ENHANCED RESPONSES TO MYCOBACTERIUM-TUBERCULOSIS ANTIGENS BY HUMAN ALVEOLAR LYMPHOCYTES DURING ACTIVE PULMONARY TUBERCULOSIS

Responses to mycobacterial and nonmycobacterial antigens were examined in bronchoalveolar cells (BAC) and peripheral blood mononuclear cells (PBMC) from patients with active pulmonary tuberculosis (n = 16) and healthy subjects (n = 23), DNA synthesis in BAC (but not PBMC) from tu berculosis patients was significantly increased in response to the myc obacterial antigens purified protein derivative (PPD), antigen 85, and mannose-capped lipoarabinomannan but not to nonmycobacterial antigens , The response to PPD was also increased in enriched alveolar lymphocy tes from tuberculosis patients (P < .05). The frequency of interferon- gamma but not interleukin-4- or -10-producing cells by ELISAspot was i ncreased in PPD-stimurated BAC from patients with tuberculosis (P < .0 5). Accessory function of alveolar macrophages for T lymphocyte respon ses was similar and suppressive activity was variably decreased in tub erculosis patients. Thus, there is compartmentalization of mycobacteri al antigen-specific lymphocytes to the lungs during active tuberculosi s that on challenge produce a Th1-type cytokine host response.