Immunogenicity and reactogenicity of modified vaccinia Ankara pre-exposure vaccination against mpox according to previous smallpox vaccine exposure and HIV infection: prospective cohort study

Background

Pre-exposure vaccination with MVA-BN has been widely used against mpox to contain the 2022 outbreak. Many countries have defined prioritized strategies, administering a single dose to those historically vaccinated for smallpox, to achieve quickly adequate coverage in front of low supplies. Using epidemiological models, real-life effectiveness was estimated at approximately 36%-86%, but no clinical trials were performed. Few data on MVA-BN immunogenicity are currently available, and there are no established correlates of protection. Immunological response in PLWH in the context of the 2022 outbreak was also poorly described.

Methods

Blood samples were collected from participants eligible for pre-exposure MVA-BN vaccination before (T1) receiving a full course of vaccine (single-dose for vaccine-experienced or smallpox-primed and two-dose for smallpox vaccine-naïve or smallpox non-primed) and one month after the last dose (T2 and T3, respectively). MPXV-specific IgGs were measured by in-house immunofluorescence assay, using 1:20 as screening dilution, MPXV-specific nAbs by 50% plaque reduction neutralization test (PRNT50, starting dilution 1:10), and IFN-γ-producing specific T cells to MVA-BN vaccine, by ELISpot assay. Paired or unpaired t-test and Wilcoxon or Mann-Whitney test were used to analyse IgG and nAbs, and T-cell response, as appropriate. The probability of IgG and nAb response in vaccine-experienced vs. vaccine-naïve was estimated in participants not reactive at T1. The McNemar test was used to evaluate vaccination's effect on humoral response both overall and by smallpox vaccination history. In participants who were not reactive at T1, the proportion of becoming responders one month after full-cycle completion by exposure groups was compared by logistic regression and then analysed by HIV status strata (interaction test). The response was also examined in continuous, and the Average Treatment Effect (ATE) of the difference from baseline to schedule completion according to previous smallpox vaccination was estimated after weighting for HIV using a linear regression model. Self-reports of adverse effects following immunization (AEFIs) were prospectively collected after the first MVA-BN dose (T1). Systemic (S-AEFIs: fatigue, myalgia, headache, GI effects, chills) and local (L-AEFIs: redness, swelling, pain) AEFIs were graded as absent (grade 0), mild (1), moderate (2), or severe (3). The maximum level of severity for S-AEFIs and L-AEFIs ever experienced over the 30 days post-dose by vaccination exposure groups were analysed using a univariable multinomial logistic regression model and after adjusting for HIV status; for each of the symptoms, we also compared the mean duration by exposure group using an unpaired t-test.

Findings

Among the 164 participants included, 90 (54.8%) were smallpox vaccine-experienced. Median age was 49 years (IQR 41-55). Among the 76 (46%) PLWH, 76% had a CD4 count >500 cells/μL. There was evidence that both the IgG and nAbs titers increased after administration of the MVA-BN vaccine. However, there was no evidence for a difference in the potential mean change in humoral response from baseline to the completion of a full cycle when comparing primed vs. non-primed participants. Similarly, there was no evidence for a difference in the seroconversion rate after full cycle vaccination in the subset of participants not reactive for nAbs at T1 (p = 1.00 by Fisher's exact test). In this same analysis and for the nAbs outcome, there was some evidence of negative effect modification by HIV (interaction p-value = 0.17) as primed people living with HIV (PLWH) showed a lower probability of seroconversion vs. non-primed, and the opposite was seen in PLWoH. When evaluating the response in continuous, we observed an increase in T-cell response after MVA-BN vaccination in both primed and non-primed. There was evidence for a larger increase when using the 2-dose vs. one-dose strategy with a mean difference of -2.01 log2 (p ≤ 0.0001), after controlling for HIV. No evidence for a difference in the risk of developing any AEFIs of any grade were observed by exposure group, except for the lower risk of grade 2 (moderate) fatigue, induration and local pain which was lower in primed vs. non-primed [OR 0.26 (0.08-0.92), p = 0.037; OR 0.30 (0.10-0.88), p = 0.029 and OR 0.19 (0.05-0.73), p = 0.015, respectively]. No evidence for a difference in symptom duration was also detected between the groups.

Interpretation

The evaluation of the humoral and cellular response one month after the completion of the vaccination cycle suggested that MVA-BN is immunogenic and that the administration of a two-dose schedule is preferable regardless of the previous smallpox vaccination history, especially in PLWH, to maximize nAbs response. MVA-BN was safe as well tolerated, with grade 2 reactogenicity higher after the first administration in vaccine-naïve than in vaccine-experienced individuals, but with no evidence for a difference in the duration of these adverse effects. Further studies are needed to evaluate the long-term duration of immunity and to establish specific correlates of protection.

Funding

The study was supported by the National Institute for Infectious Disease Lazzaro Spallanzani IRCCS "Advanced grant 5 × 1000, 2021" and by the Italian Ministry of Health "Ricerca Corrente Linea 2".

Brief Report: In cART-Treated HIV-Infected Patients, Immunologic Failure Is Associated With a High Myeloid-Derived Suppressor Cell Frequency

BACKGROUND

During HIV infection, effective combined antiretroviral therapy suppresses viral replication and restores the number of circulating CD4+ T cells. However, 15%-30% of treated patients show a discordant response to combined antiretroviral therapy. Myeloid-derived suppressor cells (MDSC) are expanded in HIV+ patients; to better understand the role of MDSC on CD4 T-cell recovery, we evaluated the frequency of MDSC in HIV+ patients under combined antiretroviral therapy and its association with immunologic response.

METHODS

We enrolled 60 HIV+ patients, including complete responders (R, n = 44), virologic nonresponders (VNR, n = 5), and immunologic nonresponders (INR, n = 11). The frequency of circulating MDSC and the percentage of activated and naïve CD4 T cells were evaluated by flow cytometry. Plasmatic cytokine levels were analyzed by automated ELISA.

RESULTS

As previously observed, polymorphonuclear MDSC (PMN-MDSC) frequency was higher in HIV+ patients compared with healthy donors. Furthermore, PMN-MDSC percentage was higher in INR than R patients, and a significant association between MDSC frequency and immunologic failure was confirmed by a receiver operator characteristic analysis. Accordingly, an inverse correlation was found between the percentages of PMN-MDSC and naïve CD4 T cells. A positive correlation was observed between PMN-MDSC frequency and the percentage of human leucocyte antigen locus DR + CD4 T cells and the plasmatic level of IL-1β and IL-8.

CONCLUSION

Our results show that a high frequency of PMN-MDSC persists in INR, possibly because of immune activation, contributing to CD4 T-cell recovery failure. These findings further highlight the detrimental role of MDSC during HIV infection, suggesting these cells as a possible new therapeutic target.

In Vitro and In Vivo Crosstalk between Type I IFN and IL-8 Responses in SARS-CoV-2 Infection

COVID-19 patients show characteristic over-expression of different cytokines that may interfere with the interferon (IFN) response, delaying its production. Within the overexpressed cytokines, IL-8 plays a key role, and it may impede IFN-I activation. PBMC from eight healthy donors were exposed to 2019-nCoV/Italy-INMI1 isolate and supernatants/cells were collected at different time points; the production of either IFN-alpha or IL-8 was assessed. The same analysis was performed on plasma samples obtained from 87 COVID-19 patients. Antagonism between IFN-alpha and IL-8 was observed, since in those PBMC with medium or high IL-8 levels, IFN-α levels were low. The same scenario was observed in SARS-CoV-2-infected patients that were divided into three groups based on IL-8 low, medium and high levels; the correlation between low levels of IFN-α and high levels of IL-8 was statistically significant in both the IL-8 medium and IL-8 high group. Overall, our results showed a crosstalk/antagonism between IL-8 and IFN-alpha in PBMC from healthy donors challenged with SARS-CoV-2 and inversely proportional IFN-alpha levels to IL-8 concentrations detected in plasma samples from COVID-19 patients, suggesting that the impairment of the innate immune response in COVID-19 patients may be linked to a dysregulated cytokine response, namely through IL-8 production.

Torquetenovirus Loads in Peripheral Blood Predict Both the Humoral and Cell-Mediated Responses to SARS-CoV-2 Elicited by the mRNA Vaccine in Liver Transplant Recipients

Three years into the COVID-19 pandemic, mass vaccination campaigns have largely controlled the disease burden but have not prevented virus circulation. Unfortunately, many immunocompromised patients have failed to mount protective immune responses after repeated vaccinations, and liver transplant recipients are no exception. Across different solid organ transplant populations, the plasma levels of Torquetenovirus (TTV), an orphan and ubiquitous human virus under control of the immune system, have been shown to predict the antibody response after COVID-19 vaccinations. We show here a single-institution experience with TTV viremia in 134 liver transplant recipients at their first or third dose. We found that TTV viremia before the first and third vaccine doses predicts serum anti-SARS-CoV-2 Spike receptor-binding domain (RBD) IgG levels measured 2-4 weeks after the second or third dose. Pre-vaccine TTV loads were also associated with peripheral blood anti-SARS-CoV-2 cell-mediated immunity but not with serum SARS-CoV-2 neutralizing antibody titers.

