Different response to human recombinant erythropoietin in patients undergoing hemodialysis treatment

Introduction. Treatment with recombinant human erythropoietin enabled the correction of anemia in the patients on regular hemodialysis but large individual differences in the dose required to achieve the target hemoglobin level were observed. In this study the erythropoietin resistance index was calculated in patients on hemodialysis in order to examine variations in the response to erythropoietin and factors that influence it. Material and Methods. The study included 48 patients (25 males) of mean age 67.5 years, who had been on regular hemodialysis in amac for 43.9 months on average. All were treated with erythropoietin from the beginning of hemodialysis treatment. Their response to erythropoietin therapy was estimated by the erythropoietin resistance index. Results. The use of erythropoietin enabled the correction of anemia but different doses were needed to achieve and maintain the target hemoglobin level. The individual weekly dose of erythropoietin ranged from 15 U/kg/week to 244 U/kg/week and the erythropoietin resistance index ranged from 0.13 U/kg/week/g/l to 2.46 U/kg/week/g/l. A satisfactory erythropoietin response with erythropoietin resistance index below 0.5 U/kg/week/g/l was found in 14 (30%) patients, while 19 (40%) patients had this index above 0.7 U/kg/week/g/l and 10 (21%) above 0.9 U/kg/week/g/l. Multivariate linear regression analysis detected C-reactive protein as a significant predictor of erythropoietin resistance index. Conclusion. Target hemoglobin levels were achieved and maintained by different doses of erythropoietin in individual patients, which resulted in great individual differences in response as estimated by the erythropoietin resistance index. Multivariate analysis indicated C-reactive protein as a variable significantly associated with this index.