Plasma thrombopoietin levels in patients with chronic renal failure.

Abstract

Thrombopoietin (Tpo) is the most important regulator of thrombocytopoiesis. The main sites of Tpo production are the liver and the kidney produce Tpo. In the current study, the influence of renal failure on overall Tpo production was evaluated. Tpo levels were measured in 23 patients on hemodialysis (HD) and 16 patients on chronic ambulatory peritoneal dialysis (CAPD). Plasma glycocalicin (GC) levels and platelet counts were measured as parameters of platelet mass and platelet turnover. Platelet counts were significantly lower in the HD group, both before 207+/-98 x 10(9)/l (P<0.001) and after hemodialysis 202+/-102 x 10(9)/l (P<0.001) when compared to healthy controls, 293+/-79 x 10(9)/l. No significant difference was found between platelet counts in patients on CAPD and healthy donors. Mean plasma Tpo levels of HD patients were higher both before 23+/-18 AU/ml (P<0.0001) and after dialysis 25+/-26 AU/ml (P<0.0001), as compared to Tpo levels in healthy controls (11+/-8 AU/ml). Patients on CAPD had significantly higher Tpo concentrations, 29+/-25 AU/ml than healthy controls (P<0.0001). There was no difference in Tpo level between the HD and CAPD group. No correlation was found between Tpo concentration and platelet count, hematocrit, creatinine or uremia levels. The GC concentration was significantly higher in HD patients and CAPD patients when compared to healthy controls. There was no correlation between GC and Tpo level or platelet count. These results confirm the increased platelet turnover in patients with chronic renal failure. Moreover this study shows that the kidney does not seem to play a major role in the overall Tpo production in the body.