Lymphocyte transformation in Chagas disease.

The in vitro response of human peripheral lymphocytes to Trypanosoma (Schizotrypanum) cruzi antigens and to phytohemagglutinin was used to study the role of cellular immunity in Chagas disease (American trypanosomiasis). Solubilized T. cruzi antigens elicited 5 to 30% transformed cells in 5-day cultures of lymphocytes from adults chronically infected with T. cruzi. No major difference was noted between the response of 22 asymptomatic individuals and of 3 patients with chagasic cardiopathy. No correlation was found between degree of lymphocytic transformation and serum antibody titer. Lymphocytes from 15 normal controls yielded no significant transformation. Intradermal tests provoked a local delayed hypersensitivity reaction in infected individuals only, as evaluated clinically and histologically. The response to phytohemagglutinin of lymphocytes from chronically infected individuals was identical with that of normal controls.