Normal variation of bronchial reactivity in nonasthmatics is associated with the level of mite-specific IgE.

OBJECTIVE

To investigate association between non-specific bronchial reactivity (NBR) and level of mite specific IgE amongst mite-sensitized non-asthmatic subjects.

METHODS

Subjects attending occupational check-up were assessed for: respiratory symptoms, atopic status (skin prick testing [SPT], total and specific IgE), spirometry and NBR. Individuals without history of respiratory disease (N = 234) were included into analysis.

RESULTS

All subjects had normal spirometry and 99% had normal NBR while 41.8% had detectable specific IgE to mites. Lung function parameters and NBR were significantly lower in mite sensitized subjects. Multiple regression analysis controlling for age, gender, smoking, family history, SPT, IgE, and lung function showed that NBR was significantly associated only with mite specific IgE level (beta = 0.26; 95% CI, 0.05-0.47; p = 0.018).

CONCLUSION

Even in subjects without allergic symptoms, IgE-mediated sensitization does not appear to be all or nothing phenomenon influencing the normal variability of underlying airway reactivity.