Seroprevalence of SARS-CoV-2 antibodies in patients with immune-mediated inflammatory diseases treated with biological and synthetic targeted therapies

Background: The seroprevalence of SARS-CoV-2 in immune-mediated inflammatory diseases (IMID) remains controversial. Aim: To compare the seroprevalence of antibodies (Ab) to SARS-CoV-2 in patients with IMID receiving treatment with biological disease-modifying antirheumatic drugs (bDMARD) or targeted synthetic (tsDMARD) versus a group of people without IMID. Methods: Study of patients with IMID and treatments with bDMARD and tsDMARD and individuals without IMID. IgG serology against SARS-CoV-2 was measured using the two-step sandwich immunoassay technique by indirect chemiluminescence between October 2020 and May 2021. Results: A total of 1100 subjects were studied, 550 patients with IMID and 550 persons without IMID. A seroprevalence of 16% (88/550) was observed in patients versus 19.3% (106/550) in the group of people without IMID, without statistical significance (OR 0.790 [95% CI 0.558-1.118]). Comparing the treatments with bDMARD or tsDMARD, there was a tendency to lower seroprevalence with rituximab, in relation to individuals without IMID (OR 0.296 [95% CI 0.087-1.007]). In addition, lower seroprevalence was found in patients who received methotrexate treatment in addition to their bDMARD, compared to the group of individuals without IMID (OR 0.432 [95% CI 0.223-0.835]). Conclusions: IMIDs in treatment with bDMARDs or tsDMARDs do not influence the seroprevalence against SARS-CoV-2 in patients. Concomitant treatment with methotrexate significantly decreased seroprevalence in these patients.