Presence of Occult Hepatitis B (32% prevalence) May Reduce Response Rates to HCV Therapy, and Should Be Looked At in Future HCV Studies

Hepatitis B virus (HBV) infection that occurs in people who lack detectable hepatitis B surface antigen (HBsAg) is called occult ("hidden") HBV infection. Usually, HBV infection is diagnosed by detection of circulating hepatitis B surface antigen (HBsAg). However, it is not uncommon for HBV infection to occur among HBsAg-negative patients.

A Colantoni from Loyola Univ Chicago and Italian researchers (G Leandro; De Bellis Hosp, Castellana Grotte, Italy) reported at the recently held Third Viral Hepatitis Conference in Hawaii on their study on this question. They concluded the prevalence of anti-HBc is high among anti-HCV, HCV-RNA positive individuals. HCV positive individuals who are anti-HBc positive had: (1) higher prevalence of cirrhosis; (2) lower HCV RNA levels; (3) an impaired ability to respond to high dose IFN treatment. 

The aim of their study was to assess the prevalence of anti-HBc and HBV DNA in the serum and liver of anti-HCV positive, HCV RNA positive subjects; and to evaluate their response to hi-dpse IFN. 285 subjects were treated in this study with IFN 5 MIU.daily for 12 months. Three different endpoints were used to assess treatment: after 6 months; at the end of treatment; and, 6 months after IFN discontinuation.  90 individuals (32%) were anti-HBc positive, 2 were HBV DNA positive in serum and seven in liver (8%). None of the anti-HBc negative individuals were HBV DNA positive in liver or serum. The prevalence of cirrhosis was higher in anti-HBc positive than in anti-HBc negative individuals (P<0.05), while HCV RNA levels were lower. Anti-HBc positive individuals had a lower response rate to IFN at 6 months and at the end-of-treatment as compared to anti-HBc negative subjects (respectively 42% versus 66%, P<0.01; and 32% versus 57%, P<0.01. No difference between the two groups in terms of sustained response was detected 6 months after IFN discontinuation.

This suggests that a masked [occult] HBV infection may interfere with the clinical outcome of chronic hepatitis C and favor or accelerate the evolution to cirrhosis. Newly starting PEG IFN studies have the opportunity to explore this potential association.