title: Studies on alternaria allergens. IV. Comparative biochemical and immunological studies of commercial Alternaria tenuis Batches.
abstract: The biochemical and immunological characteristics of a series of commercial samples of Alternaria tenuis were examined, including samples from two different companies. There was a considerable variation in the biochemical parameters such as the gel filtration profile on Sephadex G-100, isoelectric focussing pattern and immunodiffusion precipitin band pattern. The content and proportion of two high molecular weight polysaccharides, one a galactomannan and the other a glucan, also varied greatly. In contrast, the allergenic properties of the samples were more consistent. In rat IgE passive cutaneous anaphylaxis tests, extensive cross-reactivity was observed among batches from the same company, but this cross-reactivity was weaker when batches from the two companies were compared. In direct radioallergosorbent tests (RAST) the samples showed similar reactivities, but RAST inhibition tests showed a 40-fold range in activity between samples from one company and 55-fold between batches from the two sources. It was found that the proportions of the major A. tenuis allergen and a related hypoallergenic antigen in the samples were relatively constant, hence RAST inhibition can be used as a measure of allergenic potency despite the presence of this cross-reacting antigen. The lack of correlation between allergenic and biochemical properties of the various samples suggest that a simple biochemical test is unlikely to be a satisfactory replacement for the RAST inhibition assay in standardizing A. tenuis extracts.
mesh_terms: D000485:Allergens / Q000276:immunology / Q000592:standards; D000528:Alternaria / Q000276:immunology*; D000818:Animals; D000946:Antigens, Fungal / Q000276:immunology*; D002850:Chromatography, Gel; D003429:Cross Reactions; D005690:Galactose / Q000031:analogs & derivatives; D005936:Glucans / Q000032:analysis; D005779:Immunodiffusion; D007525:Isoelectric Focusing; D008297:Male; D008351:Mannans / Q000032:analysis; D051379:Mice; D008815:Mice, Inbred Strains; D003904:Mitosporic Fungi / Q000276:immunology*; D011134:Polysaccharides / Q000032:analysis; D011852:Radioallergosorbent Test; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D000485:Allergens; D000946:Antigens, Fungal; D005936:Glucans; D008351:Mannans; D011134:Polysaccharides; C012990:galactomannan; D005690:Galactose