Correlation between levels of anti-cytokine antibodies, recombination activity of the mutant RAG proteins and clinical phenotype in patients with RAG deficiency

RAG mutations cause various phenotypes: SCID, Omenn syndrome (OS), leaky SCID (LS) and combined immunodeficiency (CID). We had previously reported autoantibodies targeting IFN-alpha, IFN-omega in patients with RAG deficiency. However, how the presence of such antibodies correlated with the severity of the clinical phenotype and with the recombination activity of the mutant proteins was unknown. To address this, we have studied anti-cytokine antibodies in 118 patients with RAG defects (SCID, n = 28;OS, n = 29;LS, n = 29;CID, n = 32), and in 42 controls (protocols NCT03394053 and NCT03610802). RAG mutant proteins associated with CID and LS retained 35.6 +/- 4.3 (mean +/- SE) and 29.8 +/- 5.1% recombination activity respectively, compared to wildtype protein, which was significantly higher than the recombination activity of the mutant RAG proteins associated with OS (4.1 +/- 1.5%) and SCID (5.7 +/- 2.1%) (p < 0.0001). Among 32 CID patients, 24 tested positive for anti-IFN-alpha and 21 for anti-IFN-omega antibodies. Among 29 LS patients, 15 had high levels of anti-IFN-alpha and 13 of anti-IFN-omega antibodies. A minority of the CID and LS patients had also high levels of anti-IFN-beta and anti-IL-22 antibodies. By contrast, none of the OS patients tested positive for anti-cytokine antibodies. High levels of anti-IFN-alpha and anti-IFN-omega antibodies correlated with their neutralizing activity as demonstrated in vitro by analysis of STAT1 phosphorylation upon stimulation of healthy donor monocytes in the presence of the appropriate cytokine and patient's or control plasma. Severe viral infections were recorded in 26/41 patients with CID and LS who tested positive and in 7/20 who tested negative for anti-IFN-alpha and/or anti-IFN-omega antibodies (p <0.05). Among those with anti-IFN antibodies, EBV (n = 8), CMV (n = 6), HSV (n = 5), VZV (n = 4) and adenovirus (n = 4) infections were more common. Two patients had COVID-19, which was fatal in one. Presence of the rubella virus was documented in 5 patients with anti-type I IFN antibodies. These results demonstrate that high levels of neutralizing anti-IFN-alpha and anti-IFN-omega antibodies are common in patients with RAG mutations manifesting as CID and LS, but not in those with OS, and that their presence is associated with a high risk of serious viral infections.Copyright © 2023 Elsevier Inc.

Development of warm autoimmune hemolytic anemia after initiation of Ruxolitinib in a patient with STAT1 gain-of-function mutation

Introduction: STAT1 gain-of-function (GOF) disease is associated with chronic mucocutaneous candidiasis (CMC) and a broad spectrum of infectious, inflammatory, and vascular manifestations. The Janus Kinase inhibitor ruxolitinib has been used successfully for CMC and autoimmune phenomena. We describe a case of warm autoimmune hemolytic anemia (WAIHA) in a patient with STAT1 GOF disease after initiating ruxolitinib. Case report: A 36-year-old man with STAT1 c.850G>A (p.Glu284Lys) mutation presented with CMC as well as recurrent viral and bacterial infections, lymphadenopathy, enteritis, nodular regenerative hyperplasia (NRH) and splenomegaly. Immune workup confirmed a combined immunodeficiency with hypogammaglobulinemia and T-cell lymphopenia. Ruxolitinib was initiated at 5 mg twice daily (due to pre-existing thrombocytopenia) with up titration over 3 months to 20 mg twice daily. He improved with weight gain, increased energy, resolution of chronic anemia, and improved lymphadenopathy and splenomegaly on imaging. Serum CXCL9 only minimally decreased from 4660 pg/ml to 3990 pg/ml. Soon after reaching ruxolitinib 20 mg twice daily, he developed JC viremia, prompting dose reduction to 15 mg BID. Within two weeks, he developed a non-COVID upper respiratory tract infection followed by fatigue, shortness of breath with ambulation, and dark urine. Emergency evaluation revealed warm antibody positive hemolytic anemia with a hemoglobin of 5 g/dL, and worsened thrombocytopenia. He was treated with blood transfusions, pulse steroids, and high-dose IVIG with stabilization but continued hemolysis. Due to the JC viremia, there was concern to give rituximab with increased PML risk. Bone marrow showed trilineage hematopoiesis, a mild increase in megakaryocytes and RBC precursors, and a loss of B-cell progenitors with retention of mature B cells. His B and T lymphocyte numbers had increased since prior to ruxolitinib, with a predominance of Tfh1-cells (58.7% of total Tfh-cells). He was started on sirolimus with a slow taper of prednisone with continued stable hemoglobin and platelets, and resolution of hemolysis after 3 months. Conclusion(s): To our knowledge, this is the first case of a STAT1 GOF patient developing WAIHA while receiving ruxolitinib therapy. Treatment choices were complicated by the risks of PML. Sirolimus combined with ruxolitinib allowed wean of corticosteroid and subsequent resolution of hemolysis.Copyright © 2023 Elsevier Inc.

Mild COVID-19 outcomes in adults with inborn errors of immunity: a single-center experience

Currently, 640 million cases of coronavirus disease 2019 (COVID-19) and 6.6 million deaths have been reported world-wide. Risk factors for severe COVID-19 are known, including those with compromised immunity. Among patients with inborn errors of immunity (IEI), early reports of severe outcomes lead to strict masking and social distancing measures. While this resulted in relatively low infection rates among those with IEI, real-world data describing the clinical course of COVID-19 in this patient population have remained limited. We performed a retrospective study of adult IEI patients followed by our center in which a positive test (rapid antigen or PCR) for COVID-19 was determined between November 2021-November 2022. Medical charts were reviewed, and patient interviews conducted. All patients provided informed consent. Twenty-nine patients were enrolled (22 females, 7 males), aged between 18-69 years (median: 20-29 years). The cohort included those with antibody deficiencies (41.37%), combined immunodeficiencies (34.48%;HIES, CARD11, STAT1-GOF), immune dysregulation disorders (20.69%;LRBA deficiency, AIRE deficiency) and phagocyte defect (3.45%;CGD). The duration of symptoms ranged between 3 days-4 weeks (median: < 1 week). Upper respiratory symptoms (including sore throat, congestion) were reported in 97% while fever was present in 41% of patients. Prior to infection, 14 (48%) patients had underlying asthma or bronchiectasis - 2 subsequently experienced shortness of breath and were treated with inhalers or Sotrovimab, respectively. No treatment was required in 65.5% of cases. The remaining received Paxlovid (10.3%), Sotrovimab (13.79%), or antibiotics (10.3%). Of the 2 patients with STAT1-GOF, one tested positive during a repeat episode of febrile neutropenia which required hospitalization. No other patients were hospitalized or needed ICU admission. No deaths were recorded. In light of these favourable outcomes, patients with IEI can gradually and safely return to normal activities.Copyright © 2023 Elsevier Inc.

