Seroprevalence of SARS-CoV-2 antibodies in patients with autoimmune inflammatory rheumatic diseases.

OBJECTIVES: To assess the prevalence of anti-SARS-CoV-2 antibodies in autoimmune inflammatory rheumatic disease (AIIRD) patients, and to define clinical factors associated with seropositivity. METHODS: A cross sectional study was conducted at a tertiary rheumatology department in Israel. Consecutive patients completed a questionnaire and were tested for SARS-CoV-2 anti-nucleoprotein IgG (N-IgG). If this was positive, an anti-S1/S2 spike IgG (S-IgG) test was done. If both were positive, the patient was considered seropositive. Seropositive patients were retested after 3 months. RESULTS: The study included 572 AIIRD patients. Thirty patients were found seropositive, for a seroprevalence of 5.24%. The seropositive rate was significantly lower for patients treated with immunosuppressive medications (3.55%, p≤0.01), and specifically for patients treated with biologic disease-modifying anti-rheumatic drugs (bDMARDs) (2.7%, p≤0.05). These associations remained significant in the multivariate regressions adjusting for age, sex and exposure to a known COVID-19 patient. A second serology test 3 months later was collected in 21 of the 30 seropositive patients. In a mean±standard deviation (SD) of 166.63±40.76 days between PCR and second serology, 85% were still positive for N-IgG, and 100% were still positive for S-IgG, with a higher mean±SD titre compared to the first S-IgG (166.77±108.77 vs. 132.44±91.18, respectively, p≤0.05). CONCLUSIONS: Humoral response to SARS-CoV-2 in AIIRD patients may be affected be immunosuppressive treatment, especially bDMARDs. In patients with AIIRD, titres of SARS-CoV-2 IgG antibodies, especially N-IgG antibodies, fade with time, while S-IgG antibodies persist.

Predictors of Immunogenic Response to the BNT162b2 mRNA COVID-19 Vaccination in Patients with Autoimmune Inflammatory Rheumatic Diseases Treated with Rituximab.

Treatment with rituximab (RTX) blunts SARS-CoV-2 vaccination-induced humoral response. We sought to identify predictors of a positive immunogenic response to the BNT162b2 mRNA vaccine in patients with autoimmune inflammatory rheumatic diseases (AIIRD) treated with RTX (AIIRD-RTX). We analyzed 108 AIIRD-RTX patients and 122 immunocompetent controls vaccinated with BNT162b2 mRNA participating in a multicenter vaccination study. Immunogenicity was defined by positive anti-SARS-CoV-2 S1/S2 IgG. We used a stepwise backward multiple logistic regression to identify predicting factors for a positive immunogenic response to vaccination and develop a predicting calculator, further validated in an independent cohort of AIIRD-RTX BNT162b2 mRNA vaccinated patients (n = 48). AIIRD-RTX patients who mounted a seropositive immunogenic response significantly differed from patients who did not by a lower number of RTX courses (median (range) 3 (1-10) vs. 5 (1-15), p = 0.007; lower cumulative RTX dose (mean ± SD) 6943.11 ± 5975.74 vs. 9780.95 ± 7240.12 mg, p = 0.033; higher IgG level prior to last RTX course (mean ± SD), 1189.78 ± 576.28 vs. 884.33 ± 302.31 mg/dL, p = 0.002), and extended interval between RTX treatment and vaccination, 469.82 ± 570.39 vs. 162.08 ± 160.12 days, p = 0.0009, respectively. Patients with ANCA-associated vasculitis and inflammatory myositis had a low likelihood of a seropositive immunogenic response compared to patients with rheumatoid arthritis, odds ratio (OR) 0.209, 95% confidence interval (CI) 0.046-0.96, p = 0.044 and OR 0.189, 95% CI 0.036-0.987, p = 0.048, respectively. Based on these findings, we constructed a calculator predicting the probability of a seropositive immunogenic response following BNT162b2 mRNA vaccination which performed with 90.5% sensitivity, 59.3% specificity, and 63.3% positive and 88.9% negative predictive values. In summary, the predicting calculator could guide clinicians for optimal timing of BNT162b2 mRNA vaccination in AIIRD-RTX patients.

