EVALUATION OF RESPONSE TO ADJUVANTED RECOMBINANT ZOSTER VACCINATION IN PATIENTS WITH RHEUMATOID ARTHRITIS RECEIVING UPADACITINIB: RESULTS FROM A RANDOMIZED TRIAL SUB-STUDY

BackgroundUpadacitinib (UPA) is an oral JAK inhibitor (JAKi) approved for the treatment of RA. JAKi have been associated with an elevated risk of herpes zoster (HZ) in patients (pts) with RA. The adjuvanted recombinant zoster vaccine (RZV, Shingrix) was shown to be well-tolerated and effective in preventing HZ in adults aged ≥ 50 years.[1] The efficacy and safety of RZV have not been studied in pts with RA while on UPA in combination with MTX.ObjectivesTo assess the immunogenicity of RZV in pts with RA receiving UPA 15 mg once daily (QD) with background MTX.MethodsEligible adults aged ≥ 50 years with RA enrolled in the ongoing SELECT-COMPARE phase 3 trial (NCT02629159) received two RZV doses, administered at the baseline and week (wk) 12 visits. Pts should have been on stable doses of UPA 15 mg QD and background MTX for ≥ 8 wks before the first vaccination and ≥ 4 wks after the second vaccination. Antibody titers were collected pre-vaccination (baseline), 4 wks post-dose 1 vaccination (wk 4), and 4 wks post-dose 2 vaccination (wk 16). The primary endpoint was the proportion of pts with a humoral response to RZV defined as ≥ 4-fold increase in pre-vaccination concentration of anti-glycoprotein E [gE] titer levels at wk 16. Secondary endpoints included humoral response to RZV at wk 4 and the geometric mean fold rise (GMFR) in anti-gE antibody levels at wks 4 and 16. Cell-mediated immunogenicity to RZV was an exploratory endpoint evaluated by the frequencies of gE-specific CD4+ [2+] T cells (CD4+ T cells expressing ≥ 2 of 4 activation markers: IFN-γ, IL-2, TNF-α, and CD40 ligand) measured by flow cytometry at wks 4 and 16 in a sub-cohort of pts.ResultsOf the 95 pts who received ≥ 1 RZV dose, 93 (98%) received both RZV doses. Pts had a mean (standard deviation) age of 62.4 (7.5) years. The median (range) disease duration was 11.7 (4.9–41.6) years and duration of UPA exposure was 3.9 (2.9–5.8) years. At baseline, all but 2 pts were receiving concomitant MTX and half (50%) were taking an oral corticosteroid (CS) at a median daily dose of 5.0 mg. One pt discontinued UPA by wk 16. Blood samples were available from 90/93 pts. Satisfactory humoral responses to RZV occurred in 64% (95% confidence interval [CI]: 55–74) of pts at wk 4 and 88% (81–95) at wk 16 (Figure 1). Age (50–< 65 years: 85% [95% CI: 75–94];≥ 65 years: 94% [85–100]) and concomitant CS (yes: 87% [77–97];no: 89% [80–98]) use at baseline did not affect humoral responses at wk 16. GMFR in anti-gE antibody levels compared with baseline values were observed at wks 4 (10.2 [95% CI: 7.3–14.3]) and 16 (22.6 [15.9–32.2]). Among the sub-cohort of pts, nearly two-thirds achieved a cell-mediated immune response to RZV (wk 4: n = 21/34, 62% [95% CI: 45–78];wk 16: n = 25/38;66% [51–81]). Within 30 days post-vaccination of either RZV dose, no serious adverse events (AEs) (Table 1) or HZ were reported. AEs that were possibly related to RZV were reported in 17% of pts. One death occurred more than 30 days after wk 16 due to COVID-19 pneumonia.ConclusionMore than three-quarters (88%) of pts with RA receiving UPA 15 mg QD on background MTX achieved a satisfactory humoral response to RZV at wk 16. In a subgroup of pts, two-thirds (66%) achieved a cell-mediated immune response to RZV at wk 16. Age and concomitant CS use did not negatively affect RZV response.Reference[1]Syed YY. Drugs Aging. 2018;35:1031–40.Table 1. Safety Results Through 30-Days Post-RZV Vaccination in UPA-Treated PatientsEvent, n (%)UPA 15 mg QD (N = 95)Any AE38 (40%)AE with reasonable possibility of being related to UPAa13 (14%)AE with reasonable possibility of being related to RZVa16 (17%)Severe AEb1 (1%)Serious AE0AE leading to discontinuation of UPA0Death0AE, adverse event;QD, once daily;RZV, adjuvanted recombinant zoster vaccine;UPA, upadacitinib.aAs assessed by the investigator.bHypersensitivity.AcknowledgementsAbbVie funded this study and participated in the study design, research, analysis, data collection, interpretation of data, review, and approval of the . All authors had access to relevant data and participated in the drafting, review, and approval of this publication. No honoraria or payments were made for authorship. Medical writing support was provided by Julia Zolotarjova, MSc, MWC, of AbbVie.Disclosure of InterestsKevin Winthrop Consultant of: AbbVie, AstraZeneca, BMS, Eli Lilly, Galapagos, Gilead, GSK, Novartis, Pfizer, Regeneron, Roche, Sanofi, and UCB, Grant/research support from: AbbVie, AstraZeneca, BMS, Eli Lilly, Galapagos, Gilead, GSK, Novartis, Pfizer, Regeneron, Roche, Sanofi, and UCB, Justin Klaff Shareholder of: AbbVie, Employee of: AbbVie, Yanxi Liu Shareholder of: AbbVie, Employee of: AbbVie, CONRADO GARCIA GARCIA: None declared, Eduardo Mysler Speakers bureau: AbbVie, Amgen, AstraZeneca, BMS, Eli Lilly, GlaxoSmithKline, Pfizer, Roche, and Sandoz, Consultant of: AbbVie, Amgen, AstraZeneca, BMS, Eli Lilly, GlaxoSmithKline, Pfizer, Roche, and Sandoz, Alvin F. Wells Consultant of: AbbVie, Amgen, BMS, Eli Lilly, Novartis, Pfizer, and Sanofi, Xianwei Bu Shareholder of: AbbVie, Employee of: AbbVie, Nasser Khan Shareholder of: AbbVie, Employee of: AbbVie, Michael Chen Shareholder of: AbbVie, Employee of: AbbVie, Heidi Camp Shareholder of: AbbVie, Employee of: AbbVie, Anthony Cunningham Consultant of: GSK, Merck Sharp & Dohme, and BioCSL/Sequirus.

