Autoimmune thrombocytopenia in response to splenectomy in cirrhotic patients with accompanying hepatitis C

AIM： To estimate the contribution of autoimmune thrombocytopenia to hepatitis C virus-related liver cirrhosis （type C cirrhosis）, we evaluated the influence of splenectomy upon platelet-associated immunoglobulin G （PAIgG） levels and platelet numbers. METHODS： PAIgG titers and immune markers were determined in 24 type C cirrhotic patients with an intact spleen, 17 type C cirrhotic patients submitted to splenectomy, and 21 non-C cirrhosis with an intact spleen. RESULTS： Thrombocytopenia （PLT〈15×10^4/μL） in type C cirrhosis was diagnosed in all patients with an intact spleen, 8 patients submitted to splenectomy, and in 19 non-C cirrhosis with intact spleen. Elevated titers of PAIgG at more than 25.0 ng/107cells were detected in all cirrhotic patients except for one splenectomized patient. PAIgG titers （ng/10^7cells） were significantly higher in the type C cirrhosis with an intact spleen （247.9 ± 197.0） compared with the splenectomized patients （125.6±87.8） or non-C cirrhosis （152.4± 127.4）. PAIgG titers were negatively correlated with platelet counts in type C cirrhotic patients with an intact spleen. In comparison with the type C cirrhosis with an intact spleen, the splenectomized patients had a reduced CD4/CD8 ratio and serum neopterin levels. The spleen index （cm^2） was negatively correlated with platelet counts in the non-C cirrhosis, but not in the type C cirrhosis. CONCLUSION： Our data indicate that the autoimmune mechanism plays an important role in thrombocytosis complicated by HCV-positive cirrhosis. In addition, splenectomy may impair T cells function through, at least in part, a reduction of CD4/CD8 ratio, consequently suppressing PAIgG production.

Zebrafish for thrombocytopoiesis-and hemostasis-related researches and disorders

Platelets play vital roles in hemostasis,inflammation,and vascular biology.Platelets are also active participants in the immune responses.As vertebrates,zebrafish have a highly conserved hematopoietic system in the developmental,cellular,functional,biochemical,and genetic levels with mammals.Thrombocytes in zebrafish are functional homologs of mammalian platelets.Here,we summarized thrombocyte development,function,and related research techniques in zebrafish,and reviewed available zebrafish models of platelet-associated disorders,including congenital amegakaryocytic thrombocytopenia,inherited thrombocytopenia,essential thrombocythemia,and blood coagulation disorders such as gray platelet syndrome.These elegant zebrafish models and methods are crucial for understanding the molecular and genetic mechanisms of thrombocyte development and function,and provide deep insights into related human disease pathophysiology and drug development.