QUANTITATIVE ASSESSMENT OF EXPOSURE TO DOG (CAN-F-1) AND CAT (FEL-D-1) ALLERGENS - RELATION TO SENSITIZATION AND ASTHMA AMONG CHILDREN LIVING IN LOS-ALAMOS, NEW-MEXICO

Background: Our objective was to identify the allergens associated wit h asthma among schoolchildren in an area of the United States where du st mite growth is expected to be pool: Los Alamos, N.M., was chosen be cause it has low I rainfall and is at high altitude (7200 feet), makin g it very dry. One hundred eleven children (12 to 14 years old) from t he middle school who had been previously classified according to bronc hial hyperreactivity to histamine (BHR) were studied. Methods: Sera we re assayed for IgE antibodies to mite, cat dog, cockroach, Russian thi stle, and grass pollen, with both CRP system fluoroimmunoassay (Kabi P harmacia, Uppsala, Sweden) and conventional RAST. Allergens were measu red in dust samples from 109 homes with true-site assays for mite (Der p I and Der f I), cat (Fel d Ij, dog (Can f Ij, and cockroach (Bla g 2). Results: Concentrations of dog and cat allergens were elevated in almost all houses with pets but were also high in a significant propor tion of the houses without pets. Levels of mite allergen were less tha n 2 mu g/gm in 95% of the houses, and cockroach was undetectable in al l but two of the houses. Among the 21 with BHR who had symptoms, 67% h ad IgE antibody to dog and 62% had IgE antibody to cat. For these alle rgens IgE antibody was strongly associated with asthma (p < 0.001). By contrast, the presence of IgE antibody to mite, cockroach, or gas pol len wets not significantly associated with asthma. Conclusion: The hig h prevalence of IgE antibody to cat and dog allergens among these chil dren is in keeping with the presence of cat and/or dog allergen in mos t of the houses. Furthermore, sensitization (as judged by IgE antibodi es) to cat and clog allergens was strongly associated with asthma. On the other hand, no clear relationship was found between sensitization ol symptoms and the current level of allergen in individual houses. Th e results show that in this mite-and cockroach-free environment sensit ization to domestic animals was the most significant association with asthma.