title: Antitissue transglutaminase and antithyroid autoantibodies in children with Down syndrome and celiac disease.
abstract: OBJECTIVE
  We measured circulating autoantibodies and evaluated the potential of circulating antitissue transglutaminase (tTG) antibodies to determine the presence of celiac disease (CD) in children with Down syndrome.
  
  
  METHODS
  An ELISA based on recombinant human tTG was used to measure the levels of immunoglobulin A and immunoglobulin G antibodies in serum samples from 72 children with Down syndrome, 52 children with biopsy-verified CD, 21 disease controls with a normal small intestinal mucosa and 23 healthy controls. Of the 72 Down syndrome children, 11 under-went a small intestinal biopsy.
  
  
  RESULTS
  Four of 72 children with Down syndrome were diagnosed as having CD and three of them had serum levels of immunoglobulin A tTG antibodies greater than 6 U/mL (668, 147 and 7 U/mL). One Down syndrome child with biopsyproven CD had normal levels of immunoglobulin A tTG. Two Down syndrome children had increased levels of immunoglobulin A tTG (13 and 7 U/mL) but none of these children had an intestinal biopsy performed. Of the 52 CD subjects (median 664 U/mL) one was negative for immunoglobulin A tTG (5 U/mL) and all healthy controls (median 1.2 U/mL) and disease controls (median 0.9 U/mL) had immunoglobulin A tTG antibody levels less than 6 U/mL. Two of four Down syndrome children with CD and 36 of 52 celiac children had increased serum levels of immunoglobulin G tTG antibodies. There was no correlation between the serum levels of tTG and antithyroid autoantibodies.
  
  
  CONCLUSIONS
  Although the diagnosis of CD depends on histologic evaluation of intestinal biopsies, detection of anti-tTG antibodies provides a useful complementary diagnostic method for CD in children with Down syndrome.
authors.affiliation: Department of Rheumatology, Karolinska Hospital, Stockholm, Sweden. Tony.Hansson@cmm.ki.se
authors.forename: Tony
authors.initials: T
authors.lastname: Hansson
authors.forename: Ingrid
authors.initials: I
authors.lastname: Dahlbom
authors.forename: Siv
authors.initials: S
authors.lastname: Rogberg
authors.forename: Britt-Inger
authors.initials: BI
authors.lastname: Nyberg
authors.forename: Jörgen
authors.initials: J
authors.lastname: Dahlström
authors.forename: Göran
authors.initials: G
authors.lastname: Annerén
authors.forename: Lars
authors.initials: L
authors.lastname: Klareskog
authors.forename: Anders
authors.initials: A
authors.lastname: Dannaeus
mesh_terms: D000293:Adolescent; D001323:Autoantibodies / Q000097:blood; D016022:Case-Control Studies; D002446:Celiac Disease / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D004314:Down Syndrome / Q000150:complications*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood / Q000276:immunology; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007223:Infant; D008297:Male; D015995:Prevalence; D011503:Transglutaminases / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D011503:Transglutaminases