ASSOCIATION BETWEEN GIARDIASIS AND ALLERGY

Background: Previous studies have indicated that there may be an assoc iation between infection by the intestinal protozoan Giardia lamblia a nd the expression of allergic disease. Object: We evaluated a group of children who attended the Outpatient Clinic of the Children's Hospita l in Caracas, Venezuela, a group in which both allergic disease and gi ardiasis were common. Methods: We performed feces examination and meas ured total and specific serum IgE (immunoglobulin E) in these children . Results: We found that 70% of the children infected with G. lamblia presented symptoms of allergy, in contrast to 43% of the non-Giardia p arasitized group (P <.05). In addition, the G, lamblia parasitized chi ldren showed significantly higher levels of total serum IgE (1194 IU/m L) than the non-Giardia group (822 IU/mL) (P <.005). Children infected with G. lamblia showed higher levels of specific serum IgE antibody a gainst food allergens compared both with the non-parasitized group (P <.0001) and children infected with parasites other than Giardia (P <.0 5). In contrast, IgE responses against the house dust mite Dermatophag oides pteronyssinus were similar in all the groups studied. Conclusion s: These results reveal a clear relationship between giardiasis and al lergy, possibly because infection by this protozoon enhances sensitiza tion towards food antigens, due to increased antigen penetration throu gh damaged intestinal mucosa.