Characterization of Adaptive Immune Responses to SARS-CoV-2 Updated Bivalent Booster

Bivalent COVID-19 vaccines that contain two mRNAs encoding Wuhan-1 and Omicron BA.4/5 spike proteins are successful in preventing infection from the original strain and Omicron variants, but the quality of adaptive immune responses is still not well documented. This study aims at characterizing adaptive immune responses to the bivalent booster vaccination in 46 healthy participants. Plasma and PBMC were collected prior and three weeks after bivalent booster. We measured anti-N, anti-S, and RBD IgM, IgA, IgG plasma titers against original, Omicron BA.1, and BA.5 variants (pending) as well as total anti-S IgG titers and surrogate Virus Neutralization capacity against the Alpha, Delta, and BA.1 variant. With spectral flow-cytometry we identified peripheral blood B-cells specific for the RBD of the S-protein of the original and BA.1 variants. T-cell-specific responses were assessed by cytokine release assay after stimulation with SARS-CoV-2 peptides from the original, BA.1, BA.4, and BA.5 variants (pending). Finally, we performed TRB and IGH repertoire studies on sorted CD4+, CD8+, CD19+ lymphocytes, to study breadth of SARS-CoV-2 specific clonotypes (pending). 27/46 participants were analyzed;9 had SARS-CoV-2 infection (COVID+), while 18 are infection naive (COVID-). In both groups, median time since last dose of SARS-CoV-2 vaccine (3rd or 4th) was 11 months. All subjects were positive for anti-S IgG prior to bivalent booster. The COVID + group displayed anti-S IgG pre-booster levels and neutralization against BA.1 higher than the COVID- group. Significant increase post-boost of total anti-S IgG and BA.1 neutralizing activity was detected in the COVID- but not in the COVID+ group;however, no difference in neutralization activity post-boost was detected between the two groups. Furthermore, the COVIDgroup showed significant increase in the frequency of CD19+ and CD27+ switched memory B-cells specific for BA.1 RBD in post-boost compared to pre-boost samples. However, post-boost frequencies of the same B-cells were higher in the COVID+ compared to the COVID- group. These preliminary findings confirm that among individual immunized with the original COVID-19 mRNAvaccine, prior COVID infection provides increased protection against SARS-CoV-2 variants. They also demonstrate that booster immunization with the bivalent vaccine induces robust adaptive immune responses against Omicron variant.[Formula presented][Formula presented]Copyright © 2023 Elsevier Inc.

Association of SARS-COV-2 viral RNAemia, IL- 6 gene polymorphism, serum IL-6 and peripheral blood lymphocytes and monocytes with disease severity in COVID-19 patients

Coronavirus disease 2019 (COVID-19) is a fatal pandemic viral disease caused by the severe acute respiratory syndrome corona virus type-2 (SARS-CoV-2). The aim of this study is to observe the associations of IL-6, SARS-COV-2 viral load (RNAemia), IL- 6 gene polymorphism and lymphocytes and monocytes in peripheral blood with disease severity in COVID-19 patients. This study was carried out from March 2021 to January 2022. RT-PCR positive 84 COVID-19 patients and 28 healthy subjects were enrolled. Blood was collected to detect SARS-COV-2 viral RNA (RNAemia) by rRT-PCR, serum IL-6 level by chemiluminescence method, SNPs of IL-6 by SSP-PCR, immunophenotyping of lymphocytes and monocyte by flow cytometry. Serum IL-6 level (pg/ml) was considerably high among critical patients (102.02 +/- 149.7) compared to severe (67.20 +/- 129.5) and moderate patients (47.04 +/- 106.5) and healthy controls (3.5 +/- 1.8). Serum SARS-CoV-2 nucleic acid positive cases detected mostly in critical patients (39.28%) and was correlated with extremely high IL-6 level and high mortality (R =.912, P < 0.001). Correlation between IL-6 and monocyte was statistically significant with disease severity (severe group, p < 0.001, and 0.867*** and critical group p < 0.001 and 0.887***). In healthy controls, moderate, severe and critically ill COVID-19 patients, IL-6 174G/C (rs 1800795) GG genotype was 82.14%, 89.20%, 67.85% and 53.57% respectively. CC and GC genotype had strong association with severity of COVID-19 when compared with GG genotype. Significant statistical difference found in genotypes between critical and moderate groups (p < 0.001, OR-10.316, CI-3.22-23.86), where CC genotype was associated with COVID-19 severity and mortality. The absolute count of T cell, B cell, NK cell, CD4+ T cells and CD8+ T cells were significantly decreased in critical group compared to healthy, moderate and severe group (P < 0.001). Exhaustion marker CD94/NKG2A was increased on NK cells and CD8+ cytotoxic T cell among critical and severe group. Absolute count of monocyte was significantly increased in critical group (P < 0.001). Serum IL-6, IL-6 174 G/C gene and SARS-CoV-2 RNAaemia can be used in clinical practice for risk assessment;T cell subsets and monocyte as biomarkers for monitoring COVID-19 severity. Monoclonal antibody targeting IL-6 receptor and NKG2A for therapeutics may prevent disease progression and decrease morbidity and mortality.Copyright © 2023 Elsevier Inc.

