title: HLA class II polymorphism in children with coeliac disease in Tunisia: is there any influence on clinical manifestation?
abstract: OBJECTIVE
  To elucidate the HLA DRB1, DQB1 and DQA1 polymorphism in Tunisian children with typical form of coeliac disease (CD) in comparison with those from mass screening (atypical and silent CD).
  
  
  METHODS
  We recruited three groups: group I: 40 CD children diagnosed according to the ESPGHAN criteria. group II: 40 healthy controls matched with sex, age and geographic origin. group III: 38 CD children coming from mass screening in schoolchildren. HLA class II DRB1, DQB1 and DQA1 alleles were typed by PCR-sequence-specific primer.
  
  
  RESULTS
  Comparing the groups I and II, we found a pronounced increase of the susceptible alleles HLA DRB1*03 (relative risk, RR = 4.18, Pc = 0.001), DQB1*02 (RR = 7.9, Pc<0.0001) and DQA1*0501 (RR = 4.1, Pc = 0.001). As for protective alleles, we detected a high frequency of DRB1*13 (RR = 0.059, Pc = 0.001), DQA1*0102 (RR = 0.071, Pc = 0.009) and DQB1*06 (RR = 0.125, Pc = 0.0042). Haplotype analysis showed that the main combination observed was the conformation of DQ2 (DQA1*0501-DQB1*02) in 36 patients from group I and 30 from group III. There was no statistically significant difference between the groups I and III according to the distribution of the different alleles.
  
  
  CONCLUSIONS
  We confirmed in this study the high frequency of DQ2 haplotype in CD patients and we identified new protective alleles DRB1*13, DQA1*0102 and DQB1*06. However, HLA polymorphism seems to have no evident impact on clinical outcome of CD.
authors.affiliation: Department of Immunology, La Rabta Hospital, Tunis, Tunisia. lilia_laadhar@yahoo.com
authors.forename: Lilia
authors.initials: L
authors.lastname: Laadhar
authors.forename: Amina
authors.initials: A
authors.lastname: Toumi
authors.forename: Maryam
authors.initials: M
authors.lastname: Kallel-Sellami
authors.forename: Mondher
authors.initials: M
authors.lastname: Zitouni
authors.forename: Saadia
authors.initials: S
authors.lastname: Bouraoui
authors.forename: Ahmed
authors.initials: A
authors.lastname: Maherzi
authors.forename: Sondès
authors.initials: S
authors.lastname: Makni
authors.forename: Mongi
authors.initials: M
authors.lastname: Ben Hariz
mesh_terms: D016022:Case-Control Studies; D002446:Celiac Disease / Q000150:complications / Q000235:genetics*; D002648:Child; D003967:Diarrhea / Q000209:etiology; D005260:Female; D020022:Genetic Predisposition to Disease; D006130:Growth Disorders / Q000209:etiology; D006681:HLA-D Antigens / Q000235:genetics*; D006683:HLA-DQ Antigens / Q000235:genetics; D059848:HLA-DQ alpha-Chains; D059866:HLA-DQ beta-Chains; D006684:HLA-DR Antigens / Q000235:genetics; D059811:HLA-DRB1 Chains; D006239:Haplotypes; D006650:Histocompatibility Testing; D006801:Humans; D008297:Male; D011110:Polymorphism, Genetic
chemical_list: D006681:HLA-D Antigens; D006683:HLA-DQ Antigens; D059848:HLA-DQ alpha-Chains; D059866:HLA-DQ beta-Chains; C069050:HLA-DQA1 antigen; C069051:HLA-DQB1 antigen; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains