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Gut 56:203-209 doi:10.1136/gut.2006.100594
  • Irritable bowel syndrome

Diarrhoea-predominant IBS patients show mast cell activation and hyperplasia in the jejunum

  1. Mar Guilarte1,
  2. Javier Santos2,
  3. Inés de Torres3,
  4. Carmen Alonso2,
  5. María Vicario2,
  6. Laura Ramos2,
  7. Cristina Martínez2,
  8. Francesc Casellas2,
  9. Esteban Saperas2,
  10. Juan Ramón Malagelada2
  1. 1Allergy Unit and Digestive Diseases Research Unit, Hospital Universitari Vall d’Hebron, Department of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain
  2. 2Digestive Diseases Research Unit, Department of Gastroenterology, Hospital Universitari Vall d’Hebron, Department of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain
  3. 3Department of Pathology, Hospital Universitari Vall d’Hebron, Department of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain
  1. Correspondence to:
    Dr Javier Santos
    Digestive Diseases Research Unit, Institut de Recerca Vall d’Hebron, Hospital General Vall d’Hebron, Paseo Vall d’Hebron 119-129, 08035 Barcelona, Spain; jsantos{at}ir.vhebron.net
  • Received 16 August 2006
  • Accepted 17 August 2006
  • Published Online First 27 September 2006

Abstract

Background: Increased numbers of mast cells and mast cell activation in distal gut segments are associated with symptom onset and severity in irritable bowel syndrome (IBS). Although upper gut symptoms are common, mast cells have not been thoroughly evaluated in proximal gut in IBS patients.

Methods: Jejunal biopsies obtained by Watson’s capsule, aspiration of intestinal fluid and one blood sample were obtained in 20 diarrhoea-predominant patients with IBS (D-IBS) and 14 healthy volunteers (H). Psychological stress (Holmes-Rahe Scale) and depression (Beck’s Depression Inventory) were evaluated at baseline and food and respiratory allergy excluded. Biopsies were processed for H&E staining and microscopic inflammation assessed by counting intraepithelial lymphocytes. Mast cells in lamina propria were counted by immunohistochemistry with CD117 (c-kit). Tryptase concentration was measured in intestinal fluid and serum.

Results: D-IBS patients showed higher psychological stress than healthy volunteers (D-IBS: 203 (SD 114) v H: 112 (SD 99); p = 0.019). Immunohistochemical staining of jejunal mucosa revealed mild increase in intraepithelial CD3+ cells in D-IBS patients (D-IBS: 15.3 (SD 5.5; 95% CI 12.7 to 17.9) v H: 10.3 (SD 3.9; 95% CI 8.0 to 12.5); p = 0.006). Moreover, D-IBS patients showed marked increase in mast cells numbers (D-IBS: 34 (SD 9.3); H: 15.3 (SD 4.4) mast cells/hpf; p<0.001) and higher tryptase concentration in jejunal fluid (D-IBS: 0.45 (SD 0.38); H: 0.09 (SD 0.10) µg/l; p = 0.005). Upper gut symptoms were not associated with gender, mast cell counts, jejunal tryptase or basal stress.

Conclusion: This jejunal mucosal inflammatory profile may help identify diarrhoea-predominant IBS, a stress-related disorder.

Footnotes

  • Published Online First 27 September 2006

  • Grant support: Supported in part by the Spanish Ministry of Sanidad y Consumo, Subdirección General de Investigación Sanitaria, Instituto Carlos III, Fondo de Investigación Sanitaria. JS (F.I.S. 01/3134 and F.I.S. 02/0190), CA (CM04/00019) and LR (CM05/00055) were the recipients of these grants.

  • Competing interests: None.