Relationship between Resistance to Erythropoietin and High Anomalous Hemoglobin Levels in Hemodialysis Patients with Beta-Thalassemia Minor

Abstract

In dialysis patients β-thalassemia is a cause of resistance to erythropoietin (EPO). The aim of the present study is to evaluate the relationship between the amount of circulating anomalous hemoglobin chain and EPO resistance in hemodialysis. Ten hemodialyzed patients with β-thalassemia minor were studied. The mean hemoglobin level was 9.22 ± 0.91 g/dl, the HbA₂ ranging between 5.6 and 6.8%; the weekly EPO dose was 13,500 ± 7,185 IU/week and significantly correlated with HbA₂ (r = 0.965; p = 0.0001). When stratifying patients in two groups according to HbA₂ level (LOW <6%, n = 4; HIGH >6%, n = 6; HbA₂ levels, respectively, 5.7 ± 0.1 and 6.4 ± 0.3 g/dl, p = 0.002), it was evidenced that the need of EPO was 13,200 ± 3,033 IU/week in LOW and 36,167 ± 13,060 IU/week in HIGH (p < 0.001). The EPO Resistance Index in the two groups was 13.4 ± 4.1 IU/kg BW/week/g Hb in LOW and 21.9 ± 10.0 in HIGH (p < 0.05). No differences were evidenced between the two groups regarding age, dialysis, body weight, serum levels of urea nitrogen, creatinine, albumin, C-reactive protein, aluminum, ferritin, transferrin and parathyroid hormone. In conclusion, in patients with β-thalassemia minor on chronic hemodialysis, the amount of anomalous hemoglobin chain directly correlate with EPO dose, strongly indicating the magnitude of resistance to erythropoietin.