Relationships of active and passive smoking to total IgE in adults of the Epidemiological Study of the Genetics and Environment of Asthma, Bronchial Hyperresponsiveness, and Atopy (EGEA)

The increase of total IgE in relation to active smoking has been shown in the general population, but little is known about subjects with a personal or family history of asthma. The objective of this report is to analyze the relationships of active and passive smoking to total IgE in the Epidemiological Study of the Genetics and Environment of Asthma, Bronchial Hyperresponsiveness, and Atopy (EGEA). The sample studied includes 122 asthmatic probands, 430 first-degree relatives, and 190 control subjects, age 25 to 54 yr. As expected, first-degree relatives had total IgE intermediate between cases and control subjects and men had higher values than women. Current smokers had significantly higher IgE than never smokers. The relationship was statistically significant restricting the analysis in asthmatic probands. In a model taking into account gender, personal and familial history of asthma, sociooccupational class, and the nonindependence of subjects from the same family, IgE were in current smokers, ex-smokers, and never smokers 128, 61, and 76 IU/ml and 77, 41, and 55 IU/ml in men (p = 0.01) and women (p = 0.05), respectively. The relation was independent of skin test response. Some increase in IgE was observed in both men and women first-degree relatives in relation to passive smoking. That relation was statistically significant in women only (adjusted for asthma values: 103 IU/ml versus 48 IU/ ml, p = 0.02). Results show that an increase in total IgE in relation to active smoking may be evidenced even in asthmatics despite the healthy smoker effect. Susceptible subjects, such as women who are first-degree relatives of asthmatics, may increase total IgE in relation to passive smoking.