The allergic reaction to acid protease released by Candida albicans

: The species of Candida albicans (C. albicans) are known to colonize mucocutaneous regions as part of the endogenous flora. C. albicans is also known as an important allergen in human allergic diseases. However, the major allergen of C. albicans has not been identified yet. Acid protease released from C. albicans (CAAP) cleaves IgA or the secretory component to enable C. albicans to colonize on the mucous membrane. In this study, using CAAP and crude Candida antigen as challenging antigens, we carried out conjunctival provocation tests (CPT) on 68 adult bronchial asthmatic patients who showed immediate positive skin reactions to crude Candida antigen. In several patients we performed serum IgE antibody (RAST), histamine release from peripheral leukocytes (HRT) and bronchial provocation tests (BPT) to CAAP. Six of the 8 patients who showed positive CPT to crude Candida antigen (75%) showed positive CPT responses to CAAP. On the other hand, only 1 of the 59 patients who showed negative CPT to crude Candida antigen (1.7%) showed positive CPT reactions to CAAP. Two female patients showed positive RAST and HRT to both crude Candida and CAAP. They also showed positive CPT and BPT. One patient had positive RAST results but negative HRT, CPT and BPT results. These results show that CAAP is an important allergen for atopic patients allergic to C. albicans.