Neocytolysis contributes to the anemia of renal disease

Neocytolysis is a recently described physiological process affecting the se lective hemolysis of young red blood cells in circumstances of plethora, Er ythropoietin (EPO) depression appears to initiate the process, providing th e rationale to investigate its contributions to the anemia of renal disease . When EPO therapy was withheld, four of five stable hemodialysis patients showed chromium 51 (Cr-51) -red cell survival patterns indicative of neocyt olysis; red cell survival was short in the first 9 days, then normalized, T wo of these four patients received oral C-13-glycine and N-15-glycine, and there was a suggestion of pathological isotope enrichment of stool porphyri ns when EPO therapy was held, again supporting selective hemolysis of newly released red cells that take up the isotope (one patient had chronic hemol ysis indicated by isotope studies of blood and stool), Thus, neocytolysis c an contribute to the anemia of renal disease and explain some unresolved is sues about such anemia, One implication is the prediction that intravenous bolus EPO therapy is metabolically and economically inefficient compared wi th lower doses administered more frequently subcutaneously. (C) 1999 by the National Kidney Foundation, Inc.