Serum Erythroferrone Level as a Biomarker for Erythropoiesis in Chronic Kidney Disease Pediatric Patients

Background: Anemia is a frequent CKD complication, particularly in advanced stages. Erythroferrone (ERFE), a regulator of iron metabolism, is a promising biomarker, yet its behavior and diagnostic accuracy in pediatric CKD remain unclear. Therefore, we conducted the current study to assess ERFE levels in pediatric CKD, explore associations with anemia and iron profile, and compare ERFE across hemodialysis patients, non-dialysis CKD patients, and healthy controls. Methods: In this case-control study, we evaluated 48 children with CKD (24 on hemodialysis [HD] and 24 not on HD) and 24 age-matched healthy controls. Demographic, anthroprometric, biochemical, and hematologic data were collected. ERFE was measured for all participants. Group differences were assessed using t-test or Mann–Whitney U for two groups, ANOVA or Kruskal–Wallis for multiple groups, with post hoc tests as needed. Categorical variables were analyzed by Chi-square. Statistical significance was defined as p<0.05. Results: CKD children exhibited significantly lower hemoglobin, hematocrit, and red-cell counts than controls (all p<0.001), with greatest severity in the HD subgroup. Median ERFE level was higher in HD cases [1.812ng/mL (0.89–8.14)] than in non-HD CKD [1.017(0.50–2.33)] and controls [0.690(0.36–2.57)] (HD vs non-HD and controls, p<0.001). Overall ERFE demonstrated strong diagnostic performance for anemia (AUC 0.89; 95% CI 0.80–0.99; p=0.004) with sensitivity 86% and specificity 80% at an optimal cutoff of 0.89 ng/mL. Conclusions: Anemia and associated hematologic abnormalities are most pronounced in children receiving HD. ERFE concentrations are elevated in CKD patients, especially dialysis-dependent children and show promising diagnostic accuracy for anemia in this population.