Third dose of SARS-CoV2 mRNA vaccination produces robust persistent cellular and humoral immune responses in liver transplant recipients

Weaker responses have been described after two doses of anti-SARS-CoV2 vaccination in liver transplant recipients. At the Italian National Institute for Infectious Diseases, 122 liver transplant recipients (84% males, median age 64 years) were tested for humoral and cell-mediated immune response after a third doses of anti-SARS-CoV2 mRNA vaccines. Humoral response was measured by quantifying anti-receptor binding domain and neutralizing antibodies; cell-mediated response was measured by quantifying IFN-γ after stimulation of T cells with SARS-CoV-2-specific peptides. Humoral and cellular responses improved significantly compared to the second vaccine dose; 86.4% of previous non-responders to the first 2 vaccine doses (N=22) became responders. Mycophenolate mofetil-containing regimens were not associated with lower response rates to a third vaccine; shorter time since transplantation (<6 years) was associated with lower humoral and cellular responses to third vaccine. Protective antibodies against Omicron variant were detected in 60% of patients 12 weeks after third vaccine dose.

Immunological signature in human cases of monkeypox infection in 2022 outbreak: an observational study

BACKGROUND

An unprecedented global monkeypox outbreak started in May, 2022. No data are yet available about the dynamics of the immune response against monkeypox virus. The aim of this study was to describe kinetics of T-cell response, inflammatory profile, and pox-specific T-cell induction in patients with laboratory-confirmed monkeypox.

METHODS

17 patients with laboratory-confirmed monkeypox admitted at the Lazzaro Spallanzani National Institute for Infectious Diseases (Rome, Italy), from May 19, to July 7, 2022, were tested for differentiation and activation profile of CD4 and CD8 T (expression of CD38, PD-1, and CD57 assessed by flow cytometry), frequency of pox-specific T cells (by standard interferon-γ ELISpot), and release of interleukin (IL)-1β, IL-6, IL-8, and tumour necrosis factor (TNF) in plasma (by ELISA). All patients were tested 10-12 days after symptoms onset. In a subgroup of nine patients with a laboratory-confirmed monkeypox, the kinetics of the immune response were analysed longitudinally according to timing from symptoms onset and compared with ten healthy donors (ie, health-care workers recruited from the same institution).

FINDINGS

Among the 17 patients, ten were HIV negative and seven HIV positive, all with good viro-immunological status. On days 0-3 from symptom onset, patients with laboratory-confirmed monkeypox were characterised by a statistically significant reduction in CD4+ T cells (p=0·0011) and a concurrent increase of CD8+ T cells (p=0·0057) compared with healthy donors. A lower proportion of naive (CD45RA+CD27+) CD4+ T cells was observed in six (67%) of nine patients and a concomitant higher proportion of effector memory (CD45RA-CD27-) CD4+ T cells in all patients; this skewed immune profile tended to normalise over time. A similar differentiated profile was also observed in CD8+ T cells with a consistent expansion of terminally differentiated CD8+ T cells. Patients with monkeypox had a higher proportion of CD4+CD38+ and CD38+CD8+ T-cells than healthy donors, which normalised after 12-20 days from symptom onset. The expression of PD-1 and CD57 on CD4+ and CD8+ T-cells showed kinetics similar to that observed for CD38. Furthermore, the inflammatory cytokines (IL-1β, IL-6, IL-8, and TNF) were higher in patients with monkeypox than in healthy donors and, although they decreased over time, they remained elevated after recovery. Almost all patients (15 [94%] of 16) developed a pox-specific Th1 response. No differences in immune cells profile were observed between patients with and without HIV, whereas paucysimptomatic patients (without systemic symptoms, with less than five skin lesions, and no other mucosal localisation of monkeypox) showed a less perturbed immune profile early after symptom onset.

INTERPRETATION

Our data showed the immunological signature of monkeypox virus infection, characterised by an early expansion of activated effector CD4+ and CD8+ T cells that persisted over time. Almost all patients, even regardless of HIV infection, developed a poxvirus-specific Th1 cell response. These results might have implications on the expected immunogenicity of monkeypox vaccination, suggesting that it might not be necessary to vaccinate people who have already been infected.

FUNDING

Italian Ministry of Health.

TRANSLATION

For the Italian translation of the abstract see Supplementary Materials section.

Booster dose of SARS-CoV-2 mRNA vaccines strengthens the specific immune response of patients with rheumatoid arthritis: A prospective multicenter longitudinal study

OBJECTIVE

To characterize the kinetics of humoral and T-cell responses in rheumatoid arthritis (RA)-patients followed up to 4-6 weeks (T3) after the SARS-CoV-2 vaccine booster dose.

METHODS

Health care workers (HCWs, n=38) and RA-patients (n=52) having completed the mRNA vaccination schedule were enrolled at T3. In each cohort, 25 subjects were also sampled after 5 weeks (T1) and 6 months (T2) from the first vaccine dose. The humoral response was assessed by measuring anti-Receptor-Binding Domain (RBD) and neutralizing antibodies, the T-cell response by interferon-(IFN)-γ-release assay (IGRA), T-cell cytokine production and B-cell phenotype at T3 by flow cytometry.

RESULTS

RA-patients showed a significant reduction of antibody titers from T1 to T2 and a significant increase at T3. T-cell response by IGRA persisted over time in RA-patients, while increased in HCWs. Most RA-patients scored positive for anti-RBD, neutralizing antibody and T-cell responses, although the magnitude was lower than HCWs. The spike-specific-cytokine response was mainly CD4+ T cells-restricted in both cohorts, and significantly lower with reduced IL-2 response and CD4-antigen-responding naïve T cells in RA-patients. Unswitched memory B-cells were reduced in RA-patients compared with HCWs independently of vaccination.

CONCLUSIONS

COVID-19 vaccine booster strengthens the humoral immunity in RA-patients even with a reduced cytokine-response.

Safety and immune response kinetics of GRAd-COV2 vaccine: phase 1 clinical trial results

Despite the successful deployment of efficacious vaccines and therapeutics, the development of novel vaccines for SARS-CoV-2 remains a major goal to increase vaccine doses availability and accessibility for lower income setting. We report here on the kinetics of Spike-specific humoral and T-cell response in young and old volunteers over 6 months follow-up after a single intramuscular administration of GRAd-COV2, a gorilla adenoviral vector-based vaccine candidate currently in phase-2 of clinical development. At all three tested vaccine dosages, Spike binding and neutralizing antibodies were induced and substantially maintained up to 3 months, to then contract at 6 months. Potent T-cell responses were readily induced and sustained throughout the study period, with only minor decline. No major differences in immune response to GRAd-COV2 vaccination were observed in the two age cohorts. In light of its favorable safety and immunogenicity, GRAd-COV2 is a valuable candidate for further clinical development and potential addition to the COVID-19 vaccine toolbox to help fighting SARS-CoV-2 pandemic.

Decrease of activity of antioxidant enzymes, lysozyme content, and protein degradation in milk contaminated with heavy metals (cadmium and lead)

The aim of this study was to evaluate the effect of added Cd and Pb to milk on its stability by determining antioxidant enzymatic activities, lysozyme content, and protein degradation. Antioxidant enzymatic activities were spectrophotometrically determined by superoxide dismutase, catalase, xanthine oxidase, and glutathione peroxidase assays; lysozyme was identified and quantified by HPLC-UV analysis, and protein degradation was investigated by spectrophotometric analysis of advanced oxidation protein products (AOPP) and dityrosine content. In this study, contaminated milk samples showed a significant reduction in activity of all studied enzymes compared with control milk. The contamination of milk also led to a significant reduction in the lysozyme content; lysozyme content was decreased about 22% and 18% in Pb milk and Cd milk, respectively, compared with control milk. The presence of the contaminants in the milk resulted in a significant increase of both dityrosine concentration and AOPP compared with the control milk. Moreover, between types of contaminated milk, dityrosine and AOPP values were significantly higher in the Pb milk than in the Cd milk. Therefore, it is important to monitor the presence of these toxic elements in milk for the damage they cause to consumer health both directly due to their ingestion and indirectly due to loss of milk stability.

