Abstract

Environmental and Food Allergens Reactivity and its Association with Total IgE, Age and Gender in Karachi, Pakistan

Noreen Abbas, Ahmed Raheem and Farooq Ghani

Aim: The aim of this study is to assess the frequency of food and environmental allergens reactivity and its association in with age, gender and total IgE levels Material and methods: The study population consisted of 88 individuals including children and adults (male: 47 and female: 41). The study was conducted in the clinical laboratory, Department of Pathology and Laboratory Medicine, Aga Khan University Hospital from May 2009 till May 2010. Sera of patients positive for total IgE were tested for allergen specific IgE levels by Immulite 2000, 3gAllergyTM. We divided allergens into two panels, namely food and environmental. Results: There were a total of 27 allergens tested on 88 individuals who had elevated levels of total IgE. Median age was 18 yrs. (IQR 8-36). We have analyzed the data on two cutoffs of allergen specific IgE reactivity i.e. moderate (0.7-3.49 kU/L) and high (3.5-17.49 kU/L). In the environmental allergens group the moderate rates of reactivity were to dog epithelium (46.6%), mites (33%) and cockroach. (17%). From food panel moderate reactivity were to egg white (23.9%), milk (22.7%) and soybean (13.6%). High reactivity rates were seen to mites (6.8%), cockroach (4.5%), cat dander epithelium (3.4%), D.farinae (3.4%), molds (3.4%) and weeds (3.4%). Commonest food allergens with high reactivity were egg white (2.3%), peanuts (2.3%) and shrimps (2.3%). Very high reactivity of environmental allergens (>52.50 kU/L) were mites (2.3%), cat dander epithelium (1.1%) whereas in food panel it was shrimps (1.1%) and peanuts (1.1%). Positive significant association of food allergens reactivity is seen with gender (p=0.01), age (p ≤ 0.001) and total IgE (p=0.05). On the other hand positive significant association of environmental allergens reactivity is seen with age (p=0.02) and total IgE (p ≤ 0.001). Conclusion: Mites, cat dander, dog epithelium and cockroach were the most frequent environmental allergens and egg white, peanuts and shrimps were the most prevalent food allergens. There was a positive correlation between age, gender, total IgE levels and IgE specific allergens. Our study demonstrates high rates of reactivity to major environmental and food allergens in patients with high total IgE.