Seroprevalence of SARS-CoV-2 in patients with rheumatic diseases on disease modifying antirheumatic drugs and /or immunosuppressive medications from India: a multicentric study

Abstract

Abstract There is an uncertainty regarding the effect of the SARS-CoV-2 infection on patients with chronic rheumatic diseases who are on immunosuppressive drugs. We did a multicentric cross sectional seroprevalence study were conducted in five different cities of India prior to COVID-19 immunization. Patients with a diagnosis of rheumatic disease and on DMARDs were included. Relatives of the patients, preferably staying in the same household with no known rheumatic diseases served as controls (subjects without disease). Serum IgG antibodies to SARS-CoV-2 Receptor Binding Domain (RBD) of the spike protein and nucleoprotein (NP) was assayed. Eight hundred eighty-nine sera (subjects with disease = 379 and in subjects without disease = 510) were assayed. IgG antibodies to either RBD and/or NP were positive in 135 (36%) subjects with disease as compared to 196 (38%) in subjects without disease. The seroprevalence to RBD and NP varied between different cities but was not significantly different between subjects with and without disease in Mumbai, Ahmedabad, Bengaluru and Bhubaneswar. However, the occurrence of IgG antibodies to RBD was significantly (p < 0.05) lower in subjects with disease (28/65;43%) as compared to subjects without disease (42/65;65%) in Kolkata, where the positivity rate was lower in connective tissue disease group than in inflammatory arthritis group. Overall, patients with rheumatic diseases on DMARDs have IgG antibodies to RBD and NP of SARS-CoV-2 at a comparable level with that of subjects without disease, but the level of antibodies to RBD is lower in patients with connective tissue disease on immunosuppressive drugs in one centre.