Elevated Serum Ferritin Levels Are Predictive of Renal Function Recovery among Patients with Acute Kidney Injury

Oxidative stress (OS) frequently contributes to the development of acute kidney injury (AKI). Iron can promote oxidative stress and tissue injury by catalyzing free reactive oxygen species (ROS) generation and increasing the steady-state concentration of these potent oxidants. The anticipated role of ferritin is to protect from OS by sequestering iron and limiting its involvement in reactions that generate ROS. In this prospective study, we aimed to investigate the association between serum ferritin levels and kidney function recovery among patients with AKI. Renal recovery was determined as a return of serum creatinine to less than 1.25 times the baseline value after 90 days of follow-up. One hundred twelve patients (72 males and 40 females, 63.68 +/- 10.6 years old) were included in the final analysis. They were divided into AKI recovery (n = 76) and non-recovery groups (n = 36). Ferritin levels on admission were higher in AKI recovery group [284 (IQR 153-525) ng/mL] compared with the non-recovery group [127.4 (IQR 30-243) ng/mL], p < 0.001. Serum ferritin levels and the renal recovery significantly positively correlated (r = 0.72, p < 0.001). In multiple linear regression analysis, higher serum ferritin was associated with renal function recovery (OR 3.68, CI 2.02-3.97, p < 0.001). The optimal cut-off point of 240.5 ng/mL was determined for serum ferritin, which showed a sensitivity of 75.8% and a positive predictive value of 90%. In conclusion, serum ferritin levels on admission may be used as a prognostic marker for predicting renal recovery in AKI patients.