Mouse allergen exposure and immunologic responses: IgE-mediated mouse sensitization and mouse specific IgG and IgG4 levels

BACKGROUND: Although there is evidence that contact with mice is associated with IgE-mediated mouse sensitization and mouse specific antibody responses, the exposure-response relationships remain unclear.

OBJECTIVE: To determine whether IgE-mediated mouse sensitization and mouse specific IgG (mIgG) and mIgG4 levels increase with increasing Mus m 1 exposure.

METHODS: One hundred fifty-one workers at a mouse research and production facility were studied. Exposure assignments were made by linking participants to airborne Mus m 1 concentrations in their respective work areas. Cumulative exposure was estimated by multiplying airborne Mus m 1 concentration by duration of employment. Serum mIgG and mIgG4 levels were quantified by antigen-binding assays, and IgE-mediated mouse sensitization was evaluated by skin prick testing (SPT).

RESULTS: Prevalence rates of mouse SPT sensitivity and of high levels of mIgG and mIgG4 were increasingly higher by quintiles of increasing cumulative exposure (P < .01 for SPT, mIgG, and mIgG4). After adjusting for age, sex, and atopy, the log odds ratio (OR) of having positive mouse SPT results was linearly related to cumulative exposure (r2 = 0.87), as was the log OR of having a high mIgG level (r2 = 0.86). Quintile of cumulative exposure was an independent predictor of both SPT sensitivity (OR, 1.7; 95% confidence interval, 1.2-2.5) and a high mIgG level (OR, 1.7; 95% confidence interval, 1.2-2.4).

CONCLUSIONS: IgE-mediated mouse sensitization and mIgG and mIgG4 levels were related to cumulative exposure in a dose-dependent manner. Thus, strategies to prevent allergy to mice should remain focused on reducing mouse allergen exposure.