title: Irritable bowel syndrome immune hypothesis. Part one: the role of lymphocytes and mast cells.
abstract: OBJECTIVE
  To review the available evidence on the role of T-lymphocytes and mast cells in the etiopathogenesis of Irritable Bowel Syndrome.
  
  
  METHODS
  Bibliographic retrieval on PubMed including the terms "Irritable Bowel Syndrome, "Immune System", "T-Lymphocytes" and "Mast Cells".
  
  
  RESULTS
  Twenty-five case-control studies and one randomized controlled trial were retrieved. Noteworthy in the blood is the increase in activated T cells destined to migrate to the bowel in these patients. A high frequency of T-lymphocytes is described in the intestinal mucosa, although the study findings are, at times, contradictory. An evident increase in mast cells (and in their activity) between the terminal ileum and descending colon is also observed.
  
  
  CONCLUSIONS
  The heterogeneity of diagnostic criteria and experimentation methods could account for some of the differences in the results found in the selected research. There are indications that give reason to believe these patients have "low-grade intestinal inflammation", and the increase in T-lymphocytes and mast cells has been associated with disorders found in IBS such as the communication between the intestine and the nervous system, the increase in intestinal permeability and changes in the microbiota.
authors.affiliation: Department of Microbiology, Preventive Medicine and Public Health, University of Zaragoza. mariaortizlucas@gmail.com
authors.forename: M
authors.initials: M
authors.lastname: Ortiz-Lucas
authors.forename: P
authors.initials: P
authors.lastname: Saz-Peiró
authors.forename: J J
authors.initials: JJ
authors.lastname: Sebastián-Domingo
mesh_terms: D006801:Humans; D043183:Irritable Bowel Syndrome / Q000276:immunology*; D008214:Lymphocytes / Q000502:physiology*; D008407:Mast Cells / Q000502:physiology*