Safety and efficacy of direct oral anticoagulants in patients with atrial fibrillation on concomitant treatment with dronedarone

Funding Acknowledgements

Type of funding sources: None.

Introduction

The use of direct oral anticoagulants (DOACs) in patients with atrial fibrillation (AF) is associated with bleedings. Interactions with dronedarone may increase this risk, but data on concomitant treatment of DOACs with dronedarone are limited.

Purpose

The primary endpoint was to compare the survival free from the composite endpoint of clinically relevant bleeding, thromboembolic event and all-cause death, between AF patients on treatment with dronedarone and different DOACs. The secondary endpoints were to compare the survival free from i) clinically relevant bleeding and ii) clinically relevant major bleeding.

Methods

A retrospective study was conducted at our Local Health Unit, from January 1st 2016 to December 31st 2020. The population included AF patients with concomitant prescriptions of DOACs and dronedarone. Patients were divided into 4 groups (rivaroxaban, apixaban, edoxaban, dabigatran). Clinically relevant major bleedings were defined as fatal bleeding or bleeding leading to transfusion of ≥2 units of blood. Clinically relevant non-major bleedings were defined as any sign of hemorrhage that does not fit the criteria for major bleeding but does lead to hospitalization or emergency room admission. Thromboembolic events were defined as ischemic stroke, transient ischemic attack (TIA), and systemic embolism.

Results

165 patients were included: 46/165 (28%) on rivaroxaban, 66/165 (40%) on apixaban, 45/165 (27%) on edoxaban, and 8/165 (5%) on dabigatran (Fig.1). Over a median follow-up of 339 days, 14/165 (8%) met the primary composite endpoint: 8/165 (5%) had clinically relevant bleedings, of which 1/165 (0.6%) was a clinically relevant major bleeding (i.e., fatal spontaneous intracerebral hemorrhage), 2/165 (1%) had TIAs, and 5/165 (3%) died. We found no difference in survival free from the primary composite endpoint and from clinically relevant bleeding between groups (p=0.19 and p=0.69, respectively) (Fig. 2A-B). However, survival free from clinically relevant major bleeding was significantly lower in dabigatran users (p=0.003) (Fig. 2C). At a secondary analysis, DOACs contraindicated by 2015 EHRA guide (dabigatran, edoxaban 60 mg), and not by 2018/2021 EHRA guides (rivaroxaban, dabigatran, edoxaban 60 mg), were associated with lower survival from either clinically relevant bleeding or clinically relevant major bleeding (p=0.03 and p&lt;0.001, respectively).

Conclusions

In our study on patients on concomitant treatment with DOACs and dronedarone, there was no difference in survival free from the primary composite endpoint and from clinically relevant bleeding between groups of coadministration. However, survival free from clinically relevant major bleeding was significantly lower in dabigatran users. DOACs contraindicated by 2015 EHRA guide (and not by the latest 2018/2021 EHRA guides) are associated with lower survival from either clinically relevant bleeding or clinically relevant major bleeding.

C51 SAFETY AND EFFICACY OF DIRECT ORAL ANTICOAGULANTS IN PATIENTS WITH ATRIAL FIBRILLATION ON CONCOMITANT TREATMENT WITH DRONEDARONE

Background

The use of direct oral anticoagulants (DOACs) in patients with atrial fibrillation (AF) is associated with bleedings. Interactions with dronedarone may increase this risk, but data on concomitant treatment of DOACs with dronedarone are limited.

Aim

The primary endpoint was to compare the survival free from the composite endpoint of clinically relevant bleeding, thromboembolic event and death, between AF patients on treatment with dronedarone and different DOACs. The secondary endpoints were to compare the survival free from i) clinically relevant bleeding and ii) clinically relevant major bleeding.

Methods

A retrospective study was conducted at the Local Health Unit “Ulss3 Serenissima” of Venice, Italy, from January 1st 2016 to December 31st 2020. The eligible population included AF patients with concomitant prescriptions of DOACs and dronedarone. Patients were divided in 4 groups (rivaroxaban, apixaban, edoxaban, dabigatran).

Results

165 patients were included: 46/165 (28%) on rivaroxaban, 66/165 (40%) on apixaban, 45/165 (27%) on edoxaban, and 8/165 (5%) on dabigatran (Fig.1). Over a median follow–up of 339 days, 14/165 (8%) met the primary composite endpoint: 8/165 (5%) had clinically relevant bleedings, of which 1/165 (0.6%) was a clinically relevant major bleeding, 2/165 (1%) had TIAs, and 5/165 (3%) died. We found no difference in survival free from the primary composite endpoint and from clinically relevant bleeding between groups (log–rank test p = 0.19 and p = 0.69, respectively) (Fig. 2A–B). However, survival free from clinically relevant major bleeding was significantly lower in dabigatran users (p = 0.003) (Fig. 2C). At a secondary analysis, DOACs contraindicated by 2015 EHRA guide (dabigatran, edoxaban 60 mg), and not by 2018/2021 EHRA guides (rivaroxaban, dabigatran, edoxaban 60 mg), were associated with lower survival from either clinically relevant bleeding or clinically relevant major bleeding (log–rank test p = 0.03 and p &lt; 0.001, respectively) (Fig. 3).

Conclusions

In our study, there was no difference in survival free from the primary composite endpoint and from clinically relevant bleeding between groups of coadministration. However, survival free from clinically relevant major bleeding was significantly lower in dabigatran users. DOACs contraindicated by 2015 EHRA guide (and not by the latest 2018/2021 EHRA guides) are associated with lower survival from either clinically relevant bleeding or clinically relevant major bleeding.

Myeloid-Derived Suppressor Cells in COVID-19: The Paradox of Good

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the ongoing coronavirus disease 2019 (COVID-19) pandemic. Viral replication in the respiratory tract induces the death of infected cells and the release of pathogen- associated molecular patterns (PAMPs). PAMPs give rise to local inflammation, increasing the secretion of pro- inflammatory cytokines and chemokines, which attract immune cells from the blood into the infected lung. In most individuals, lung-recruited cells clear the infection, and the immune response retreats. However, in some cases, a dysfunctional immune response occurs, which triggers a cytokine storm in the lung, leading to acute respiratory distress syndrome (ARDS). Severe COVID-19 is characterized by an impaired innate and adaptive immune response and by a massive expansion of myeloid-derived suppressor cells (MDSCs). MDSCs function as protective regulators of the immune response, protecting the host from over-immunoreactivity and hyper-inflammation. However, under certain conditions, such as chronic inflammation and cancer, MDSCs could exert a detrimental role. Accordingly, the early expansion of MDSCs in COVID-19 is able to predict the fatal outcome of the infection. Here, we review recent data on MDSCs during COVID-19, discussing how they can influence the course of the disease and whether they could be considered as biomarker and possible targets for new therapeutic approaches.

Use of Pembrolizumab for Treatment of Progressive Multifocal Leukoencephalopathy in People Living with HIV

Progressive Multifocal Leukoencephalopathy (PML) is a demyelinating disease occurring in advanced HIV infection, caused by the reactivation of poliomavirus JC (JCV). The use of pembrolizumab for treatment is based on the inhibition of programmed cell death protein 1 (PD-1), potentially improving the anti JCV-specific response. We used pembrolizumab with combined antiretroviral treatment (cART) on a compassionate-use basis. At each administration, clinical evaluation, MRI and laboratory testing, including CD3, CD4, CD8, PD-1 markers, HIV-RNA and JCV-DNA in cerebrospinal fluid (CSF)/plasma pairs, were performed. The JCV-specific T cell response was analysed by Elispot assay. This study included five HIV patients: four male, median age 43 years (29–52), median CD4 and CD8 count 150 (15–158) and 973 (354–1250) cell/mm3, respectively; median JCV-DNA and HIV-RNA in CSF/plasma pairs 9.540/1.503 cps/mL and 2.230/619 cp/mL, respectively. Overall, patients received between two and seven doses of pembrolizumab. After treatment, we observed JCV-DNA reduction and PD-1 down-regulation both in CSF and in plasma (high in circulating CD4 and CD8 at baseline), which remained stable at low levels in all patients. Three out of five patients showed stability of clinical picture and neuroimaging, while two others died. More data are needed in order to identify predictors of response to therapy.

Kinetics of the B- and T-Cell Immune Responses After 6 Months From SARS-CoV-2 mRNA Vaccination in Patients With Rheumatoid Arthritis

Objective

To assess the kinetics of the humoral and cell-mediated responses after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination in rheumatoid arthritis (RA) patients treated with different immunosuppressive therapies.

