Purification of soluble specific antigens of systemic candidiasis by antibody affinity chromatography.

Serological methods can be applied to the diagnosis of systemic candidiasis, but cell wall mannans can detect antibodies occurring in several cases unrelated to candidiasis. The present study proposes a procedure for the preparation of specific antigens obtained from an experimental infectious model. The specific immunoglobulins were obtained from rabbits with chronic systemic candidiasis. After precipitation by ammonium sulfate and purification by ion-exchange chromatography on DEAE-Sephadex A-50, these immunoglobulins were fixed on cyanogen bromide-activated Sepharose 4B and used for the preparation of an affinity chromatography column. This column allowed isolation of specifically bound fractions of Candida albicans soluble antigens. When analyzed by quantitative immunoelectrophoresis with a polyvalent hyperimmune antiserum, these fractions showed eight precipitation lines, whereas the complete soluble antigen exhibited 48 lines. Possible applications of these antigens to specific serodiagnosis of systemic candidiasis are being evaluated.