In vitro lymphocyte responses of coccidioidin skin test-positive and -negative persons to coccidioidin, spherulin, and a coccidioides cell wall antigen.

The biological activity of C-ASWS, an alkali-soluble, water-soluble cell wall antigen isolated from mycelial-phase cells of Coccidioides immitis, was compared with that of a commercial coccidioidin (CDN; Cutter Laboratories); CDN-TS, a toluene-induced lysate of mycelial-phase cells; and spherulin, a spherule-derived extract of C. immitis. Lymphocytes obtained from healthy CDN skin test-positive donors (group I), healthy skin test-negative donors (group II), and patients with active coccidioidomycosis (group III) were assayed for lymphocyte transformation and production of macrophage inhibitory factor in response to the Coccidioides antigens. C-ASWS, CDN CDN-TS, and spherulin were each effective in eliciting blastogenic responses in lymphocytes of group I subjects. However, only C-ASWS and CDN-TS were effective in eliciting macrophage inhibitory factor production. The responses of group III subjects (patients) were depressed and, in most instances, were indistinguishable from those obtained in lymphocytes of group II subjects.