[The antigen (CANDTEC antigen) detected by CAND TEC test for diagnosis of candidiasis]

Most guinea pigs inoculated with 5.4 x 10(9) of C. albicans intraperitoneally, produce CANDTEC antigen (GPCANDTECAG) in sera. The antigen is heat-labile (at 56 degrees C for 30 min) as is that in humans. According to gel filtration, the molecule size of the antigen from guinea pigs was 4000KDa or more. ELISA revealed the antigen-positive gel fractions to contain a small amount of mannan from the yeasts and C3. ELISA using rabbit anti-GPCANDTECAG serum indicated that the two CANDTEC antigens from guinea pigs and humans shared determinants. Gel filtration indicated that the CANDTEC antigen from patients was from 4000KDa to 3000KDa. In the antigen-positive gel fractions, IgM was detected by ELISA, but mannan and C3 were not detected. However, immunoblotting analysis on the antigen-positive fraction revealed a unique band of 200KDa, stained with concanavalin A-ALP. These findings indicate that CANDTEC antigens in guinea pigs and humans are immune complexes formed after infection of Candida, although the antigens have different components.