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.

Dynamic and spatial transcriptional responses in COVID-19-related chilblains

"COVID-toes" are chilblains that occurred in patients who may have been exposed to SARS-CoV-2, but without COVID-19 symptoms and/or with negative PCR or serology. The literature suggests that chilblains are an unexpected consequence of a strong interferon-mediated antiviral response, but the underlying molecular mechanisms remain poorly understood. We thus sought to explore the physiopathology of COVID-related chilblains by using spatially and temporally resolved transcriptomics. We included 19 patients with COVID-toes, and performed a complete virological assessment to exclude SARS-CoV-2 infection including skin viral metagenomics. Some patients had clinical symptoms evoking viral infection, but none had COVID-19. Apart from low levels of non-conventional antiphospholipid antibodies, biological tests were unremarkable. We performed spatially resolved transcriptomics (Visium, 10X Genomics) in 3 patients at different timepoints and compared them with 1 vaccination-related chilblain. We observed a different transcriptional profile in COVID-toes compared with COVID-19 vaccine-related chilblains. IRF1, CXCL10, ISG15 and STAT1 were highly expressed in COVID-toes and their expression decreased over time, confirming an activation of interferon and JAK/STAT pathways that was absent in vaccine-related chilblains. The proportion of inflammatory cell types obtained by spatial deconvolution varied over time in COVID-toes. Migratory dendritic cells were present at early stages, while T lymphocytes populations increased later. Overall, this work explores the mechanisms of COVID-19-related chilblains using spatially and temporally resolved transcriptomics.Copyright © 2023

Neoadjuvant nivolumab (N) + platinum-doublet chemotherapy (C) for resectable NSCLC: 3-y update from CheckMate 816

