A four year follow up study of filaria specific IgE response in individuals with hydrocele

Background & objectives: Hydrocele is the most common clinical manifestatio n in males infected with Wuchereria bancrofti. IgE response to a filarial a llergen Sd30 was evaluated in hydrocele patients living in a W. bancrofti e ndemic region of Orissa, India. Methods : IgE levels to Sd30, an antigenic fraction isolated from Setaria d igitata, were determined By ELISA in sera from patients of filariasis (n=93 ). IgG and IgM levels were also determined. Results :It was observed that microfilaraemic patients with hydrocele (n=16 ) exhibited considerably reduced (P<0.01) IgE levels in comparison to hydro cele patients without microfilariae (n=27) and to other filarial groups (el ephantiasis, asymptomatic microfilaraemics). The reduced IgE response in mi crofilariae positive patients with hydrocele persisted even after a gap of four years in the majority of patients. Interpretation & conclusions : The results show low IgE levels in microfila raemic patients with hydrocele in comparison to other groups in filaria end emic regions. The exact mechanism of this reduction in IgE, is not known bu t these patients make a distinct group in filaria endemic regions and shoul d be considered separately for immunological evaluation.