title: Immediate hypersensitivity to cockroach. Isolation and purification of the major antigens.
abstract: Crude cockroach extract elicited positive skin tests in 50% of patients with positive and in 4% with negative environmental history for cockroach exposure, suggesting a possible role of cockroach in perennial atopic disease. Three major allergens in crude American and German cockroach extracts have been identified using sequential purification steps on Sephadex G-75, diethylaminoethyl (DEAE) cellulose, and agarose gel electrophoresis. Cr-I elicits positive skin tests in 70% of patients sensitive to the crude extracts. It has a molecular weight of approximately 25,500 daltons, is highly acidic, and resists boiling for four hours. Boiling in 4 N acetic acid completely abolishes its allergenicity. The purified allergen elicits positive skin tests at a concentration of 3 mug/ml and is capable of inducing greater than 50% histamine release from sensitive leukocytes at 0.05 ng/ml. A second antigen, Cr-II, elicits positive skin tests also in approximately 70% of cockroach-sensitive individuals, has a molecular weight of approximately 63,000 to 65,000 daltons, and has similar heat stability and acid hydrolysis characteristics to Cr-I. A third, less well-characterized antigen, Cr-III, has a molecular weight less than 10,000 daltons and elicits positive skin tests in 30% of individuals sensitive to the crude extract.
mesh_terms: D000085:Acetates; D000485:Allergens / Q000302:isolation & purification* / Q000528:radiation effects; D002648:Child; D002675:Child, Preschool; D003058:Cockroaches / Q000276:immunology*; D004391:Dust; D006636:Histamine Release; D006358:Hot Temperature; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000209:etiology*; D008970:Molecular Weight; D012882:Skin Tests; D014466:Ultraviolet Rays
chemical_list: D000085:Acetates; D000485:Allergens; D004391:Dust