Evidence that cellular immune responses to soluble and membrane associated antigens are independently regulated during human schistosomiasis mansoni.

We have made a comparative analysis of human cellular and antibody responses to membrane associated adult worm antigens (Mb-A), soluble adult worm antigens (SWAP) and soluble egg antigens (SEA) derived from Schistosoma mansoni. Chronically infected patients with the intestinal (I) and hepatosplenic (HS) forms of the disease as well as non-infected putative immune 'endemic normals' (EN), were studied. We observed that the cellular responses, of individuals, to the two adult worm preparations, SWAP and Mb-A, may be distinct and can be related to the occurrence of resistance or pathology. The resistant group (EN) presented higher levels of both cellular proliferation, and IFN-gamma production, in response to Mb-A as compared with SWAP whereas HS individuals presented higher levels of cellular proliferation to SWAP as compared with Mb-A. Individuals with intestinal disease had similar levels of proliferation to both antigens. The response to SEA by all groups was generally similar, and not predictive of any clinical form. The specific antibody response to the three antigens were in general higher among infected patients than in resistant EN individuals. These results support the hypothesis that the response to adult worm antigens may be pivotal in determining both the development of resistance and severity of disease.