Methods

Following vaccine completed schedule, health care workers (HCWs, n = 49) and RA patients (n = 35) were enrolled at 5 weeks (T1) and 6 months (T6) after the first dose of BNT162b2-mRNA vaccination. Serological response was assessed by quantifying anti-receptor-binding domain (RBD)-specific immunoglobulin G (IgG) and SARS-CoV-2 neutralizing antibodies, while cell-mediated response was assessed by a whole-blood test quantifying the interferon (IFN)-γ response to spike peptides. B-cell phenotype and IFN-γ-specific T-cell responses were evaluated by flow cytometry.

Results

After 6 months, anti-RBD antibodies were still detectable in 91.4% of RA patients, although we observed a significant reduction of the titer in patients under Cytotoxic T-Lymphocyte Antigen 4 (CTLA-4)-Ig [median: 16.4 binding antibody units (BAU)/ml, interquartile range (IQR): 11.3–44.3, p &lt; 0.0001] or tumor necrosis factor (TNF)-α inhibitors (median: 26.5 BAU/ml, IQR: 14.9–108.8, p = 0.0034) compared to controls (median: 152.7 BAU/ml, IQR: 89.3–260.3). All peripheral memory B-cell (MBC) subpopulations, in particular, the switched IgG+ MBCs (CD19+CD27+IgD-IgM-IgG+), were significantly reduced in RA subjects under CTLA-4-Ig compared to those in HCWs (p = 0.0012). In RA patients, a significantly reduced anti-RBD IgG titer was observed at T6 vs. T1, mainly in those treated with CTLA-4-Ig (p = 0.002), interleukin (IL)-6 inhibitors (p = 0.015), and disease-modifying antirheumatic drugs (DMARDs) ± corticosteroids (CCSs) (p = 0.015). In contrast, a weak nonsignificant reduction of the T-cell response was reported at T6 vs. T1. T-cell response was found in 65.7% of the RA patients at T6, with lower significant magnitude in patients under CTLA-4-Ig compared to HCWs (p &lt; 0.0001). The SARS-CoV-2 IFN-γ-S-specific T-cell response was mainly detected in the CD4+ T-cell compartment.

Conclusions

In this study, in RA patients after 6 months from COVID-19 vaccination, we show the kinetics, waning, and impairment of the humoral and, to a less extent, of the T-cell response. Similarly, a reduction of the specific response was also observed in the controls. Therefore, based on these results, a booster dose of the vaccine is crucial to increase the specific immune response regardless of the immunosuppressive therapy.

In Acute Dengue Infection, High TIM-3 Expression May Contribute to the Impairment of IFNγ Production by Circulating Vδ2 T Cells

γδ T cells are innate cells able to quickly eliminate pathogens or infected/tumoral cells by their antiviral and adjuvancy activities. The role of γδ T cells during Dengue Viral Infection (DENV) infection is not fully elucidated. Nevertheless, human primary γδ T cells have been shown to kill in vitro DENV-infected cells, thus highlighting their possible antiviral function. The aim of this work was to characterize the phenotype and function of Vδ2 T cells in DENV patients. Fifteen DENV patients were enrolled for this study and peripheral blood mononuclear cells (PBMC) were used to analyze Vδ2-T-cell frequency, differentiation profile, activation/exhaustion status, and functionality by multiparametric flow cytometry. Our data demonstrated that DENV infection was able to significantly reduce Vδ2-T-cell frequency and to increase their activation (CD38 and HLA-DR) and exhaustion markers (PD-1 and TIM-3). Furthermore, Vδ2 T cells showed a reduced capability to produce IFN-γ after phosphoantigenic stimulation that can be associated to TIM-3 expression. Several studies are needed to depict the possible clinical impact of γδ-T-cell impairment on disease severity and to define the antiviral and immunoregulatory activities of γδ T cells in the first phases of infection.

Coordinated cellular and humoral immune responses after two-dose SARS-CoV2 mRNA vaccination in liver transplant recipients

Limited data are available on risks and benefits of anti-SARS-CoV2 vaccination in solid organ transplant recipients, and weaker responses have been described. At the Italian National Institute for Infectious Diseases, 61 liver transplant recipients underwent testing to describe the dynamics of humoral and cell-mediated immune response after two doses of anti-SARS-CoV2 mRNA vaccines and compared with 51 healthy controls. Humoral response was measured by quantifying both anti-spike and neutralizing antibodies; cell-mediated response was measured by PBMC proliferation assay with IFN-γ and IL-2 production. Liver transplant recipients showed lower response rates compared with controls in both humoral and cellular arms; shorter time since transplantation and multi-drug immunosuppressive regimen containing mycophenolate mofetil were predictive of reduced response to vaccination. Specific antibody and cytokine production, though reduced, were highly correlated in transplant recipients.

GRAd-COV2, a gorilla adenovirus-based candidate vaccine against COVID-19, is safe and immunogenic in younger and older adults

[Figure: see text].

Metabolic syndrome is related to vascular structural alterations but not to functional one both in hypertensives and healthy subjects

Background

Metabolic Syndrome (MS) has been related to an impairment in arterial structural and functional properties with heterogeneous results.

Purpose

In this study we focused on the effects of MS on arterial carotid-femoral Pulse Wave Velocity (PWV) and common carotid Intima Media Thickness (IMT) in two different populations, one of hypertensive patients and one of healthy controls.

Methods

We enrolled 816 consecutive hypertensive (HT) and 536 healthy controls. Vascular structural (IMT) and functional (PWV) properties were evaluated. NCEP-ATP-III criteria were used for diagnosis of MS.

Results

MS was diagnosed in 26.9% and 6.9% in hypertensive and control subjects, respectively. PWV was similar in controls with and without MS (7.7±1.9 vs 7.6±1.1 m/s, p=0.69), while IMT was higher in controls with than those without MS (0.64±0.18 vs 0.57±0.13 mm, p=0.02). Hypertensives with MS were older (57.9±12.2 vs 52.7±14.1 years, p&lt;0.001) and showed higher PWV (9.0±2.3 vs 8.4±2.1 m/s, p=0.001) and IMT (0.72±0.22 vs 0.65±0.17 mm, p&lt;0.001) than those without MS, however at the age-adjusted analysis only the difference in IMT was confirmed (p=0.007). Regression models showed that MS was an independent determinant of IMT in both controls (β=0.08, p=0.03) and hypertensives (β=0.08, p=0.01), but not of PWV either in controls (β=0.006, p=0.886 and β=0.04, p=0.19, respectively).

Conclusions

The main finding of our work is that MS is a significant determinant of IMT while this is not the case for PWV. This result has been confirmed both in hypertensive subjects and in healthy controls.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): ASST Grande Ospedale Metropolitano Niguarda

ImmunosuppressiveTherapies Differently Modulate Humoral- and T-Cell-Specific Responses to COVID-19 mRNA Vaccine in Rheumatoid Arthritis Patients

Objective

To assess in rheumatoid arthritis (RA) patients, treated with different immunosuppressive therapies, the induction of SARS-CoV-2-specific immune response after vaccination in terms of anti-region-binding-domain (RBD)-antibody- and T-cell-specific responses against spike, and the vaccine safety in terms of clinical impact on disease activity.

Methods

Health care workers (HCWs) and RA patients, having completed the BNT162b2-mRNA vaccination in the last 2 weeks, were enrolled. Serological response was evaluated by quantifying anti-RBD antibodies, while the cell-mediated response was evaluated by a whole-blood test quantifying the interferon (IFN)-γ-response to spike peptides. FACS analysis was performed to identify the cells responding to spike stimulation. RA disease activity was evaluated by clinical examination through the DAS28crp, and local and/or systemic clinical adverse events were registered. In RA patients, the ongoing therapeutic regimen was modified during the vaccination period according to the American College of Rheumatology indications.

Results

We prospectively enrolled 167 HCWs and 35 RA patients. Anti-RBD-antibodies were detected in almost all patients (34/35, 97%), although the titer was significantly reduced in patients under CTLA-4-inhibitors (median: 465 BAU/mL, IQR: 103-1189, p<0.001) or IL-6-inhibitors (median: 492 BAU/mL, IQR: 161-1007, p<0.001) compared to HCWs (median: 2351 BAU/mL, IQR: 1389-3748). T-cell-specific response scored positive in most of RA patients [24/35, (69%)] with significantly lower IFN-γ levels in patients under biological therapy such as IL-6-inhibitors (median: 33.2 pg/mL, IQR: 6.1-73.9, p<0.001), CTLA-4-inhibitors (median: 10.9 pg/mL, IQR: 3.7-36.7, p<0.001), and TNF-α-inhibitors (median: 89.6 pg/mL, IQR: 17.8-224, p=0.002) compared to HCWs (median: 343 pg/mL, IQR: 188-756). A significant correlation between the anti-RBD-antibody titer and spike-IFN-γ-specific T-cell response was found in RA patients (rho=0.432, p=0.009). IFN-γ T-cell response was mediated by CD4+ and CD8+ T cells. Finally, no significant increase in disease activity was found in RA patients following vaccination.

