Lactase persistence, NOD2 status and Mycobacterium avium subsp. paratuberculosis infection associations to Inflammatory Bowel Disease

In our study, CD and UC patients and controls from the North of Spain were genotyped for the lactase gene (LCT) and for three NOD-2 variants, R702W, G908R and Cins1007fs. MAP PCR was carried out in order to assess MAP infection status and these results were correlated with LCT and NOD2 genotypes.As for LP, no association was found with IBD, although UC patients were less likely to present the T/T？13910 variant compared to controls, showing a higher C-allele frequency and a tendency to lactase non-persistence (LNP). NOD2 mutations were associated to CD being the per-allele risk higher for the Cins1007fs variant. MAP infection was more extended among the healthy controls (45.2%) compared to CD patients (21.38%) and UC patients (19.04%) and this was attributed to therapy. The Asturian CD cohort presented higher levels of MAP prevalence (38.6%) compared to the Basque CD cohort (15.5%), differences also attributed to therapy. No interaction was found between MAP infection and LCT or NOD2 status.We conclude that LP is not significantly associated with IBD, but that MAP infection and NOD2 do show not mutually interacting associations with IBD.Inflammatory bowel disease (IBD) is a pathological enteritis characterized by chronic regional inflammatory infiltrate of the intestinal wall and associated lymph nodes that comprises Crohn’s disease (CD) and ulcerative colitis (UC). Etiology of IBD remains unclear, although inflammation can be a result of inappropiate chronic activation of the innate and adaptive mucosal immune systems in individuals with genetic modifications [1]. Exposure to pathogens seems to be a potential cofactor for disease development [2] meaning that the disease could be induced by an infectious agent in genetically susceptible individuals. Mycobacterium avium subsp. paratuberculosis (MAP) is a probable pathogen candidate for at least one subtype of IBD, CD, since it is responsible for a disease in ruminants of similar clinical and histological conditions na