Presence of eosinophils may represent an earlier stage in achalasia pathogenesis

Background: Intraepithelial eosinophils have been described in patients with esophageal motor disorders. Conversely, motor disorders and even achalasia have been reported in patients with eosinophilic esophagitis (EoE). Objectives: This prospective study aimed to further investigate the association between eosinophilia and achalasia. Design: This is a prospective study. Methods: A series of 30 consecutive treatment-naïve achalasia patients (mean age: 45.5 years, 53% female) undergoing laparoscopic myotomy were prospectively enrolled. Preoperative demographic and clinical data, radiological findings, and high-resolution manometry (HRM) features were collected. Patients underwent upper endoscopy with biopsy sampling before surgery, and two samples of distal esophageal muscle were obtained during myotomy. Histopathologic findings were analyzed, and clinical characteristics were compared based on the presence and absence of eosinophils on biopsy samples. Results: Intraepithelial eosinophils were found in seven patients (23%; mean 8 eos/high-power field, 95% CI 0-15), but only one patient demonstrated >15 eos/high-power field, and one had eosinophilic infiltration of the esophageal muscle. Patients with intraepithelial eosinophilia had a narrower esophageal diameter on barium radiography (2.4 vs 3.6 cm without eosinophilia, p < 0.05). There were no additional differences in histopathology or preoperative and postoperative data between patients with and without intraepithelial eosinophilia. Conclusion: Our study confirmed that intraepithelial and intramuscular eosinophils are present in some patients with achalasia, but seldom meet the criteria for EoE. Only a narrower esophagus was found in patients with intraepithelial eosinophils as compared to those without, possibly reflecting an earlier stage of the disease.