Platelet autoantibodies are common in hepatitis C infection, irrespective of the presence of thrombocytopenia

: Objective: To investigate the generation of platelet antibodies in hepatitis C virus (HCV)‐infected individuals and their relation to the development to thrombocytopenia with the aim of using their detection as a diagnostic aid of immune thrombocytopenia in these patients. Materials and methods: We tested by the monoclonal antibody‐specific immobilization of platelet antigen assay (MAIPA) for the presence of platelet antibodies against specific glycoprotein (GP) targets (GPIIb/IIIa, GPIb/IX, GPIa/IIa, GPIIIb, GPV, and FcRγIIa) in 48 HCV‐infected individuals of various stages of disease and compared the results with those from 35 patients with alcoholic liver cirrhosis. Results: Thirty‐two HCV‐infected individuals (66%) had detectable platelet antibodies. The most common target was GPIIb/IIIa, but all other GP were also targets. Results were not different from patients with alcoholic liver cirrhosis. There was no correlation between antibodies and platelet counts, or the stage of disease, or the viral genotype, or a discernible influence of treatment with α‐interferon. Conclusion: While platelet autoantibodies are common in individuals with HCV infection, their detection does not assist in the diagnosis of immune thrombocytopenia.