Evidence for an immunological pathogenesis of thrombocytopenia in chronic liver disease.

Abstract

To elucidate the role of platelet-associated IgG (PA-IgG) in the mechanism of thrombocytopenia associated with chronic liver disease. Platelet count in blood, PA-IgG, and scintigraphic spleen/liver ratio as a marker of splenomegaly was examined in 214 individuals, including 16 controls showing nonspecific reactive change in liver biopsy and 198 patients with chronic liver disease. The mean blood platelet count decreased significantly according to severity of liver disease, from control to liver cirrhosis. PA-IgG levels increased significantly in relation to severity of liver disease, as did spleen/liver ratio. In chronic hepatitis or liver cirrhosis, an inverse correlation was found between platelet counts and PA-IgG levels. An inverse correlation was also observed between platelet count and spleen/liver ratio in liver cirrhosis. The splenic embolization resulted in a significant rise in platelet count and a significant fall in PA-IgG in the 14 cirrhotic patients. These results may give support to evidence for an immunological mechanism mediated by PA-IgG for the thrombocytopenia occurring in chronic liver disease. In the case of liver cirrhosis, this mechanism would act in addition to platelet pooling in the spleen on thrombocytopenia. PA-IgG may also have an important role in thrombocytopenia associated with chronic hepatitis, in which splenic platelet pooling is less marked.