Conclusion

This study showed for the first time that antibody-specific and whole-blood spike-specific T-cell responses induced by the COVID-19 mRNA-vaccine were present in the majority of RA patients, who underwent a strategy of temporary suspension of immunosuppressive treatment during vaccine administration. However, the magnitude of specific responses was dependent on the immunosuppressive therapy administered. In RA patients, BNT162b2 vaccine was safe and disease activity remained stable.

Hidden hypercortisolism: a too frequently neglected clinical condition

PURPOSE

Classic Cushing's syndrome (CS) is a severe disease characterized by central obesity, hypertension, easy bruising, striae rubrae, buffalo hump, proximal myopathy and hypertricosis. However, several CS cases have also been reported with unusual or camouflaged manifestations. In recent years, several authors investigated the prevalence of "hidden hypercortisolism" (HidHyCo) among subjects affected with bone fragility, hypertension and type 2 diabetes mellitus (DM2). The prevalence of the HidHyCo is estimated to be much higher than that of classic CS. However, similarly to classic CS, HidHyCo is known to increase the risk of fractures, cardiovascular disease and mortality.

METHODS

We reviewed all published cases of unusual presentations of hypercortisolism and studies specifically assessing the HidHyCo prevalence in diabetic, osteoporotic and hypertensive patients.

RESULTS

We found 49 HidHyCo cases, in whom bone fragility, hypertension and diabetes were the presenting manifestations of an otherwise silent hypercortisolism. Amongst these cases, 34.7%, 32.7%, 6.1% and 19.0%, respectively, had bone fragility, hypertension, DM2 or hypertension plus DM2 as the sole clinical manifestations of HidHyCo. Overall, 25% of HidHyCo cases were of pituitary origin, and bone fragility was the very prevalent first manifestation among them. In population studies, it is possible to estimate that 1-4% of patients with apparent primary osteoporosis has a HidHyCo and the prevalence of this condition among diabetics ranges between 3.4 and 10%.

CONCLUSION

These data indicate that patients with resistant or suddenly worsening hypertension or DM2 or unexplainable bone fragility should be screened for HidHyCo using the most recently approved sensitive cut-offs.

PMN-MDSC Frequency Discriminates Active Versus Latent Tuberculosis and Could Play a Role in Counteracting the Immune-Mediated Lung Damage in Active Disease

Tuberculosis (TB), due to Mycobacterium tuberculosis infection, is still the principal cause of death caused by a single infectious agent. The balance between the bacillus and host defense mechanisms reflects the different manifestations of the pathology. Factors defining this variety are unclear and likely involve both mycobacterial and immunological components. Myeloid derived suppressor cells (MDSC) have been shown to be expanded during TB, but their role in human TB pathogenesis is not clear. We evaluated the frequency of circulating MDSC by flow-cytometry in 19 patients with active TB, 18 with latent TB infection (LTBI), and 12 healthy donors (HD) as control. Moreover, we investigated the capacity of MDSC to modulate the mycobactericidal activity of monocytes. The association between MDSC level and TB chest X-ray severity score was analyzed. We observed that, unlike active TB, polymorphonuclear (PMN)-MDSC are not expanded in LTBI patients, and, by performing a receiver operating characteristic (ROC) curve analysis, we found that PMN-MDSC frequency supported the discrimination between active disease and LTBI. Interestingly, we observed an association between PMN-MDSC levels and the severity of TB disease evaluated by chest X-ray. Specifically, PMN-MDSC frequency was higher in those classified with a low/mild severity score compared to those classified with a high severity score. Moreover, PMN-MDSC can impact mycobacterial growth by inducing ROS production in Bacillus Calmette et Guerin (BCG)-infected monocytes. This effect was lost when tested with M. tuberculosis (MTB), In conclusion, our data indicate that the elevated frequency of PMN-MDSC in IGRA-positive individuals is associated with active TB. Our findings also pointed out a beneficial role of PMN-MDSC during human active TB, most likely associated with the limitation of inflammation-induced tissue damage.

An Inflammatory Profile Correlates With Decreased Frequency of Cytotoxic Cells in Coronavirus Disease 2019

Increased production of inflammatory cytokines and myeloid-derived suppressor cells occurs in patients with coronavirus disease 2019. These inversely correlated with perforin-expressing natural killer (NK) and CD3+ T cells. We observed a lower number of perforin-expressing NK cells in intensive care unit (ICU) patients compared with non-ICU patients, suggesting an impairment of the immune cytotoxic arm as a pathogenic mechanism.

Minding the gap between cortisol levels measured with second-generation assays and current diagnostic thresholds for the diagnosis of adrenal insufficiency: a single-center experience

PURPOSE

The current cut-offs for the diagnosis of adrenal insufficiency (AI) have been established using outdated immunoassays. We compared the cortisol concentrations measured with Roche Cortisol I (R1), the newly available Roche Cortisol II (R2), and liquid chromatography tandem mass spectrometry (LC-MS/MS), the gold standard procedure to measure steroids in patients undergoing the corticotropin (ACTH) test.

METHODS

We enrolled 30 patients (age 47 ± 21 years) referred to undergo the ACTH test (1 or 250 μg). Cortisol was measured at 0, 30, and 60 min after stimulation with R1, R2, and LC-MS/MS. AI was diagnosed for R1-stimulated peak cortisol concentrations < 500 nmol/L.

RESULTS

Mean cortisol concentrations measured with R2 and LC-MS/MS were comparable, while mean cortisol concentrations measured by R1 were higher than those of both R2 and LC-MS/MS (respectively, basal 411 ± 177, 287 ± 119, and 295 ± 119 nmol/L; at 30 min, 704 ± 204, 480 ± 132, and 500 ± 132 nmol/L; at 60 min, 737 ± 301, 502 ± 196, and 519 ± 201 nmol/L, p ≤ 0.01 for R1 vs. both R2 and LC-MS/MS at each point). Considering the 500 nmol/L cortisol peak cut-off, AI was diagnosed in 5/30 patients using R1 and in 12/30 using R2 (+ 140%). Based on the correlation between R1 and R2, the threshold of 500 nmol/L became 351 nmol/L (12.7 μg/dL) when cortisol was measured with R2, and 368 nmol/L (13.3 μg/dL) with LC-MS/MS.

CONCLUSIONS

The use of more specific cortisol assays results in lower cortisol concentrations. This could lead to misdiagnosis and overtreatment when assessing AI with the ACTH test if a different cut-off for cortisol peak is not adopted.

Per2 Upregulation in Circulating Hematopoietic Progenitor Cells During Chronic HIV Infection

Chronic HIV infection accelerates immune aging and is associated with abnormal hemato-lymphopoiesis, but the relationship between HIV-induced aging and Hematopoietic Progenitor Cells (HPC) function is not well-defined. In the context of aging, it has been demonstrated using a murine model that Per2 (Period circadian clock 2) is a negative regulator of HPC survival and lineage potential. A possible involvement of Per2 modulation on hematopoietic failure during HIV infection has not yet been investigated. The aim of this study was to analyze whether Per2 is differently expressed and regulated on HPC during HIV infection, possibly providing a therapeutic target to restore lymphoid potential in the HPC compartment. To this purpose, Per2 expression in circulating HPC was compared in 69 chronic HIV infected patients under successful ART and in matched 30 uninfected healthy donors (HD). HPC aging was assessed by measuring relative telomere length (RTL), and HPC functionality was evaluated by Colony Forming Cell (CFC) assay from both ex vivo HIV+ patients and in vitro Per2 overexpressing donors. Our results showed a lower RTL in HPC and a decrease of white progenitor colonies from HIV+ patients with lower CD4 respect to those with higher CD4 T cell count (<500 respect to >500 CD4 T cell/mmc). Interestingly, we found that the frequency of Per2-expressing HPC is higher in HIV+ patients than in HD and correlated to RTL of CFC derived cells, highlighting a relationship between low proliferative rate and Per2 expression. Indeed, the in vitro overexpression of Per2 resulted in a significant decrease of white progenitor colonies respect to control cells. Finally, we showed that the deacetylase Sirtuin 1, a negative regulator of Per2, was downregulated in HPC from HIV+ patients, and the peripheral blood treatment with resveratrol (Sirtuin 1 inducer) determined a decrease of Per2 expressing HPC. Altogether, these results suggest that during HIV infection, Per2 is involved in the regulation of HPC expansion and differentiation and its overexpression may impair the immune reconstitution. These data support the rationale to explore the role of this regulatory mechanism during aged-associated hemato-lymphopoiesis impairment in HIV infection.

