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 microg/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%, > or = 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%, > or = 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; > or = 10%, 1.6+/-1.4; P=0.02) and the proportion of patients showing a > or = 1 g/dl increase in Hb was greater (0-3%, 27%; 4-9%, 57%; > or = 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.