In order to investigate the therapeutic efficacy of subcutaneously administered erythropoietin (rHuEPO) and the effects of rHuEPO-induced hemopoiesis on peritoneal transport and on cellular immune responses, we performed standardized peritoneal equilibration tests and measured T cell subsets and phytohemagglutinin (PHA)-induced interleukin-2 receptor (IL-2R) expression of PBMC by flow cytometry before and after subcutaneous rHuEPO (Eprex-, Cilag), 4000 U twice weekly, in 13 stable CAPD patients. Hct increased from 21.3 +/- 3.4% to 30.0 +/- 4.8% after 1 mo and to 32.7 +/- 4.9% after 2 mon of rHuEPO. Drained volume after 4 hrs of dwell with 4.25% dialysate increased from 2,675 +/- 204 ml to 2,807 +/- 174 ml (P < 0.05). D4/P4 creatinine increased from 0.68 +/- 0.07 to 0.71 +/- 0.06 (P < 0.05) and creatinine clearance from 7.57 +/- 0.71 to 8.03 +/- 0.63 ml/min (P < 0.05). The number of total circulating lymphocytes, T4,T8, T4/T8 with or without PHA did not change after rHuEPO. PHA-induced IL-2R expression by PBMC as expressed by mean channel of fluorescence intensity increased from 149.8 +/- 6.7 to 156.8 +/- 6.1 (P < 0.05).
Conclusion: Subcutaneous rHuEPO is effective in correcting anemia in CAPD patients. rHuEPO-induced hemopoiesis is associated with increase in peritoneal creatinine and water transport and also with PHA-induced IL-2R expression.