Platelet Function In Thrombocytopenic Patients With Chronic Liver Disease

Background: Thrombocytopenia, the most common hematologic abnormality encountered in patients with chronic liver disease (CLD), results from multiple factors including splenic sequestration, relatively reduced production of thrombopoietin for the degree of thrombocytopenia, consumption of platelets secondary to autoantibodies directed against platelets, and bone marrow suppression. Elevated plasma levels of von Willebrand factor (VWF) in CLD patients may partly compensate for the reduced platelet count via interaction of VWF with the platelet receptors glycoprotein (GP) Ib-IX-V and GPIIb-IIIa (integrin αIIβ3), to promote platelet adhesion and aggregation following vessel injury. Platelets in patients with CLD are reported to have reduced function as measured by light transmission platelet aggregation (LTA) and other assays. However, LTA and most other platelet function tests are unreliable in thrombocytopenic samples. In contrast, platelet function evaluated by whole blood flow cytometry is accurate in samples with low platelet counts. Therefore, in the present study we used whole blood flow cytometry to determine whether platelet function as measured by platelet surface P-selectin, activated GPIIb-IIIa and GPIb on in vivo -circulating and in vitro -stimulated platelets is altered in thrombocytopenic CLD patients compared to healthy controls.