Cross-reactivity of antibodies in human infections by the kinetoplastid protozoa Trypanosoma cruzi, Leishmania chagasi and Leishmania (Viannia) braziliensis Reatividade cruzada de anticorpos em pacientes com infecções pelos protozoários Trypanosoma cruzi, Leishmania chagasi e Leishmania (Viannia) braziliensis

• Published in: Revista do Instituto de Medicina Tropical de São Paulo
• Main Authors: Ana de Cássia Vexenat, Jaime M. Santana, Antonio R.L. Teixeira
• Format: Article in Journal/Newspaper
• Language: English
• Published: Universidade de São Paulo (USP) 1996
• Subjects: Kinetoplastid protozoa; Trypanosoma cruzi; Leishmania chagasi; Leishmania (Viannia) braziliensis; Cross-reactive antibodies; Human infections; Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic; Azar
• Online Access: https://doi.org/10.1590/S0036-46651996000300003; https://doaj.org/article/16e20b6d0b4e4d68a81d34acd0fc8f7f

We have detected antibodies, in the sera of Chagas disease, Kala-azar and Mucocutaneous leishmaniasis patients, that bind multiple antigens shared between the three causative agents. The Chagas disease sera showed 98 to 100% positive results by ELISA when the Leishmania braziliensis and Leishmania chagasi antigens were used, respectively. The Kala-azar sera showed 100% positive results with Trypanosoma cruzi or L. braziliensis antigens by immunofluorescence assays. The antibodies in the sera of Mucocutaneous leishmaniasis patients showed 100% positive results by ELISA assays with T. cruzi or L. chagasi antigens. Furthermore, the direct agglutination of L. chagasi promastigotes showed that 95% of Kala-azar and 35% of Mucocutaneous leishmaniasis sera agglutinated the parasite in dilutions above 1:512. In contrast, 15% of Chagas sera agglutinated the parasite in dilutions 1:16 and below. Western blot analysis showed that the Chagas sera that formed at least 24 bands with the T. cruzi also formed 13 bands with the L. chagasi and 17 bands with the L. braziliensis. The Kala-azar sera that recognized at least 29 bands with the homologous antigen also formed 14 bands with the T. cruzi and 10 bands with the L. braziliensis antigens. Finally, the Mucocutaneous leishmaniasis sera that formed at least 17 bands with the homologous antigen also formed 10 bands with the T. cruzi and four bands with the L. chagasi antigens. These results indicate the presence of common antigenic determinants in several protozoal proteins and, therefore, explain the serologic cross-reactions reported here. Foram detectados anticorpos, nos soros de pacientes com doença de Chagas, Calazar e Leishnnaniose cutâneo-mucosa, que se ligam a antígenos compartilhados pelos três agentes causais. Os pacientes chagásicos mostraram 98 a 100% de soropositividade pelo ELISA quando antígenos de Leishmania braziliensis e de Leishmania chagasi foram usados, respectivamente. Os soros de Calazar mostraram resultados positivos com antígenos de Trypanosoma cruzi ou ...