title: Paediatric celiac patients carrying the HLA-DR7-DQ2 and HLA-DR3-DQ2 haplotypes display small clinical differences.
abstract: OBJECTIVE
  The aim of this study was to determine the relevance of HLA-DR7-DQ2 typing in a prospective cohort of paediatric coeliac disease patients from Southern Europe.
  
  
  METHODS
  This cross-sectional study tested 249 paediatric patients with coeliac disease. HLA-DR3-DQ2 was typed in combination with HLA-DR7-DQ2 to screen for the HLA-DQ2 haplotype. The histological, analytical and clinical characteristics of the subjects were recorded.
  
  
  RESULTS
  A total of 91 coeliac patients were diagnosed: 96.7% carried HLA-DQ2 and 4.4% carried HLA-DQ8. In percentage terms, 80.2% of patients carried HLA-DR3-DQ2 and 34.1% carried HLA-DR7-DQ2. We did not find significant differences between HLA-DR7-DQ2 and HLA-DR3-DQ2 paediatric patients with respect to histological damage and clinical characteristics, except for irritability and weight loss. These characteristics were more frequent in HLA-DQ2trans than in HLA-DQ2cis (22.2% vs. 0.0% [p = 0.035] and 55.6% vs. 21.4% [p = 0.017], respectively). Coeliac-specific autoantibody levels were higher in HLA-DQ2cis than one half of HLA-DQ2trans patients (105.5 vs. 19.2 U/mL, p = 0.014).
  
  
  CONCLUSIONS
  Small clinical differences were found between paediatric coeliac patients carrying HLA-DR7-DQ2 and HLA-DR3-DQ2. For a correct screening of HLA-DQ2, at least in our geographical population, the HLA-DR7-DQ2 haplotype should be typed due to its frequency and clinical presentation.
authors.affiliation: Immunology Section Laboratory, UDIAT-Centre Diagnòstic, Corporació Sanitària Parc Taulí, Sabadell, Spain; Institut Universitari Parc Taulí-UAB, Universitat Autònoma de Barcelona, Campus d'Excelència Internacional, Bellaterra, Spain.
authors.forename: Juan F
authors.initials: JF
authors.lastname: Delgado
authors.forename: María J
authors.initials: MJ
authors.lastname: Amengual
authors.forename: Ana
authors.initials: A
authors.lastname: Veraguas
authors.forename: Encarnación
authors.initials: E
authors.lastname: Rodríguez
authors.forename: Mariela M
authors.initials: MM
authors.lastname: de Los Santos
authors.forename: María P
authors.initials: MP
authors.lastname: Guallarte
mesh_terms: D002446:Celiac Disease / Q000235:genetics*; D016009:Chi-Square Distribution; D002648:Child; D003430:Cross-Sectional Studies; D005060:Europe; D005260:Female; D005820:Genetic Testing; D006683:HLA-DQ Antigens / Q000235:genetics*; D015803:HLA-DR3 Antigen / Q000235:genetics*; D015809:HLA-DR7 Antigen / Q000235:genetics*; D006239:Haplotypes; D006801:Humans; D056724:Immunity, Humoral / Q000235:genetics; D008297:Male; D010372:Pediatrics; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D018709:Statistics, Nonparametric
chemical_list: D006683:HLA-DQ Antigens; C109756:HLA-DQ8 antigen; D015803:HLA-DR3 Antigen; D015809:HLA-DR7 Antigen
keywords: Coeliac disease; HLA-DQ2; HLA-DQ2.2; HLA-DQ2trans; HLA-DR7-DQ2