, including health problems that started one week following their return.

RESULTS

Most travelers (N = 320, 80%) reported at least one illness or injury. Illnesses/injuries were more common among females than males (84.9% vs. 75.1%, p = 0.01), travel periods longer than 30 days (87.7% vs. 77.2%, p = 0.03), and travelers accompanied by their friends or solo travelers compared with those who traveled with their family/partner (83.8% and 70.0%, respectively, p = 0.002). The most common complaint was diarrhea (N = 159, 49.6%), followed by high-altitude sickness (N = 118, 36.9%) and fever (N = 100, 31.2%). Altitude sickness symptoms were more common in females than in males (58.9% vs. 41.0%, p = 0.006) and in those who ascended rapidly in comparison to those who ascended gradually (58.7% vs. 44.6%, p = 0.04). Animal injury was reported by 30 (7.5%) participants yet only eight (27.0%) received medical care, seven of whom (23.3%) were vaccinated against rabies.

CONCLUSIONS

Being a female, traveling with friends or alone and longer travel periods were associated with illness/injury. Practitioners at pre-travel clinics should inform travelers of the possible risks including the potential severe consequences of rabies and altitude sickness.

Comparison of deep learning with traditional models to predict preventable acute care use and spending among heart failure patients

 

Recent health reforms have created incentives for cardiologists and accountable care organizations to participate in value-based care models for heart failure (HF). Accurate risk stratification of HF patients is critical to efficiently deploy interventions aimed at reducing preventable utilization. The goal of this paper was to compare deep learning approaches with traditional logistic regression (LR) to predict preventable utilization among HF patients. We conducted a prognostic study using data on 93,260 HF patients continuously enrolled for 2-years in a large U.S. commercial insurer to develop and validate prediction models for three outcomes of interest: preventable hospitalizations, preventable emergency department (ED) visits, and preventable costs. Patients were split into training, validation, and testing samples. Outcomes were modeled using traditional and enhanced LR and compared to gradient boosting model and deep learning models using sequential and non-sequential inputs. Evaluation metrics included precision (positive predictive value) at k, cost capture, and Area Under the Receiver operating characteristic (AUROC). Deep learning models consistently outperformed LR for all three outcomes with respect to the chosen evaluation metrics. Precision at 1% for preventable hospitalizations was 43% for deep learning compared to 30% for enhanced LR. Precision at 1% for preventable ED visits was 39% for deep learning compared to 33% for enhanced LR. For preventable cost, cost capture at 1% was 30% for sequential deep learning, compared to 18% for enhanced LR. The highest AUROCs for deep learning were 0.778, 0.681 and 0.727, respectively. These results offer a promising approach to identify patients for targeted interventions.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): internally funded by Diagnostic Robotics Inc.

63 The “Brighton Connector”: A Simple, Reproducible and Cost-Effective Technique for Bilateral Antegrade Cerebral Perfusion During Aortic Arch Surgery

Aim

Surgery of the aortic arch presents significant technical and physiological challenges. Selective antegrade cerebral perfusion (SACP) during arch surgery has been shown to improve mortality and neurological outcomes in these patients. At our centre, we aimed to develop a safe, reliable, and cost-effective technique to provide bilateral antegrade cerebral perfusion without the need of another pump head.

Method

We developed our system using equipment that is included in the accessory packaging for the Sorin Xtra cell saver system, which is readily available in cardiac surgical units nationwide, but often discarded as it is not required. An EOPA arterial return cannula and the TRUE FLOW RDB SACP cannula were joined using our novel connection.

Results

A single surgeon has used the “Brighton Connector” for 6 patients in the last two years. All patients made a satisfactory recovery with a 0% rate of mortality or permanent neurological deficit.

Conclusions

All components in our circuit are already approved for use in cardiac theatres, and the connection tubing would normally be discarded, making our method cost neutral. We demonstrate through a case series that mortality and neurological outcomes are good and comparable with other techniques.

DROP: Molecular voucher database for identification of Drosophila parasitoids

Molecular identification is increasingly used to speed up biodiversity surveys and laboratory experiments. However, many groups of organisms cannot be reliably identified using standard databases such as GenBank or BOLD due to lack of sequenced voucher specimens identified by experts. Sometimes a large number of sequences are available, but with too many errors to allow identification. Here, we address this problem for parasitoids of Drosophila by introducing a curated open-access molecular reference database, DROP (Drosophila parasitoids). Identifying Drosophila parasitoids is challenging and poses a major impediment to realize the full potential of this model system in studies ranging from molecular mechanisms to food webs, and in biological control of Drosophila suzukii. In DROP, genetic data are linked to voucher specimens and, where possible, the voucher specimens are identified by taxonomists and vetted through direct comparison with primary type material. To initiate DROP, we curated 154 laboratory strains, 856 vouchers, 554 DNA sequences, 16 genomes, 14 transcriptomes, and six proteomes drawn from a total of 183 operational taxonomic units (OTUs): 114 described Drosophila parasitoid species and 69 provisional species. We found species richness of Drosophila parasitoids to be heavily underestimated and provide an updated taxonomic catalogue for the community. DROP offers accurate molecular identification and improves cross-referencing between individual studies that we hope will catalyse research on this diverse and fascinating model system. Our effort should also serve as an example for researchers facing similar molecular identification problems in other groups of organisms.