High Molecular Weight Proteins ofTrypanosoma cruziReduce Cross-Reaction withLeishmaniaspp. in Serological Diagnosis Tests

Abstract

Chagas disease is caused by the parasiteTrypanosoma cruzi. Because of its distribution throughout Latin America, sometimes it can overlap with other parasitic diseases, such as leishmaniasis, caused byLeishmaniaspp. This might represent a problem when performing serological diagnosis, because both parasites share antigens, resulting in cross-reactions. In the present work we evaluated Mexican sera samples: 83.8% of chagasic patients recognized at least one antigen of high molecular weight (>95 kDa) when evaluated by Western blot. Proteins of 130 kDa and 160 kDa are predominantly being recognized by asymptomatic chagasic patients. When the proteins were extracted using Triton X-100 detergent, a larger number of specificT. cruziproteins were obtained. This protein fraction can be used to increase specificity to 100% in Western blot assays without losing sensitivity of the test. High molecular weight proteins ofT. cruziinclude glycoproteins with a great amount ofαMan (α-mannose),αGlc (α-glucose), GlcNAc (N-acetylglucosamine), andαGal (α-galactose) content and these structures play an essential role in antigens recognition by antibodies present in patients’ sera.