Ferritin as prognostic marker in COVID-19: the FerVid study

In COVID-19 patients the progressive clinical deterioration seems secondary to the activation of a cytokine storm. Ferritin is considered a direct mediator of the immune system and some evidences suggested a shared physio-pathogenic basis between COVID-19 and 'Hyperferritinemic Syndromes.' The aim of our study was to evaluate the prognostic role of ferritin in COVID-19 patients.

We retrospectively studied consecutive COVID-19 patients admitted to four Italian Internal Medicine Units. Role of potential prognostic markers was evaluated with binary logistic regression analysis and results were expressed as odds ratios (ORs) with the corresponding 95% confidence intervals (CIs). Poor outcome was defined as death or need to transfer in the intensive care unit.

Two hundred patients were included (mean age 68.75 ± 13.22 years). Ferritin value was highly elevated (>3000 ng/mL) in 8% of our population; 13% of patients were transferred to intensive care units and 12% of patients died. At multivariate analysis, highly elevated ferritin levels (OR 16.67 C.I. 4.89-57.57 p < 0.001) and hemoglobin < 10 g/dL (OR 8.88 C.I. 2.02-39.09 p = 0.004) were independently associated with a bad outcome.Patients with ferritin values > 3000 ng/ml appeared to have an inflammatory activation with elevated values of CRP and D-dimer and low values of lymphocyte count.

Our results confirm the prognostic role of ferritin in hospitalized COVID-19 patients. Patients with high ferritin levels should be considered critically ill and treated in an adequate setting. Furthermore, COVID-19 seems to share some characteristics with hyperferritinemic syndromes with potential therapeutic implications.