The Number of Cajal Cells in Muscle Layer of the Esophagus in Patients With Achalasia

Background Cajal cells (interstitial pacemaker cells), due to spontaneous electrical activity, cause the contraction of smooth muscle cells, and regulate the motility of the gastrointestinal tract along with neuronal structures. Data on the number of these cells in the muscle lining of the esophagus in achalasia are few and contradictory. The aim of our study was to investigate the distribution of cells regulating motility in the muscular layer of the esophagus in patients with achalasia. Methods Seven patients with achalasia were included in this study. During the peroral endoscopic myotomy and the formation of a tunnel in the esophagus before dissection a biopsy of the muscle membrane was performed at the level of the upper, middle and lower third of the esophagus. An immunohistochemical reaction with CD117 antibodies (c-kit) was used to detect Cajal cells. The number of positive cells was counted at an increase of x500 in 5 random fields of vision. The detection of neuronal structures was carried out using an immunohistochemical reaction with antibodies to the S100 protein, followed by a semi-quantitative assessment. Results Histological examination in the upper third of the esophagus found small groups of striated muscle fibers among the bundles of smooth muscle cells. Cajal cells in the upper third of the esophagus were not numerous 2.2 [0–10]. Their number increased in the middle third of 6.8 [3–15] and reached a maximum in the lower third of the esophagus of 11.3 [10–25]. S100-positive neuronal structures among bundles of smooth muscle cells were rare, and in some cases were not detected at all. Conclusion The quantitative distribution of Cajal cells in the muscular layer of the esophagus in patients with achalasia is uneven with a significant increase in the lower third of the esophagus, against the background of a deficiency of neuronal structures in smooth muscle tissue.