Prognostic Value of Serum Ferritin for Patients with Severe Fever with Thrombocytopenia Syndrome: A Single-Center Retrospective Cohort Study

INTRODUCTION: This article aims to evaluate the prognostic value of ferritin in patients with severe fever with thrombocytopenia syndrome (SFTS). METHODS: Patients with SFTS diagnosed at the Infection Department of Wuhan Union Medical College Hospital from July 2018 to November 2021 were included. The best cutoff value was determined by receiver-operating characteristic (ROC) curve. The survival curve was analyzed by Kaplan-Meier method and compared among different serum ferritin subgroups by log-rank test. Cox regression model was used to evaluate the effect of prognosis on overall survival (OS). RESULTS: A total of 229 patients with febrile thrombocytopenia syndrome were enrolled. There were 42 fatal cases, with a fatality rate of 18.3%. The best critical value of serum ferritin was 16.775 mg/l. With increasing serum ferritin level, the cumulative mortality increased significantly (log-rank, P < 0.001). Cox univariate regression analysis and adjusted confounding factors such as age, viral load, liver and kidney function and blood coagulation function showed that, compared with the low ferritin group, the high ferritin group demonstrated poorer OS. CONCLUSIONS: The serum ferritin level before treatment can be considered a valuable index for predicting the prognosis of patients with SFTS.