Background The phase III CheckMate 816 study demonstrated statistically significant and clinically meaningful improvements in event-free survival (EFS) and pathologic complete response (pCR) with neoadjuvant N + C vs C in patients (pts) with resectable NSCLC. Here, we report 3-y efficacy, safety, and exploratory biomarker analyses from CheckMate 816. Methods Adults with stage IB (tumors >=4 cm)-IIIA (per AJCC 7th ed) resectable NSCLC, ECOG PS <= 1, and no known EGFR/ALK alterations were randomized to N 360 mg + C Q3W or C alone Q3W for 3 cycles followed by surgery. Primary endpoints were EFS and pCR, both per blinded independent review. Exploratory analyses included EFS by surgical approach and extent/completeness of resection, and EFS and pCR by a 4-gene (CD8A, CD274, STAT-1, LAG-3) inflammatory signature score derived from RNA sequencing of baseline (BL) tumor samples. Results At a median follow-up of 41.4 mo (database lock, Oct 14, 2022), continued EFS benefit was observed with N + C vs C (HR, 0.68;95% CI, 0.49-0.93);3-y EFS rates were 57% and 43%, respectively. N + C improved EFS vs C in pts who had surgery, regardless of surgical approach or extent of resection, and in pts with R0 resection (table). Recurrence occurred in 28% and 42% of pts who had surgery in the N + C (n = 149) and C arms (n = 135), respectively. In the N + C arm, BL 4-gene inflammatory signature scores were numerically higher in pts with pCR vs pts without, and EFS was improved in pts with high vs low scores (data to be presented). Grade 3-4 treatment-related and surgery-related adverse events occurred in 36% and 11% of pts in the N + C arm, respectively, vs 38% and 15% in the C arm. Conclusions Neoadjuvant N + C continues to provide long-term clinical benefit vs C in pts with resectable NSCLC, regardless of surgical approach or extent of resection. Exploratory analyses in pts treated with N + C suggested that high BL tumor inflammation may be associated with improved EFS and pCR. Clinical trial identification NCT02998528. Editorial acknowledgement Medical writing and editorial support for the development of this , under the direction of the authors, was provided by Adel Chowdhury, PharmD, Samantha Dwyer, PhD, and Michele Salernitano of Ashfield MedComms, an Inizio company, and funded by Bristol Myers Squibb. Legal entity responsible for the study Bristol Myers Squibb. Funding Bristol Myers Squibb. Disclosure P.M. Forde: Financial Interests, Personal, Advisory Board: Amgen, AstraZeneca, Bristol Myers Squibb, Daiichi Sankyo, F-Star, G1 Therapeutics, Genentech, Iteos, Janssen, Merck, Novartis, Sanofi, Surface;Financial Interests, Institutional, Research Grant: AstraZeneca, BioNTech, Bristol Myers Squibb, Corvus, Kyowa, Novartis, Regeneron;Financial Interests, Personal, Other, Trial steering committee member: AstraZeneca, BioNTech, Bristol Myers Squibb, Corvus;Non-Financial Interests, Personal, Member of the Board of Directors: Mesothelioma Applied Research Foundation;Non-Financial Interests, Personal, Advisory Role, Scientific advisory board member: LUNGevity Foundation. J. Spicer: Financial Interests, Institutional, Research Grant: AstraZeneca, Bristol Myers Squibb, CLS Therapeutics, Merck, Protalix Biotherapeutics, Roche;Financial Interests, Personal, Other, Consulting fees: Amgen, AstraZeneca, Bristol Myers Squibb, Merck, Novartis, Protalix Biotherapeutics, Regeneron, Roche, Xenetic Biosciences;Financial Interests, Personal, Speaker's Bureau: AstraZeneca, Bristol Myers Squibb, PeerView;Non-Financial Interests, Personal, Other, Data safety monitoring board member: Deutsche Forschungsgemeinschaft;Non-Financial Interests, Personal, Leadership Role, Industry chair: Canadian Association of Thoracic Surgeons. [Formula presented] N. Girard: Financial Interests, Personal, Invited Speaker: AstraZeneca, BMS, MSD, Roche, Pfizer, Mirati, Amgen, Novartis, Sanofi;Financial Interests, Personal, Advisory Board: AstraZeneca, BMS, MSD, Roche, Pfizer, Janssen, Boehringer Ingelheim, Novartis, Sanofi, AbbVie, Amgen, Eli Lilly, Grunenthal, Tak da, Owkin;Financial Interests, Institutional, Research Grant, Local: Roche, Sivan, Janssen;Financial Interests, Institutional, Funding: BMS;Non-Financial Interests, Personal, Officer, International Thymic malignancy interest group, president: ITMIG;Other, Personal, Other, Family member is an employee: AstraZeneca. M. Provencio: Financial Interests, Institutional, Research Grant: AstraZeneca, Bristol Myers Squibb, Janssen, Pfizer, Roche, Takeda;Financial Interests, Personal, Speaker's Bureau: AstraZeneca, Bristol Myers Squibb, MSD, Pfizer, Roche, Takeda. S. Lu: Financial Interests, Personal, Advisory Role: AstraZeneca, Boehringer Ingelheim, GenomiCare, Hutchison MediPharma, Roche, Simcere, ZaiLab;Financial Interests, Personal, Speaker's Bureau: AstraZeneca, Hanosh, Roche. M. Awad: Financial Interests, Personal, Other, Consulting fees: ArcherDX, Ariad, AstraZeneca, Blueprint Medicine, Bristol Myers Squibb, EMD Serono, Genentech, Maverick, Merck, Mirati, Nektar, NextCure, Novartis, Syndax;Financial Interests, Institutional, Research Grant: AstraZeneca, Bristol Myers Squibb, Genentech, Eli Lilly. T. Mitsudomi: Financial Interests, Institutional, Research Grant: Boehringer Ingelheim, BridgeBio Pharma;Financial Interests, Personal, Other, Consulting fees: AstraZeneca, Boehringer Ingelheim, Bristol Myers Squibb, Chugai, MSD, Novartis, Ono, Pfizer;Financial Interests, Personal, Speaker's Bureau: Amgen, AstraZeneca, Boehringer Ingelheim, Bristol Myers Squibb, Chugai, Daiichi Sankyo, Eli Lilly, Guardant, Invitae, Merck, MSD, Novartis, Ono, Pfizer, Taiho;Financial Interests, Personal, Advisory Board: AstraZeneca;Non-Financial Interests, Personal, Leadership Role, Former president: IASLC. E. Felip: Financial Interests, Institutional, Research Grant: Fundacion Merck Salud, Merck KGAa;Financial Interests, Personal, Other, Consulting fees: Amgen, AstraZeneca, Bayer, BerGenBio, Bristol Myers Squibb, Daiichi Sankyo, Eli Lilly, F. Hoffmann-La Roche, GlaxoSmithKline, Janssen, Merck, MSD, Novartis, Peptomyc, Pfizer, Sanofi, Takeda;Financial Interests, Personal, Speaker's Bureau: Amgen, AstraZeneca, Bristol Myers Squibb, Eli Lilly, F. Hoffmann-La Roche, Janssen, Medical Trends, Medscape, Merck, MSD, PeerVoice, Pfizer, Sanofi, Takeda, touchONCOLOGY;Non-Financial Interests, Personal, Member of the Board of Directors: Grifols. S.J. Swanson: Financial Interests, Personal, Speaker's Bureau: Ethicon. F. Tanaka: Financial Interests, Institutional, Research Grant: Boehringer Ingelheim, Chugai, Eli Lilly, Ono, Taiho;Financial Interests, Personal, Other, Consulting fees: AstraZeneca, Chugai, Ono;Financial Interests, Personal, Speaker's Bureau: AstraZeneca, Boehringer Ingelheim, Bristol Myers Squibb, Chugai, Covidien, Eli Lilly, Intuitive, Johnson & Johnson, Kyowa Kirin, MSD, Olympus, Ono, Pfizer, Stryker, Taiho, Takeda. P. Tran: Financial Interests, Personal, Full or part-time Employment: Bristol Myers Squibb;Financial Interests, Personal, Stocks/Shares: Bristol Myers Squibb. N. Hu: Financial Interests, Personal, Full or part-time Employment: Bristol Myers Squibb. J. Cai: Financial Interests, Personal, Full or part-time Employment: Bristol Myers Squibb;Financial Interests, Personal, Stocks/Shares: Bristol Myers Squibb;Financial Interests, Personal, Other, Travel support for attending meetings and travel: Bristol Myers Squibb. J. Bushong: Financial Interests, Personal, Full or part-time Employment: Bristol Myers Squibb;Financial Interests, Personal, Stocks/Shares: Bristol Myers Squibb. J. Neely: Financial Interests, Personal, Full or part-time Employment: Bristol Myers Squibb;Financial Interests, Personal, Stocks/Shares: Bristol Myers Squibb. D. Balli: Financial Interests, Personal, Other, patents planned, issued, or pending: Bristol Myers Squibb;Financial Interests, Personal, Stocks/Shares: Bristol Myers Squibb. S.R. Broderick: Financial Interests, Personal, Advisory Board: AstraZeneca. All other authors have declared no conflicts of interest.Copyright © 2023 International Association for the Study of Lung Cancer. Published by E sevier Inc.

ENDOTHELIAL INFLAMMATION AND DYSFUNCTION INDUCED BY SARS-COV-2 SPIKE PROTEIN 1 INVOLVE ADAM17 AND INTERFERON ACTIVATION PATHWAYS

