Anti-Ascaris immunoglobulin E associated with bronchial hyper-reactivity in 9-year-old rural Bangladeshi children.

Background Studies have addressed the immunomodulatory effects of helminths and their protective effects upon asthma. However, anti- Ascaris IgE has been reported to be associated with an increased risk of asthma symptoms. We examined the association between serum levels of anti- Ascaris IgE and bronchial hyper-responsiveness (BHR) in children living in rural Bangladesh. Methods Serum anti- Ascaris IgE level was measured and the BHR test done in 158 children aged 9 years selected randomly from a general population of 1705 in the Matlab Health and Demographic Surveillance Area of the International Centre for Diarrhoeal Disease Research, Bangladesh. We investigated wheezing symptoms using a questionnaire from the International Study of Asthma and Allergies in Childhood. BHR tests were successfully done on 152 children (108 ‘current wheezers’; 44 ‘never-wheezers’). We examined the association between anti- Ascaris IgE level and wheezing and BHR using multiple logistic regression analyses. Results Of 108 current-wheezers, 59 were BHR-positive; of 44 never-wheezers, 32 were BHR-negative. Mean anti- Ascaris IgE levels were significantly higher (12.51 U A /ml; 95% confidence interval (CI), 9.21–17.00) in children with current wheezing with BHR-positive than in those of never-wheezers with BHR-negative (3.89; 2.65–5.70; t test, p < 0.001). A BHR-positive test was independently associated with anti- Ascaris IgE levels with an odds ratio (OR) = 7.30 [95% CI, 2.28–23.33], p = 0.001 when adjusted for total IgE, anti- Dermatophagoides pteronyssinus IgE, pneumonia history, parental asthma, Trichuris infection, forced expiratory volume in one second, eosinophilic leukocyte count, and sex. Conclusions Anti- Ascaris IgE level is associated with an increased risk of BHR among 9-year-old rural Bangladeshi children. [ABSTRACT FROM AUTHOR]