[Determination of specific IgE against 16 widespread mould genera. Improvement of the efficacy of the diagnosis of allergy to moulds].

Serum samples from 55 Scandinavian and US patients with a clinical history of mould allergy were screened for specific IgE Ab against 16 different moulds, the 6 mould in the Phadebas RAST panel and 10 new moulds. The studies were performed using RAST-based techniques and the nitrocellulose immunoblotting method. The RAST screening of the patient panel, revealed that 42 patients (76%) had specific IgE to at least one of the 16 moulds. The two most frequent moulds were Rhizopus and Botrytis positive in 29 patients (53%) and 27 patients (42%), respectively. Top three in terms of frequency in the US patient group were: Rhizopus greater than Botrytis greater than Phoma and in the Scandinavian group: Cladosporium greater than Botrytis greater than Helminthosporium. 15 patients (27%) were negative against the moulds in the Phadebas RAST panel, but had specific IgE against one or more of the 10 new moulds. IgE Ab concentrations measured with different genera showed different degrees of positive concordance, e.g. Botrytis-Helminthosporium (79%) and Alternaria-Rhizopus (38%), indicating complex patterns of crossreacting and genus specific allergens. This was confirmed by immunoblotting with 22 (greater than 1 PRU/ml) of the 55 sera showing up to 25 IgE binding components. The results strongly suggest that the importance of some mould genera has been underestimated as allergens.