IgE, IgA and IgG antibodies and delayed skin response towards Candida albicans antigens in atopics with and without saprophytic growth.

Immunoblotting and RAST were used to analyse IgE, IgA and IgG responses to antigens of Candida albicans. These were compared with the delayed skin response and C. albicans carriage in 40 atopic subjects. The majority of the atopic patients showed a strong IgG and IgA antibody response towards mannan, a carbohydrate, but only occasionally to proteins. Altogether 22 of the 40 patients showed specific IgE towards C. albicans by immunoblotting. The IgE response was mainly towards proteins, particularly to ones with molecular weights of 29 kD and 46 kD, and only in eight out of 22 IgE-positive subjects towards mannan. The IgG and IgA responses to mannan and the total IgE response towards C. albicans assessed by RAST showed an association with C. albicans carriage, whereas the delayed skin response showed an inverse relationship. The immunological parameters characteristic of C. albicans carriage were found to be C. albicans-specific depressed delayed skin response and elevated IgE, IgA and IgG responses. This situation in the atopics presenting such parameters may favour simultaneous sensitization and exposure by colonization. The degree of sensitization may be sufficiently high to produce symptomatic allergy, such as asthma, in some individuals during occasional overgrowth of C. albicans, e.g. due to antibiotic therapy.