Immunotherapy: SYNERGISTIC PERITONEAL ANTI-TUMOR EFFECT OF ALLOCETRAOTS, A CELLULAR IMMUNE-THERAPY, IN COMBINATION WITH IMMUNE CHECKPOINT INHIBITORS/CHEMOTHERAPY, THROUGH IN-VIVO REPROGRAMMING OF MACROPHAGES AND DENDRITIC CELLS

Background & Aim: Immune checkpoint inhibitors (ICI) revolutionized solid tumor treatment, however, in many tumors only partial response is achieved. Allocetra-OTS has an immune modulating effect on macrophages and dendritic cells and showed an excellent safety profile in patients including patients with sepsis and Covid-19. Here we investigated the anti-tumoral effect of Allocetra-OTS cellular therapy, in peritoneal solid tumor animal models. Methods, Results & Conclusion(s): Allocetra-OTS is manufactured from enriched mononuclear fractions and induced to undergo early apoptosis. Balb/c mice were inoculated intraperitoneally (IP) with AB12 (mesothelioma) with pLenti-PGK-V5-Luc-Neo and treated with anti- CTLA4 with or without Allocetra-OTS. Mice were monitored daily for clinical score and weekly using IVIS (Fig.1). Kaplan-Meier log rank test was done for survival. For Allocetra-OTS preparation, enriched mononuclear fractions were collected by leukapheresis from healthy eligible human donors and induced to undergo early apoptosis. Anti- CTLA4 standalone therapy significantly improved survival (Fig.2) from mean 34+/-9 to 44.9 +/-20 days. However, OTS standalone therapy was non-inferior and improved survival to 52.3 +/-20 days. Anti-CTLA4 + Allocetra-OTS combination therapy, ameliorated survival to 86.7+/-20 days with complete cancer remission in 60-100% of mice. Similar anti- tumoral effects of Allocetra-OTS were seen in mesothelioma model in a combination therapy with either anti-PD1 or cisplatin and using anti-PD1 in ID8 ovary cancer model. Based on single cell analysis confirmed by flow cytometry and pathology, the mechanism of action seems to be related or at least associated with an increase in f/480high peritoneal macrophages and a decrease in recruited macrophages, and to f/480high infiltration of the tumor. However, further studies are needed to confirm these observations. During IP tumor progression, Allocetra-OTS as a standalone therapy or in combination with ICI, or cisplatin, significantly reduced tumor size and resulted in complete remission in up to 100% treated mice. Similar results were obtained in ID8 ovary cancer. Based on excellent safety profile in > 50 patients treated in prior clinical trials for sepsis and Covid-19, Phase I/II clinical trial of Allocetra-OTS plus chemotherapy has started and three patient already recruited. A second phase I/II clinical trial of Allocetra- OTS plus anti-PD1, as a second- and third-line therapy in various cancers, was initiated in Q1 2023. [Figure presented]Copyright © 2023 International Society for Cell & Gene Therapy

Clinical significance of serum interleukin 6 in elderly patients infected with severe acute respiratory syndrome coronavirus 2 omicron variant and its correlation with underlying diseases.

