Recombinant human erythropoietin treatment improves platelet function in uremic patients

Recombinant human erythropoietin treatment improves platelet function in uremic patients. The effect of recombinant human erythropoietin (rHuEPO) on primary hemostasis was tested in 19 hemodialyzed patients. Bleeding time, platelet aggregation and platelet interaction with vessel subendothelium (SE) under flow conditions were determined before treatment and after patients reached hematocrits ≥30%. Two thrombotic events (an acute myocardial infarction and an AV fistula clotting) were recorded during the early stages of treatment. A shortening of average bleeding times (P < 0.01), an increase in platelet count (P < 0.01) and an improvement of platelet aggregation (P < 0.01) and of platelet-SE interaction (P < 0.01) were observed. A low correlation index was found between hematocrit and bleeding time (r = -0.351, P < 0.05). To assess a possible effect of rHuEPO on platelet function, the same parameters were evaluated before and after receiving three doses of rHuEPO (40 U/kg i.v. post-hemodialysis) in 14 of the patients. No changes in platelet or erythrocyte counts were observed, the mean bleeding time remained unchanged, but platelet aggregation induced by arachidonic acid (P < 0.05), ADP (P < 0.01) and ristocetin (P < 0.05) improved. Perfusion studies confirmed moderate but significant increases in the parameters that quantify platelet-SE interaction (P < 0.05). Improvement of ADP-induced aggregation correlated with the increase of platelet adhesion to SE (r = 0.675, P < 0.05). We conclude that rHuEPO treatment improves primary hemostasis in uremia through an increase of red cell mass but also through a beneficial effect on platelet function, which is independent of the hematocrit rise