Intestinal endocrine cells in myotonic dystrophy: an immunocytochemical and computed image analytical study

To study intestinal endocrine cell types in patients suffering from myotonic dystrophy (MD) and diarrhoea.

Comparative study between MD patients and matched controls.

Departments of Medicine, Central Hospital, Boden, and University Hospital, Umeå, Sweden.

Ten patients with MD (four males and six females) and suffering from diarrhoea. Ten healthy volunteers served as controls for the duodenal study and 13 patients under investigation for rectal bleeding and with endoscopically normal mucosa were controls for the rectal study.

The duodenal and rectal endocrine cell types were identified by immunohistochemical investigation and quantified by computed image analysis.

The total endocrine cell area in the duodenum as demonstrated by chromogranin A-immunoreactivity was significantly increased in MD as compared with the controls (126 +/- 58 vs. 48 +/- 22 x 10(3) micron 2 mm-2 in crypts and 230 +/- 183 vs. 28 +/- 22 in villi, respectively, P < 0.01). The increase included all types of endocrine cells studied, namely those positive for serotonin, cholecystokinin (CCK)/gastrin, secretin, gastric inhibitory peptide (GIP) and somatostatin. In the rectum, the total endocrine cell area as determined by chromogranin A-immunoreactivity was also significantly increased, but there was no statistical difference between the controls and patients with respect to the area of serotonin-, peptide YY (PYY)-, pancreatic polypeptide (PP)- or somatostatin-immunoreactive cells.

The increase in endocrine cell area indicates a disturbed endocrine regulation of the gastrointestinal tract that may contribute to the development of gastrointestinal symptoms encountered in MD patients.