In vivo and in vitro cell mediated responses in coccidioidomycosis

Chest roentgenograms of 58 children who were skin test positive to coccidioidin and resided in an area endemic for coccidioidomycosis revealed that 34 per cent had roentgenographic evidence of an active inflammatory process, 14 per cent showed calcific densities, and 52 per cent showed no evidence of infection. The in vitro lymphocyte responses of children who had evidence of an inflammatory process (Group I) were compared with: those of children who had calcific densities (Group II); those of children who were coccidioidin skin test negative and had normal chest roentgenograms (Group III); and those of patients who had active coccidioidomycosis (Group IV). The mean lymphocyte transformation responses (expressed as cpm x 10 ^-4) of Groups I, II, III, and IV to a coccidioides antigen were 16.8, 19.5, 4.2, and 7.0 respectively. The mean migration inhibitory factor responses of these groups were 22.4, 20.0, 1.2 and 4.0 per cent, respectively. Thus, the over all responses of children in Groups I and II were comparable to each other, whereas the responses of patients in Group IV were depressed to the extent that they were indistinguishable from those of coccidioidin skin test negative donors in Group III. Follow up chest roentgenograms taken 3 months after the immunologic assays were performed revealed that the one subject in Group I who had been nonresponsive in the lymphocyte assays had now stabilized his infection, as evidenced by calcifications. In contrast, the 2 subjects in Group I who had yet to stabilize their infection exhibited strong in vitro lymphocyte responses. These findings suggest that primary, asymptomatic coccidioidomycosis is not associated with an immunologically nonresponsive state. However, patients with active, progressive coccidioidomycosis do have a depressed immunologic response to coccidioides antigens.