Serologic and clinical outcomes of 1536 Alaska Natives chronically infected with hepatitis B virus.

BACKGROUND

Knowledge of the outcome of chronic hepatitis B virus (HBV) infection is limited.

OBJECTIVE

To determine the incidence of and risk factors for adverse events (hepatocellular carcinoma and end-stage liver disease) and clearance of hepatitis B e antigen (HBeAg) and surface antigen (HBsAg) in carriers of HBV.

DESIGN

Population-based cohort study of hepatitis B carriers who were observed for a median of 12.3 years as part of an active surveillance program to detect carriers with hepatocellular carcinoma.

SETTING

126 communities in Alaska.

PATIENTS: 1536 Alaska Natives with chronic hepatitis B.

MEASUREMENTS: Bivariate comparisons, multivariable models, and other statistical methods were used to examine the relationships of risk factors to outcomes and clearance of HBeAg and HBsAg.

RESULTS

1536 chronic HBV carriers were followed up for 19 430 person-years from their first HBsAg-positive test result. At the first serologic test, 641 were HBeAg positive and 893 were anti-HBe positive. Older carriers were more likely than younger carriers to clear HBeAg (P < 0.001). The observed probability of clearing HBeAg within 10 years of diagnosis was 72.5%. Clearance of HBsAg occurred in 106 (7%) of all carriers and 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, and the incidence of hepatocellular carcinoma was 1.9 per 1000 carrier-years (2.3 in men and 1.2 in women). Risk for hepatocellular carcinoma increased with age, among those of Yupik Eskimo ethnicity, and among carriers who reverted from anti-HBe to HBeAg.

CONCLUSION

In HBsAg-positive carriers, observed clearance of HBeAg was more than 70% during the first 10 years of follow-up.