[Study of cockroach allergen in adult asthmatics in Japan]

To study the clinical significance of cockroach allergen in adult asthmatics in Japan, we performed intradermal skin test to four commercial base cockroach extracts. The specific IgE antibody to cockroach was measured in sera by CAP-RAST. Positive rates of immediate intradermal skin response to cockroach extracts were 10.2-12.6%. Positive rate of CAP-RAST to cockroach was 12.6%. We performed bronchial provocation test on 6 cockroach sensitive asthmatics. Immediate asthmatic response was provoked in 2 cases and late asthmatic response was provoked in one case. Positive histamine release from peripheral leukocytes (HRT) to cockroach was shown in cockroach sensitive asthmatics. RAST-inhibition studies of cockroach showed several inhibition patterns and indicated partial cross-reactivity between cockroach species and mite. These results indicate that there is a possibility that cockroach is one of the important inhalent allergens in Japan.