Systematic review: noncoeliac gluten sensitivity.

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. Aim 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. [ABSTRACT FROM AUTHOR]