Plasma thrombopoietin levels in liver cirrhosis and kidney failure

Background. Recently, c-Mpl ligand (thrombopoietin, TPO) has been cloned by several groups and found to be a primary regulator of thrombopoiesis. Its mRNA expression has been detected in several organs including kidneys, bone marrow stroma cells, muscles, and is very strongly expressed in the liver. Objective. To clarify thrombopoiesis and the regulation of TPO in severe liver and renal failure. Design. We analysed plasma TPO levels in patients with biopsy verified liver cirrhosis (n = 18; mean platelet count 115 ± 54 x 10⁹ L^-1), in patients on chronic haemodialysis as a result of end-stage renal failure (n = 20; mean platelet count 295 ± 94 x 10⁹ L^-1), and in healthy individuals (n = 20; mean platelet count 250 ± 40 x 10⁹ L^-1). Plasma was prepared from EDTA-anticoagulated whole blood and a commercially available ELISA kit was used for the analysis. Results. The mean plasma TPO concentration amongst the normal individuals was 50 ± 14 pg mL^-1. In the patients with liver cirrhosis and in patients on haemodialysis the mean TPO levels were 62 ± 19 pg mL^-1 and 46 ± 17 pg mL^-1, respectively. The mean plasma TPO concentration for the cirrhotic patients was significantly higher than the mean recorded for the healthy volunteers (P = 0.031), whereas no statistically significant differences in plasma TPO were seen between the group of end-stage renal failure and normals. Conclusion. Our results suggest that TPO production is maintained in liver cirrhosis and in renal failure, and that the thrombocytopenia in liver cirrhosis is not due to an impaired TPO production.