Objective To investigate the clinical significance of serum interleukin 6 (IL-6) in elderly patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) omicron variant and its correlation with underlying diseases. Methods A total of 22 elderly patients (80 years old) infected with omicron variant, who were admitted to Department of Infectious Diseases, The First Affiliated Hospital of Naval Medical University (Second Military Medical University) from Apr. to Jun. 2022 and tested positive for SARS-CoV-2 RNA, were included. The level of serum IL-6 was measured by flow cytometry, and the level of serum C reactive protein (CRP) was measured by immunonephelometry. Patients were divided into pneumonia group (16 cases) and non-pneumonia group (6 cases) according to the imaging examination results, and were divided into severe group (severe and critical type, 5 cases) and non-severe group (mild and normal type, 17 cases) according to the condition. Binary logistic regression model and receiver operating characteristic (ROC) curve were used to analyze the correlation between serum IL-6 and CRP levels and the severity of the disease and whether it would progress to pneumonia. Meanwhile, the relationships between underlying diseases and serum IL-6 level were explored. Results Among the 22 patients, 6 were mild, 11 were normal, 3 were severe, and 2 were critical. The baseline serum IL-6 level in the pneumonia group was significantly higher than that in the non-pneumonia group (20.16+/-12.36pg/mL vs 5.42+/-1.57 pg/mL, P=0.009), and there was no significant difference in baseline serum CRP level between the 2 groups (P0.05). There were no significant differences in baseline serum IL-6 or CRP levels between the severe group and the non-severe group (both P0.05). Logistic regression analysis showed that the baseline serum IL-6 and CRP might be related to pneumonia after infection with omicron variant (odds ratio OR=2.407, 95% confidence interval CI0.915-6.328;OR=1.030, 95% CI 0.952-1.114). ROC curve analysis showed that the area under curve values of serum IL-6 and CRP in predicting the progression to pneumonia were 0.969 (95% CI 0.900-1.000) and 0.656 (95% CI 0.380-0.932), respectively, with statistical significance (Z=2.154, P=0.030). There were no significant differences in the baseline serum IL-6 level or proportions of severe patients or pneumonia patients among patients with or without hypertension, diabetes mellitus, coronary heart disease, chronic kidney disease or chronic obstructive pulmonary disease (all P0.05). The baseline serum IL-6 levels of the omicron variant infected elderly patients with 1, 2, and 3 or more underlying diseases were 12.50 (9.15, 21.75), 23.55 (9.63, 50.10), and 10.90 (5.20, 18.88) pg/mL, respectively, with no statistical significance (P0.05). Conclusion For omicron variant infected patients, serum IL-6 level is significantly increased in patients with pneumonia manifestations and is correlated with disease progression. Serum IL-6 level is of great guiding significance to judge disease progression and evaluate efficacy and prognosis of elderly coronavirus disease 2019 patients.Copyright © 2022, Second Military Medical University Press. All rights reserved.

Exosomes/EVs: IMMUNOMODULATORY EFFECTS OF AMNITOIC FLUID EXTRACELLULAR VESICLES IN AN IN-VITRO MODEL OF IMMUNE ACTIVATION

Background & Aim: Amniotic fluid (AF)-derived EVs are currently under investigation for use as anti-inflammatory therapeutics in COVID-19 and COVID-19 long haulers. The dysregulation of the immune response induced by SARS-COV-2 is a key driver of both acute COVID-19 induced lung injury and long term COVID-19 sequela. There is a clear need to identify therapeutics that suppress excessive inflammation and reduce immune cell exhaustion to improve patient short term and long-term outcomes. Amniotic fluid (AF)- derived extracellular vesicles (EVs) have previously been shown to deliver anti-inflammatory and immune-modulatory signals to diverse cellular targets. We aimed to test if AF-EVs carry immune-suppressive molecules and can suppress T-cell immune activation and exhaustion in vitro. Methods, Results & Conclusion(s): The AF-EV biologic tested was derived from AF collected from consenting donors during planned, fullterm cesarean sections. AF was centrifuged and filtered to remove cellular debris and create a product containing AF-EVs and soluble extracellular components. Fluorescent EXODOT analysis was performed to demonstrate the presence of EV markers CD9, CD81, ALIX, and immune suppressive molecule PD-L1. T-cell activation/exhaustion was induced in vitro by treating human peripheral blood mononuclear cells with activation agent PHA for 3 days with the addition of AF-EVs or saline control. Immune activation/exhaustion was measured by flow cytometry to determine the expression of PD-1 on CD3+ T-cells. The AF-EV biologic was characterized to contain EVs with positive expression of CD9, CD81, ALIX, and PL-L1. T-cell activation/exhaustion was upregulated in response to PHA and was significantly reduced by 8% in AF-EV treated T-cells compared to saline control (77.7% vs 85.7%, respectively P<0.05). These findings demonstrate that AF-EVs do express PD-L1, a surface marker that has previously been demonstrated to contribute to exosome-mediated immunosuppression. Furthermore, we confirmed in vitro that AF-EVs suppress T-cell activation/ exhaustion in the presence of a T-cell activation agent. COVID-19 long haulers have been described to have upregulated and pro-longed immune activation and T-cell exhaustion, marked by an increase in PD1+ T-cells. Therefore, this finding serves as a starting point for the development of a potential mechanism of action that may describe AF-EV's therapeutic effect in COVID-19 long hauler patients.Copyright © 2023 International Society for Cell & Gene Therapy

Anti-interferon-alpha autoantibodies in patients with inborn errors of Immunity and rheumatic diseases before and during the COVID-19 pandemic

