title: Prevalence of coeliac disease in siblings of patients with Type I diabetes is related to the prevalence of DQB1*02 allele.
abstract: OBJECTIVE
  Coeliac disease is more prevalent among patients with Type I (insulin-dependent) diabetes mellitus and coeliac disease-related antibodies have been reported to increase in frequency in their first-degree relatives. Our aim was to find out if coeliac disease is more common among siblings of children with Type I diabetes than in the normal population.
  
  
  METHODS
  IgA endomysium antibodies were measured by indirect immunofluorescence in 550 subjects (mean age 11.8 years, range 3.1-26.9 years) with a sibling with Type I diabetes. We performed jejunal biopsy on as many subjects with positive antibodies as agreed. HLA-DQB1 genotyping was done in 427 subjects.
  
  
  RESULTS
  Endomysium antibodies were positive in nine subjects (1.6 %). Jejunal biopsy was diagnostic for coeliac disease in five out of seven patients. An additional patient with coeliac disease, one already on a gluten-free diet, was identified by questionnaire. The prevalence of coeliac disease was 1.1 %. Five of six patients with coeliac disease had HLA-DQB1*02 allele, compared with 118 of 421 of those without coeliac disease (p = 0.009). The sixth patient was positive for HLA-DQB1*0302 allele, which was also found in 241 of 421 of those without coeliac disease (p = 0.4).
  
  
  CONCLUSIONS
  We found the prevalence of coeliac disease among siblings of children with Type I diabetes to be similar to figures reported from recent population-based studies and to be correlated with the prevalence of coeliac disease associated HLA-DQB1 alleles. We propose that routine screening for coeliac disease among all first-degree relatives of patients with Type I diabetes is not warranted.
authors.affiliation: Hospital for Children and Adolescents, University of Helsinki, Helsinki, Finland. tero.saukkonen@hus.fi
authors.forename: T
authors.initials: T
authors.lastname: Saukkonen
authors.forename: J
authors.initials: J
authors.lastname: Ilonen
authors.forename: H K
authors.initials: HK
authors.lastname: Akerblom
authors.forename: E
authors.initials: E
authors.lastname: Savilahti
mesh_terms: D000293:Adolescent; D000328:Adult; D000483:Alleles; D001323:Autoantibodies / Q000097:blood; D001706:Biopsy; D002446:Celiac Disease / Q000150:complications / Q000453:epidemiology* / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000150:complications / Q000235:genetics*; D019084:Fluorescent Antibody Technique, Indirect; D005838:Genotype; D006683:HLA-DQ Antigens / Q000235:genetics*; D059866:HLA-DQ beta-Chains; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007583:Jejunum / Q000473:pathology; D018485:Muscle Fibers, Skeletal / Q000276:immunology; D009679:Nuclear Family
chemical_list: D001323:Autoantibodies; D006683:HLA-DQ Antigens; D059866:HLA-DQ beta-Chains; C069051:HLA-DQB1 antigen; D007070:Immunoglobulin A