Differential cellular reactivity to adult worm antigens of patients with different clinical forms of schistosomiasis mansoni.

Analysis of the proliferation in vitro of peripheral blood mononuclear cells and the production of interferon-gamma (IFN-gamma) in individuals infected with Schistosoma mansoni and showing different clinical forms of the disease, as well as normal putatively immune individuals from an endemic area, was undertaken using total and fractionated soluble adult worm antigens (SWAP). A higher frequency of detectable response to fractionated antigens in T cell Western blot assays was observed in individuals with the more severe forms of the disease. Analysis of variance showed that, in the Western blot assays, there was a statistically significant difference in the level of cellular proliferation to antigens with low molecular weight (less than 21 kDa) between hepatosplenic patients and those with intestinal and hepatointestinal forms of the disease. No correlation between cellular proliferation and IFN-gamma production was observed. Most of the normal individuals from an endemic area failed to show significant proliferative responses to SWAP T cell Western blot assays or to antigen immobilized on nitrocellulose; they did show significant proliferative responses to whole soluble SWAP with positive IFN-gamma production. The results are consistent with the hypothesis that variations in the cellular immune responses to SWAP influence both the development of pathology and resistance to infection in schistosomiasis mansoni.