Introduction: Type 1 interferon (IFN) autoantibodies, such as anti-IFNalpha, have pathogenic significance in life-threatening COVID-19 pneumonia. Ten to twenty percent of severe COVID cases are associated with type I IFN autoantibodies. These autoantibodies likely pre-exist while others arise de novo relative to SARS-CoV-2 infection. It is unclear to what extent type I anti-IFN autoantibodies are induced by SARS-CoV-2 infection and contribute to COVID-19 severity. We investigated these phenomena in those with inborn errors of immunity (IEI) and rheumatic disease (RHE). Aim(s): We aim to compare the prevalence and neutralization ability of anti-IFNalpha autoantibodies in IEI and RHE patients using archived blood samples before and after the COVID-19 pandemic began. Method(s): We determined the presence of autoantibodies against IFNalpha in plasma samples by enzyme linked immunosorbent assay in 453 patients with IEI or RHE who were testing either before or after the COVID-19 pandemic began in March 2020. Using flow cytometry, we determined the function of IFNalpha autoantibodies in plasma to block CD4T cell activation by inhibiting STAT-1 phosphorylation. Result(s): We found that 25 patients with IEI or RHE were positive for anti-IFNalpha autoantibodies. 10 out of 229 patient samples collected before the pandemic (4.2%) tested positive whereas 15 out of 224 patient samples collected after the pandemic began (7.0%) were positive. Seven of the 25 patients (28%) who tested positive had neutralizing antibodies in plasma, which prevented STAT-1 phosphorylation in CD4T cells;all of these patients had partial recombination activating gene deficiency (pRD) except for one patient with autoimmunity, leukemia and selective IgA deficiency. One pRD patient had anti-IFNalpha autoantibodies with neutralization capacity before the pandemic, which persisted after hematopoietic stem cell transplantation (HSCT) with full immune reconstitution. The patient was immunized for SARS-CoV-2 before and after HSCT and acquired COVID-19 infection a year after HSCT. The patient was symptomatic but never hospitalized and fully recovered despite having anti-IFNalpha autoantibodies. Conclusion(s): Anti-IFNalpha autoantibody levels were comparable before and after the start of the COVID-19 pandemic in IEI and RHE patients but only 28% of cases were neutralizing. The clinical implications of these autoantibodies are yet to be determined.Copyright © 2023 Elsevier Inc.

IDDF2023-ABS-0045 Spatiotemporal immune landscape of Mas-driven pro-inflammatory microenvironment with hyperactivated glycolysis in acetaminophen-induced liver injury

IDDF2023-ABS-0045 Figure 1 IDDF2023-ABS-0045 Figure 2 IDDF2023-ABS-0045 Figure 3 IDDF2023-ABS-0045 Figure 4

Blood Transfusion in Covid-19 Patients: One Year Survey

Introduction: Due to the COVID-19 outbreak, many chronic patients and elective surgical procedures have been postponed to create spaces for the hospitalization of COVID-19 patients, raising issues related to this change. The objective of this study is to assess the effect of the COVID-19 pandemic on the demand for blood products transfusion. Materials ant methods: The study presents the results of a retrospective study of blood transfusions in COVID-19 patients admitted to the Constanta County Emergency Clinical Hospital. The period of study was January-December 2021. We compared the transfusion requirement for each type of blood component in COVID 19 patients versus patients with non-COVID pathology. Results and discussions: During 2021, we transfused 282 COVID-19 patients;150 patients had only Covid pneumonia (of which 19 patients with severe forms needed intensive care in ICU-Covid), and 132 patients had various co-morbidities. The maximum blood requests was registered in the period February - April 2021, with a peak of 63 patients in April 2021. The main co-morbidities in patients with Covid 19 were: severe anemia in patients with malignant hemopathies. Anemia at admission in patients with Covid pneumonia is reported in more than 40% of patients. Moderate anemia (Hb <11 g/dL) is considered as an independent risk factor for the severe course of COVID-19 infection and mortality in these patients. The transfusion requirement in these patients was greater than 1.43 RBC (units/patient), 0.81 Plasma units/patient, 0.40 Platelets concentrate units + single donor platelet concentrate units/patient, in accordance with the associated pathology. Conclusion(s): The most requested product was packed red blood cells, the correction of anaemia being an important factor in preventing the severe course of the disease. The platelet requirement was 0.15 units/patient, thrombocytopenia being present in patients with severe evolution of the infection (hospitalized in ICU-COVID). The most requested blood groups were O+ and A+. COVID-19 transfusion data will help plan and prepare for the use of blood resources during the pandemic.Copyright © 2022 Sevigean Ali et al., published by Sciendo.

Cellular and humoral immune responses after SARS-CoV-2 vaccination in pediatric kidney recipients

