Characterization of esophageal inflammation in patients with achalasia. A retrospective immunohistochemical study

Autoimmunologic phenomena triggered by CD8-positive cytotoxic T cells may be involved in the pathogenesis of achalasia, but the pathogenic mechanisms generally remain unknown, and the concomitant histopathologic changes in the esophageal epithelium in achalasia are incompletely described. This study was designed to characterize the inflammation within the esophageal epithelium of these patients. We collected 72 esophageal specimens from 38 consecutive patients with achalasia (16 men, 22 women) representing different disease stages. The inflammatory cells were characterized immunohistochemically. Seven end-stage disease esophagectomy specimens were also included. Our data show a T-cell–rich inflammatory response predominantly composed of CD4-positive T cells with an overall CD4/CD8 ratio of 1.82 and only few CD4-CD25-FoxP3–positive regulatory T cells or CD20-positive B cells. Signs of inflammation were most pronounced in the middle esophagus, followed by upper and lower esophagus. Between different stages of disease, there were statistically significant differences among CD25-positive lymphocytes in the upper esophagus and CD4-, CD8-, and CD25-positive lymphocytes in the middle esophagus. The esophageal epithelial inflammation in achalasia seems to be of reactive and unspecific nature and does not reflect the composition of the CD8-dominant inflammatory infiltrate within the muscular esophageal wall in active disease. The statistically significant differences in unspecific inflammation between different stages of disease are more likely due to effects of the dysmotility and cannot be assumed pathognomic for the disease. In conclusion, we assume that it is not possible to diagnose or confirm achalasia by means of esophageal biopsy alone. •Little is known about the composition of the inflammatory infiltrate of achalasia.•Our results suggest that esophageal inflammation in achalasia is of reactive nature.•We conclude that it is not possible to diagnose achalasia by means of biopsy alone.