[The specific IgE responses to three cockroach strains antigens in patients with asthma].

OBJECTIVE: The purpose of the present study was to determine the cross-reactive allergens from three strains of cockroach (Periplaneta americana, Periplaneta fuliginosa and Blattella germanica) by human serum specific IgE (sIgE) in allergic asthma. METHODS: The allergens were extracted from Periplaneta americana, Periplaneta fuliginosa and Blattella germanica respectively. Serum sIgE of allergic asthma was determined with ELISA. RESULTS: The sIgE positive rates to Periplaneta americana, Periplaneta fuliginosa and Blattella germanica were 23.5%, 16.0% and 14.0% respectively. The reactive coincidence rate between Periplaneta americana and Periplaneta fuliginosa was 74.0%. The reactive coincidence rate between Periplaneta americana and Blattella germanica was 73.5%. The reactive coincidence rate between Periplaneta fuliginosa and Blattella germanica was 85.0%. The sIgE positive rates of the head and the body of Periplaneta americana were 17.5% and 14.5% respectively. The sIgE positive rates of the head and the body of Periplaneta fuliginosa were 12.5% and 10.5% respectively. The reactive coincidence rate between head and body of Periplaneta americana was 86.0%. The reactive coincidence rate between head and body of Periplaneta fuliginosa was 88.0%. There were some cross-inhibition among the three strains of cockroach according to ELISA cross-inhibition test. CONCLUSION: Cockroach is one of the main allergens which cause allergic asthma. There exists significant cross-reactive allergic components in the three strains of cockroach and between the head and the body of Periplaneta fuliginosa and Periplaneta americana.