Profile of asymptomatic chronic HBV infection in India

In India, horizontal transmission in early childhood has been shown to be a significant mode of transmission of hepatitis B virus (HBV). This prospective, cross-sectional study was undertaken to study the biochemical, serological and histological profile of incidentally detected asymptomatic HBsAg positive subjects (IDAHS) picked up at a tertiary care referral centre.

In 157 (M:F::123:34) HBsAg positive subjects, clinical, biochemical, virological and histological assessment was done. The histological activity index (HAI) of > 3 was considered as chronic hepatitis. Serum was tested for HBsAg, HBeAg, HBeAb, HBV DNA and alanine transaminase (ALT).

Seventy (45%) subjects were HBeAg and 83 (53%) anti-HBe positive. While 71 per cent of the subjects with elevated ALT had an HAI > 3, only 36 per cent with normal ALT showed significant histological changes (P < 0.001). Significant histopathological lesions in the liver biopsy were seen in 92 (59%) subjects, with moderate to severe lesions in 14. IDAHS who were HBeAg +ve were more likely to have significant histological lesion than those who were anti-HBe +ve (P < 0.01). In the anti-HBe +ve group, 35 of 57 (61%) subjects for whom HBV-DNA was available, were HBV-DNA positive. Anti-HBe+ve, HBV-DNA+ ve IDAHS with elevated ALT were more likely to have chronic hepatitis vis-a-vis those subjects in this group who had a normal ALT (P < 0.001).

ALT is a reliable discriminant of significant histological lesion in IDAHS. The relatively young mean age of Anti-HBe +ve IDAHS suggests an early age of infection and hence, early seroconversion or mutant virus infection in this cohort. A significant proportion of these IDAHS have HBV-DNA positivity and HAI > 3. Our results clearly demonstrate ongoing liver disease in asymptomatic, so-called "HBV carriers". We propose that the term hepatitis B 'carrier' should be abandoned and replaced by 'chronic HBV infection'.