Presence of IgM antibodies to Trypanosoma cruzi urinary antigen in sera from patients with acute Chagas' disease

CORRAL RS; ALTCHEH JM; FREILIJ HL

INTERNATIONAL JOURNAL FOR PARASITOLOGY

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 1998 vol. 28 p. 589 - 594

0020-7519

An 80-kilodalton Trypanosoma cruzi antigen is eliminated in the urine of infectedhosts during the acute stage of Chagas' disease. We show that affinity-purifiedurinary antigen is recognised by IgM antibodies in the sera from acute chagasicpatients. Comparing our urinary antigen assay with that using a whole T. cruzilysate antigen for IgM antibody detection, we demonstrated that ELISA withurinary antigen increases the diagnostic sensitivity and specificity of IgMserology in recent chagasic infection. Twenty-six of 30 patients with acute T.cruzi infection had serum IgM antibodies that reacted with urinary antigen byELISA, while lysate antigen IgM was detected in 24 sera. When sera from patients suffering other parasitoses were tested, strong cross-reactions occurred in ELISAwith T. cruzi lysate antigen, whereas ELISA with urinary antigen proved to betterdiscriminate acute chagasic patients. Human antibodies to urinary antigenimmunoprecipitated this T. cruzi urinary antigen and also inhibited the bindingof monoclonal antibody to urinary antigen in an inhibition assay. These findings suggest that urinary antigen may be useful for the development of serodiagnostic procedures for acute T. cruzi infection