Association of serum ferritin with severity and clinical outcome in COVID-19 patients: An observational study in a tertiary healthcare facility

Background: Ferritin, an intracellular protein, has a pivotal role in immune dysregulation. Hyperferritinemia has been associated with higher disease severity and adverse clinical outcomes in COVID-19, including mortality. We aimed to study the association of serum ferritin levels with disease severity and clinical outcomes and its severity prediction potential in COVID-19 patients. Methods: This retrospective study included 870 adult patients with symptomatic COVID-19 infection hospitalized between July 1, 2020 to December 21, 2020. All the patients had a positive polymerase chain reaction test result of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Results: The median age was 55 (IQR:40, 65) years with a male predominance [66.32% (n = 577)], among 870 COVID-19. Of these, 413 (47.47%) had mild COVID-19, and 457 (52.53%) had moderate plus severe COVID-19 disease. Median ferritin levels were significantly high in moderate to severe COVID-19 infection compared to mild [545.8 (326.0, 1046.0) vs 97.3 (52.65–155.5) (p = 0.001)], and in patients who developed a complication compared to without complications [380 (177.05, 863.15) vs 290 (110.9, 635) (p = 0.002). A slight elevation in median ferritin levels was observed in patients who had an ICU stay than non-ICU [326 (129.8, 655) vs 309 (119.1, 684) (p = 0.872)]. The cut-off for ferritin was identified at >287.4 ng/ml for mild versus moderate plus severe COVID-19 infections. Conclusion: Moderate to severe COVID-19 patients have elevated ferritin levels. Patients with more than 287.4 ng/ml ferritin value would have greater chances of developing moderate to severe COVID-19 infections.