Objective: Humoral and cellular immune responses to SARS-CoV-2 vaccination are reduced in adult kidney recipients. After pediatric kidney transplantation there are only few data available - mostly limited to monitoring of SARS-CoV-2 antibodies. Method(s): Cellular and humoral immune responses have been monitored before and after SARS-CoV-2 vaccination in pediatric kidney recipients. After in vitro stimulation with SARS-CoV-2 antigen (spike glycoprotein) virus-specific CD4 and CD8 T cells (SARS-CoV-2-Tvis) have been identified by cytokine flow cytometry. SARS-CoV-2 IgG was measured by CMIA. Result(s): Immune response after SARS-CoV-2 vaccination was analyzed in a total of 30 pediatric kidney recipients (age at 1st vaccine dose 5.2 - 17.8 years, median 14.8 years;43% male;30/30 2 vaccine doses;23/30 3 vaccine doses). At time of vaccination 22 patients (73%) received a tacrolimus (Tac)-based immunosuppression combined with mycophenolate mofetil (MMF;n = 15) or everolimus (n = 6) or neither of them (n = 1);3 patients were exposed to cyclosporine A and 5 patients to a calcineurin inhibitor (CNI)- free immunosuppression. MMF was used in 18/30 patients. After 1st dose of mRNA vaccine SARS-CoV-2 antibodies were detectable in 50% of pediatric kidney recipients, after 2nd dose in 78% and after 3rd dose in 88%. After the 2nd vaccine dose absence of humoral immune response (< 33.8 BAU/ml) was only found in case of MMF use (predominately combined with Tac). Peak IgG values (> 2,080 BAU/ml) were only detected in MMF-free regimens (6/7). Cellmediated response partially differed from humoral response, e. g., in some patients SARS-CoV2-Tvis were found despite lack of virus-specific antibodies. After 1st vaccine dose SARS-CoV-2-Tvis were detectable in 50% of pediatric kidney recipients, after 2nd dose in 92%. After 2nd vaccine dose absence or very low levels of SARS-CoV-2-Tvis (< 0.3 cells/mul) were only found in Tac-based immunosuppressive regimens, whereas higher levels (> 1.3 cells/mul) were exclusively detected in patients with MMFfree medication. Conclusion(s): After pediatric kidney transplantation humoral and cellular immune responses to SARS-CoV-2 vaccination were suboptimal, but more pronounced than in adult kidney recipients. Use of Tac and MMF was associated with impaired immune response to vaccination. SARS-CoV-2-specific humoral response corresponded only partially to cell-mediated response. Additional monitoring of SARS-CoV- 2-Tvis might be recommendable to improve assessment of the individual vaccine response and thereby to personalize the decision on the necessity of further vaccine doses.

COVID-19: Using high-throughput flow cytometry to dissect clinical heterogeneity.

Here we consider how high-content flow cytometric methodology at appropriate scale and throughput rapidly provided meaningful biological data in our recent studies of COVID-19, which we discuss in the context of other similar investigations. In our work, high-throughput flow cytometry was instrumental to identify a consensus immune signature in COVID-19 patients, and to investigate the impact of SARS-CoV-2 exposure on patients with either solid or hematological cancers. We provide here some examples of our 'holistic' approach, in which flow cytometry data generated by lymphocyte and myelomonocyte panels were integrated with other analytical metrics, including SARS-CoV-2-specific serum antibody titers, plasma cytokine/chemokine levels, and in-depth clinical annotation. We report how selective differences between T cell subsets were revealed by a newly described flow cytometric TDS assay to distinguish actively cycling T cells in the peripheral blood. By such approaches, our and others' high-content flow cytometry studies collectively identified overt abnormalities and subtle but critical changes that discriminate the immuno-signature of COVID-19 patients from those of healthy donors and patients with non-COVID respiratory infections. Thereby, these studies offered several meaningful biomarkers of COVID-19 severity that have the potential to improve the management of patients and of hospital resources. In sum, flow cytometry provides an important means for rapidly obtaining data that can guide clinical decision-making without requiring highly expensive, sophisticated equipment, and/or "-omics" capabilities. We consider how this approach might be further developed.

MICaFVi: A Novel Magnetic Immuno-Capture Flow Virometry Nano-Based Diagnostic Tool for Detection of Coronaviruses.

COVID-19 has resulted in a pandemic that aggravated the world's healthcare systems, economies, and education, and caused millions of global deaths. Until now, there has been no specific, reliable, and effective treatment to combat the virus and its variants. The current standard tedious PCR-based tests have limitations in terms of sensitivity, specificity, turnaround time, and false negative results. Thus, an alternative, rapid, accurate, and sensitive diagnostic tool that can detect viral particles, without the need for amplification or viral replication, is central to infectious disease surveillance. Here, we report MICaFVi (Magnetic Immuno-Capture Flow Virometry), a novel precise nano-biosensor diagnostic assay for coronavirus detection which combines the MNP-based immuno-capture of viruses for enrichment followed by flow-virometry analysis, enabling the sensitive detection of viral particles and pseudoviruses. As proof of concept, virus-mimicking spike-protein-coated silica particles (VM-SPs) were captured using anti-spike-antibody-conjugated MNPs (AS-MNPs) followed by detection using flow cytometry. Our results showed that MICaFVi can successfully detect viral MERS-CoV/SARS-CoV-2-mimicking particles as well as MERS-CoV pseudoviral particles (MERSpp) with high specificity and sensitivity, where a limit of detection (LOD) of 3.9 µg/mL (20 pmol/mL) was achieved. The proposed method has great potential for designing practical, specific, and point-of-care testing for rapid and sensitive diagnoses of coronavirus and other infectious diseases.

Advanced flow cytometry for biomedical applications.

Flow cytometry (FC) is a versatile tool with excellent capabilities to detect and measure multiple characteristics of a population of cells or particles. Notable advancements in in vivo photoacoustic FC, coherent Raman FC, microfluidic FC, and so on, have been achieved in the last two decades, which endows FC with new functions and expands its applications in basic research and clinical practice. Advanced FC broadens the tools available to researchers to conduct research involving cancer detection, microbiology (COVID-19, HIV, bacteria, etc.), and nucleic acid analysis. This review presents an overall picture of advanced flow cytometers and provides not only a clear understanding of their mechanisms but also new insights into their practical applications. We identify the latest trends in this area and aim to raise awareness of advanced techniques of FC. We hope this review expands the applications of FC and accelerates its clinical translation.

Impact of peptide:HLA complex stability for the identification of SARS-CoV-2-specific CD8+T cells.

