Defined epitopes: in vivo and in vitro studies using recombinant allergens.

BACKGROUND

The aim of the studies was to investigate the biologic activity of recombinant cockroach and mite allergens and their potential for use in diagnosis and treatment of allergic disease.

METHODS

Cockroach allergens Bla g 2, Bla g 4 and Bla g 5 and mite group 5 allergens were produced in bacterial expression vectors and used for immediate skin and serum IgE antibody tests.

RESULTS

The cockroach allergens showed very good skin test reactivity in allergic patients, giving positive reactions at 10(-2)-10(-5) microg/ml; controls were negative at 10(0) microg/ml. These reactions correlated with serum IgE antibody results. The prevalence of reactivity to group 5 mite allergens varied with exposure. There was a high prevalence (70%) of sensitization to Blomia tropicalis allergen, Blo t 5, among patients from Brazil and Singapore, whereas < 20% of patients from Charlottesville, US and Manchester, UK gave positive skin tests to Blo t 5 (p < 0.001).

CONCLUSIONS

The results show that recombinant allergens retain biologic activity and suggest that cocktails of two to four recombinant allergens could be used for diagnostic or therapeutic purposes. The phased introduction of recombinant allergens should improve the management of allergic disease.