NITROCELLULOSE-RAST ANALYSIS OF ALLERGENIC CROSS-REACTIVITY OF CANDIDA-ALBICANS AND SACCHAROMYCES-CEREVISIAE MANNANS

Two chemically purified mannan preparations and one affinity purified mannan preparation of Candida albicans and Saccharomyces cerevisiae we re analyzed for allergenic cross-reactivity. Simultaneous IgE binding in radioallergosorbent test (RAST) was studied with all preparations a nd the chemically purified mannans were also used for RAST inhibitions . The yeast mannans were purified with the Peat method, using repeated ethanol precipitations and Fehling's precipitation in alkaline condit ions, and the Cetavlon method, using hexadecyltrimethylammonium bromid e and ethanol precipitations. Affinity purification of the mannans was performed with concanavalin A lectin bound to a Sepharose column. Man nan from pityrosporum ovale was purified with the Cetavlon method for analysis of simultaneous RAST reactivity. Simultaneous IgE binding to all the studied yeast mannans was generally seen in all the studied se ra of patients suffering from atopic dermatitis. The strongest respons es were seen against C. albicans mannan, especially the Cetavlon manna n. In the RAST inhibition studies IgE binding to S. cerevisiae mannan was completely inhibited by C. albicans mannan preparations, whereas r eciprocal inhibition was not complete. These results indicate that in atopic dermatitis simultaneous IgE response to yeast polysaccharides o ccurs and that the major sensitizer is C. albicans and IgE antibodies against S. cerevisiae mannan are cross-reacting.