Management of iron deficiency anemia in hemodialysis patients based on mean corpuscular volume

Abstract

Background: To manage the anemic status in hemodialysis (HD) patients, a well-balanced combination therapy based on the use of erythropoiesis-stimulating agents (ESAs) and iron supplementation is essential. Serum ferritin level and transferrin saturation rate (TSAT) are the current standard tests for screening iron deficiency status. However, these are not included in frequently checked regular blood measurements in many HD centers. Other parameters that could predict a hemoglobin (Hb) increase response from iron supplementation have yet to be established. To determine a frequently checked and regularly measured biomarker for predicting iron deficiency status, this study investigated the value of mean corpuscular volume (MCV) as a clinical parameter for HD patients receiving intravenous iron supplementation (Fe-IV) therapy. Methods and results: One hundred thirty four HD patients, 88 non-HD patients with anemia, and 50 HD patients on Fe-IV therapy from the Nozatomon clinic were assessed. Comparison of MCV values of anemic HD patients and anemic non-chronic kidney disease (CKD) patients showed that anemic HD patients had significantly higher MCV values (93.9 ± 7.3 fL) compared with anemic non-CKD patients (82.8 ± 8.8fL). Fifty HD patients, who received Fe-IV therapy at ten consecutive HD sessions (inclusion criteria: Hb ≤ 12.0 g/dL, TSAT < 20%, and serum ferritin < 100 ng/mL) showed a rapid increase during the Fe-IV period in MCV, Hb, and TSAT levels. After the completion of the Fe-IV therapy, MCV persisted at the increased levels, whereas Hb levels further increased and peaked at 1 month with a gradual decline after, largely influenced by ESA dosage reductions. The 50 patients were divided into three groups according to the MCV levels obtained immediately prior to the Fe-IV therapy (MCV ≤ 85 fL, 85 fL < MCV ≤ 90 fL, MCV > 90 fL), and Hb changes at 50 days after the initiation of the Fe-IV therapy were compared. All the patients in the MCV ≤ 85 fL group and most of the patients in the 85 fL < MCV ≤ 90 fL group showed linear and consistent Hb increase during the 50-day period. In marked contrast, patients in the MCV > 90 fL group showed dispersed trends in their Hb increase. The present study also revealed that successful ESA dosage reduction could be achieved after the Fe-IV therapy in both the MCV ≤ 85 fL and 85 fL < MCV ≤ 90 fL groups. Conclusions: The present study underscored the value of MCV in perceiving iron deficiency status as well as predicting iron-based therapeutic response in HD patients.