title: Thrombopoietin receptor (c-Mpl) is constitutively expressed on platelets of patients with liver cirrhosis, and correlates with its disease progression.
abstract: Thrombocytopenia is one of the major complications of liver cirrhosis. Except for hypersplenism associated with portal hypertension, it is not known which abnormalities of thrombopoiesis cause thrombocytopenia. To evaluate thrombopoiesis in liver cirrhosis, we analyzed thrombopoietin (TPO) and its receptor c-Mpl levels in cirrhotic patients. Expression of c-Mpl on platelets and the serum level of TPO were investigated from 38 patients with various stages of liver cirrhosis by flow-cytometric analysis and enzyme-immuno assay. Samples obtained from 22 individuals without evidence of liver disease were used as controls. Neither platelet counts nor TPO levels correlated with disease progression defined by the Child-Pugh classification. c-Mpl was constitutively expressed on the platelets of cirrhotic patients, and its expression level was reduced with disease progression defined by the Child-Pugh classification. In this study, serum TPO did not fluctuate according to the grade of cirrhosis. However, its receptor c-Mpl, which is expressed on platelets, was decreased significantly in severely cirrhotic patients with thrombocytopenia. Thus, a correlation between reduced c-Mpl expression and the progression of liver cirrhosis was demonstrated. We conclude that, in addition to hypersplenism, the reduced expression of c-Mpl may play a significant role in the thrombocytopenia observed in severe liver cirrhosis.
authors.affiliation: Department of Internal Medicine III, Niigata University School of Medicine, 757, Asahimachi-Dori 1, Niigata, Japan
authors.forename: Toru
authors.initials: T
authors.lastname: Ishikawa
authors.forename: Takafumi
authors.initials: T
authors.lastname: Ichida
authors.forename: Satoshi
authors.initials: S
authors.lastname: Sugahara
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yamagiwa
authors.forename: Yasunobu
authors.initials: Y
authors.lastname: Matsuda
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Uehara
authors.forename: Takashi
authors.initials: T
authors.lastname: Kato
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Miyazaki
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Asakura