Objective: COVID19 is associated with vascular inflammation. IFN-alpha (IFNa) and IFN-lambda3 (IFNl3) are potent cytokines produced in viral infections. Their effects involve interferon-stimulated genes (ISGs) and may influence expression of angiotensin-converting enzyme 2 (ACE2), the receptor for S-protein (S1P) of SARS-CoV-2. We hypothesized that S1P-induced immune/inflammatory responses in endothelial cells (EC) are mediated via IFN-activated pathways Design and methods: Human ECs were stimulated with S1P (1 mg/mL), IFNa (100ng/mL) or IFNl3 (100IU/mL). Because ACE2, ADAM17 and TMPRSS2 are important for SARS-CoV-2 infection, we used inhibitors of ADAM17 (marimastat, 3.8 nM), ACE2 (MLN4760, 440pM), and TMPRSS2 (camostat, 50 mM). Gene and protein expression was investigated by real-time PCR and immunoblotting, respectively. Vascular function was assessed in mesenteric arteries from wild-type (WT) normotensive and hypertensive (LinA3) mice and in ISG15-deficient (ISG15KO) mice. Results: S1P increased expression of IFNa (3-fold), IFNl3 (4-fold) and ISGs (2-fold) in EC (p < 0.05). EC responses to IFNa (ISG15: 16-fold) were greater than to IFNl3 (ISG15: 1.7-fold) (p < 0.05). S1P increased gene expression of IL-6 (1.3-fold), TNFa (6.2-fold) and IL-1b (3.3-fold), effects that were amplified by IFNs. Only the ADAM17 inhibitor marimastat inhibited S1P effects. IFNa and IFNl3 increase protein expression of ADAM17 (27%) and TMPRSS2 (38%). No changes were observed on ACE2 expression. This was associated with increased phosphorylation of Stat1 (134%), Stat2 (102%), ERK1/2 (42%). EC production of IL-6 was increased by IFNa (1,230pg/mL) and IFNl3 (1,124pg/mL) vs control (591pg/mL). Nitric oxide generation and eNOS phosphorylation (Ser1177) were reduced by IFNa (40%) and IFNl3 (40%). Vascular functional responses demonstrated that endothelium-dependent vasorelaxation (% Emax) in vessels from WT-mice stimulated with IFNa (67%) and IFNl3 (71%) were reduced vs control (82%) (p < 0.05). Responses were not altered in vessels from ISG15KO mice. Increased contraction was observed only in vessels from hypertensive mice treated with IFNa (9.1 ± 0.5mN vs control: 7.3 ± 0.3mN) (p < 0.05). Conclusions: In ECs, S1P, IFNa and IFNl3 increased ISG15 and IL-6 by mechanisms dependent on ADAM17. IFNs amplifies endothelial cell inflammatory responses and induced vascular dysfunction through ISG15-dependent mechanisms, with augmented effects in hypertension. Our findings demonstrate that S1P induces immune/inflammatory responses that may be important in endotheliitis associated with COVID-19. This may be especially important in the presence of cardiovascular risk factors, including hypertension.

ROLE OF IFNgamma IN PATHOGENESIS OF SARS-CoV-2 INFECTION.

To date, there is no consensus explaining the relationship between varying concentrations of IFNgamma and the severity of infection caused by SARS-CoV-2. The aim of this article was to analyze and formulate conclusions from the selected studies and publications, which, in sum, provide a potentially reasonable view on the role of IFNgamma in COVID-19 pathogenesis. This article highlights current data on the immunological role of IFNgamma which affects differentiation of naive T helper cells, acting as a polarizing factor. It activates the major histocompatibility complex (MHC) class I and II, by increasing the expression of MHC I/II subunits, inhibiting replication of the viral particles by initiating activation of interferon-stimulated genes followed by subsequent synthesis of antiviral proteins. Moreover, IFNgamma activates the production of cytokines by T cells, enhancing cytotoxic activity of the T killers. IFNgamma exerts immunostimulatory and immunomodulatory effects via STAT1, SOCS1 and PIAS genes, thus regulating activation of the JAK-STAT signaling pathway. A number of studies were considered where the patterns of changes in serum IFNgamma concentration were examined in viral infections and SARS-CoV-2. We performed a systemic analysis of the results of studies that showed a relationship between high concentrations of IFNgamma and COVID-19 severity. In a number of studies, the significantly high levels of IFNgamma in COVID-19 patients were often associated with a poor outcome of the disease. The median values of the IFNgamma concentration in severe COVID-19 were found to be significantly higher compared to the results obtained in the cases of moderate severity. It shows an increase, in parallel with viral load in the nasopharyngeal samples upon worsening of the clinical condition. Based on the data on the decreased IFNgamma concentrations in convalescent patients, the mechanism of antagonism between IFNgamma and IL-4 is considered, where the decreases serum concentrations of IFNgamma along with increasing level of IL-4 may be an indirect proof of normal adaptive immune response with subsequent development of antibodies to SARS-CoV-2 and gradual elimination of the virus from the body. Moreover, the evidence is discussed that the patients harboring some parasitic infections (Toxoplasma gondii, Cryptosporidium, Blastocystis hominis, Giardia duodenalis, Entamoeba histolytica) with persistently elevated level of IFNgamma are at reduced risk for severe course of COVID-19. Copyright © 2022, SPb RAACI.

INTERFERON-A MEDIATED THERAPEUTIC RESISTANCE in EARLY RA IMPLICATES EPIGENETIC REPROGRAMMING

Background: An interferon gene signature (IGS) is present in approximately 50% of early, treatment naive rheumatoid arthritis (eRA) patients. We previously demonstrated it negatively impacts on initial disease outcomes. Objectives: To 1) reproduce previous fndings demonstrating the harmful effects of the IGS on early RA clinical outcomes, 2) identify which IFN class is responsible for the IGS and 3) seek evidence that IFN-a exposure contributes to harmful epigenetic footprint at disease onset. Methods: In a large multicentre inception cohort (n=190) of eRA patients (RA-MAP TACERA) whole blood transcriptome, IGS (MxA, IFI44L, OAS1, ISG15, IFI6) and circulating interferons (IFN)-a,-β,-y and-), was examined at baseline and 6 months in conjunction with disease activity and clinical characteristics. A separate eRA cohort of paired methylome and transcriptome from CD4 T and CD19 B cells (n=41 for each) was used to explore any epigenetic influence of the IGS. Results: The baseline IGS reproducibly and signifcantly negatively impacts on 6-month clinical outcomes. In the high IGS cohort there was increased DAS-28 (p=0.025) and reduced probability of achieving a good EULAR response (p=0.034) at 6-months. In addition, the IGS in eRA is shown for the frst time to predominantly refect raised circulating IFN-a protein, not other classes of IFN and examination of whole blood upstream nucleic acid sensors expression suggest a RNA trigger. Both the IGS and IFN-a signifcantly fell in parallel at 6 months (p<0.0001), whereas other classes of IFN remained statistically static. There was a signifcant association with IFN-a and RF titre but not ACPA. Comparison of CD4 T and CD19 B cells between IGS high and low eRA patients demonstrated differentially methylated CPG sites and altered transcript expression of disease relevant genes e.g. PARP9, STAT1, EPTSI1 which was similarly, and persistently altered 6 months in the separate TACERA cohort. Differentially methylated CPGs implicated altered transcription factor binding in B cells (GATA3, ETSI, NFATC2, EZH2) and T cells (p300, HIF1a) which cumulatively suggested IFN-a induced epigenetic changes promoting increased, and sustained, lymphocyte activation, proliferation and loss of anergy in the IGS high cohort. Conclusion: We validate that the IGS is a robust prognostic biomarker in eRA predicting poor therapeutic response. Its persistent harmful effects may be driven via epigenetic modifcations. These data have relevance for other IFN-a states, such as COVID-19, but also provide a rationale for the initial therapeutic targeting of IFN-a signalling, such as with JAKi, at disease onset in stratifed eRA subsets.

