Anergy, AIDS and tuberculosis.

Human immunodeficiency virus causes an immunological 'state of anergy'. This state is due to a defective function of antigen-presenting cells, a depletion of CD4+ helper cells, a reduction in the production of soluble factors required for signal transduction, and a decrease in cytotoxic cell activation. The human immunodeficiency virus epidemic has resulted in a global resurgence of tuberculosis. Tuberculin skin testing is negative in 58% of the patients with acquired immunodeficiency syndrome who develop tuberculosis. The mechanism leading to a state of anergy and the mechanism leading to dissemination of dormant tuberculosis appear to be identical.