RELATIONSHIPS BETWEEN TOTAL SERUM IGE, ATOPY, AND SMOKING - A 20-YEARFOLLOW-UP ANALYSIS

Background: A number of cross-sectional studies have demonstrated that higher levels of IgE are found in subjects who currently smoke cigare ttes and/or who are atopic and that IgE levels decline with age. Objec tive: This report examines the interactions among atopic status, smoki ng, and IgE with longitudinal data and methods. Methods: Subjects were participants in the Tucson Epidemiological Study of Airways Obstructi ve Disease and were 6 years of age and older. Total serum IgE measures and allergen skin test results were obtained during three surveys spa nning a period of rep to 20 years. Results: The results showed no sign ificant gender differences between nonatopic nonsmoking subjects, who were considered the reference group. Nonatopic current smokers had IgE levels similar to those of the reference subjects initially, but IgE levels did nor decline with age at the same rate as in the reference s ubjects, causing significant differences at older ages. There was a si gnificant relationship between number of cigarettes smoked and IgE lev el. Conclusions: Atopy and smoking are both associated with elevated t otal serum IgE levels. Although the exact mechanism for elevated IgE l evels in smokers is not known, the significant dose relationship is su ggestive of a causal association.