The rate and associated factors with antibody response in patients with COVID-19 infection

Abstract

Background/Aim: It remains unknown in what form and to what extent antibodies to SARS-CoV-2 confer immunity and whether these antibodies from previous infections could ensure protection from reinfection. This study aimed to investigate the rate of antibody positivity among patients who recovered from COVID-19 infection and the factors influencing antibody production among these patients. Methods: This prospective case control study included 111 males (mean age: 34 years, range: 18-60 years) who recovered from PCR-confirmed COVID-19. The patients underwent antibody testing on the 28th day of recovery. Sixty-seven patients (60.4%) had antibodies against COVID-19 as well as positive IgM and IgG, and 39.6% of patients were negative for Ab production. Results: The mean ages of the antibody-positive and negative groups were 43 and 29 years, respectively, the age of the positive group was significantly higher than the age of the negative group (P<0.001). The rate of antibody production in symptomatic patients was approximately 4.5 times higher than that in asymptomatic patients. The factors that were associated with antibody production were advanced age (OR=1.1), cough (OR=6.1), fever (OR=4.5), shortness of breath (OR=12.4), myalgia (OR=4.7), increased levels of CRP (OR=32.1), sedimentation rate (OR=17.3), LDH (OR=6.9), D-dimer (OR=10.6), ferritin (OR=29.4), and the presence of lymphopenia (OR=4.2) and thrombocytopenia (OR=7.1). Conclusion: The finding that a substantial number of patients recovering from COVID-19 did not develop antibody response suggests that these patients are still at risk for reinfection. In addition, patients who have experienced symptomatic disease course, advanced age and developed higher inflammatory response may be better candidates for plasma donation.