title: MHC class I region plays a role in the development of diverse clinical forms of celiac disease in a Saharawi population.
abstract: OBJECTIVE
  The aim of this study was to investigate the association of MHC genes in the development of celiac disease (CD) and its diverse clinical forms in a Saharawi population.
  
  
  METHODS
  One hundred and twenty-five CD patients and 98 healthy controls were selected from the Saharawi refugee camps in Tindouf. All were investigated for the presence of antitransglutaminase 2 antibodies. Patients were divided into two groups according to their clinical manifestations: 70 typical and 55 atypical. Patients and controls were typed for HLA-B, DRB1, DQB1, and DQA1, and for MICA transmembrane polymorphism.
  
  
  RESULTS
  The frequency of HLA-DQ2 in Saharawi controls was notably increased compared with other populations. No differences in the distribution of DQ2 in either group of patients were found. However, the haplotype B8/DR3/DQ2 was notably overrepresented in atypical patients compared to typical ones (pc= 0.001). The MICA-A5.1 allele was increased in atypical CD patients compared to those with typical forms (pc= 0.0006). Finally, we found that the increased frequency of MICA-A5.1 in the atypical group was independent of the linkage disequilibrium with B8/DR3/DQ2 haplotype (p= 0.02).
  
  
  CONCLUSIONS
  The elevated prevalence of CD in Saharawi seems to be related to the high frequency of HLA-DQ2 in this population. However, the development of atypical or typical forms of the disease may be due to a gene or genes located in the class I side of the haplotype B8/DR3/DQ2, especially MICA. This appears not to be implicated in the susceptibility to CD but may play an important role in the development of the different forms of the disease.
authors.affiliation: Department of Immunology, Hospital Universitario Central de Asturias, Oviedo, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: López-Vázquez
authors.forename: Dolores
authors.initials: D
authors.lastname: Fuentes
authors.forename: Luis
authors.initials: L
authors.lastname: Rodrigo
authors.forename: Segundo
authors.initials: S
authors.lastname: González
authors.forename: María
authors.initials: M
authors.lastname: Moreno
authors.forename: Eloy
authors.initials: E
authors.lastname: Fernández
authors.forename: Jesús
authors.initials: J
authors.lastname: Martínez-Borra
authors.forename: Carlos
authors.initials: C
authors.lastname: López-Larrea
mesh_terms: D000328:Adult; D000352:Africa, Northern; D002446:Celiac Disease / Q000235:genetics*; D002648:Child; D005260:Female; D005805:Genes, MHC Class I / Q000235:genetics*; D015395:Histocompatibility Antigens Class I / Q000235:genetics; D006650:Histocompatibility Testing; D006801:Humans; D008297:Male; D012036:Refugees
chemical_list: D015395:Histocompatibility Antigens Class I; C099187:MHC class I-related chain A