In vitro assessment of cellular immunity in human coccidioidomycosis: relationship between dermal hypersensitivity, lymphocyte transformation, and lymphokine production by peripheral blood mononuclear cells from healthy adults.

Dermal hypersensitivity in coccidioidomycosis was compared with three simultaneous measures of in vitro cellular immunity using 35 healthy donors living in an area endemic for coccidioidomycosis. Twenty donors had greater than 5 mm induration to usual-strength spherulin and were considered skin test-positive. Mononuclear cells from these individuals were more responsive by lymphocyte transformation (12,541 +/- 3746 vs. -112 +/- 260 cpm, P = .007) and produced significantly more interleukin-2 (3481 +/- 1067 vs. -5 +/- 69 cpm, P less than .001) and interferon-gamma (1831 +/- 481 vs. 75 +/- 58 pg/ml, P less than .001) than cells from skin test-negative donors in response to a coccidioidal antigen. However, the correlation between the skin test size and the magnitude of the in vitro response among skin test-positive donors was poor (R2 = 0.08, P = .24). These results indicate that healthy individuals with dermal hypersensitivity to Coccidioides immitis can be distinguished from those without hypersensitivity by their cellular in vitro response to a coccidioidal antigen.