Mechanisms of action (MOA) for proxalutamide, an androgen receptor (AR) antagonist, for the treatment of mild, moderate and severe COVID-19 patients

As of November 2021, there were 21 million confirmed active cases of COVID-19, including 77,016 patients in serious or critical condition (virusncov.com). However, there are no effective oral drugs for the treatment of severe COVID 19 patients. We here discuss the mechanism of action for Proxalutaminde to treat mild, moderate and severe COVID-19 Patients. Cellular entry and infection of SARS-CoV-2 virus are mediated by two key proteins in host cells, angiotensin converting enzyme 2 (ACE2), a host transmembrane protein, providing the binding sites for SARS-CoV-2 on the host cell surface, and transmembrane protease serine 2 protein (TMPRSS2), priming the S protein of SARS-Cov-2 to facilitate the viral entry into the host cells. Both ACE2 and TMPRSS2 proteins are regulated by androgen receptor (AR) signaling. Previously, Proxalutamide has been reported to downregulate the expression of ACE2 and TMPRSS2 in cells derived from prostate, lung cancer and normal lung epithelial cells. In this study, we demonstrate that Proxalutamide inhibited the infection of SARS-COV-2 wild type, alpha and delta variants, with IC50s of 69, 48 and 39 nM, respectively. Moreover, Proxalutamide reduced SARS-COV-2 viral load in outpatients with COVID-19 (82% viral RT-PCR negative rate in active group vs. 31% in placebo group after treatment for 7 days (p-value<0.0001). Severe COVID-19 disease leads to cytokine storm resulting in pulmonary inflammation and extensive damage in lung and other organs. Anti-inflammatory drugs, including Baricitinib and dexamethasone, have shown limited clinical benefit for hospitalized COVID-19 patients. Therefore, more effective drugs are in urgent need for patients suffering from severe COVID-19. Recently, Proxalutamide has been reported to reduce the mortality rate (HR=0.16) and lung injury (by 57%, active drug vs placebo groups) in hospitalized patients with COVID-19 in an IIT phase III study. We presented here the mechanism of action of Proxalutamide for targeting cytokine storm in severe COVID-19 patients. Proxalutamide was demonstrated to activate nuclear factor erythroid 2-related factor 2 (Nrf2) in macrophages, which stimulates the antioxidant response element (ARE) for reducing cytokine storm-induced organ damage in COVID-19. In addition, Proxalutamide inhibited TNF alpha and IL-6 expression and blocked INF gamma signaling by downregulating STAT1 expression in immune cells. Importantly, Proxalutamide reduced inflammatory cells in lungs in a Poly (I:C), pseudoviral induced-lung injury animal models. Further, Proxalutamide decreased C-reactive protein, D-Dimer and improved lymphocyte count, biomarkers for COVID-19 progression in clinical studies. Together, these results provide a strong rationale for the treatment of severe COVID-19 patients with Proxalutamide.

Studies on the Role of SARS-CoV-2 Nucleocapsid as an Interferon Antagonist

Introduction: The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV2), responsible for the coronavirus disease 2019 (COVID-19) pandemic, has resulted in significantly disruptive global impacts. Cytokine storm syndrome (CSS) can accompany SARSCoV2 infection, and involves the excessive release of pro-inflammatory cytokines that lead to acute respiratory distress syndrome (ARDS) in infected patients. Given the correlation between ARDS and poor patient prognosis, inflammatory pathways (e.g., interferon-1 (IFN-1)) would be a target area for antiviral development. Our preliminary results have demonstrated a direct correlation between the SARS-CoV-2 nucleocapsid (N) protein and host intracellular IFN-1 pathway components IRF3 and STAT1. Methods: A549 cells were transfected with pCMV-GFP vectors expressing N protein and harvested. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western Blotting were performed. The membranes were then incubated with STAT-1, p-STAT1 and IRF3 antibodies and visualised. Protein content was quantified using ImageJ software. Results: Transfection with SARS-CoV-2 N was correlated with a decrease in intracellular IRF3 and reduced phosphorylation of STAT1, suggesting the involvement of N protein in the delayed IFN-1 response commonly observed in SARS-CoV-2 patients. These findings suggest that IRF3 and STAT1 may be part of the innate immune response affected by SARS-CoV-2 infection. Conclusion: Our results show that IRF3 and STAT1 are responsible for stimulating transcription of interferon signalling genes (ISGs). Future studies on SARS-CoV-2 N and its downstream effectors could provide further insight into the IFN-1 response during infection, and assist in future antiviral development strategies.

IMMUNE DYSREGULATION INDUCED BY SPIKE PROTEIN 1 OF SARS-COV-2 INCREASES ENDOTHELIAL CELL DYSFUNCTION VIA TYPE I AND TYPE III INTERFERON ACTIVATION PATHWAYS

