Ferritin/lymphocyte percentage ratio to predict the severity and mortality of COVID-19

Objective In this study, we aimed to investigate the relationship between ferritin/lymphocyte percentage ratio (FLPR) with clinical and radiological disease severity and mortality in COVID-19 patients. Methods This retrospective study was conducted with patients who had polymerase chain reaction positive results for COVID-19. We calculated FLPRs from laboratory tests taken during emergency clinic admission. The relationship between chest computed tomography (CT) scores, disease severity, and 30-day mortality with FLPR was evaluated. Results Our study included 309 patients. 30-day mortality occurred in 12.3% (n=38) of the patients. A statistically significant association was found between FLPR and clinical disease severity (p <0.001). In the post hoc analysis, the difference was caused by the critical and severe groups and FLPR was significantly higher in these groups. A significant correlation was found between CT scores and FLPR (r=0.496, p<0.001). Logistic regression analysis revealed that hypertension, smoking, C-reactive protein (CRP), and FLPR levels were independent risk factors for mortality in COVID-19 patients. In the receiver operating characteristics curve analysis, determined the predictive value and the optimal cut-off value of FLPR. The areas under the curve of WBC, lymphocyte, neutrophil, ferritin, CRP, FLPR were found 0.707, 0.233, 0.735, 0.878, 0.831, 0.924 (p<0.001), respectively. This analysis showed that the FLPR can predict 30-day mortality better than the other biomarkers in the comparison. When the optimal cut-off value of FLPR is 42.4, the sensitivity is 84.2% and specificity is 86.7%. Conclusion FLPR can be used as an independent biomarker of disease severity and mortality in COVID-19