CLINICAL IMPROVEMENT OF ASTHMA AFTER ANTHELMINTIC TREATMENT IN A TROPICAL SITUATION

Intestinal helminths are among the most common infectious organisms of humans, particularly in tropical regions, and can induce the producti on of large quantities of IgE antibody. Part of this response is direc ted against the helminths own antigens, but a polyclonal stimulation a lso occurs that may increase the allergic reactivity toward environmen tal allergens. The importance of this in the symptomatology of asthma its these regions is, however, uncertain. In the present study we eval uated the effect of regular anthelminthic treatment with albendazol fo r 1 yr on a group Of asthmatic patients in a zone in which these paras ites are endemic, The number of asthmatic crises, need for maintenance therapy with inhaled steroids, and use of inhaled beta(2)-agonists we re compared both with those in the year prior to the study for the tre ated patients, and with those in a group of asthmatic subjects evaluat ed in parallel, but in whom the parasitic infections were not controll ed, Significant improvement in all of these indicators of clinical sta tus occurred in the treated group, not only for the period of anthelmi nth administration, but also for the year following. However, after 2 yr without treatment, the severity of asthma reverted to the initial s tate. No significant changes were observed in the control group over t he entire period of evaluation. Eat the beginning of the study, the pa tients' pulmonary function was below the levels predicted gear normal individuals, but this was not changed by the anthelminthic treatment. The patients' total serum IgE levels, which were elevated at the begin ning of the study, were significantly diminished by the anthelminth ad ministration, as were the specific IgE antibody levels and positivity in skin tests for immediate hypersensitivity to the common environment al allergen Dermatophagoides sp. However, the specific response to Asc aris lumbricoides, a common helminth in the area, was maintained despi te treatment. These results indicate that intestinal helminthic infect ions can contribute to the clinical symptoms of asthma in an endemic s ituation. This may occur via a direct response to the parasite and/or a nonspecific potentiation of allergic reactivity to environmental all ergens.