Serum ferritin as a predictive biomarker in COVID-19. A systematic review, meta-analysis and meta-regression analysis

Ferritin is a known inflammatory biomarker in COVID-19. However, many factors and co-morbidities can confound the level of scrum ferritin. This current metaanalysis evaluates serum ferritin level in different severity levels in COVID-19. Studies evaluating serum ferritin level in different clinical contexts (COVID-19 vs. control, mild to moderate vs. severe to critical, non-survivor vs. survivor, organ involvement, ICU and mechanical ventilation requirement) were included (total 9 literature databases searched). Metaanalysis and metaregression was carried out using metaphor R package. Compared to control (COVID-19 negative), higher ferritin levels were found among the COVID-19 patients [SMD -0.889 (95% C.I. -1.201. -0.577), I-2 = 85%]. Severe to critical COVID-19 patients showed higher ferritin levels compared to mild to moderate COVID-19 patients [SMD 0.882 (0.738. 1.026), I-2 = 85%]. In meta-regression, high heterogeneity was observed could be attributed to difference in mean age, and percentage of population with concomitant co-morbidities. Non-survivors had higher serum ferritin level compared to survivors [SMD 0.992 (0.672, 1.172), I-2 = 92.33%]. In meta-regression, high heterogeneity observed could be attributed to difference in mean age and percentage of male sex. Patients requiring ICU [SMD 0.674 (0.515 to 0.833), I-2= 80%] and mechanical ventilation [SMD 0.430 (0.258, 0.602), I-2 = 32%] had higher serum ferritin levels compared to those who didn't. To conclude, serum ferritin level may serve as an important biomarker which can aid in COVID-19 management. However, presence of other co-morbid conditions/confounders warrants cautious interpretation. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

This study conducted a meta-analysis on the serum ferritin levels of COVID-19 patients at different severity levels, finding that higher severity corresponds to higher ferritin levels. Patients requiring ICU and mechanical ventilation also showed elevated ferritin levels. Serum ferritin level may serve as an important biomarker in the management of COVID-19.