Anti-helminth treatment lead to a reduction on asthma severity

RATIONALE: Helminthic infections reduce asthma severity. This prospective study evaluates the influence of anti-helminth treatment on the asthma severity in asthmatics living in a polyhelminthic endemic area, in Brazil. METHODS: Fifty-five subjects aged between 6 and 40 years infected with S. mansoni and other helminths were selected for this study (group I). Another 21 asthmatic subjects aged between 6 and 40 years, infected with other helminths, except S. mansoni (group II). Asthma severity was evaluated using scores obtained by a questionnaire to access the severity, physical exams, and pulmonary function tests. The evaluations were performed in the beginning of the study (D0) and every 3 months thereafter (D1, D2, D3 and D4), for a year. Subjects from group I were treated with Mebendazole and Praziquantel, while subjects from group II received Mebendazole, immediately after first evaluation on D0. RESULTS: At D0 all of the subjects from group I and II had mild asthma. However, when we compare the score of asthma at D0 with D1, D2 and D3 there was an increase in the asthma severity in asthmatics from both, group I and group II (p<0,005). Twelve months after treatment, there was a decrease in asthma severity in subjects from group I - they returned to the basal levels, while subjects from group II maintained the symptoms of asthma. CONCLUSIONS: Our data show that anti-helminth treatment of asthmatic subjects living in a polyhelminthic endemic area leads to an increase in asthma symptoms. Helminthic infection through regulatory mechanisms could modulate the asthma inflammatory response.