Percentage hypochromic red cells and the response to intravenous iron therapy in anaemic haemodialysis patients

Introduction. Iron deficiency is commonly encountered in haemodialysis (HD) patients and may be overcome by i.v. iron therapy. We have examined the percentage hypochromic red cells (%HRC) for predicting response to i.v. iron in subjects with a low serum ferritin. Methods. Prospective study of i.v. iron saccharate (trivalent iron 200 mg/week for 8 weeks) in anaemic (Hb < 10 g/dl) HD patients with serum ferritin < 100 mu g/l despite oral iron therapy. Response to i.v. iron was assessed by comparing Hb at 0 and 8 weeks according to %HRC at baseline (0-3%, 4-9%, greater than or equal to 10%). Results are mean +/- 1 SD. Results. For all subjects (n = 82), Hb and ferritin increased between 0 and 8 weeks (8.9 +/- 1.0 to 10.1 +/- 1.4, P < 0.0001; 55 +/- 24 to 288 +/- 126, P < 0.0001). Patients were stratified into three groups according to %HRC at baseline (0-3%, 4-9%, greater than or equal to 10%). Hb increased significantly in all three groups. The mean increase in Hb was greater (0-3%, 0.6 +/- 1.2, 4-9%, 1.2 +/- 1.0; greater than or equal to 10%, 1.6 +/- 1.4; P = 0.02) and the proportion of patients showing a greater than or equal to 1 g/dl increase in Hb was greater (0-3%, 27%; 4-9%, 57%; greater than or equal to 10%, 67%; P = 0.02) in those with the largest %HRC pre-treatment. Conclusion. Intravenous iron therapy is effective in improving Hb in anaemic HD patients with a low ferritin. However, the magnitude of this response and the proportion of patients responding is related to the percentage hypochromic red cells prior to treatment.