A Modified Antigen for Serodiagnosis of Systemic Candidiasis

Abstract

Systemic candidiasis is emerging as a major obstacle in the successful management of leukemia and other conditions requiring immunosuppressive, steroid, or antibiotic therapy. Because there are no clearcut diagnostic criteria, the infection is rarely recognized and treated in time. Additional means of diagnosis are therefore urgently needed. Previous studies by the writers have indicated that precipitin reaction in agar gel against cytoplasmic candidal antigens permits diagnosis of systemic candidiasis with S5 to 90% reliability. Verifiably false-positive precipitin reactions have been observed thus far only in patients with autoimmune endocrinopathies in association with chronic cutaneous and mucocutaneous candidiasis. False-negative reactions may, however, be expected in the presence of terminal or disease-related aiiergy. Widespread diagnostic evaluation of the precipitin reaction has hitherto been precluded by lack of a generally available, standardized antigen. A candidal extract, developed for this purpose by Hollister-Stier Laboratories, is evaluated in the present studies. Positive and negative precipitin reactions obtained with this antigen in gel diffusion tests against 50 human sera corresponded closely with those of the control, a cytoplasmic sonicate of C. albicans prepared and used by the writers for the past several years. Although not standardized and poorer in antigenic components than the control, the test antigen proved satisfactory enough to merit further evaluation by other investigators.