Fig. 1.

Sarcoidosis subjects recognize multiple mycobacterial antigens. Using enzyme-linked immunospot assay (ELISPOT) analysis, each of the study participants were tested for interferon-γ production after stimulation by catalase-peroxidase (katG), early secreted antigenic target protein (ESAT-6) and superoxide dismutase A (sodA) antigens. Sixteen of 30 sarcoidosis subjects had systemic responses to mycobacterial antigens which paralleled more closely the responses observed in purified protein derivative positive (PPD⁺) subjects, but was statistically significant from the response observed in PPD⁻ controls.