Hyperuricemia and Risk of Cardiovascular Outcomes: The Experience of the URRAH (Uric Acid Right for Heart Health) Project

The latest European Guidelines of Arterial Hypertension have officially introduced uric acid evaluation among the cardiovascular risk factors that should be evaluated in order to stratify patient's risk. In fact, it has been extensively evaluated and demonstrated to be an independent predictor not only of all-cause and cardiovascular mortality, but also of myocardial infraction, stroke and heart failure. Despite the large number of studies on this topic, an important open question that still need to be answered is the identification of a cardiovascular uric acid cut-off value. The actual hyperuricemia cut-off (> 6 mg/dL in women and 7 mg/dL in men) is principally based on the saturation point of uric acid but previous evidence suggests that the negative impact of cardiovascular system could occur also at lower levels. In this context, the Working Group on uric acid and CV risk of the Italian Society of Hypertension has designed the Uric acid Right for heArt Health project. The primary objective of this project is to define the level of uricemia above which the independent risk of CV disease may increase in a significantly manner. In this review we will summarize the first results obtained and describe the further planned analysis.

Performance assessment of amplification and discrimination electronic devices for passive neutron measurements

The knowledge of the fissile material mass is a key challenge to enhance radioactive waste management and to ensure a high level of safety in nuclear industry. Data is analyzed according to the principles of the neutron measurement techniques. As proportional counters filled with 3He gas display high neutron detection efficiency and a good gamma-ray discrimination, they are the reference detector for passive neutron coincidence counting. A charge preamplifier or a current amplifier, depending on applications, collects the electric pulse produced by neutron interaction in the 3He gas and a threshold discriminator produces a logic pulse used for neutron counting. This paper describes the performance assessment of different commercially available electronics from Mirion Technologies, Precision Data Technology (PDT), Mesytec, as well as MONACO electronics originally developed by CEA LIST for fission chamber measurements in experimental reactors. Comparative passive neutron measurements are carried out with these electronics at CEA/DEN Nuclear Measurement Laboratory in Cadarache. Overall, PDT and Mesytec electronics show similar detection efficiency as the ACH-NA98 charge amplifier, which is commonly used in our laboratory for such applications. However, MONACO electronics have a lower detection efficiency, similar to Mirion 7820 current amplifier used in specific high-count rate applications. An optimisation of MONACO settings would probably be necessary to adapt to 3He counters instead of fission chambers.

Pathophysiology and Management of Type 2 Diabetes Mellitus Bone Fragility

Individuals with type 2 diabetes mellitus (T2DM) have an increased risk of bone fragility fractures compared to nondiabetic subjects. This increased fracture risk may occur despite normal or even increased values of bone mineral density (BMD), and poor bone quality is suggested to contribute to skeletal fragility in this population. These concepts explain why the only evaluation of BMD could not be considered an adequate tool for evaluating the risk of fracture in the individual T2DM patient. Unfortunately, nowadays, the bone quality could not be reliably evaluated in the routine clinical practice. On the other hand, getting further insight on the pathogenesis of T2DM-related bone fragility could consent to ameliorate both the detection of the patients at risk for fracture and their appropriate treatment. The pathophysiological mechanisms underlying the increased risk of fragility fractures in a T2DM population are complex. Indeed, in T2DM, bone health is negatively affected by several factors, such as inflammatory cytokines, muscle-derived hormones, incretins, hydrogen sulfide (H2S) production and cortisol secretion, peripheral activation, and sensitivity. All these factors may alter bone formation and resorption, collagen formation, and bone marrow adiposity, ultimately leading to reduced bone strength. Additional factors such as hypoglycemia and the consequent increased propensity for falls and the direct effects on bone and mineral metabolism of certain antidiabetic medications may contribute to the increased fracture risk in this population. The purpose of this review is to summarize the literature evidence that faces the pathophysiological mechanisms underlying bone fragility in T2DM patients.

P3405Association between heart rate thresholds for cardiovascular risk defined by new ESC/ESH Guidelines and neuroadrenergic markers

Background

The ESC/ESH Guidelines for hypertension issued in 2018 identify resting heart rate (HR) values greater than 80 beats/minute as predictors of cardiovascular risk, with the undocumented evidence that this detection might represent the occurrence of a sympathetic cardiovascular overdrive.

Purpose

In the present study we tested this hypothesis throughout the use of direct and indirect markers of sympathetic neural function.

Methods

In 167 untreated and uncomplicated mild-to moderate essential hypertensives recruited for different investigations and aged 51.8±3.2 years (mean±SEM) without other cardiovascular or non-cardiovascular disease, we measured clinic and ambulatory blood pressure (BP), HR (EKG), venous plasma norepinephrine (NE, HPLC assay) and efferent postganglionic muscle sympathetic nerve traffic (MSNA, microneurography). We then subdivided the study population in 2 groups according to HR values ≤ or >80 beats/minute.

Results

Sixty-eight patients displayed resting HR >80 beats/minute while the remaining 99 below this threshold value, the 2 groups showing superimposable age values and gender distribution. Body mass index, clinic and ambulatory BP were similar in the 2 groups this being the case also for LVMI and metabolic variables. In contrast MSNA values were significantly greater (P<0.02) in the former than in the latter group both when expressed as bursts incidence over time (49.2±1.8 vs 39.5±1.4 bs/min) and when corrected for HR (60.7±3.0 vs 51.4±2.5 bs/100 hb). NE showed a tendency to be greater in the former group without achieving, however, statistical significance. In the whole population there was a significant direct relationship between MSNA and HR values (r=0.61, P<0.01)

Conclusions

Thus hypertensive patients displaying HR >80 beats/minute are characterized by a marked sympathetic overdrive, particularly when direct adrenergic markers are employed. This finding suggests that cardiac and peripheral sympathetic activation may participate at the increased cardiovascular risk detected in this group of patients.

P1566Identification of the cardiovascular threshold limit for serum uric acid. Analysis from a general Italian population

Background

Serum uric acid (SUA) is increasingly recognised as an important predictor of cardiovascular disease (CVD) and total mortality. However, the levels of SUA that discriminate across the different strata of risk for CVD and total mortality remain unknown, complicating the identification of subjects at high or low mortality risk for SUA in clinical practice.

Purpose

In this study we used a large Italian population comprising >3ehz748.0326 subjects to assess the threshold of SUA that increases the risk of total and CVD mortality.

Methods

The URic Acid Right for heArt Health (URRAH) study is a regional-basis multicentre cohort study which collected data from prospective studies and databases from different hypertension centres, including subjects with at least one measure of SUA and a follow-up of about 20 years. Total mortality was defined as mortality for any causes, cardiovascular mortality as death due to fatal myocardial infraction, stroke or heart failure. Multivariate dichotomic logistic and Cox regression models were used to confirm the relationship between SUA and mortality status both from cardiovascular and any causes, while ROC curves were used to identify the threshold of SUA that better discriminated people at higher or lower mortality risk.

Results

A total of 22.275 subjects had SUA and mortality information. Logistic regression identified a direct and strong association between SUA and an increased risk of total (OR 1.176, 95% CI 1.127–1.227) and CVD (OR 1.147, 95% CI 1.093–1.203) mortality, independently of other CVD risk factors (age, BMI, LDL cholesterol, diagnosis of diabetes, hypertension, chronic kidney disease, alcohol consumption and smoking). Cox models confirmed the presence of an independent association between SUA and any causes (HR 1.123, 95% CI 1.090–1.567) and CVD (HR 1.124, 95% CI 1.081–1.169) mortality. ROC curve analysis identified a cut-off value od SUA [(4.79 mg/dL (95% CI 4.7–5.4 mg/dl)] able to discriminate total mortality status, and a different one [(5.60 mg/dL (95% CI 5.09–5.89 mg/dl)] able to identify CVD mortality status. Multivariate Cox analysis adjusted for confounders confirmed that subjects with SUA >4.79 mg/dl had a significantly higher total mortality (HR 1.293, 95% CI 1.181–1.416) compared to those with SUA <4.79 mg/dl, independently of covariables. Similarly, subjects with SUA >5.60 mg/dl had a significantly higher CVD mortality (HR 1.428, 95% CI 1.273–1.600) than those with SUA <5.60 mg/dl after adjustment for the same confounders.

Conclusion

Levels of SUA that increase the risk of total and CVD mortality are significantly lower than those commonly used for the definition of hyperuricemia in clinical practice. Our data provide the first large evidence of a level of “cardiovascular” SUA that might be used in clinical practice to identify subjects at greater risk of total and CVD mortality.

