The haematopoietic effect of recombinant human erythropoietin in haemodialysis is independent of the mode of administration (i.v. or s.c.).

Background: Previous studies comparing intravenous (i.v.) and subcutaneous (s.c.) administration of recombinant human erythropoietin (rHuEpo) often did not achieve optimal iron reserve, were restricted to a limited follow-up period (not allowing equilibration) and/or did not exclude the role of other confounding factors. In addition all papers focused on the conversion from i.v. to s.c.

Methods: In this study, 30 equilibrated patients on s.c. rHuEpo were randomized into two groups, one converting to i.v. after 6 months of follow-up and one remaining on s.c. rHuEpo. In both groups rHuEpo was administered three times weekly. Only patients completing a further 6 months follow-up were considered for statistical evaluation. Serum ferritin was targeted at 200 ng/ml and haematocrits between 28 and 36% were pursued.

Results: The average haematocrit levels before conversion were 31.9 +/- 1.1% in the conversion group and 31.4 +/- 1.6% at the same time point in the nonconversion group (P = NS). After 6 months haematocrits were 31.5 +/- 0.5% in the conversion group and 31.1 +/- 0.9% in the non-conversion group (P = NS). Ferritin concentration in the conversion group was 219 +/- 49 ng/ml before and 230 +/- 83 ng/ml after the conversion. For the non-conversion group ferritin was 224 +/- 25 ng/ml and 236 +/- 52 ng/ml respectively (P = NS). The weight-standardized average rHuEpo dose per injection remained the same in the conversion group before and after conversion (44.0 +/- 1.8 U/kg/injection vs 45.4 +/- 4.7 U/kg/injection) (P = NS). In the non-conversion group the corresponding rHuEpo doses were 32.9 +/- 4.2 U/kg/injection and 39.6 +/- 7.0 U/kg/injection respectively (P = NS). There were no differences in serum PTH, aluminium, vitamin B12, folic-acid levels, and intake of co-trimoxazole, ACE inhibitors or theophylline.

Conclusion: No changes in rHuEpo dose were observed after conversion from s.c. to i.v. There were no significant differences between the conversion and non-conversion group. These results are in contrast to some earlier studies suggesting lower rHuEpo requirements in case of s.c. administration.