Deficiency of c-kit+ cells in patients with a myopathic form of chronic idiopathic intestinal pseudo-obstruction.

Objectives: Chronic idiopathic intestinal pseudo-obstruction (CIIP) is a syndrome characterized by a failure of intestinal movement, but the cause of dysmotility remains unknown. Because interstitial cells of Cajal (ICCs) are believed to initiate basic contractile activity of the gastrointestinal tract, there is a possibility that changes in ICCs are involved in the development of CIIP. ICCs express c-kit in mice, and it has been reported that the c-kit+ cells, the location and shape of which resemble those in mice, are detected in the human gastrointestinal muscular layer using immunohistochemistry. In the present study, we counted the number of c-kit+ cells in the affected intestine of two patients with myopathic form of CIIP and compared this number with the number of c-kit+ cells in the normal intestine.
Methods: The c-kit+ cells in the external muscle layer were detected by immunohistochemistry, and the number of them was counted under the microscope. Mast cells, which are known to express c-kit, were detected by staining with Alcian blue, and the number of them was also counted.
Results: Immunohistochemistry revealed that the distribution pattern of c-kit+ cells resembles that of ICCs in the external muscle layer of normal control subjects. The numbers of c-kit+ cells apart from mast cells in two patients with myopathic form of CIIP decreased to about 3% of those in normal subjects.
Conclusions: The failure of intestinal movement in patients with CIIP, at least in a subpopulation, might be related to a deficiency of c-kit+ cells, probably ICCs.