Differential proliferative and interleukin-10 responses to fractionated filarial antigens: preferential recognition by patients with chronic lymphatic dysfunction.

To characterize filarial antigens that may be associated with the development of chronic lymphatic dysfunction in persons with lymphatic filariasis, T cell responsiveness to Brugia pahangi adult worm extracts and SDS-PAGE antigen fractions were examined among Haitians from an area in which Wuchereria bancrofti is endemic. Greater T cell proliferation and interleukin-10 (IL-10) production were observed in amicrofilaremic patients with hydrocele or elephantiasis than in amicrofilaremic or microfilaremic asymptomatic persons. Antigen fractions that stimulated the highest proliferative responses (in the 25-49 kDa range) and IL-10 production were not identical. Further separation of an immunodominant 30- to 38-kDa fraction by ion exchange high-pressure liquid chromatography identified several subfractions, including a 32-kDa protein band, that elicited T cell responses from patients with elephantiasis or hydrocele. By immunoblot, these patients also had markedly greater humoral reactivity to parasite antigens of approximately 52, 43, 32, and 30 kDa.