The association of non-O blood group and severity of liver fibrosis in patients with chronic hepatitis C infection

Background: The progression rate of liver fibrosis is variable among patients with hepatitis C virus (HCV) infection. It is affected by environmental and genetic factors. We determined the association between ABO blood groups and the severity of liver fibrosis in HCV patients. Materials and Methods: This cross-sectional study was conducted on adult patients with chronic HCV infection who referred to university clinics in Isfahan, Iran in 2009-10. Patients with positive hepatitis B surface antigen (HBS Ag), human immunodeficiency virus antibody (HIV Ab), or other liver disorders, as well as those who had received anti-HCV treatments were not included. Blood type was determined and liver biopsy was obtained from all patients. The severity of hepatic fibrosis was graded from F0 to F4 based on METAVIR system. Results: Non-O blood groups were present in 53.8%, 72.3%, 75%, 87.5%, and 90.4% of the patients with F0-F4 grades of liver fibrosis, respectively (p = 0.019). There was no relationship between the severity of hepatic fibrosis and age or gender. In ordinal regression analysis, only the viral load (p = 0.028) and non-O blood group (p = 0.001) were associated with the severity of hepatic fibrosis. Conclusion: Non-O blood group is a genetic risk factor for progression of liver fibrosis in patients with HCV infection. It can play an important role in determining the prognosis and appropriate treatment among these patients. The association between blood group and liver fibrosis is probably due to the increased risk of venous thrombosis. Such relation can be the goal of preventive/treatment strategies.