Invitro cellular immunity inChagas' disease

SUMMARY In vitro delayed hypersensitivity wasstudied in patients with either the chronicor the indetermi-nate phase ofChagas' disease. Normal healthy individuals were used as controls. The leucocyte migration inhibition test wasapplied usingas antigen anextract ofculture formsofT. cruzi or an extractofnormalrat heart. Theresults showedthatpatients withthechronicphaseofthe diseasereacted significantly with both antigens, whereas mostpatients with the indeterminate phase didnot react with heart antigen and only five out of fourteen (35%) reacted with T. cruzi antigen. It is suggested that these individuals mayrepresent patients about to develop the chronic phase ofthe disease. Therelevance ofthese findings to the immunemechanism influencing the onset ofthe chronic phase ofChagas' disease is discussed.INTRODUCTIONChagas' disease is a complex clinical entity resulting from the infection of man by an intracellularprotozoan, Trypanosoma cruzi. It is characterized by an initial