title: Overrepresentation of HLA-DQ2 in small intestinal neuroendocrine tumor patients.
abstract: OBJECTIVE
  To investigate whether celiac disease risk haplotypes HLA-DQ2 and DQ8 also increase the risk for developing small intestinal neuroendocrine tumor (SI-NET).
  
  
  METHODS
  Thirty-five patients with serotonin-producing jejunal and ileal SI-NET were examined with HLA-DQ genotyping and serology for IgA anti-tissue transglutaminase (tTG) antibodies.
  
  
  RESULTS
  Twenty-one patients (60 %) carried HLA-DQ2 or DQ8, twice the frequency of the general population (P < 0.001). In particular DQ2 was overrepresented (P = 0.013). Gender, age, disease stage, histopathological grade, or multifocality of primary tumor did not differ between patients with DQ2 or DQ8 and patients with other HLA-DQ haplotypes. No patient in the study was diagnosed with celiac disease (latent or symptomatic) as anti-tTG antibodies were negative in all 35.
  
  
  CONCLUSIONS
  HLA-DQ haplotypes associated with celiac disease are overrepresented also in patients with SI-NET, in particular HLA-DQ2.
authors.affiliation: Department of Surgery, Ryhov County Hospital, SE-551 85, Jönköping, Sweden, kalle.landerholm@lj.se.
authors.forename: Kalle
authors.initials: K
authors.lastname: Landerholm
authors.forename: Ursula
authors.initials: U
authors.lastname: Falkmer
authors.forename: Roland
authors.initials: R
authors.lastname: Persson
authors.forename: Najme
authors.initials: N
authors.lastname: Wall
authors.forename: Claes
authors.initials: C
authors.lastname: Hallert
authors.forename: Johannes
authors.initials: J
authors.lastname: Järhult
mesh_terms: D005260:Female; D020022:Genetic Predisposition to Disease; D006683:HLA-DQ Antigens / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D006239:Haplotypes; D006801:Humans; D007078:Ileal Neoplasms / Q000235:genetics / Q000276:immunology*; D007580:Jejunal Neoplasms / Q000235:genetics / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000235:genetics / Q000276:immunology*
chemical_list: D006683:HLA-DQ Antigens; C053186:HLA-DQ2 antigen; C109756:HLA-DQ8 antigen