Effects of recombinant human erythropoietin on functional and injury endothelial markers in peritoneal dialysis patients

Abstract

Clinical effects of recombinant human erythropoietin (rHuEPO) such as thrombosis, convulsions, hyperviscosity, hypertension, and angiogenic effect in culture cells have been described. We studied the rHuEPO effect on endothelial damage markers and endothelial function markers: tissue-type plasminogen activator (t-PA), nitrate (NO3), thrombomodulin (TM), and von Willebrand factor (vWF). Twenty-six peritoneal dialysis patients treated with rHuEPO and 19 controls were included. The study design for rHuEPO patients consisted of four periods: long-term treatment (rHuEPO-1); 2 months of withdrawal (rHuEPO-2); and 4 months on 5000 IU/week rHuEPO subcutaneously, with markers being measured after 2 months (rHuEPO-3) and after 4 months (rHuEPO-4). After 2 months of rHuEPO withdrawal, a decrease in hemoglobin level appeared (11 ± 1.8 g/dL to 9.2 ± 1.5 g/dL, p < 0.01). After rHuEPO reintroduction, this value reached 10.6 ± 1.5 g/dL at two months, and 11.1 ± 1.4 g/dL at four months. A significant increase in t-PA ratio was observed from two months without rHuEPO to two months on rHuEPO, returning to previous values after four months. Similarly, TM increased for patients with creatinine clearances (CrC) < 5 mL/min. No changes in the higher-than-normal plasma vWF levels were found during the various periods. A statistically significant lower value was found in controls compared with rHuEPO-4 patients. A statistically significant increase in NO3 levels was observed in the pre-venous occlusion (VO) test immediately after the re-introduction of rHuEPO. This increment returned to prior values four months after rHuEPO was reintroduced. Our results show that rHuEPO treatment causes an increase in some endothelial damage markers (TM, t-PA) and modifies endothelial function markers (t-PA ratio, NO3). These changes might favor thrombosis and atherosclerosis.