HLA genotyping unhelpful as celiac screen in children with type 1 diabetes

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Takeaway

  • Counter to recent European Society for Paediatric Gastroenterology, Hepatology, and Nutrition guidelines, HLA genotyping in patients with type 1 diabetes (T1D) is not useful to screen for celiac disease (CD).
  • Instead, celiac-specific antibody screens should be performed regularly in patients with T1D.

Why this matters

  • CD and T1D are associated.

Study design

  • HLA genotyping via PCR performed on 121 pediatric patients with T1D.
  • Funding: None listed.

Key results

  • Positive celiac-specific HLA DQ genotypes found in 92% of patients.
  • In 17% (20 patients) of the celiac-specific HLA-positive individuals, a tissue-transglutaminase IgA antibody (tTGA) was detected, but 1 patient tested mildly positive for tTGA although HLA DQ2 and DQ8 were negative.
  • All patients who were diagnosed with CD had tTGA levels >200 kU/L.
  • In 3 patients (2%) with positive screening for tTGA and for celiac-specific HLA genotypes who had endoscopy and diagnostic biopsy performed, all were classified as CD. Another patient was classified as likely CD.
  • All 4 patients labeled as CD were female and diagnosed with T1D before the age of 3 y.

Limitations

  • Australian study population may differ from others, although no differences were seen in HLA distribution between the 19% who were immigrants and the Australian natives.