Differences in response of the proximal esophagus to wet swallows in patients of Chagas' disease and idiopathic achalasia.

Chagas' disease and idiopathic achalasia have similar esophageal manifestations such as absent or incomplete lower esophageal sphincter relaxation and aperistalsis in the esophageal body (alterations seen mainly in the distal esophageal body). Our aim in this paper was to study the response of the proximal esophageal body to wet swallows in patients with Chagas' disease and patients with idiopathic achalasia. We retrospectively analyzed the time interval between the onset of the pharyngeal contractions 1 cm proximal to the upper esophageal sphincter, as well as 5 cm distal to the pharyngeal measurement. Amplitude, duration and area under the curve of contractions in the proximal esophagus were also determined in 42 patients with Chagas' disease (15 with associated esophageal dilatation), 21 patients with idiopathic achalasia (14 with concomitant esophageal dilatation) and 31 control subjects. The time between the onset of pharyngeal and proximal esophageal contractions was longer in patients with Chagas' disease and in those with esophageal dilatation (1.39 +/- 0.16 s) than in control subjects (0.86 +/- 0.04 s, P < 0.01). The amplitude of proximal esophageal contractions was lower in patients with idiopathic achalasia and esophageal dilatation (60.9 +/- 16.3 mmHg) than in control subjects (89.7 +/- 6.9 mmHg, P = 0.06). The authors conclude that in patients with advanced esophageal disease, the proximal esophageal contractions in Chagas' disease have a delayed response to wet swallows when compared with controls, and that the amplitude of proximal esophageal contractions was lower than expected in patients with idiopathic achalasia.

Functional implications of circulating muscarinic cholinergic receptor autoantibodies in chagasic patients with achalasia.

BACKGROUND & AIMS: Autoantibodies against M(2)-muscarinic acetylcholine receptors (M(2) mAChR) have been reported in patients with chronic Chagas' disease who have cardiac dysautonomia. The aim of this study was to investigate the presence of such antibodies in chronic chagasic and non-chagasic patients with esophageal achalasia and their ability to activate M(2) mAChR in the isolated esophagus. METHODS: Enzyme-linked immunosorbent assay was used to detect serum immunoglobulin (Ig) G antibodies against a synthetic 24-mer peptide corresponding to the second extracellular loop of human M(2) mAChR. The effects of both total serum IgG and affinity-purified antipeptide antibodies on the contractile activity and adenosine 3', 5'-cyclic monophosphate (cAMP) production in rat esophageal strips were also tested. RESULTS: Circulating IgG antibodies from chagasic achalasia patients recognized the M(2)-peptide more often than those from non-chagasic achalasia patients (P < 0.0005) and normal subjects (P < 0.0001). A strong association between the existence of circulating anti-M(2) mAChR antibodies and the presence of achalasia in chagasic patients was found (P < 0.01). Both the total IgG fraction and anti-M(2)-peptide antibodies increased the basal tone, reduced the relaxant effect of isoproterenol, and decreased cAMP accumulation in esophageal strips, displaying a muscarinic agonist-like activity on M(2) mAChR. CONCLUSIONS: Patients with chronic Chagas' disease have circulating autoantibodies against M(2) mAChR. These antibodies could be involved in the pathophysiological mechanism of chagasic achalasia.