Hepatitis B virus replication and tuberculin reactivity: studies in Alaska

Area of Science:

• Immunology
• Hepatology
• Infectious Diseases

Background:

• Previous research indicated an inverse association between tuberculin (purified protein derivative - PPD) skin test reactivity and hepatitis B e antigen (HBeAg) positivity in Southeast Asian refugees.
• The cause of PPD reactivity (natural infection vs. bacille Calmette-Guérin (BCG) vaccination) remained undetermined in the initial study population.

Purpose of the Study:

• To investigate the association between PPD reactivity and HBeAg status in a population not vaccinated with BCG.
• To confirm the inverse relationship between PPD reactivity and HBeAg positivity in Alaskan Native hepatitis B carriers.

Main Methods:

• A study was conducted in 1985 involving Alaskan Native individuals who were carriers of the hepatitis B virus.
• Participants' reactivity to a purified protein derivative (PPD) skin test was assessed.
• Hepatitis B e antigen (HBeAg) status was determined for all participants.

Main Results:

• The study confirmed an inverse association between PPD reactivity and HBeAg positivity among Alaskan Native hepatitis B carriers.
• This association was consistent across all age groups and comparable in magnitude to findings in the refugee population.
• The results suggest that the host's immune response to tubercle bacilli may inhibit hepatitis B virus replication.

Conclusions:

• The findings support the hypothesis that immune responses to mycobacterial antigens are inversely correlated with hepatitis B e antigen presence.
• If the immune response to BCG vaccination is similar to that of natural infection, BCG may hold therapeutic potential for chronic hepatitis B.
• Further research into the immunomodulatory effects of BCG in chronic hepatitis B is warranted.