Standard operating procedure for initial management of serology positive patients with T1DM

• Anti TTG IgA > 50, repeat serology at next opportunity.
  • If repeat result > 50, refer to diabetes dietitians for GFD – and discussion with family re a ‘no-biopsy’ diagnosis or endoscopy if they wish
  • If repeat result 5 - 50, diabetes team to discuss with family recommendation for referral for endoscopy.
• Anti TTG IgA 10-50, repeat serology in 3 to 4 months.
  • If repeat result 10-50, diabetes team to discuss with family recommendation for refer for upper endoscopy.
  • If repeat result > 50, refer to diabetes dietitians for GFD.
• Anti TTG IgA 5-10 (low positive), discuss amount of gluten exposure, and advise to maximise if required, and repeat after 3 to 4 months.
  • If repeat result 5 - 50, refer for upper endoscopy.
  • If repeat > 50, refer to diabetes dietitians for GFD.
• Selective IgA deficiency (SIgAD) with anti TTG IgG raised at any level (normal is under 10 U/mL), repeat serology.

If repeat result raised, refer for endoscopy. Note: 1. patients with SIgAD cannot be diagnosed using the no-biopsy strategy irrespective of titre value. 2. If symptomatic and repeat is normal, discuss merits of endoscopy anyway.

• Repeat the test at 6 monthly intervals. Watch for symptom development and monitor glucose control, growth, and antibody titre (i.e. upward trend).
• Repeat earlier if symptoms develop, and / or consider earlier listing for endoscopy.
• If serology remains positive at 18 months of follow up, despite being asymptomatic, discussion with family and refer for discussion with coeliac team and likely upper endoscopy.

• Definite evidence of coeliac disease – refer to diabetes dietitians for gluten-free diet (GFD)
• No evidence of coeliac disease (for example, serology test normalised on day of scope or is ‘potential coeliac disease’ with positive serology and normal biopsies).
  • If symptomatic, discussion regarding a trial of GFD.
  • If asymptomatic, repeat serology annually. Watch for symptom development and monitor glucose control, growth, and antibody titre (i.e. upward trend). Repeat earlier if symptoms develop, and/or consider earlier listing for endoscopy.

• In symptomatic patients, consider referral for endoscopy, although likely not coeliac disease
• In asymptomatic patients, repeat serology after 6 months.
  • If repeat test normal, return to routine monitoring as per diabetes pathway.
  • If repeat test raised, continue to monitor 6-monthly, as per pathway for asymptomatic patients with raised serology.