Distribution of serum erythropoietin levels in Japanese patients with myelodysplastic syndromes.

Erythropoiesis-stimulating agents (ESAs) are used to ameliorate anemia in lower-risk myelodysplastic syndromes (MDS). Serum erythropoietin (EPO) level <500 IU/L is widely accepted as a major predictive factor for response to ESAs. However, few data about EPO levels in the Japanese population are available. We therefore evaluated distribution of serum EPO levels in Japanese patients with MDS. Forty-three cases were analyzed; 30 were classified as lower-risk MDS (low or intermediate-1 by the international prognostic scoring system). Twenty-two cases were transfusion dependent. The overall median hemoglobin level was 7.7 g/dL. The median value of serum EPO was 254 IU/L (range: 16.4-23,000). Serum EPO levels had a strong inverse correlation with hemoglobin levels, and a significantly larger proportion of patients showed high EPO levels (>500 IU/L) in the transfusion-dependent group. In the higher-risk group, no significant correlation between EPO and hemoglobin was observed. Regression analyses showed that serum EPO of 500 IU/L corresponds to 8.29 g/dL of hemoglobin in lower-risk MDS. The results indicate that patients with hemoglobin levels of 8.0 g/dL or more, who are still transfusion independent, may be good candidates for ESA treatment.