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

Objectives. To study intestinal endocrine cell types in patients suffering from myotonic dystrophy (MD) and diarrhoea. Design. Comparative study between MD patients and matched controls. Setting. Departments of Medicine, Central Hospital, Boden, and University H ospital, Umea, Sweden. Subjects. Ten patients with MD (four males and six females) and suffering f rom diarrhoea. Ten healthy volunteers served as controls for the duodenal s tudy and 13 patients under investigation for rectal bleeding and with endos copically normal mucosa were controls for the rectal study. Measurements. The duodenal and rectal endocrine cell types were identified by immunohistochemical investigation and quantified by computed image analy sis. Results. The total endocrine cell area in the duodenum as demonstrated by c hromogranin A-immunoreactivity was significantly increased in MD as compare d with the controls (126 +/- 58 vs. 48 +/- 22 x 10(3) mu m(2) mm(-2) in cry pts and 230 +/- 183 vs. 28 +/- 22 in villi, respectively, P < 0.01). The in crease 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 ar ea 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)-, pancre atic polypeptide (PP)- or somatostatin-immunoreactive cells. Conclusions. The increase in endocrine cell area indicates a disturbed endo crine regulation of the gastrointestinal tract that may contribute to the d evelopment of gastrointestinal symptoms encountered in MD patients.