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The objective of the study was to assess skin prick test and IgE changes in a working population surveyed 5 yr apart and to determine whether age and smoking habits modify these changes. SPTs were performed on 223 subjects by the same method and common allergens (a mixture of grass pollens and a mixture of 95% house dust and 5% house dust mite). IgE measurements were done in duplicate by the same technique at each survey. A SPT-positive response at the first survey was highly predictive of a positive value at the second survey. The prevalence of positive SPT significantly increased in 5 yr (from 17.5 to 24.7%). A strong correlation was observed between IgE levels 5 yr apart (r = 0.92), and the IgE level appeared very stable. The initial IgE level was significantly greater among the converters than in consistently negative subjects (92.3 versus 30.1 IU/ml). Conversely, the initial IgE level was lower for the reverters than in consistently positive subjects (36.8 versus 97.0 IU/ml). In SPT negatives, non- and exsmokers had a greater decrease in IgE than current smokers (p = 0.06). IgE level appears to be a good predictor of SPT changes for both conversion and reversion. The IgE level appears very stable in midadulthood, which suggests that the adult environment may play a small effect in IgE level.

International audience; A previous cross-sectional analysis of 1980 data from a population of working men in the Paris area has shown a significant relationship of blood eosinophilia to a reduced FEV1 among nonsmokers, remaining after excluding men with a history of asthma. In the present report, we reexamine this relationship, after taking into account asthma, bronchial hyperresponsiveness, and positive skin prick tests, using data collected in 1985 in a subsample of 363 men from the initial population. Blood eosinophilia, defined by 5% or more eosinophils or by 250 or more eosinophils per cubic millimeter appeared to be associated with a lower FEV1, primarily in nonsmokers. A difference of approximately 0.40 L was observed in never-smokers with eosinophilia (greater than or equal to 5% of eosinophils) compared with those without. This association persisted after exclusion of subjects with atopy, asthma, and bronchial hyperresponsiveness. Longitudinally, no significant association was observed between 1980 eosinophilia and the annual FEV1 decline between 1980 and 1985, even in nonsmokers. The results of our cross-sectional analyses suggest that asthma or asthma-like disorder does not explain the association between eosinophilia and FEV1. The role of eosinophil in respiratory disorders may go beyond its intervention in allergy. Further longitudinal studies are needed to better understand discrepancies between cross-sectional and longitudinal data and whether eosinophilia is a risk factor for chronic air-flow limitation.