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 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 times 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 had 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.