What is the management plan for a patient with elevated Tissue Transglutaminase Antibody (TTG ab) and positive Endomysial Antibody (EMA) results?

Management of Elevated TTG Antibody and Positive Endomysial Antibody

Diagnosis Confirmation

The patient with elevated Tissue Transglutaminase Antibody (TTG ab = 84.2) and positive Endomysial Antibody (EMA 1:10) should undergo duodenal biopsy via upper endoscopy while maintaining a gluten-containing diet to confirm celiac disease diagnosis. 1

The combination of positive TTG and EMA antibodies is highly specific for celiac disease:

• TTG-IgA has 97.7% sensitivity in children
• EMA-IgA has 94.5% sensitivity and 93.8% specificity in children 1
• These antibodies have over 99% specificity when small bowel villous atrophy is present on biopsy 2

Biopsy Procedure Requirements

• Must be performed while patient remains on a gluten-containing diet
• Multiple biopsies (at least 4-6) from different parts of the duodenum
• Histological analysis should look for:
  • Increased intraepithelial lymphocytes (≥25 IELs per 100 enterocytes)
  • Crypt hyperplasia
  • Villous atrophy (classified using Marsh criteria) 1

Treatment Plan

After confirmation of celiac disease diagnosis:

1. Initiate strict lifelong gluten-free diet (GFD) - the only effective and safe treatment for celiac disease 1, 3

2. Refer to a dietitian with expertise in celiac disease for:

   • Comprehensive nutritional consultation
   • Education on gluten-free food selection
   • Guidance on avoiding hidden sources of gluten 1

3. Evaluate for nutritional deficiencies commonly associated with celiac disease:

   • Iron
   • Folate
   • Vitamin B12
   • Vitamin D 1

Monitoring Protocol

1. Measure anti-TTG antibody levels at:

   • 6 months after starting GFD
   • 12 months after starting GFD
   • Annually thereafter 1

2. Conduct annual clinical assessments to evaluate:

   • Symptom resolution
   • Nutritional status
   • Weight management
   • Development of complications 1

3. For persistent symptoms despite apparent GFD adherence:

   • Perform detailed dietary review to identify inadvertent gluten exposure
   • Consider additional testing for:
     • Microscopic colitis
     • Pancreatic exocrine insufficiency
     • Bacterial overgrowth
     • Disaccharidase deficiency 1

Special Considerations

IgA Deficiency

• If total IgA levels are low, IgG-based testing (IgG-DGP, IgG-TTG) should be used
• Patients with IgA deficiency and positive IgG-based tests should follow the same GFD approach 1

Risk Assessment for Family Members

• First-degree relatives have a 7.5% risk of developing celiac disease
• Consider screening family members, especially those with symptoms 1

Common Pitfalls to Avoid

1. Do not rely solely on symptom resolution to assess GFD adherence:

   • Anti-TTG has poor sensitivity for identifying persistent villous atrophy
   • Negative serology doesn't guarantee mucosal healing 1

2. Do not start a gluten-free diet before testing:

   • Can lead to false-negative results 1
   • Diagnosis requires positive serology and biopsy while on gluten-containing diet 4

3. Do not overlook IgA deficiency:

   • Can lead to inaccurate test results
   • Total IgA or simultaneous IgG testing should always be performed 1

4. Do not take inadequate biopsy samples:

   • Multiple samples from different duodenal sites are required
   • Patchy distribution of lesions can lead to misdiagnosis if sampling is limited 1, 3