title: Systematic review: noncoeliac gluten sensitivity.
abstract: BACKGROUND
  Noncoeliac gluten sensitivity (NCGS) is a controversial emerging disorder. Despite reported symptoms related to the ingestion of gluten, NCGS remains a diagnosis based on the exclusion of coeliac disease, given the absence of reliable biomarkers.
  
  
  OBJECTIVE
  To evaluate the prevalence, diagnostic exclusion of coeliac disease and the efficacy of a gluten-free diet (GFD) for NCGS patients.
  
  
  METHODS
  A PubMed search was performed up to December 2014. According to consensus diagnostic criteria, NCGS was defined as self-reported gluten intolerance, negative coeliac serology and absence of villous atrophy. Studies evaluating the impact of a GFD on patients with irritable bowel syndrome (IBS) were also included.
  
  
  RESULTS
  Prevalence rates of NCGS (0.5-13%) differed widely. Seventeen studies, including 1561 patients (26 children), met the inclusion criteria for NCGS. HLA haplotypes could not be linked to histology [normal or lymphocytic enteritis (LE)] in 1123 NCGS patients. HLADQ2/DQ8 haplotypes were present in 44% of NCGS patients. After advanced diagnostic techniques in 189 NCGS patients combining LE and HLADQ2/DQ8 haplotypes, 39 (20%) were reclassified as coeliac disease. There was a higher than expected family history of coeliac disease and autoimmune disorders in NCGS patients. A GFD resulted in variable results for variable, but significantly improved stool frequency in HLADQ2 positive diarrhoea-predominant IBS patients.
  
  
  CONCLUSIONS
  Prevalence rates for NCGS are extremely variable. A subset of NCGS patients might belong in the so-called 'coeliac-lite' disease. The benefit of a GFD for NCGS patients is currently controversial. HLADQ2 positive diarrhoea-type IBS patients might gain symptom improvement from a GFD.
authors.affiliation: Department of Gastroenterology, Hospital San Pedro de Alcantara, Caceres, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Molina-Infante
authors.forename: S
authors.initials: S
authors.lastname: Santolaria
authors.forename: D S
authors.initials: DS
authors.lastname: Sanders
authors.forename: F
authors.initials: F
authors.lastname: Fernández-Bañares
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D002446:Celiac Disease / Q000175:diagnosis / Q000178:diet therapy; D003967:Diarrhea / Q000453:epidemiology / Q000209:etiology; D055050:Diet, Gluten-Free; D005260:Female; D005512:Food Hypersensitivity / Q000178:diet therapy*; D005983:Glutens / Q000009:adverse effects; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000178:diet therapy*; D008297:Male; D015995:Prevalence
chemical_list: D015415:Biomarkers; D005983:Glutens