epoetin-alfa and Vascular-Diseases

Data from four prospective, multicenter, randomized studies involving 869 major, elective orthopedic surgery patients were examined by means of a retrospective integrated analysis to evaluate whether perioperative Epoetin alfa use was associated with the occurrence of thrombotic/vascular events. The incidence of thrombotic/vascular events was similar between 619 patients treated with Epoetin alfa and 250 patients receiving placebo (7.4% versus 8.0%, respectively). Regression analyses identified age, cardiac history, hypertension, and cardiac medications, but not Epoetin alfa, as risk factors for thrombotic/vascular events. The analysis did not implicate an increase in the rate of rise in hematocrit or maximum hematocrit obtained prior to surgery as contributors to thrombotic events. Thus, Epoetin alfa, which enhances preoperative erythropoiesis and increases hematocrit, did not affect the probability of thrombotic/vascular events.

Topics: Epoetin Alfa; Erythrocyte Count; Erythropoietin; Hematinics; Hematocrit; Hip; Humans; Incidence; Knee; Multicenter Studies as Topic; Placebos; Postoperative Complications; Prospective Studies; Randomized Controlled Trials as Topic; Recombinant Proteins; Regression Analysis; Retrospective Studies; Risk Factors; Thrombosis; Vascular Diseases

Patients with advanced chronic renal disease (CRD) suffer from excessive morbidity and mortality due to complications of accelerated atherosclerosis. Recombinant human erythropoietin (EPO), which is routinely used to treat the anaemia present in approximately 90% of dialysis-dependent patients with end-stage renal disease, may induce vascular dysfunction by reducing nitric oxide (NO) availability. Pathophysiologic concentrations of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase (NOS), are found in patients with CRD and correlate with vascular disease and cardiovascular mortality. The aim of the current study was to investigate the effect of EPO on ADMA concentrations and NO generation in vitro and in vivo. Furthermore, we wanted to study the effect of EPO on the expression of the enzymes that regulate ADMA metabolism and NO generation.. Human umbilical vein endothelial cells (HUVECs) were exposed to therapeutic concentrations of EPO. The expression and metabolic activity of dimethylarginine dimethylaminohydrolase II (DDAH II), the enzyme that degrades ADMA, was evaluated. Following subcutaneous administration of EPO to Balb/c mice for 10 weeks, serum ADMA concentrations were determined. Systolic blood pressure was measured noninvasively. Urinary nitrite and nitrate (NOx) concentrations were assessed by Griess assay. Protein expression of DDAH and NOS in livers and kidneys was measured by western blotting.. EPO suppressed ADMA elaboration by HUVECs. Systolic blood pressure and serum concentrations of ADMA were significantly elevated in EPO-treated mice. The protein expression of DDAH I in the kidney and liver was upregulated while hepatic expression of DDAH II was decreased and renal DDAH II expression remained unchanged by EPO administration. However, EPO augmented urinary NOx concentrations as well as the expression of NOS 1 and NOS 2 in the kidney.. In spite of elevating serum ADMA concentrations, EPO does not appear to compromise overall NO generation in Balb/c mice.

Topics: Amidohydrolases; Animals; Arginine; Base Sequence; Cells, Cultured; DNA Primers; Endothelial Cells; Epoetin Alfa; Erythropoietin; Humans; Kidney; Kidney Failure, Chronic; Liver; Male; Mice; Mice, Inbred BALB C; Nitric Oxide; Nitric Oxide Synthase Type II; Recombinant Proteins; Up-Regulation; Vascular Diseases