title: The role of colonic mast cells and myenteric plexitis in patients with diverticular disease.
abstract: BACKGROUND
  Gut mast cells represent an important cell population involved in intestinal homeostasis and inflammatory processes. However, their possible role has not to date been investigated in colonic diverticular disease.
  
  
  OBJECTIVE
  This study aims to evaluate colonic mast cells in patients undergoing surgery for diverticular disease.
  
  
  METHODS
  Surgical resection samples from 27 patients undergoing surgery for diverticular disease (12 emergency procedures for severe disease and 15 elective procedures) were evaluated. The number of mast cells was assessed in the various layers by means of a specific antibody (tryptase) and compared with those evaluated in ten controls. In patients with mast cells degranulation, double immunohistochemistry, also assessing nerve fibres, was carried out. In addition, the presence of myenteric plexitis was sought.
  
  
  RESULTS
  Compared with controls, the number of mast cells in diverticular patients was significantly increased, both as an overall figure and in the various layers of the large bowel. In patients in whom mast cells degranulation was present, these were always closed to nerve fibres. No differences were found between the two subgroups of patients with respect to the number and distribution of mast cells; however, all patients undergoing emergency surgery (but none of those undergoing elective procedures) had myenteric plexitis, represented by lymphocytic infiltration in 67 % and eosinophilic infiltration in 33 % of cases.
  
  
  CONCLUSIONS
  Patients with diverticular disease display an increase of mast cells in the large bowel. The presence of myenteric plexitis in those with complicated, severe disease, suggest that this could represent a histopathologic marker of more aggressive disease.
authors.affiliation: Gastroenterology and Hepatology Section, Department of Clinical and Experimental Medicine, University of Perugia, Perugia, Italy. gabassot@tin.it
authors.forename: Gabrio
authors.initials: G
authors.lastname: Bassotti
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Villanacci
authors.forename: Riccardo
authors.initials: R
authors.lastname: Nascimbeni
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Antonelli
authors.forename: Moris
authors.initials: M
authors.lastname: Cadei
authors.forename: Stefania
authors.initials: S
authors.lastname: Manenti
authors.forename: Luisa
authors.initials: L
authors.lastname: Lorenzi
authors.forename: Amin
authors.initials: A
authors.lastname: Titi
authors.forename: Bruno
authors.initials: B
authors.lastname: Salerni
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D015550:Cell Degranulation; D003106:Colon / Q000473:pathology*; D004238:Diverticulitis / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008407:Mast Cells / Q000473:pathology* / Q000502:physiology; D008875:Middle Aged; D009197:Myenteric Plexus / Q000473:pathology*; D009412:Nerve Fibers / Q000473:pathology