Background: Factor V plays a crucial role in the coagulation process. Factor V Leiden (FVL) is considered a mutant form of factor V, which may contribute to blood vessel thrombosis. Also, Hepatitis C Virus (HCV) infection may exert some coagulation changes leading to Portal Vein Thrombosis (PVT). Thrombocytopenia in patients with chronic HCV infection constitutes a major challenge.

Objective: This study aimed to investigate the incidence of FVL (factor V gene G1691A mutation) and its influence on coagulation among HCV chronically infected patients suffering from thrombocytopenia. Besides, it was designed to demonstrate the association of chronic HCV infection with coagulation disturbances in such patients.

Methods: This study was conducted on blood samples of a total of 54 subjects (33 HCV chronically infected patients and 21 healthy controls). HCV chronically infected patients with thrombocytopenia (Platelet Count [PLC] below 150 thousand/microliter) were selected. Prothrombin Time (PT) and Activated Partial Thromboplastin Time (aPPT) were previously determined as coagulation parameters. Protein C and protein S antigens were determined by ELISA as coagulation-regulating (anticoagulants) parameters. All samples were investigated for the presence of FVL by real-time PCR.

Results: PLC, PT, and protein C antigen showed highly significant differences (p < 0.001) between controls (group 1) and HCV chronically infected patients (group 2). Likewise, a highly significant change (p = 0.006) was achieved for the protein S antigen. A non-significant change was detected for the incidence of FVL with a heterozygous pattern between controls (group 1) and HCV chronically infected patients (group 2). Additionally, non-significant changes were detected for all of the investigated coagulation and coagulation-regulating (anticoagulants) parameters between control subjects with negative FVL (subgroup 1) and others with positive FVL (subgroup 2). Similarly, non-significant changes for such parameters were recoded for HCV chronically infected patients with negative FVL (subgroup 3) and others with positive FVL (subgroup 4).

Conclusion: Chronic HCV infection in the presence of thrombocytopenia is associated with coagulation disturbances. The incidence of FVL with its heterozygous pattern is unaffected by chronic HCV infection, and no association is shown with worsening of coagulation in chronic hepatitis C patients suffering from thrombocytopenia.