title: NOD2 gene mutations in ulcerative colitis: useless or misunderstood?
abstract: OBJECTIVE
  NOD2 mutations have been linked to an increased risk of Crohn's disease and to some of its phenotypes. The association between NOD2 mutations and susceptibility to ulcerative colitis (UC) remains somewhat controversial and potential correlations between these mutations and UC phenotype have not been studied.
  
  
  OBJECTIVE
  To assess whether NOD2 mutations are a risk factor for UC in Portugal and if there are any genotype-phenotype correlations in these patients.
  
  
  METHODS
  The three main NOD2 mutations were searched in 200 patients with UC and in 202 healthy controls.
  
  
  RESULTS
  NOD2 mutations were present in 28 patients with UC (14.0 %) and in 27 controls (13.4 %) (p = 0.853). Mutation carriers were more likely to receive steroids during the first year of disease than non-carriers (54.2 % vs. 29.6 %, p = 0.018) and among these patients the need for intravenous administration was more frequent in those with the R702W polymorphism (90.0 % vs. 45.5 %, p = 0.014). In patients with severe colitis admitted for intravenous steroids, a greater proportion of mutation carriers was considered intravenous-steroid refractory and required salvage therapy (90.0 % vs. 38.1 %, p = 0.004). Patients with NOD2 mutation were submitted to colectomy more frequently than non-carriers (17.9 % vs. 4.1 %. p = 0.015). No correlation with the need for immunosuppressants/immunomodulators was found.
  
  
  CONCLUSIONS
  In the Portuguese population, NOD2 mutations do not increase the risk of UC but are associated with a more aggressive course including greater need of steroids in the first year, increased incidence of intravenous-steroid refractoriness and a higher colectomy rate.
authors.affiliation: Department of Gastroenterology, Centro Hospitalar e Universitário de Coimbra, Avenida Bissaya Barreto, 3000, Coimbra, Portugal, pauloavfreire@gmail.com.
authors.forename: Paulo
authors.initials: P
authors.lastname: Freire
authors.forename: Ricardo
authors.initials: R
authors.lastname: Cardoso
authors.forename: Pedro
authors.initials: P
authors.lastname: Figueiredo
authors.forename: Maria M
authors.initials: MM
authors.lastname: Donato
authors.forename: Manuela
authors.initials: M
authors.lastname: Ferreira
authors.forename: Sofia
authors.initials: S
authors.lastname: Mendes
authors.forename: Ana Margarida
authors.initials: AM
authors.lastname: Ferreira
authors.forename: Helena
authors.initials: H
authors.lastname: Vasconcelos
authors.forename: Francisco
authors.initials: F
authors.lastname: Portela
authors.forename: Carlos
authors.initials: C
authors.lastname: Sofia
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003082:Colectomy; D003093:Colitis, Ulcerative / Q000188:drug therapy / Q000235:genetics* / Q000601:surgery; D004351:Drug Resistance; D005260:Female; D020022:Genetic Predisposition to Disease; D005938:Glucocorticoids / Q000627:therapeutic use; D006579:Heterozygote; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D053473:Nod2 Signaling Adaptor Protein / Q000235:genetics*; D010641:Phenotype; D011110:Polymorphism, Genetic; D011379:Prognosis
chemical_list: D005938:Glucocorticoids; C429018:NOD2 protein, human; D053473:Nod2 Signaling Adaptor Protein