Objective: COVID19-associated immunopathology is associated with increased production of interferon (IFN)-alpha (IFNα) and lambda3 (IFNL3). Effects of IFNs are mediated by interferon-stimulated genes (ISGs) and influence expression of angiotensin-converting enzyme 2 (ACE2), the receptor for S-protein (S1P) of SARS-CoV-2. Increasing evidence indicates vascular inflammation in cardiovascular sequelae of COVID19. We hypothesized that S1P-induced immune/inflammatory responses in endothelial cells (EC) are mediated via IFNα and IFNL3. Design and method: Human ECs were stimulated with S1P (1 μg/mL), IFNα (100ng/mL) or IFNL3 (100IU/mL). Because ACE2, metalloproteinase domain-17 (ADAM17) and type-II transmembrane serine protease (TMPRSS2) are important for SARS-CoV-2 infection, cells were treated with inhibitors of ADAM17 (marimastat, 3.8 nM), ACE2 (MLN4760, 440pM), and TMPRSS2 (camostat, 50 μM). Gene and protein expression was investigated by real-time PCR immunoblotting, respectively. Vascular function was assessed in mesenteric arteries from wild-type (WT) normotensive and hypertensive mice and in ISG15-deficient (ISG15KO) mice. Results: EC stimulated with S1P increased expression of IFNα (3-fold), IFNL3 (4-fold) and ISG (2-fold)(p < 0.05). EC exhibited higher responses to IFNα (ISG15: 16-fold) than to IFNL3 (ISG15: 1.7-fold)(p < 0.05). S1P increased gene expression of IL-6 (1.3-fold), TNFα (6.2-fold) and IL-1β (3.3-fold), effects that were maximized by IFNs. Only marimastat inhibited S1P effects. IL-6 was increased by IFNα (1,230pg/mL) and IFNL3 (1,124pg/mL) vs control (591pg/ mL). This was associated with increased phosphorylation of Stat1 (134%), Stat2 (102%), ERK1/2 (42%). Nitric oxide production and eNOS phosphorylation (Ser1177) were reduced by IFNα and (40%) and IFNL3 (40%). Reduced endothelium relaxation maximal response (%Emax) was observed in vessels from WTmice stimulated with IFNα (67%) and IFNL3 (71%) vs control (82%)(p < 0.05) but not in vessels from ISG15KO mice. Increased contraction was observed only in vessels from hypertensive mice treated with IFNα (9.1 ± 0.5mN vs control: 7.3 ± 0.3mN, p < 0.05). Conclusions: In ECs, S1P, IFNα and IFNL3 increased ISG15 and IL-6, processes that involve ADAM17. Inflammation induced by S1P was amplified by IFNs. IFNs induce vascular dysfunction through ISG15-dependent mechanisms, with augmented effects in hypertension. Our findings demonstrate that S1P induces immune/inflammatory responses that may be important in endotheliitis associated with COVID-19. This is especially important in the presence of cardiovascular risk factors, including hypertension.

Impact of Influenza Virus and E-cigarette Vaping Pre-Exposures on Outcomes of SARS-CoV-2 Infection in Hamster

Rationale. Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is the third leading cause of death in the United States. While many risk factors for severe COVID-19 are emerging, the effects by which other inhalational exposures affect susceptibility are not well defined. Patients with COVID-19 demonstrate high rates of co-infection with respiratory viruses, including influenza A (IAV). When infected with IAV, human small airway epithelial cells (SAEC) exhibit increased abundance of angiotensin-converting enzyme 2 (ACE2), the primary receptor for SARS-CoV-2. However, it remains unknown if this effect increases the risk for COVID-19. Similarly, there are conflicting reports of the effect of e-cigarette (E-cig) vaping on COVID-19 manifestations. We hypothesized that exposures to IAV or E-cig increase the severity of SARS-CoV-2 infection. Methods. Golden Syrian hamsters (male and female) were exposed to E-cig vapor via nebulization for 5d. IAV was administered intranasally once on day 6 (A/California/07/2009 H1N1, 106 PFU/hamster). On day 3 post-IAV infection, SARSCoV- 2 was administered intranasally (WA01;104 PFU/hamster). On day 7 post-SARS-CoV-2 infection animals were sacrificed, bronchoalveolar lavage fluid (BALF) cell differentials were obtained, and inflated lung sections were stained and scored for immunohistology. Lung RNA was quantified for ACE2, TMPRSS2, STAT1, CXCL10, IFN-gamma, gene expression using RT-qPCR. Results: SARS-CoV-2 infection caused progressive weight loss that was less pronounced in animals pre-infected with IAV. SARS-CoV-2 titers from nasal swabs peaked at day 2 in both groups. IAV pre-infection reduced PMN and eosinophils in the BALF, and the overall inflammatory cell infiltration in the lung parenchyma of SARS-CoV-2-infected animals. IAV pre-infection reduced lung levels of STAT1, CXCL10 (2.5-fold;p<0.01), CCL5, and IFN-gamma in SARS-CoV-2-infected animals compared to animals that were only infected with SARS-CoV-2. Pre-exposure to E-cig worsened the SARS-CoV-2-induced weight loss in female animals only. E-cig pre-exposure increased lymphocytes and decreased PMN and eosinophils in the BALF compared to animals that were only infected with SARS-CoV-2. E-cig pre-exposure increased lung levels of STAT1, CXCL10 (2.5-fold;p<0.05), CCL5, and IFN-gamma in SARS-CoV-2-infected animals compared to animals that were only infected with SARS-CoV-2. Conclusion: Pre-infection with IAV resulted in decreased inflammatory response to SARS-CoV-2 infection. In contrast, pre-exposure to E-cig vaping increased the severity of the inflammatory response to SARS-CoV-2 with notable differences between sexes. Whereas anti-viral priming effects of prior viral infection are well described, the mechanisms that explain the worsening effects of E-cig on SARS-CoV-2 outcomes remain unknown.

Brain borders take center stage: role of meningeal macrophages in neuroinfection

The surface of the central nervous system (CNS) is seeded by two meningeal macrophage (MM) populations: MHC-II- MM which are abundant neonatally and MHC-II+ MM which appear over time. Using histocytometry, flow cytometry, and single-cell RNA sequencing approaches, we show that those two barrier macrophage populations have different behaviors in response to in vivo peripheral challenges such as LPS, SARS-CoV-2 and lymphocytic choriomeningitis virus (LCMV). Focusing on LCMV peripheral infection, we found that in mice with Stat1- or Ifnar-deficient macrophages, the virus readily spread into the CNS. Unexpectedly, the post-natal MHC-II+ MM population efficiently blocked intrinsic viral replication and promoted a broad antiviral state in the meninges. Using innovative genetic and pharmacological depletion strategies, we show that in the absence of MM, specific areas of the meninges became highly infected, leading to fatal brain disease. Thus, MM represent a major line of protection against neuroinfection.

