Hepatitis B virus replication and tuberculin reactivity: studies in Alaska.

In a previous study in 1982-1984 of southeast Asian refugees in Philadelphia, the authors found that hepatitis B virus carriers who reacted to a tuberculin (purified protein derivative (PPD)) skin test were more likely to be negative for the hepatitis B e antigen (HBeAg) than carriers who did not react to PPD. Because it was not known whether the PPD reactivity was due to natural infection or vaccination with bacille Calmette-Guérin (BCG), the authors conducted a further study in 1985 in Alaskan Native hepatitis B carriers, a group not vaccinated with BCG. The inverse association of HBeAg and PPD reactivity was confirmed across all age groups and was similar in magnitude to that observed in the refugee population. The host response to tubercle bacilli may inhibit the replication of hepatitis B virus. If the host response to BCG is similar, BCG vaccination may be of therapeutic value in chronic hepatitis B infection.