Purification and characterization of a 94 KD high molecular weight allergen from house dust mite, Dermatophagoides...

House dust mite allergens from Dermatophagoides pteronyssinus is an important cause of severe allergic asthma and rhinitis in many countries. Although several low to medium molecular weight allergens had been well characterized, limited studies on the high molecular weight IgE-binding components were reported. In this study, a 94 kD high molecular weight allergen from crude mite body extract of D. pteronyssinus was purified and characterized. Monoclonal antibody (mAb) affinity chromatography and high performance liquid chromatography were used to purify 94 kD allergen. Its antigenicity and allergenicity were confirmed by in vitro and in vivo studies. Two mAbs 2205-3.45 and 2220-7.25 specific to 94 kD high molecular weight component of D. pteronyssinus were generated. The epitopes recognized by these mAbs were species-specific. Enzyme-linked immunosorbent assay (ELISA) of IgE reactivity in the sera from 40 asthmatic children allergic to D. pteronyssinus showed that 37.5% of them had significantly higher optical density values (range 0.011 to 0.452) than normal (range 0.013 to 0.035). In in vivo skin test showed that 9 out of 20 (45%) asthmatic children were positive to 94 kD allergen. The results demonstrate that 94 kD high molecular weight component is an important allergen existing in house dust mite in Taiwan.