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 li
ver and renal failure.
Design. We analysed plasma TPO levels in patients with biopsy verified live
r cirrhosis (n = 18; mean platelet count 115 +/- 54 x 10(9) L-1), in patien
ts on chronic haemodialysis as a result of end-stage renal failure (n = 20;
mean platelet count 295 +/- 94 x 10(9) L-1), and in healthy individuals (n
= 20; mean platelet count 250 +/- 40 x 10(9) L-1). Plasma was prepared fro
m EDTA-anticoagulated whole blood and a commercially available ELISA kit wa
s used for the analysis.
Results. The mean plasma TPO concentration amongst the normal individuals w
as 50 +/- 14 pg mL(-1). In the patients with liver cirrhosis and in patient
s 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 cirrh
otic patients was significantly higher than the mean recorded for the healt
hy volunteers (P = 0.031), whereas no statistically significant differences
in plasma TPO were seen between the group of end-stage renal failure and n
ormals.
Conclusion. Our results suggest that TPO production is maintained in liver
cirrhosis and in renal failure, and that the thrombocytopenia in liver cirr
hosis is not due to an impaired TPO production.