Association of Seroconversion Status with Outcome in Admitted Covid-19 Patients

Objective: To determine the association between seroconversion status and outcome in admitted COVID-19 patients and compare inflammatory markers amongst them. Study Design: Single cohort observational study. Place and Duration of study: Indus Hospital and Health Network between 10th May and 10th July 2020. Methodology: All admitted patients were tested serially for anti-COVID-IgM and IgG until their sera showed positive results. This was continued until their expiry or discharge. Those patients who remained negative for both anti-COVID-19-IgG and IgM were labeled as non-seroconverts. Demographics, comorbidities, inflammatory marker levels and outcome (alive/expired) were compared between seroconverts and non-seroconverts. Results: In 224 admitted patients, the median seroconversion time of IgM and IgG was six and seven days in survivors and non-survivors respectively. Expired patients displayed higher levels of procalcitonin (maximum), C-reactive protein, and Inter- leukin-6 (baseline and maximum). Of 34 non-seroconverts, 17 (50%) expired. Non-seroconverts significantly failed to develop fever and had lower levels of ferritin, CRP, and LDH. Conclusion: Non-seroconversion in hospitalised COVID-19 infected patients indicated muted immune and acute phase response and was associated with poor outcomes. Hence these patients need to be carefully evaluated and managed. Key Words: Antibody response, Corticosteroids, Immunosuppression, SARS-Cov-2, Seroconversion.