[Presence of antibodies to cardiac neuroreceptors in patients with Chagas disease].

Introduction: The presence of antibodies against cardiac neuroreceptors has been established in several kinds of heart diseases as well as in Chagas disease. The antibody type most frequently identified is that which recognizes the muscarinic acetyl choline receptor type II (anti-m2MAChR).

Objective: The frequency of the anti-m2MAChR was determined in a group of Colombian patients with permanent pacemaker implantation and Chagas disease.

Materials And Methods: Fifty-two patients with Chagas disease and permanent heart pacemaker implantation were matched by implantation diagnosis with 52 individuals that required pacemaker, but without Chagas disease. The presence of antibodies that recognized the m2MACh was assessed in the two groups by ELISA and Western blot by using two peptide sequences of the (m2MAChR), the second extracellular domain (2e) and the third intracellular domain (3i).

Results: Serological response frequency against 2e-m2MAChR in Chagas patients was 32.7% compared with 3.8% (p<0.01) in the controls; response against 3i-m2MAChR was 51.9% compared with 19.2% (p<0.01) for the controls. No clinical differences were observed between individuals that presented anti-m2MAChR and those who did not.

Conclusion: The frequency of anti-m2MAChR was higher in patients with Chagas disease for two of the receptor domains. Furthermore, patients with pacemaker therapy are more likely to have anti-m2MAChR and infection by Trypanosoma cruzi. The anti-m2MAChR response is not associated with any discernable clinical manifestation in this group of patients.