[Total and specific IgE levels in adolescents and adults with bronchial asthma]

The prevalence of elevated total and specific IgE antibody levels among Japanese adults with bronchial asthma has not been comprehensively investigated. We examined the prevalence of IgE levels in patients with asthma, and analyzed factors that are associated with elevated levels of IgE.

A total of 5067 patients with asthma (2047 were men) aged 16 or older and who had visited our clinic during a recent 9-year period (1997 through 2005) were classified into 4 birth period (groups, G) according to their year of birth: G1 (before 1926), G2 (1926 to 1945), G3 (1946 to 1965), and G4 (after 1965). First, we investigated the prevalence of elevated total IgE level (> or = 300 IU/mL) and the prevalence rates of specific IgE antibodies to house dust mites (mite), cedar pollen (cedar), and Candida albicans (Candida). Then, we investigated trends in the prevalence of antibodies among the 4 age groups during a 9-year period.

1. The prevalence of elevated levels of total IgE and specific IgE antibodies to mites and cedar pollen significantly increased in ascending order from G1 to G4. 2. Compared with women, men had a significantly higher prevalence of elevated levels of total IgE and specific IgE antibodies to mites, cedar pollen, and Candida. 3. Compared with never smokers, current smokers had a significantly higher prevalence of elevated levels of total IgE and specific IgE antibodies to mites, cedar pollen, and Candida. 4. During the 9-year period, the prevalence of elevated levels of total IgE and specific IgE antibodies to mites and Candida significantly decreased in the G2, G3, and G4 groups. 5. Multiple logistic regression analysis revealed that elevated levels of total IgE and specific IgE antibodies to Candida were significantly associated with younger age, male gender, and smoking. Elevated levels of mite-specific IgE were associated with age and gender, and elevated levels of cedar-specific IgE were associated with gender, age, and generation.

Gender, age, generation, and smoking status were associated with elevated levels of total and specific IgE antibodies to mites, cedar pollen, and Candida in patients with asthma; however, the degree of association varied.