title: High densities of serotonin and peptide YY cells in the colon of patients with lymphocytic colitis.
abstract: OBJECTIVE
  To investigate colonic endocrine cells in lymphocytic colitis (LC) patients.
  
  
  METHODS
  Fifty-seven patients with LC were included. These patients were 41 females and 16 males, with an average age of 49 years (range 19-84 years). Twenty-seven subjects that underwent colonoscopy with biopsies were used as controls. These subjects underwent colonoscopy because of gastrointestinal bleeding or health worries, where the source of bleeding was identified as haemorrhoids or angiodysplasia. They were 19 females and 8 males with an average age of 49 years (range 18-67 years). Biopsies from the right and left colon were obtained from both patients and controls during colonoscopy. Biopsies were fixed in 4% buffered paraformaldehyde, embedded in paraffin and cut into 5 μm-thick sections. The sections immunostained by the avidin-biotin-complex method for serotonin, peptide YY (PYY), pancreatic polypeptide (PP) enteroglucagon and somatostatin cells. The cell densities were quantified by computerised image analysis using Olympus software.
  
  
  RESULTS
  The colon of both the patient and the control subjects were macroscopically normal. Histopathological examination of colon biopsies from controls revealed normal histology. All patients fulfilled the diagnosis criteria required for of LC: an increase in intraepithelial lymphocytes (> 20 lymphocytes/100 epithelial cells) and surface epithelial damage with increased lamina propria plasma cells and absent or minimal crypt architectural distribution. In the colon of both patients and control subjects, serotonin-, PYY-, PP-, enteroglucagon- and somatostatin-immunoreactive cells were primarily located in the upper part of the crypts of Lieberkühn. These cells were basket- or flask-shaped. There was no statistically significant difference between the right and left colon in controls with regards to the densities of serotonin- and PYY-immunoreactive cells (P = 0.9 and 0.1, respectively). Serotonin cell density in the right colon in controls was 28.9 ± 1.8 and in LC patients 41.6 ± 2.6 (P = 0.008). In the left colon, the corresponding figures were 28.5 ± 1.9 and 42.4 ± 2.9, respectively (P = 0.009). PYY cell density in the right colon of the controls was 10.1 ± 1 and of LC patients 41 ± 4 (P = 0.00006). In the left colon, PYY cell density in controls was 6.6 ± 1.2 and in LC patients 53.3 ± 4.6 (P = 0.00007).
  
  
  CONCLUSIONS
  The change in serotonin cells could be caused by an interaction between immune cells and serotonin cells, and that of PYY density might be secondary.
authors.affiliation: Section for Gastroenterology, Department of Medicine, Stord Helse-Fonna Hospital, Box 4000, 5409 Stord, Norway. magdy.el-salhy@helse-fonna.no
authors.forename: Magdy
authors.initials: M
authors.lastname: El-Salhy
authors.forename: Doris
authors.initials: D
authors.lastname: Gundersen
authors.forename: Jan Gunnar
authors.initials: JG
authors.lastname: Hatlebakk
authors.forename: Trygve
authors.initials: T
authors.lastname: Hausken
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D016022:Case-Control Studies; D046730:Colitis, Lymphocytic / Q000378:metabolism* / Q000473:pathology; D003106:Colon / Q000737:chemistry* / Q000473:pathology; D003113:Colonoscopy; D019858:Enteroendocrine Cells / Q000737:chemistry* / Q000473:pathology; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D019894:Peptide YY / Q000032:analysis*; D011237:Predictive Value of Tests; D012701:Serotonin / Q000032:analysis*; D055815:Young Adult
chemical_list: D019894:Peptide YY; D012701:Serotonin