Women Have Higher Rate of Spontaneous Clearance of Hepatitis C Virus

A study of patients infected with acute hepatitis C virus (HCV) infection found that women had higher rates of spontaneous viral clearanceundetectable levels of the virus without initiating drug therapy. Findings published in Hepatology, a journal of the American Association for the Study of Liver Diseases, indicate that the gene IL28B (rs12979860) and HCV genotype 1 are also independent predictors of spontaneous HCV clearance.

In 2011, there were 1,229 cases of acute HCV reported to the Centers for Disease Control and Infection (CDC), which represents a 44 percent increase over 2010. Medical evidence indicates that 25 percent of those with acute HCV spontaneously clear their infection. Previous prospective studies link female sex, immune responses, neutralizing antibodies and genetics to viral clearance.

Knowledge of acute HCV clearance is limited given that patients are typically asymptomatic during the initial stages of infection and at-risk populations, such as people who inject drugs, are often marginalized, explains lead author Dr. Jason Grebely at The Kirby Institute, University of New South Wales in Australia. Our research aims to advance understanding of time to and predictors of HCV clearance to improve early therapeutic intervention options.

Researchers used data from the InC3 Studya collaboration of nine prospective studies from Australia, Canada, the Netherlands, and the U.S. funded by the National Institutes of Health and led by professor Kimberly Page from the University of California San Franciscowhich included participants with HCV and human immunodeficiency virus (HIV) who were recruited between 1985 and 2010. The present study included 632 individuals diagnosed with acute HCV with 35 percent of the group being female and 82 percent Caucasian. Roughly 96 percent of participants had injected drugs, 47 percent were infected with HCV genotype 1 and 5 percent were co-infected with HIV.

Results show that 173 of the 632 participants had spontaneously cleared the virus during follow-up. At one year post-infection, 25 percent had HCV clearance. The average time to clearance among those who cleared HCV was 16.5 weeks, with 34 percent, 67 percent and 83 percent demonstrating clearance at 3, 6 and 12 months, respectively.

Our findings indicate that females, those with the IL28B gene, and those with HCV genotype 1 are independent predictors of spontaneous clearance of acute HCV, says Page. Further research is necessary to understand the effect of sex in controlling HCV infection.

Reference: Grebely J, et al. The Effects of Female Sex, Viral Genotype and Il28b Genotype on Spontaneous Clearance of Acute Hepatitis C Virus Infection.  Hepatology; (DOI: 10.1002/hep.26639); Published Online: August 2, 2013.