Induction of a lasting protective immune response is dependent on presentation of epitopes to patrolling T cells through the HLA complex. While peptide:HLA (pHLA) complex affinity alone is widely exploited for epitope selection, we demonstrate that including the pHLA complex stability as a selection parameter can significantly reduce the high false discovery rate observed with predicted affinity. In this study, pHLA complex stability was measured on three common class I alleles and 1286 overlapping 9-mer peptides derived from the SARS-CoV-2 Spike protein. Peptides were pooled based on measured stability and predicted affinity. Strikingly, stability of the pHLA complex was shown to strongly select for immunogenic epitopes able to activate functional CD8+T cells. This result was observed across the three studied alleles and in both vaccinated and convalescent COVID-19 donors. Deconvolution of peptide pools showed that specific CD8+T cells recognized one or two dominant epitopes. Moreover, SARS-CoV-2 specific CD8+T cells were detected by tetramer-staining across multiple donors. In conclusion, we show that stability analysis of pHLA is a key factor for identifying immunogenic epitopes.

Clinical significance of serum interleukin 6 in elderly patients infected with severe acute respiratory syndrome coronavirus 2 omicron variant and its correlation with underlying diseases

Objective To investigate the clinical significance of serum interleukin 6 (IL-6) in elderly patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) omicron variant and its correlation with underlying diseases. Methods A total of 22 elderly patients (>80 years old) infected with omicron variant, who were admitted to Department of Infectious Diseases, The First Affiliated Hospital of Naval Medical University (Second Military Medical University) from Apr. to Jun. 2022 and tested positive for SARS-CoV-2 RNA, were included. The level of serum IL-6 was measured by flow cytometry, and the level of serum C reactive protein (CRP) was measured by immunonephelometry. Patients were divided into pneumonia group (16 cases) and non-pneumonia group (6 cases) according to the imaging examination results, and were divided into severe group (severe and critical type, 5 cases) and non-severe group (mild and normal type, 17 cases) according to the condition. Binary logistic regression model and receiver operating characteristic (ROC) curve were used to analyze the correlation between serum IL-6 and CRP levels and the severity of the disease and whether it would progress to pneumonia. Meanwhile, the relationships between underlying diseases and serum IL-6 level were explored. Results Among the 22 patients, 6 were mild, 11 were normal, 3 were severe, and 2 were critical. The baseline serum IL-6 level in the pneumonia group was significantly higher than that in the non-pneumonia group ([20.16+/-12.36]pg/mL vs [5.42+/-1.57] pg/mL, P=0.009), and there was no significant difference in baseline serum CRP level between the 2 groups (P>0.05). There were no significant differences in baseline serum IL-6 or CRP levels between the severe group and the non-severe group (both P>0.05). Logistic regression analysis showed that the baseline serum IL-6 and CRP might be related to pneumonia after infection with omicron variant (odds ratio [OR]=2.407, 95% confidence interval [CI]0.915-6.328;OR=1.030, 95% CI 0.952-1.114). ROC curve analysis showed that the area under curve values of serum IL-6 and CRP in predicting the progression to pneumonia were 0.969 (95% CI 0.900-1.000) and 0.656 (95% CI 0.380-0.932), respectively, with statistical significance (Z=2.154, P=0.030). There were no significant differences in the baseline serum IL-6 level or proportions of severe patients or pneumonia patients among patients with or without hypertension, diabetes mellitus, coronary heart disease, chronic kidney disease or chronic obstructive pulmonary disease (all P>0.05). The baseline serum IL-6 levels of the omicron variant infected elderly patients with 1, 2, and 3 or more underlying diseases were 12.50 (9.15, 21.75), 23.55 (9.63, 50.10), and 10.90 (5.20, 18.88) pg/mL, respectively, with no statistical significance (P>0.05). Conclusion For omicron variant infected patients, serum IL-6 level is significantly increased in patients with pneumonia manifestations and is correlated with disease progression. Serum IL-6 level is of great guiding significance to judge disease progression and evaluate efficacy and prognosis of elderly coronavirus disease 2019 patients.Copyright © 2022, Second Military Medical University Press. All rights reserved.

Lymphocyte Populations and Autoantibodies, in a Cohort of Patients with Rheumatoid Arthritis: A Long-Term Study of Covid-19 Cases and Non-Covid-19 Controls

Objectives: To assess the immunological [Lymphocyte populations (LP) and Autoantibodies (Ab)] and clinical profile of rheumatoid arthritis (RA) patients who suffered from COVID-19 compared with non-COVID-19 RA patients. Method(s): A nested case-control study of RA patients treated under a strict follow-up model. RA patients and confirmed COVID-19 infection (last 24 months) and RA patients without the infection were included. Subgroups of cases: Long COVID (LC): symptoms after infection for >=4 weeks;Post COVID syndrome (PCS): symptoms for >=12 weeks;and patients with symptoms alpha4 weeks. Sociodemographic, clinical, and paraclinical variables of RA and COVID-19 infection (in cases) were captured. Antinuclear antibodies (ANA), anticardiolipin antibodies, lymphocyte populations (BD FACSDuetTM-BDFACSLyricTMmultiparameter flow cytometry) T cells, B cells, and NK were evaluated. Univariate and bivariate analyzes (STATA 17) were done. Result(s): 300 patients were included (148 cases/152 controls;87.3% women). Median age 59 years (IQR 11). 71.86% were in low disease activity. There were no significant differences in sociodemographic and clinical characteristics between cases and controls. Cases had a time since infection of 18.5 months (IQR 7). Of the total cases, 69%presented LC and 63%PCS.No significant differences were found between cases and controls in the lymphocyte population nor in the antibodies evaluated. There were no differences in the immune profile when comparing patients with LC and PCS with those with symptoms alpha4 weeks after COVID-19 infection. Conclusion(s): No differences were found in the behavior of the immunological profile (independent of symptoms of LC and PCS) in RA patients under strict follow up, evaluated long-term after infection with those who did not have COVID-19. This suggest that patients returned to their baseline homeostatic state, something that has not yet been reported up to now. These results should be replicated in populations with different RA characteristics.

