POS1206 SEROPREVALENCE OF SARS-CoV-2 ANTIBODIES IN AUTOIMMUNE INFLAMMATORY RHEUMATOLOGIC PATIENTS
Authors: T. Eviatar, D. Levartovsky, V. Furer, A. Polachek, O. Elalouf, M. Zisapel, T. Halperin, D. Turner, D. Paran, S. Pel, S. Nevo, O. Elkayam
Journal: Annals of the Rheumatic Diseases (2021)

Background: Immune responses in AIIRD patients may be reduced and influenced by immunosuppressive treatments[1].The effect of immunosuppression on the mounting of SARS-CoV-2 antibodies in AIIRD is not clear. Objectives: To assess the prevalence of SARS-CoV-2 antibodies in AIIRD patients and to define clinical factors affecting this prevalence. Methods: Consecutive consenting AIIRD patients from the Rheumatologic department in Tel Aviv Medical Center participated in the study. Patients answered a questionnaire and were tested for SARS-CoV-2 antibodies. A two stage antibody testing was done in order to increase specificity. Results: The study included 560 AIIRD patients (229 RA, 149 PsA, 84 SLE, 55 vasculitidies, 40 SpA, 3 other CTD), of them 26 patients were found to have SARS-CoV-2 IgG antibodies (4.6%) (Table 1). This was more than double than a previous prevalence in the same clinic population studied after the first wave of the pandemic in Israel, which was 2.07% (accepted for publication). A lower rate of immunosuppression was found for positive SARS-CoV-2 IgG patients compared to negative serology patients (Table 1, p =0.009). There was also a trend for the subgroup of patients on biologic DMARDS (26.92% vs. 47% respectively, p=0.06). Positive SARS-CoV-2 PCR test was reported and confirmed in 36 patients, of them 14 (38.89%) had negative serology. Patients who did not have antibodies had numerically more than double rates of glucocorticoids and bDMARDs treatment. The time between positive PCR test to positive serology test was significantly shorter (mean±standart deviation 75.57±40.44 days) than the time between positive PCR to negative serology test (130.79±86.47 ( p =0.04) (Table 1 and Figure 1) suggesting a fading of the antibody response with time. Conclusion: The prevalence of SARS-CoV-2 IgG was 4.6% in a population of AIIRD patients from a single tertiary medical center in Israel. SARS-CoV-2 seroprevalence tended to be low among AIIRD patients on immunosuppressive treatment, including in patients with a confirmed history of positive SARS-CoV-2 PCR, similar to other studies [3]. As in individuals without AIIRD, the mounting of SARS-CoV-2 IgG seems to fade with time. Larger studies are needed to confirm the potential effect of immunosuppression on the antibody response in AIIRDs. Table 1. Demographic and clinical characteristics of patients with negative and positive SARS-CoV-2 IgG, and in the subgroup with positive SARS-CoV-2 PCR test Total population ( n =560 ) Positive PCR population ( n =36 ) Negative IgG( n =534 ) Positive IgG( n =26 ) P Negative IgG( n =14 ) Positive IgG( n =22 ) P Female n (%) 360 (67.42) 22 (84.62) 0.08 10 (71.43) 18 (81.82) 0.68 Age median (95% CI) 57 (54.95-57.58) 52.5 (46.55-58.6) 0.23 42 (35.46-53.11) 52.5 (47.62-60.65) 0.06 No. of comorbidities mean±STD (95%CI) 0.88±1.15 (0.78-0.98) 0.92±1.2 (0.44-1.41) 0.86 0.79±1.12 (0.14-1.43) 0.96±1.3 (0.4-1.51) 0.68 AIIRD treatments n(%) Total immunosuppression 401 (75.09) 13 (50) 0.009 11 (78.57) 12 (54.54) 0.175 GC 113 (21.16) 3 (11.54) 0.32 5 (35.71) 3 (13.64) 0.32 csDMARDS 257 (48.13) 13 (50) 1 7 (50) 13 (59.09) 0.73 bDMARDS 251 (47) 7 (26.92) 0.06 9 (64.29) 7 (31.82) 0.09 Anti CD-20 36 (6.74) 0 0.4 1 (7.14) 0 0.39 SARS-CoV-2, severe acute respiratory syndrome-coronavirus-2; IgG, immunoglobulin G; PCR, polymerase chain reaction; n, number; 95%CI, 95% confidence interval; GC, glucocorticoids; csDMARDS, conventional synthetic disease modifying antirheumatic drugs; bDMARDS, biologic disease modifying antirheumatic drugs. References: [1]V. Furer et al. , “Incidence and prevalence of vaccine preventable infections in adult patients with autoimmune inflammatory rheumatic diseases (AIIRD): a systemic literature review informing the 2019 update of the EULAR recommendations for vaccination in adult patients wit,” RMD Open , vol. 5, no. 2, p. e001041, Sep. 2019. [2]D. Simon et al. , “Patients with immune-mediated inflammatory diseases receiving cytokine inhibitors have low prevalence of SARS-CoV-2 seroconversion,” Nat. Commun. , vol. 11, no. 1, pp. 1–7, 2020. Acknowledgements: This study was performed in collaboration with the Israeli Ministry of Health. Disclosure of Interests: None declared.