TGF-Β2 IS ASSOCIATED with ASYMPTOMATIC/MILD SARS-CoV-2 INFECTION during PREGNANCY

Background: COVID-19 has been a devastating disease and a major public health concern mainly to susceptible populations. Methods: We accessed two groups of pregnant women at the time of delivery: SARS-CoV2 active infection and convalescents. To investigate the factors contributing to COVID19 severity we have assessed several immunological parameters including cytokines/chemokine levels in the maternal and cord blood plasma. We have evaluated 33 cytokines. Our findings were validated in vitro in HTBE (Human tracheobronchial epithelial) cells infected with live SARS-COV2 (wild type). Results: Our cohort was enriched in high-risk subjects, including African American and obese women. Only 6% had severe or critical disease, contrasting with the 20-25% reported in some pregnant cohorts. TGFb2 levels were significantly associated with asymptomatic/mild disease in both active and convalescent cohorts, and inversely correlated with IP10, IL6 and IL8, known to be part of the cytokine storm post-infection. Pre-treatment of HTBE with TGFb2 for 48 hours led to a significant decay in viral loads at 72h post-infection. This control was associated with significantly higher IL-6 (IFNb2) levels prior to infection, and significantly higher expression of anti-viral genes at 72h pi (MX1, IFNA1, IFNA2, IFNL1, STAT1). Additionally, TGFb2 pre-treatment suppressed the expression of the cytokines IP-10, IL1b and IL8. Conclusion: Altogether this data suggested that TGFB2 plays a protective role in SARS-COV2 infection in this high-risk population by improving epithelial cells intrinsic antiviral function and by modulating the expression of the cytokines associated to the heightened inflammation in severe cases.

DIFFERENTIALLY EXPRESSED IMMUNOLOGICAL GENES in MILD and SEVERE CASES of COVID-19

Background: Coronavirus disease 2019 (COVID19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has varied clinical presentations from mild subclinical to severe disease with high mortality. Our aim was to determine whether examining immune-related gene expression early in infection could predict progression to severe disease. Methods: In subjects of the All Ireland Infectious Diseases Cohort study, we analysed expression of 579 genes with the NanoString nCounter Immunology panel in peripheral blood mononuclear cells in those with confirmed SARS-CoV-2 infection collected within 5 days of symptom onset and matched SARS-CoV-2 negative controls with respiratory infection. Subsequent maximum COVID19 disease severity was classified as mild or severe. Read counts were normalized using panel housekeeping genes. Expression changes in severity groups were estimated against control baseline. Results: Between April and July of 2020, we recruited 120 subjects, 62 with COVID19 and 58 controls, with average age 59 y.o. (IQR 34-88), 66% males and 69% Caucasian ethnicity. Maximal disease severity was used to separate COVID19 cases into mild (n=31) and severe (n=31). We identified 20 significantly deregulated genes between those with COVID19 and controls (;log2 fold;>0.5, p<0.05, Benjamin-Yekutieli p-adjustment). Function of 12 of these genes related to cytokine signaling, 9 upregulated genes to type I interferon signaling (MX1, IRF7, IFITM1, IFI35, STAT2, IRF4, PML, BST2, STAT1), while 7 downregulated genes mapped to innate immune function (IRF7, ICAM2, SERPING1, IFI16, BST2, FCER1A, PTK2). Expression in the severe group showed downregulation of FCER1A (innate immunity regulation), IL1B and TNF (inflammatory cytokines), and PTGS2 (inflammatory mediator) and greater upregulation of TNFSF4 (cytokine signaling) and PTK2 (innate immunity). Mild cases presented higher upregulation of IFIT2 (type I interferon signaling). Conclusion: Observed early downregulation of regulators and mediators of inflammation in those who developed severe COVID19, suggested dysregulation of inflammation. Specifically, IFIT2 upregulation in mild cases and FCER1A downregulation in severe cases, points to early differences in host responses centered on deregulation of the interferon and inflammation responses. Whether these patterns reflect delayed interferon involvement in pathways to control the infection and contribute to pathological inflammation and cytokine storms observed in severe COVID19 requires further research.

SOCS1 Haploinsufficiency Presenting As Incidental Refractory Thrombocytopenia in a Pediatric Patient with Inflammatory Symptoms and History of Sars Cov-2 Infection

BACKGROUND: Immune thrombocytopenia purpura (ITP) has a complex pathogenesis and may be a primary diagnosis or secondary to an underlying condition 1. Evaluation for underlying diagnoses in patients presenting with atypical features of classic ITP is key, as this can impact treatment decisions, therapy response, and prognosis. Genetic variants that predispose patients to ITP are especially important to investigate as patients may be at risk for additional autoimmune phenomenon or malignancy. The SARS CoV-2 pandemic has added further complexity as reports suggest the infection can lead to autoimmunity in those with genetic predispositions 2,3. Loss of the suppressor of cytokine signaling 1 (SOCS1) function has been described to manifest with autoinflammatory syndrome, with or without immunodeficiency 4,5. Reports of autoimmunity developing in patients with SOCS1 haploinsufficiency after SARS CoV-2 infection are documented, including multi-system inflammatory syndrome (MIS-C) 2. A proposed mechanism of this virus-triggered autoimmunity includes a transient innate and adaptive immunodeficiency 3. This raises the question whether patients harboring genetic variants with risk of autoimmunity are placed at an even higher risk for ITP in the wake of SARS-CoV2 infection. CASE PRESENTATION: We present a 6-year-old female with isolated thrombocytopenia of 4,000/uL identified during evaluation for severe arthralgias unresponsive to corticosteroid treatment (maximum dose 1mg/kg/day) over a 6-month period. Laboratory results at presentation were consistent with ITP, including presence of platelet autoantibodies. Evaluation revealed hypocellularity for age (~50%) on bone marrow evaluation as well as elevated IgE (2080 kU/L), with IgA, IgM, and IgG levels within reference range. She had a remote history of SARS CoV-2-like illness and SARS CoV-2 antibodies were found present in serologic assay, without a history of vaccination. Genetic testing, including chromosomal microarray from peripheral blood and marrow, was included in the diagnostic workup given concern for a history of developmental delays with macrocephaly and necessity to rule-out malignancy with the patient noted to have a 5 mega-base deletion at 16p13.2p13.11, which includes the SOCS1 gene. Comprehensive next generation sequencing for additional immune dysregulation/primary immunodeficiency associated variants was unremarkable. Functional studies of surface expression of interferon-inducible genes (CD169 (SIGLEC-1)) and STAT1 phosphorylation via analysis of CD14+ monocytes revealed excess interferon signaling previously described in patients with SOCS1 haploinsufficiency (Figure 1). Measurements of B-cell-activating factor were also found to be extremely elevated at 6432 pg/mL. The patient's ITP course was complicated by hematuria, melena and refractory platelet response to first line therapy consisting of intravenous immunoglobulin 1 g/kg x2 doses and 2 mg/kg/day prednisolone. She required escalation to high dose methylprednisolone (30mg/kg), rituximab 375 mg/m 2/weekly x4 doses, and concurrent romiplostim (2 doses) for control of thrombocytopenia and bleeding manifestations. Her rheumatologic symptoms subsided with initiation of corticosteroids, and she has subsequently completed a prolonged corticosteroid taper. She currently has a normal platelet count with non-steroidal anti-inflammatory therapy utilized for arthralgia management with plan to transition to JAK inhibition for maintenance therapy. CONCLUSION: This case highlights the potential impact of investigating for susceptibility genes for ITP with consideration for broader testing including targeted next generation sequencing panels or microarray analysis in patients with atypical ITP presentations or response to therapy, as knowledge of this patient's underlying genetics led to earlier treatment and use of alternative agents. Additionally, the case adds the novel finding of bone marrow hypocellularity to the clinical phenotype of SOCS1 haploinsufficiency, as this has not yet been reported and contributes to the literature on the relationship of autoimmunity and SARS CoV-2 infections in patients with predisposing genetic variants. [Formula presented] Disclosures: Walkovich: Horizon Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees;Pharming: Honoraria, Membership on an entity's Board of Directors or advisory committees;Swedish Orphan Biovitrum AB (Sobi): Consultancy, Honoraria;X4 Pharmaceuticals: Other: Local PI for clinical trial involving mavorixafor and patients with neutropenia.

