Effects of long-term erythropoietin therapy on fibrinolytic system in haemodialyzed patients.

Background: Recombinant human erythropoietin (rHuEPO) is the cornerstone of anaemia therapy in uraemic patients however the effects of this hormone on fibrinolytic system are difficult to interpret.

Methods: Assessment of fibrinolytic parameters: tissue-type plasminogen activator (tPA) antigen, urokinase-type plasminogen activator (uPA) and its soluble receptor (suPAR), plasminogen activator inhibitor 1 (PAI-1) and plasmin/antiplasmin (PAP) complexes were performed in haemodialyzed (HD) patients without rHuEPO therapy: Group I (n=8, Hg<10 g/dl); Group II (n=12, Hg>10 g/dl); and in HD patients treated with rHuEPO for more than 6 months (Group III, n=10) or for more than 12 months (Group IV, n=9) in relation to the healthy controls.

Results: Patients of Group I had the significantly lower haematological parameters than those of Groups II, III and IV. All the fibrinolytic parameters studied, except PAI-1, were significantly higher in HD patients without rHuEPO therapy when compared to the controls. There were no significant differences in fibrinolytic system between the Groups I and II. Erythropoietin therapy resulted in progressive decrease in antigenic tPA levels, which reach normal range values after 6 months rHuEPO administration. uPA and PAP concentrations were also decreased and reached normal values after 12 months of rHuEPO therapy. In these patients a significant decrease in uPAR levels was also observed. Therapy with rHuEPO did not alter PAI-1 concentrations in HD patients.

Conclusions: These results suggest that long-term rHuEPO therapy can correct fibrinolytic parameters in patients undergoing regular HD irrespective from haemoglobin levels and in the absence of concomitant iron supplementation.