Immunogenicity and safety of the BNT162b2 mRNA COVID-19 vaccine in adult patients with autoimmune inflammatory rheumatic diseases and in the general population: a multicentre study.

INTRODUCTION: Vaccination represents a cornerstone in mastering the COVID-19 pandemic. Data on immunogenicity and safety of messenger RNA (mRNA) vaccines in patients with autoimmune inflammatory rheumatic diseases (AIIRD) are limited. METHODS: A multicentre observational study evaluated the immunogenicity and safety of the two-dose regimen BNT162b2 mRNA vaccine in adult patients with AIIRD (n=686) compared with the general population (n=121). Serum IgG antibody levels against SARS-CoV-2 spike S1/S2 proteins were measured 2-6 weeks after the second vaccine dose. Seropositivity was defined as IgG ≥15 binding antibody units (BAU)/mL. Vaccination efficacy, safety, and disease activity were assessed within 6 weeks after the second vaccine dose. RESULTS: Following vaccination, the seropositivity rate and S1/S2 IgG levels were significantly lower among patients with AIIRD versus controls (86% (n=590) vs 100%, p<0.0001 and 132.9±91.7 vs 218.6±82.06 BAU/mL, p<0.0001, respectively). Risk factors for reduced immunogenicity included older age and treatment with glucocorticoids, rituximab, mycophenolate mofetil (MMF), and abatacept. Rituximab was the main cause of a seronegative response (39% seropositivity). There were no postvaccination symptomatic cases of COVID-19 among patients with AIIRD and one mild case in the control group. Major adverse events in patients with AIIRD included death (n=2) several weeks after the second vaccine dose, non-disseminated herpes zoster (n=6), uveitis (n=2), and pericarditis (n=1). Postvaccination disease activity remained stable in the majority of patients. CONCLUSION: mRNA BNTb262 vaccine was immunogenic in the majority of patients with AIIRD, with an acceptable safety profile. Treatment with glucocorticoids, rituximab, MMF, and abatacept was associated with a significantly reduced BNT162b2-induced immunogenicity.

Prevalence of COVID-19 and seroprevalence to SARS-CoV-2 in a rheumatologic patient population from a tertiary referral clinic in Israel.

BACKGROUND: It is unclear if the prevalence of COVID-19 in rheumatologic patients is similar to that of the general population. There are no reports of seroprevalence of SARS-CoV-2 in these patients. AIMS: To investigate prevalence of COVID-19 cases and seroprevalence among rheumatologic patients and the risk factors for infection. METHODS: A cross-sectional study in a rheumatologic population. An online questionnaire was sent on 31 April 2020. Blood samples from 20% sample of patients were drawn for SARS-CoV-2 antibodies. Patients were divided based on autoimmune (AI) diagnosis. Prevalence of COVID-19 by nasopharyngeal swab and by serology (seroprevalence) was compared to national data. Risk factors for infection of SARS-CoV-2 were assessed. RESULTS: The study group included 1204 patients, 74.5% had an AI diagnosis. The prevalence of COVID-19 was 0.16% in the rheumatologic patient population and 0.22% in the AI group, which was not different from prevalence in Israel on 4 May 2020 (0.18%, P = 0.912 and P = 0.759 respectively). Serologic tests were performed in 242 patients, of which five were found positive pointing to a seroprevalence of 2.07%. Exposure to a known COVID-19 patient was the only significant risk factor for being positive by swab or by serology. AI diagnosis, immunosuppression, corticosteroid, hydroxychloroquine did not influence the risk. CONCLUSIONS: The prevalence of COVID-19 in a population of rheumatologic patients was similar to that of the general population. Mild/asymptomatic cases may be prevalent according to serologic tests. The major risk factor for infection is exposure to a known case of COVID-19, and immunosuppression did not play a role in the risk of infection.