Is Anergy the Achilles Heel?
Madhukar Pai, M.D., Ph.D.a and David M. Lewinsohn, M.D., Ph.D.b a San Francisco General Hospital, University of California, San Francisco, San Francisco, California b Portland Veterans Affairs Medical Center, Oregon Health and Sciences University, Portland, Oregon Anergy in individuals with immunosuppressive conditions (e.g., HIV infection and in those undergoing immunosuppressive therapies) can result in false-negative tuberculin skin test (TST) results, reducing sensitivity for this test in those who are at risk for progression from latent to active tuberculosis (TB) (1 3). Because it is impossible to distinguish a true negative TST result from a lack of response due to generalized anergy, and because a negative TST result cannot definitively rule out TB infection, skin tests (e.g., with mumps and Candida antigens) were used in the past to assess the competence of the cellular immune response (2, 3). However, for various reasons, including inadequate standardization, poor reproducibi