Seroconversion for SARS-CoV-2 in rheumatic patients on synthetic and biologics Disease Modifying Anti-Rheumatic Drugs in São Paulo, Brazil

Abstract

Introduction - To date, there is a lack of information on how immunomodulatory drugs for autoimmune rheumatic diseases (ARD) impair humoral immune response following SARS-CoV-2 exposure. Hence, we examined anti-SARS-CoV-2 IgG/IgM positivity in ARD patients on Disease Modifying Anti-Rheumatic Drugs (DMARDs).Methods - We conducted a prospective study with ARD patients on different synthetic or biologic DMARDs (sDMARDs or bDMARDs) and control patients without DMARDs. All patients underwent a clinical baseline interview. They were tested for anti-SARS-CoV-2 IgG/IgM at baseline and three months later. Patients were monitored for incident respiratory symptoms during the follow-up. rRT-PCR for SARS-CoV-2 was performed for suspected COVID-19 infection. A univariate analysis was conducted according to antibody positivity to find significant associations for seroconversion. Results - We included one hundred patients for the analysis. Half of the patients who turned IgG positive in the study remained asymptomatic. All positive rRT-PCR patients showed seroconversion for anti-SARS-CoV-2 IgG. A borderline significant association was found for bDMARD use in IgG positive patients (42.9% vs. 19.8%, p=0.056). On the other hand, none of the patients on non-antimalarial sDMARD had detectable anti-SARS-CoV-2 IgG as compared to 35.4% of the remainder sample, reaching borderline statistical significance (0.0% vs. 35.4%, p=0.050). Conclusions - Serology for COVID-19 yielded a 14% incidence in our sample, half evolving asymptomatically. Temporally withholding bDMARD therapy in ARD patients during the pandemic based on possible humoral response impairment is not suitable. sDMARD was associated with a lower incidence of anti-SARS-CoV-2 IgG positivity and further studies on this possible impact is warranted.