P1688Behavior of indices of sympathetic activity in relation to sleep time duration in untreated hypertensives

Background

Short sleep duration and poor sleep quality has been reported to be associated with increased cardiovascular risk and increased incidence of cardiovascular events.

Purpose

Whether and what extent the pathophysiology of this association includes sympathetic abnormalities has never been examined via microneurography.

Methods

In 28 untreated mild-to moderate essential hypertensives aged 66.4±3.1 (mean±SEM) without other cardiovascular or non-cardiovascular disease (including obstructive sleep apnea) recruited from the outpatient clinic and referred for short sleep duration, we directly assessed at patients home via actigraphy (actiwatch spectrum activity monitor, Phillips) time sleep duration and efficiency. Measurements, performed during a day preceding or following the 7 day actigraphy evaluation, included microneurographic recording of efferent postganglionic sympathetic nerve traffic (MSNA), venous plasma norepinephrine (HPLC), clinic, 24 hour and beat to beat blood pressure and heart rate values. Sleep diary and a sleep questionnaire were also administered.

Results

Nine patients slept less than 6 hours per night (LSD), while the remaining ones between 6 to 7 (MSD, n=8) or more than 7 hours (GSD,N=11). The 3 groups showed similar age and gender distribution and a body mass index amounting to 28.1±0.8, 28.6±0.5 and 27.3±0.5 kg/m2 (P=NS). For similar mean blood pressure values LSD showed MSNA values significantly greater than GSD (53.4±4.9 vs 40.1±3.8bs/100hb, P<0.03), this being the case also for MSD (49.7±4.4, P<0.05 vs GSD but not SLD). HR was significantly elevated only in LSD group when compared to GSD, while no significant difference was found in plasma NE between the 3 groups.

Conclusions

The present study provides the first microneurographic direct evidence that short sleep duration is linked to a marked sympathetic activation, which may participate at the high cardiovascular risk of these subjects. The sympathetic overdrive affects both the cardiac and peripheral district but is not reflected by NE, which thus does not represent in this condition a valuable adrenergic marker.

Myeloid Derived Suppressor Cells Expansion Persists After Early ART and May Affect CD4 T Cell Recovery

Myeloid-derived suppressor cells (MDSC) are expanded during HIV-1 infection and correlated with disease progression. MDSC expand in the early phase of primary infection depending on TRAIL level. In this study we evaluated the effect of ART on the frequency of MDSC in patients with primary HIV infection (PHI), and their impact on CD4 T cell reconstitution. MDSC frequency was evaluated by flow-cytometry in 60 PHI patients at 12, 24 and 48 weeks after ART initiation. Cytokine plasma levels were evaluated by Luminex technology at the same time points. The capacity of MDSC to modulate hematopoietic early progenitor cells' expansion was evaluated using the OP9/Dl1 in vitro system. As previously described, polymorphonuclear-MDSC (PMN-MDSC) frequency was higher in PHI compared to healthy donors. Interestingly, 48 weeks of successful ART failed to normalize the PMN-MDSC frequency. Moreover, PMN-MDSC frequency was not correlated with residual viral load, suggesting that the persistence of PMN-MDSC was not due to residual viral replication. Interestingly, patients with low PMN-MDSC frequency (<6%) at T0 had a higher HIV DNA at the same time point than individuals with high PMN-MDSC frequency (>6%). We also found an inverse correlation between PMN-MDSC frequency and CD4-T cell count at 48 weeks post-ART, which was confirmed by multivariate analysis adjusting for age and CD4 T cell number at baseline. These data suggest that the persistence of PMN-MDSC may impact CD4 T cell recovery. Indeed, in vitro PMN-MDSC impaired the expansion of CD34+CD38- hematopoietic early progenitors. Further, a balance between TRAIL and GM-CSF may be necessary to maintain a low MDSC level. In conclusion, early ART initiation was not able to normalize PMN-MDSC frequency that might impact the CD4 T cell recovery. These data open new questions regarding the clinical impact of MDSC persistence in HIV+ patients, in particular on non-AIDS related diseases.

In Human Immunodeficiency Virus primary infection, early combined antiretroviral therapy reduced γδ T-cell activation but failed to restore their polyfunctionality

Primary and chronic human immunodeficiency virus (HIV) infection alters γδ T-cell features. However, there is no evidence about early combined antiretroviral therapy (cART) and γδ T-cell dynamics. In the present study, HIV-positive individuals were divided into those with early primary infection (EPI) and those with late primary infection (LPI). The analysis of γδ T cells was performed by flow cytometry before and after therapy. Polyfunctional profile was assessed after in vitro peripheral blood mononuclear cell (PBMC) exposure to specific antigens. The results show that primary infection induced an expansion of Vδ1 T cells in LPI. Before treatment, a massive activation of γδ T-cell subsets was observed in both groups of patients, that correlated with disease progression and was significantly reduced after cART introduction. Despite this, CD107A-expressing Vδ1 T cells in both groups were significantly fewer than in healthy donors, but were restored by therapy introduction. Polyfunctional analysis of Vδ1 T cells from HIV-positive individuals revealed a lower frequency of CD107A⁺  CCL-4⁺ Vδ1 T-cell subsets than healthy donors that persists after therapy. Functional profile of Vδ2 was similar to that in healthy donors before therapy but, at 6 months, a lower frequency of CD107A, interferon-γ- or tumor necrosis factor-α-producing Vδ2 T cells was observed in the EPI group. Finally, individuals with LPI showed a lower frequency of quadruple-functional Vδ2 T-cell subset. In conclusion, during primary HIV infection, the baseline Vδ1 T-cell activation is correlated with immune reconstitution potential. Moreover, an altered γδ polyfunctional profile occurred, persisting after cART. Further studies are needed to understand whether a longer treatment of primary infection may increase γδ T-cell functionality.

Combined effects of nanoplastics and copper on the freshwater alga Raphidocelis subcapitata

Nanoplastics are recognized as able to interact with other pollutants including heavy metals, and with natural organic matter, with implications for the potential risks to biota. We investigated the interaction of carboxylated polystyrene nanoparticles (PS-COOH NPs) with copper (Cu) and algal exudates (EPS) and how such interaction could affect Cu toxicity towards the freshwater microalga Raphidocelis subcapitata. PS-COOH NPs behavior in the presence of Cu and EPS was determined by dynamic light scattering (DLS), while PS-COOH NPs surface interaction with Cu ions and EPS was investigated by fluorimetric analysis. ICP-MS was used to test Cu ion adsorption to PS-COOH NPs in the presence and absence of algae. The interaction between PS-COOH NPs and the algal cell wall was assessed by fluorescence microscopy. Short- and long-term toxicity tests were carried out in parallel to assess the impact of PS-COOH NPs on algal growth. Results showed altered nanoparticle surface charge and hydrodynamic diameter following algal EPS exposure, supporting the hypothesis of a protein corona formation. In contrast, no absorption of Cu ions was observed on PS-COOH NPs, either in the presence or absence of algae. No differences on algal growth inhibition were observed between exposure to Cu only, and to Cu in combination with PS-COOH NPs, in short-term as well as long-term tests. However, after 72 h of exposure, the adsorption of PS-COOH NPs to algal cell walls appeared to correspond to morphological alterations, revealing potential disturbances in the mitotic cycle. Our findings confirm the ability of PS-COOH NPs to interact with EPS as shown for other nanomaterials. Environmentally realistic exposure scenarios are thus needed for evaluating nanoplastic toxicity, as nanoparticles will not maintain their pristine nature once released into natural media. Prolonged exposure and use of different end-points such as cell morphological changes and EPS production seem more reliable for the investigation of nanoplastic/algal cell interactions which can drive food chain transfer of nanoplastics and ultimately toxicity.

Investigation on the thermal gelation of Chitosan/β-Glycerophosphate solutions

This work deals with the effect of temperature on the thermal-gelation process of water solutions containing chitosan β-glycerolphosphate disodium salt hydrate. In particular, the attention is focused on the role played by temperature on the gel final properties, a very important aspect in the frame of drug delivery systems. The study was performed by combining rheology and low field nuclear magnetic resonance, two approaches that revealed to be highly synergic as they can detect different aspects of the developing polymeric network. This study indicates that 30 °C represent a sort of threshold for both the gelation kinetics and the gel final properties. Indeed, above this temperature, gelation kinetics was rapid and yielded to a strong gel. On the contrary, a slow kinetics and a final weak gel occurred below 30 °C. Finally, rheology and low field NMR allowed, independently, evaluating the time evolution of the network mesh size upon gelation.

