Immunopathology of schistosomiasis in athymic mice

EOSINOPHILIA—tissue eosinophil infiltrates—granuloma and IgE formation are associated with helminth infections. Eosinophils phagocytose antigen-antibody complexes, neutralise histamine and serotonin, mediate inflammatory reactions and modify delayed hypersensitivity 1 . The tissue-invasive stage of some parasitic infections provides suitable antigen and stimulates the production of IgE, which in turn induce eosinophilotaxis. We have investigated the need of T-cell participation in the eosinophil response, IgE formation and granuloma formation in schistosomiasis in con-genitally athymic mice which have profound deficiency in T-cell dependent immune response. We looked in particular at eggs as they are important in the pathogenesis of schistosomiasis. They are trapped in tissues and induce chronic granulomatous inflammation with numerous eosinophils. Warren et al. 2–6 reported that egg granuloma is a cell-mediated hypersensitivity reaction and it is significantly altered in immunosuppressed mice.