Immunochemical characterization and therapeutic effect of house dust extract in bronchial asthma.

The immunochemical characteristics of house dust extract used in hyposensitization were studied by SDS-polyacrylamide gel, isoelectrofocusing, counterimmunoelectrophoresis and Western blot. The gel electrophoregram and isoelectrofocusing plate demonstrated a complex mixture of acid proteins with molecular weights ranging from 56 to 12 KD and isoelectric point distributing from 4.6 to 5.6. The counterimmunoelectrophoresis revealed as many as five precipitating bands in sera from 60% asthmatic patients after hyposensitization. The Western blot showed heterogeneous IgE reaction bands varied from 45 to 22 KD, including a strong 27 KD reaction band found in 40% of the asthmatic patients not receiving hyposensitization. The efficacy of house dust extract hyposensitization was evaluated in 102 asthmatic patients, followed up at the Allergic Clinic since 1980. There were 42 malea and 60 females with a mean age of 30.8 (16 to 60), and the total follow-up patient-year was 512.6 with a mean of 5.0 year per patient (1 to 11). Complete remission of asthmatic symptoms and medication was found in 5% patients, and 12% patients had little or no improvement. The majority of patients (83%) had improvement in asthmatic symptoms and medication dosage. The average serum IgE levels and total eosinophil count dropped significantly after hyposensitization (p < 0.001). In conclusion, the immunochemical characteristics of house dust extract were analyzed and mite allergens, especially Group I antigens, may be the important constituents. Good therapeutic effect, both clinically and with laboratory evaluation, was obtained with more than 80% of the asthmatic patients achieving improvement under house dust hyposensitization.