Comparison of the Diagnostic Efficacy of Anemia Indices in Patients Undergoing Hemodialysis and Peritoneal Dialysis

Abstract

PURPOSE: Anemia is a common complication of chronic kidney disease (CKD), and assessing iron levels is crucial for managing anemia in CKD patients. However, traditional laboratory markers for iron deficiency, like ferritin and transferrin saturation (TSAT), exhibit significant variability in CKD patients and have certain diagnostic limitations. As a result, newer and less variable markers such as soluble transferrin receptor (sTfR), cellular hemoglobin in reticulocytes (CHr), and hypochromic red blood cell percentage (HYPO) have been proposed. This study aimed to compare these newer markers with the classical biomarkers to investigate iron deficiency in dialysis patients. METHODS: This cross-sectional study involved 140 patients receiving dialysis in Isfahan City, Iran, from 2021 to 2022. Classical markers of iron status were measured using routine hematology laboratory methods. sTfR levels were determined using a commercial ELISA kit, while HYPO was measured through the hemoglobin concentration chart image processing. The collected data were analyzed to compare the classical and newer biomarkers regarding the more accurate prediction of anemia. RESULTS: Significant differences were observed in mean HYPO, TSAT, hemoglobin, and hematocrit indices between the peritoneal dialysis and hemodialysis groups. Hemoglobin and hematocrit had the highest area under the ROC curve (AUC > 0.9), significantly higher than the first and third halves. The diagnostic efficiency of sTfR, as determined by ROC curve analysis, was 0.408. CONCLUSIONS: Compared to hemoglobin as the gold standard, neither the classical nor the newer laboratory biomarkers of iron status demonstrated sufficient predictive ability when used independently to determine iron deficiency in CKD patients.