Mouse allergen–specific antibody responses in inner-city children with asthma

BackgroundAlthough mouse allergen exposure is common in inner-city homes, little is known about the relationships between exposure and humoral immune responses to mouse allergen in this population.ObjectiveTo examine relationships between mouse allergen exposure and allergen-specific IgE and IgG responses in inner-city children with asthma.MethodsInner-city children with asthma underwent skin testing and venipuncture for determination of mouse allergen–specific IgE and IgG levels. Settled dust samples were collected from their homes for allergen analysis.ResultsThe study population (n = 112) was predominantly African American (92%) with a mean age of 4.4 years. The prevalence rate of mouse sensitization was 25% and did not consistently increase with increasing Mus m 1 levels. Instead, the prevalence rate was lowest among those exposed to <2 μg/g, increased among those exposed to 2-7.9 μg/g and 8-29.9 μg/g, and then decreased among participants exposed to >29.9 μg/g (14%, 20%, 40%, and 28%, respectively). Similarly, the prevalence rates of mouse allergen–specific IgG and IgG4 did not increase across increasing exposure categories. Mouse allergen–specific IgG and IgG4 were strongly associated with IgE sensitization (odds ratios [95% CI], 82.8 [20.5-334.4] and 50.4 [14.0-181.7], respectively).ConclusionHigh-level exposure to mouse allergen in children may be associated with attenuated humoral responses of all isotypes rather than selective attenuation of IgE.Clinical implicationsProtection against allergic sensitization by high-dose allergen exposure may not be mediated by preferential production of IgG over IgE.