Crossreacting IgE antibodies toPityrosporum ovaleandCandida albicansin atopic children

摘要

SummarySera from 13 patients with positivePityrosporum ovaleskin prick test were analysed with IgE immunoblotting. BothP. ovaleandCandida albicansantigens were used to reveal possible crossreactivity of these yeasts. Of the 13 sera, eight sera showed IgE binding toP. ovaleand six sera toC. albicans.Simultaneous IgE‐binding to bothC. albicansandP. Ovalewas observed in five of these sera. The most common IgE‐binding band pairs were, a 23 kD band ofP. ovaleand a 27 kD band ofC. albicans, as one pair, and a 26 kD band and a 13 kD band, respectively, as another pair. In addition to these protein bands, simultaneous reactivity was observed toC. albicansmannan, a polysaccharide, and to a diffuse high molecular weight component ofP. ovale, possibly also a polysaccharide. The five sera with simultaneous IgE‐binding were analysed with RAST‐inhibition, which revealed presence of crossreacting IgE‐antibodies toP. ovaleandC. albicansin two of these sera. Crossreacting epitopes were suggested to be located in the mannan polysaccharide ofC. albicansand high molecular weight diffuse stain ofP. ovale, based on the immunoblotting and RAST‐inhibition patterns of the studied sera. Crossreacting sera were pooled and used as an IgE probe in CRIE and Tandem‐CRIE. These experiments revealed a fused precipitin line indicating presence of a common structure ofP. ovaleandC. albicans.This suggested crossreactivity may imply an interesting phenomenon in atopics who are sensitized byC. albicansgrowth in the gastrointestinal tract and get exposed byP. ovalegrowing on the skin. Further studies are thus needed to clarify the clinical significance of these prelimi