RESUMO
Mice experimentally infected with H. nana and injected with immunosuppressant [cyclophosphamide [Cp] and lead nitrate [Ln] showed significant increase in infection intensity, significant decrease in intestinal mast cell count, dissemination of larvae to the liver, toxic hepatitis and absence of specific serum IgG. Cyclophosphamide caused morphological abnormalities in adult worms, prolongation of patent period and more severe villous changes. Immuno-stimulants represented by Levamisol [Lv] and gamma interferon [IFN-alpha] caused significant decrease in infection intensity, significant shortening of patent period and early improvement of histopathological changes. Immunostimulants, particularly IFN-alpha, were highly effective in counteracting hyperi nfection seen with immuno-suppression. The study confirmed the deleterious effects of immunosuppression on hymenolepiasis and suggested a beneficial role for immunotherapy for immunosuppressed patients