Effect of BNT162b2 mRNA COVID-19 vaccine on sperm morphokinetics and DNA integrity: A prospective observational study in Japan

Objective: To assess whether the coronavirus disease 2019 (COVID-19) mRNA vaccine affects sperm morphokinetics using a computer-assisted semen analyzer and other semen parameters using a sperm chromatin structure assay. Method(s): Healthy male volunteers in two Japanese clinics between May 2021 and December 2021 were prospectively analyzed. Participants donated sperm twice, two days apart, in the following phases: before vaccination, 2 weeks after the first vaccine dose, and 2, 4, and 12 weeks after the second dose. Basic sperm parameters, sperm motility characteristics, and the percentage of DNA-damaged sperm were compared among the different phases. Result(s): Ninety-six semen samples from ten volunteers, who were vaccinated with the BNT162b2 mRNA vaccine, were evaluated. There were no significant differences between any phases in basic semen findings and parameters of the sperm chromatin structure assays. Regarding sperm motion characteristics, the average linear velocity, beat-cross frequency, and sperm motility index significantly decreased after the second vaccine dose (P=0.018, P=0.003, and P=0.027, respectively), with no significant differences between any two phases by post-hoc pairwise comparisons. Conclusion(s): After COVID-19 mRNA vaccination, while sperm motion characteristics might fluctuate, no apparent deterioration of basic sperm parameters or sperm DNA integrity was observed. Given the adverse effects of COVID-19 on sperm, our findings suggest that there might be no reason to refrain from vaccination for healthy individuals.Copyright © 2023 Asian Pacific Journal of Reproduction Produced by Wolters Kluwer- Medknow.

Whole Blood Procoagulant Platelet Flow Cytometry Protocol for Heparin-Induced Thrombocytopenia (HIT) and Vaccine-Induced Immune Thrombotic Thrombocytopenia (VITT) Testing.

Heparin-induced thrombocytopenia (HIT) is a well-characterized, iatrogenic complication of heparin anticoagulation with significant morbidity. In contrast, vaccine-induced immune thrombotic thrombocytopenia (VITT) is a recently recognized severe prothrombotic complication of adenoviral vaccines, including the ChAdOx1 nCoV-19 (Vaxzevria, AstraZeneca) and Ad26.COV2.S (Janssen, Johnson & Johnson) vaccines against COVID-19. The diagnosis of HIT and VITT involve laboratory testing for antiplatelet antibodies by immunoassays followed by confirmation by functional assays to detect platelet-activating antibodies. Functional assays are critical to detect pathological antibodies due to the varying sensitivity and specificity of immunoassays. This chapter presents a protocol for a novel whole blood flow cytometry-based assay to detect procoagulant platelets in healthy donor blood in response to plasma from patients suspected of HIT or VITT. A method to identify suitable healthy donors for HIT and VITT testing is also described.

A flow cytometry-based neutralization assay for simultaneous evaluation of blocking antibodies against SARS-CoV-2 variants.

Vaccines against SARS-CoV-2 have alleviated infection rates, hospitalization and deaths associated with COVID-19. In order to monitor humoral immunity, several serology tests have been developed, but the recent emergence of variants of concern has revealed the need for assays that predict the neutralizing capacity of antibodies in a fast and adaptable manner. Sensitive and fast neutralization assays would allow a timely evaluation of immunity against emerging variants and support drug and vaccine discovery efforts. Here we describe a simple, fast, and cell-free multiplexed flow cytometry assay to interrogate the ability of antibodies to prevent the interaction of Angiotensin-converting enzyme 2 (ACE2) and the receptor binding domain (RBD) of the original Wuhan-1 SARS-CoV-2 strain and emerging variants simultaneously, as a surrogate neutralization assay. Using this method, we demonstrate that serum antibodies collected from representative individuals at different time-points during the pandemic present variable neutralizing activity against emerging variants, such as Omicron BA.1 and South African B.1.351. Importantly, antibodies present in samples collected during 2021, before the third dose of the vaccine was administered, do not confer complete neutralization against Omicron BA.1, as opposed to samples collected in 2022 which show significant neutralizing activity. The proposed approach has a comparable performance to other established surrogate methods such as cell-based assays using pseudotyped lentiviral particles expressing the spike of SARS-CoV-2, as demonstrated by the assessment of the blocking activity of therapeutic antibodies (i.e. Imdevimab) and serum samples. This method offers a scalable, cost effective and adaptable platform for the dynamic evaluation of antibody protection in affected populations against variants of SARS-CoV-2.