Tuberculin anergy in clinically normal individuals. I. Lymphokine and lymphocyte transformation studies

Tuberculin anergy was demonstrated in a number of clinically normal individuals who, on being immunized with Bacillus Calmette-Guérin (BCG), failed to demonstrate a positive Mantoux skin test. Lymphoid cells from these anergic subjects when stimulated with purified protein derivative (PPD) in vitro did not produce macrophage migration inhibition factor (MIF). Lymphocyte transformation studies demonstrated that while Mantoux-positive, non-BCG immunized Mantoux-negative and anergic individuals could all undergo blast cell transformation in the presence of PHA, only lymphoid cells from Mantoux-positive and a proportion of anergic people were capable of blast cell transformation when cultured with PPD. These results suggest that more than one mechanism may account for tuberculin anergy in clinically normal people operating at the level of lymphokine production and in some cases lymphocyte transformation.