Hepatitis C virus infection in patients with hemophilia in Korea: Is antiviral therapy effective and safe?

Hepatitis C virus (HCV) infection is often observed in hemophilic patients who received a blood transfusion of clotting factor concentrates before the mid-1980s, and this increases comorbidity and mortality rates. About 80% of HCV-infected patients have chronic HCV infections, and at least 20% develop end-stage liver disease (ESLD). In Korea, anti-HCV positivity in 1999 was reported to be 49.1% and 47.9% for hemophilia A and B, respectively; since then, it has steadily decreased to 40.1% and 34.1% in 2005 and 33% and 23.8% in 2012. However, among hemophilic patients with antiHCV positivity, about 31% were positive in HCV RNA testing, and about half remain untreated. A cross-sectional study on the prevalence of hepatitis C and the use of antiviral treatment among patients with hemophilia in the Netherlands showed that about 68% of patients remained untreated. The reasons for non-treatment included the fear of unpleasant side effects of antiviral treatment by the patients (46%), normal liver enzyme values (45%), and doctors’ beliefs that the treatment was not very effective (35%). The response rate of hemophilic patients to interferon (IFN) monotherapy treatment was reported to be low, with a sustained virologic response (SVR) of about 20% (6.5-47.6%); combination therapy of IFN plus ribavirin showed a higher SVR than IFN monotherapy at about 36% (17.7–50.0%). Reasons for the low SVR with IFN monotherapy compared to non-hemophilic patients include a long duration of HCV infection, male gender, greater prevalence of HCV genotype 1, and high levels of viremia. In many studies, combination therapy of pegylated interferon (PegIFN) plus ribavirin resulted in variable treatment response rates due to differences in ethnicities and comorbidities in the patients enrolled. In those studies, the rate of SVR was generally high, at about 49-63% (33-51% in genotype 1/4, 71-86% in genotype 2/3) and showed no difference compared to non-hemophilic patients. Also, severe thrombocytopenia and bleeding tendency, side effects to be considered with the treatment, showed no difference in hemophilic patients compared to non-hemophilic patients; major bleeding has not been reported in hemophilic patients. Recently, Fransen van de Putte et al. compared patients with inherited bleeding disorders (including mainly hemophilia) who either did or did not receive antiviral therapy. The rates of developing ESLD were 0.6%, 1%, 16%, and 19% in the spontaneous clearance group, successful treatment group, never-treated group, See Article on Page 125 Hepatitis C virus infection in patients with hemophilia in Korea: Is antiviral therapy effective and safe?