Detection of allergens in a cat pelt extract

Allergenic components of cat pelt extract fractionated by SDS-polyacrylamide gel electrophoresis (PAGE) and transferred to nitrocellulose membranes were identified using sera from 15 allergic patients who showed positive skin test and RAST to cat extract. Two components showed the highest IgE-binding frequency; 14 kD (being recognized by 86% of the sera examined) and 29 kD (73% of the sera tested). Both components were purified by electroelution and subjected to RAST inhibition assays. The 29 kD fraction was able to bind specific IgE to D. pteronyssinus and inhibited a RAST assay of 29 kD component (Der p I) purified from a D. pteronyssinus extract. These results could explain the finding of positive skin test with some commercial cat allergen solutions in patients with D. pteronyssinus allergy.