A new procedure to analyze polymorphonuclear myeloid derived suppressor cells in cryopreserved samples cells by flow cytometry

Myeloid derived suppressor cells (MDSC) is a heterogeneous subset of immature and mature cells of the myeloid lineage, undergoing expansion during pathologic conditions, and able to perform strong immune suppressive functions. It has been shown that cryopreservation selectively impacts the polimorphonuclear (PMN) MDSC viability and recovery, and alters the correct analysis of MDSC subsets. In laboratory practice, cryopreservation is often inevitable, in particular in multicenter studies where samples have to be shipped to a centralized laboratory. Aim of the present work was to set out a new protocol to evaluate the frequency of PMN-MDSC in thawed cells by flow-cytometry. PBMC were isolated from HIV+ patients and healthy donors, and were cryopreserved for at least ten days. After thawing, two different protocols were used: 1. standard protocol (SP) consisting of staining with the antibodies mix and then fixing with formalin 1%; 2. thawed protocol (TP) in which fixation foregoes the staining with the antibodies mix. Results showed that PMN-MDSC frequency in ex vivo PBMC evaluated by means TP was comparable to that analysed by SP, indicating that the protocol did not alter PMN-MDSC quantification in ex vivo cells. We then demonstrated that PMN-MDSC frequency in thawed PBMC tested by TP was almost identical to the frequency obtained in ex vivo cells evaluated by using SP. However, we observed that after three hours of culture post-thawing, PMN-MDSC were not assessable anymore with both SP and TP. In conclusion, we herein demonstrated that fixing PBMC soon after thawing and before antibody staining allows preservation of PMN-MDSC integrity and a reliable cells quantification. Thus, it is possible to phenotipically identify PMN-MDSC in cryopreserved PBMC, consenting adequate test precision and accuracy as well as making multicentre research more feasible.

Myeloid-Derived Suppressor Cells Specifically Suppress IFN-γ Production and Antitumor Cytotoxic Activity of Vδ2 T Cells

γδ T cells represent less than 5% of circulating T cells; they exert a potent cytotoxic function against tumor or infected cells and secrete cytokines like conventional αβ T cells. As αβ T cells γδ T cells reside in the typical T cell compartments (the lymph nodes and spleen), but are more widely distributed in tissues throughout the body. For these reasons, some investigators are exploring the possibility of immunotherapies aimed to expand and activate Vδ2 T cells, or using them as Chimeric Antigen Receptor carriers. However, the role of immunosuppressive microenvironment on Vδ2 T cells during infections and cancers has not been completely elucidated. In particular, the effects of myeloid-derived suppressor cells (MDSC), largely expanded in such pathologies, were not explored. In the present work, we demonstrated that MDSC may inhibit IFN-γ production and degranulation of phosphoantigen-activated Vδ2 T cells. Moreover, the Vδ2 T cells cytotoxic activity against the Burkitt lymphoma cell line Daudi and Jurkat cell line were impaired by MDSC. The Arginase I seems to be involved in the impairment of Vδ2 T cell function induced by both tumor cells and MDSC. These data open a key issue in the context of Vδ2-targeted immunoteraphy, suggesting the need of combined strategies aimed to boost Vδ2 T cells circumventing tumor- and MDSC-induced Vδ2 T cells suppression.

Co-exposure to titanium dioxide nanoparticles does not affect cadmium toxicity in radish seeds (Raphanus sativus)

Recent developments on environmental fate models indicate that as nano waste, engineered nanomaterials (ENMs) could reach terrestrial ecosystems thus potentially affecting environmental and human health. Plants can be therefore exposed to ENMs but controversial data in terms of fate and toxicity are currently available. Furthermore, there is a current lack of information on complex interactions/transformations to which ENMs undergo in the natural environment as for instance interacting with existing toxic compounds. The aim of the present study was to assess the behavior and biological effects of titanium dioxide nanoparticles (n-TiO₂) (Aeroxide P25, Degussa Evonik) and its interaction with cadmium (CdCl₂) in plants using radish seeds (Raphanus sativus L. Parvus) as model species. Radish seeds were exposed to n-TiO₂ (1-1000mg/L) and CdCl₂ (1-250mg/L) alone and in combination using a seed germination and seedling growth toxicity test OECD 208. Percentage of seed germination, germination index (GI) and root elongation were calculated. Cell morphology and oxidative stress parameters as glutathione-S-transferase (GST) and catalase activities (CAT) were measured in radish seeds after 5 days of exposure. Z-Average, PdI and Z-potential of n-TiO₂ in Milli-Q water as exposure medium were also determined. DLS analysis showed small aggregates of n-TiO₂, negative Z-potential and stable PdI in seed's exposure media. Germination percentage, GI and root length resulted affected by n-TiO₂ exposure compared to controls. In particular, n-TiO₂ at 1mg/L and 100mg/L did not affect radish seeds germination (100%) while at concentration of 10mg/L, 200mg/L, 500mg/L, and 1000mg/L a slight but not significant decrease of germination % was observed. Similarly root length and GI resulted significantly higher in seeds exposed to 10mg/L and 200mg/L compared to 1mg/L, 100mg/L, 500mg/L, 1000mg/L and control (p < 0.05). On the opposite, CdCl₂ significantly abolished germination % and GI compared to control seeds and a concentration dependent decrease on root elongation was observed against controls (p < 0.05). As well, significant decrease of germination %, GI and root elongation was observed in seeds co-exposed to n-TiO₂ and CdCl₂ at the highest concentrations (1000mg/L n-TiO₂ and 250mg/L CdCl₂) compared to co-exposed seeds at low concentration (1mg/L n-TiO₂ and 1mg/L CdCl₂) and controls (p < 0.05). Root elongation significantly increase compared to control at the lowest co-exposure concentration (p < 0.05). Similarly at intermediate concentrations of 10 and 100mg/L in co-exposure conditions, n-TiO₂ did not affect CdCl₂ toxicity. Concerning antioxidant enzymes, a significant increase of CAT activity in seeds exposed to single high n-TiO₂ concentration (1000mg/L) was observed while n-TiO₂ (1mg/L), CdCl₂ (1 and 250mg/L) and co-exposure resulted significantly decreased compared to controls (p < 0.05). Regarding GST activity, a slight increase in seeds exposed to 1000mg/L n-TiO₂ but no significantly was observed, however both n-TiO₂ and CdCl₂ alone (1 and 250mg/L, respectively) or in combinations caused a significant decrease in GST activity (p < 0.05). Therefore, overall data support the hypothesis that the presence of n-TiO₂ do not affect the toxicity of CdCl₂ at least at the highest concentration (100 and 250mg/L) in radish seeds. Morphological alterations in nuclei, vacuoles and shape of radish root cells were observed upon single Cd exposure and not abolished in the presence of n-TiO₂. Nevertheless, although n-TiO₂ seems not to reduce Cd toxicity at high concentration (up to 250mg/L), interactions cannot be excluded based on obtained results.

Comparative ecotoxicity of polystyrene nanoparticles in natural seawater and reconstituted seawater using the rotifer Brachionus plicatilis

The impact of nanoplastics using model polystyrene nanoparticles (PS NPs), anionic (PS-COOH) and cationic (PS-NH₂), has been investigated on the marine rotifer Brachionus plicatilis, a major component of marine zooplanktonic species. The role of different surface charges in affecting PS NP behaviour and toxicity has been considered in high ionic strength media. To this aim, the selected media were standardized reconstituted seawater (RSW) and natural sea water (NSW), the latter resembling more natural exposure scenarios. Hatched rotifer larvae were exposed for 24h and 48h to both PS NPs in the range of 0.5-50μg/ml using PS NP suspensions made in RSW and NSW. No effects on lethality upon exposure to anionic NPs were observed despite a clear gut retention was evident in all exposed rotifers. On the contrary, cationic NPs caused lethality to rotifer larvae but LC₅₀ values resulted lower in rotifers exposed in RSW (LC₅₀=2.75±0.67µg/ml) compared to those exposed in NSW (LC₅₀=6.62±0.87µg/ml). PS NPs showed similar pattern of aggregation in both high ionic strength media (RSW and NSW) but while anionic NPs resulted in large microscale aggregates (Z-average 1109 ± 128nm and 998±67nm respectively), cationic NP aggregates were still in nano-size forms (93.99 ± 11.22nm and 108.3 ± 12.79nm). Both PDI and Z-potential of PS NPs slightly differed in the two media suggesting a role of their different surface charges in affecting their behaviour and stability. Our findings confirm the role of surface charges in nanoplastic behaviour in salt water media and provide a first evidence of a different toxicity in rotifers using artificial media (RSW) compared to natural one (NSW). Such evidence poses the question on how to select the best medium in standardized ecotoxicity assays in order to properly assess their hazard to marine life in natural environmental scenarios.