Study of the interstitial cells of Cajal in infantile hypertrophic pyloric stenosis

Background & Aims: The interstitial cells of Cajal form a network in close association with the smooth muscle of the gut. They are regarded as pacemaker cells and might be involved in motility disorders. Their distribution was studied in a common disorder with a dysfunction of the pyloric sphincter called infantile hypertrophic pyloric stenosis. Methods: Specimens from 27 infants with pyloric stenosis and 12 controls were processed for immunohistochemistry using a specific antiserum raised against c-kit, a tyrosine kinase receptor expressed by interstitial cells. Results: In the normal pylorus, numerous interstitial cells were labeled throughout the tissue. In pyloric stenosis, c-kit immunoreactivity was absent in the major part of the tissue. Interstitial cells were observed only in the inner part of the musculature, near the submucosal edge, and in the antrum, at the proximal end of the biopsy specimens. Conclusions: The lack of interstitial cells in the pylorus possibly contributes to the motility disturbance of infantile pyloric stenosis.