Assessment of CD59 expression in Hepatitis C Virus induced thrombocytopenia

Abstract

Background: A variety of pathogenic mechanisms are reported to be implicated in thrombocytopenia related to chronic HCV infection: (1) Auto-immunity (2) sequestration of platelets in the enlarged spleen secondary to portal hypertension (hyper-splenism), (3) inadequate production of thrombopoietin in advanced stage liver disease , (4) Anti-viral for HCV. The CD59 protein, formerly known as a membrane inhibitor of reactive lysis (MIRL) , inhibits the final and most important step of membrane attack complex (MAC) formation. There are many studies had been done specially on autoimmune diseases and founded that abnormalities in the expression of CD55 and CD59 surface molecules on peripheral blood cells. Objective: to assess the expression of CD59 on the platelet surface in patients with HCV associated thrombocytopenia specially if the cause of thrombocytopenia is autoimmune. Subjects and methods: This cross section study was conducted on 50 individual (30patient and 20 healthy control) who were subjected to flowcytometric determination of the expression of human CD59 at the platelet surface from peripheral blood sample. Results: The groups included 30 males and 20 females with their ages ranging between 17 and 79 years with mean +SD[53.17±12.76] for group (I) and (53.3±11.85) for group (II). The ranged and mean( for group I) of HGB 10-15.9 [13.18±1.50], TLC 3.5-9.1 [5.70±1.62] and PLT 43-130 [84.27±22.36]of CBC, For the PCR low (26.7%) and PCR high (73.3%). For CD59 range(79-96.9%) mean (87.99±6.52% ) in patient group(I), range (82.7-98.7%) mean (93.48±4.08%) in control group (II). There is significant decrease mean of patients group compared to control group as regard CD59 percent(p-value=0.002), and there is positive significant correlation between CD59% and PLT, with (r=0.924 and p-value <0.001). Conclusion: Auto immunity is one of the mechanisms of HCV associated thrombocytopenia and in our study there is deficiency in CD59 in positive correlation between CD59 and platelet count and other studies revealed this correlation in auto immune thrombocytopenia and this denotes that CD59 may have a role in HCV associated thrombocytopenia , so thrombocytopenia could be explained by deficient CD59.