Anti-M2-pyruvate kinase autoantibodies are correlated with digestive damage in human Chagas disease.

Background: Determining esophageal and colon involvement in patients with Chagas disease occurs through invasive and uncomfortable examinations, which in most cases are not performed. The objective of this study was to assess the involvement of anti-M2-pyruvate kinase (M2-PK) autoantibodies in the development of digestive alterations and/or in the diagnosis of the digestive form of human Chagas disease.

Methods: The total IgG and isotype (IgG1, IgG2, IgG3, IgG4) production was quantified using the antigen of Trypanosoma cruzi and the human M2-PK recombinant protein via the ELISA technique. The tests were conducted with serum samples from patients with indeterminate, cardiac, digestive and cardiodigestive clinical forms of Chagas disease, and the results were correlated with the dilatation degree of the esophagus and colon.

Results: Patients with the digestive form of Chagas disease had higher IgG4 anti-M2-PK autoantibody production compared with patients with the indeterminate and cardiac forms and the healthy control group. Furthermore, a positive correlation was observed between sigmoid and rectum size with IgG4 anti-M2-PK autoantibody production.

Conclusions: These results demonstrate that IgG4 anti-M2-PK autoantibodies correlate with digestive damage in human Chagas disease, and their presence may also be implicated in the development of digestive lesions.