Detection of IgE antibody against Candida albicans enolase and its crossreactivity to Saccharomyces cerevisiae enolase.

Candida albicans 46 kDa protein, a glycolytic enolase enzyme, is an important allergen of the yeast. The purpose of the study was to detect circulating IgE and IgG antibodies against C. albicans enolase (CAE). We isolated CAE using sequential DEAE Sephacel and P11 column chromatography from spheroplasts of C. albicans, and detected IgE and IgG antibody against CAE by immunoblotting. Crossreactivity of enolase of C. albicans and Saccharomyces cerevisiae was also examined by immunoblotting and immunoblot inhibition test. Among 54 sera with positive IgE RAST to C. albicans, IgE antibody against CAE was detected in 20 sera (37%) and IgG antibody in 27 sera (50%). The allergenic potency of CAE was confirmed using a skin-prick test in three patients. Simultaneous IgE binding to S. cerevisiae enolase was only observed in four out of 20 sera reacting to CAE. Pre-treatment of sera with CAE completely inhibited IgE binding to S. cerevisiae enolase. Whereas the latter only partially inhibited IgE binding to CAE. These results suggest that CAE shares some crossreacting epitopes with S. cerevisiae enolase, representing minor components of CAE but dominant segments of S. cerevisiae enolase.