Whole exome sequencing of MIS-C patients: Analysis of genes involved in inborn errors of type I IFN immunity, hemophagocytic lymphohistiocytosis (HLH), Kawasaki disease (KD) and TLR7 gene

Introduction: After spring 2020, a series of reports from Europe and USA described clusters of children, presenting life-threatening multisystem inflammatory syndrome in children (MIS-C), associated with antecedent exposure to SARS-CoV-2 (1). In patients with life threatening COVID-19 3.5% were found to have inborn errors in type I IFN signalling pathway (2). A case series of 4 young patients with severe COVID-19 reported rare loss-of-function variants in the TLR7 gene associated with impaired type I IFN responses (3). Clinically, MIS-C shares features with secondary hemophagocytic lymphohistiocytosis (HLH) and Kawasaki disease (KD), which were also associated with possible infectious trigger and might share a common genetic cause (4). Objectives: We analysed whether MIS-C patients have an underlying presence of genetic variants in exomes associated with inborn errors of type I IFN immunity, HLH, KD and presence of variants in TLR7 gene. Methods: Blood was drawn from 17 MIS-C patients upon submission into the hospital, DNA from peripheral blood was isolated and whole exome sequencing was performed. Variants in the following genes were investigated: type I IFN immunity (TLR3, UNC93B1, TRAF3, TBK1, IRF3/9, IRF7, IFNAR1/2, STAT1/2, IKBKG, TRIF), HLH (AP3B1, CD27, FADD, FAS, FASLG, HPLH1, ITK, LYST, MAGT1, MYO5A, NLRC4, PRF1, RAB27A, RECQL4, SH2D1A, STX11, STXBP2, UNC13D, XIAP, TNFRSF9, CDC42), KD (ITPKC, CD40, FCGR2A, BLK, CASP3, TRX-CAT1-7, PGBD1, LTA, TSBP1, HLA-DQB1/2, HLA-DOB, IGHV1-69) and TLR7 genes. Analysis was focused on rare (GnomAD<0.01) exonic or splicing variants. Results: No common genetic denominators were found in analysed genes. Five rare variants were observed in four patients (4/17). According to ACMG classification variants of uncertain significance (VUS) were found in LYST (2), IKBKG (1), IRF3 (1) and NLRC4 (1) in heterozygous genotype. No clinical evidence was found in ClinVar database for any of the variants, except for one variant in LYST (c.3931A>G:p.M1311V) with uncertain significance for Chédiak-Higashi syndrome and medium prediction scores. Variants in LYST (c.5990C>G:p.A1997G), NLRC4 (c.772T>C:p.C258R) and IRF3 (c.325G>C: p.G109R) have high CADD, Mutation Taster, Polyphen and SIFT prediction scores. And IKBKG (c.325C>G:p.L109V) variant had medium prediction scores. Conclusion: Our findings suggest that MIS-C patients do not share a rare loss-of-function variant in type I IFN immunity genes, TLR7 gene or genes associated either with HLH or KD. Despite numerous clinical, immunological and genetic research of the MIS-C patients, the syndromes pathogenesis and etiologic cause remain elusive.

PASC, reinfections and variants: COVID-19 in patients with inborn errors of immunity in São paulo-Brazil

Background: Inborn Errors of Immunity (IEI) are a heterogeneous group of diseases which immune defect may be related to a complications by COVID 19. Although there are few studies on the evolution and the real clinical impact of infection by SARS-CoV 2 in this group of patients. The aim of the study was to describe the clinical evolution of COVID-19 in patients with different IEI, in a reference center in Brazil. Method: Retrospective and longitudinal study, with analysis of electronic medical charts of patients with IEI and diagnosis of suspected/ confirmed COVID-19 from March 2020 until now. Results: Eighteen patients (61% male), with a median age of 26.6 years (range 12,3-53,4 y), were included in the study. Four X-linked agammaglobulinemia (XLA), 7 common variable immunodeficiency (CVID), 1 specific antibody deficiency, one Good Syndrome-GS, 2 STAT1-GOF, 2 MSMD and one AT. Ten patients (55,5%) had mild flu syndrome and only one patient was asymptomatic. Hospitalization was necessary for 7 patients (38,8%) due to respiratory complications and 3 (16.6%) deceased (2 XLA and 1 GS). Two patients were reinfected (STAT1-GOF and MSMD), with no need for hospitalizations or long-term complications. One of the XLA patients remains hospitalized, with fever for more than 90 days. Five patients experience coughing and tiredness after more than three months of the disease, one also persists with anosmia. Conclusion: Almost 40% of our sample required hospitalization and 16% died. This rate is worrying and reveals how much immunological competence is required by SARS-CoV-2 as well as the fact that Brazil has increasing death rates from COVID-19. Post-acute COVID-19 syndrome (PASC) has presented in more than 25% of IEI patients infected with SARS-CoV-2.