Antigenic heterogeneity of strains of Saccharomyces cerevisiae and Candida albicans recognised by serum antibodies from patients with Crohn's disease.

The antigenic heterogeneity of twelve strains of Saccharomyces cerevisiae and serovar A and B strains of Candida albicans was investigated by cross-absorption of serum antibodies from a patient with Crohn's disease. On the basis of common antibody absorption patterns, eleven of the yeast strains were divided into Group 1 (five S. cerevisiae), Group 2 (two C. albicans, one S. cerevisiae) and Group 3 (three S. cerevisiae). The remaining three S. cerevisiae strains (Group 4) showed unique absorption patterns. The antigenic relationship between S. cerevisiae and C. albicans was further studied by cross-absorption of sera from eight patients with Crohn's disease. This confirmed a limited degree of cross-reaction between most strains of S. cerevisiae and C. albicans, but C. albicans serovar B significantly absorbed antibodies to more S. cerevisiae strains than did C. albicans serovar A. The results demonstrate considerable antigenic heterogeneity of S. cerevisiae and suggest that the elevated serum antibody levels to S. cerevisiae found in Crohn's disease are directed against multiple antigens.