Cockroach allergen levels and associations with cockroach-specific IgE.

BACKGROUND

Among inner-city children with asthma, cockroach allergen exposure has been associated with allergic sensitization.

OBJECTIVE

We hypothesized that cockroach allergen levels in homes would be associated with sensitization to cockroach allergens in children.

METHODS

From a low-income preschool program, 341 four-year-old children selected on the basis of the willingness of their caregivers to participate in the study were enrolled. Dust from their beds and kitchens were analyzed for cockroach (Bla g 2), mouse (mouse urinary proteins), and cat allergens (Fel d 1). Serum samples were analyzed for allergen-specific IgE antibodies by immunoassay.

RESULTS

Bla g 2 levels >1 U/g in children's bed and kitchen dust samples were independently associated with cockroach-specific IgE (odds ratio [OR], 2.7; 95% CI, 1.1-6.4; and OR, 3.4; 95% CI, 1.2-9.4, respectively), adjusting for sex, ethnicity, asthma, pet ownership, mother's allergic sensitization, environmental tobacco smoke, and having lived in other homes. Bla g 2 was associated (OR, 3.6; 95% CI, 1.0-13.1) with cockroach-specific IgE among children with asthma. Among children without asthma, the ORs were similar (OR, 3.0; 95% CI, 0.9-10.3), but the association was not statistically significant.

CONCLUSION

Concentrations of the major cockroach allergen, Bla g 2, in settled dust were associated with cockroach-specific IgE independent of other factors in a cohort of 4-year-old inner-city children.