Platelet dysfunction: status of thrombopoietin in thrombocytopenia associated with chronic liver failure

Thrombocytopenia is a common hematological abnormality in patients with chronic liver disease, and its prevalence is higher in patients with liver failure. Although the presence of thrombocytopenia has historically been associated with portal hypertension, the characterization of thrombopoietin has improved our understanding of the determinants of platelet count in patients with liver disease. In particular, the association between thrombopoietin levels and residual liver function helped disclose the multifaceted pathophysiology of thrombocytopenia in patients with chronic liver failure. In this regard, important results were provided by studies performed in patients with chronic viral hepatitis that assessed the complex interplay between thrombocytopenia induced by the myelosuppressive effect of interferon-based treatment and thrombopoietin pathophysiology. These studies showed that successful antiviral therapy is accompanied by improved hepatic thrombopoietin production. Moreover, studies that evaluated thrombopoietin and platelet count dynamics before and after liver transplantation were instrumental in describing how restoration of liver function determines a normalization of the thrombopoietin–platelet count feedback that is deranged in patients with end-stage liver disease.