The researchers determined the outcome of chronic hepatitis B virus (HBV) infection amongst 126 communities in Alaska, and reported their findings in the latest issue of the Annals of Internal Medicine.
The incidence of and risk factors for hepatocellular carcinoma and end-stage liver disease in HBV carriers were evaluated.
In addition, clearance of hepatitis B e antigen (HBeAg) and surface antigen (HBsAg) were assessed.
A total of 1536 Alaska natives with chronic hepatitis B were observed for a median of 12.3 years as part of an active surveillance program to detect carriers with hepatocellular carcinoma.
At the first serologic test, 641 of the subjects were HBeAg positive and 893 were anti-HBe positive.
Older carriers were more likely than younger carriers to clear HBeAg.
| HbsAg clearance occurred in 7% of all carriers.
| Annals of Internal Medicine |
The observed probability of clearing HBeAg within 10 years of diagnosis was found to be 73%.
The researchers found that clearance of HBsAg occurred in 106 (7%) of all carriers. Clearance was positively associated with older age and positive result on initial anti-HBe test.
The incidence of adverse events was 2.3 per 1000 carrier-years. Incidence of hepatocellular carcinoma was 1.9 per 1000 carrier-years (2.3 in men and 1.2 in women).
Risk for hepatocellular carcinoma was found to increase with age, among those of Yupik Eskimo ethnicity, and among carriers who reverted from anti-HBe to HBeAg.
Dr Brian J. McMahon, of the Alaska Native Medical Center, concluded on behalf of fellow authors, "In HBsAg-positive carriers, observed clearance of HBeAg was more than 70% during the first 10 years of follow-up."