Immunological tests for coeliac disease

Antibodies to components of cereals are common in the serum of patients with coeliac disease.

The sensitivity and specificity of serology in patients with suspected coeliac disease are given below:

Anti-gliadin antibody test:

• sensitivity: 75-95%
• specificity: 80-95%

Anti-endomysial antibody test (3):

• sensitivity: >= 90%
• specificity: >= 97%

transglutaminase antibody test (3):

• sensitivity: >= 90%
• specificity: >= 97%

The presently available serological tests cannot substitute for a diagnostic biopsy (1,3).

NICE guidance suggests a preferred serological test and algorithms (4):

• when healthcare professionals request serological tests to investigate suspected coeliac disease in young people and adults, laboratories should: When healthcare professionals request serological tests to investigate suspected coeliac disease in children, laboratories should: Only consider using HLA DQ2 (DQ2.2 and DQ2.5)/DQ8 testing in the diagnosis of coeliac disease in specialist settings (for example, in children who are not having a biopsy, or in people who already have limited gluten ingestion and choose not to have a gluten challenge)
  • test for total immunoglobulin A (IgA) and IgA tissue transglutaminase (tTG) as the first choice
    
    
  • use IgA endomysial antibodies (EMA) if IgA tTG is weakly positive
    
    
  • consider using IgG EMA, IgG deamidated gliadin peptide (DGP) or IgG tTG if IgA is deficient
    
    
  • test for total IgA and IgA tTG as the first choice
    
    
  • consider using IgG EMA, IgG DGP or IgG tTG if IgA is deficient
    
    
• after serological testing
  
  
  • referral of people with suspected coeliac disease
    • refer young people and adults with positive serological test results to a gastrointestinal specialist for endoscopic intestinal biopsy to confirm or exclude coeliac disease
    • refer children with positive serological test results to a paediatric gastroenterologist or paediatrician with a specialist interest in gastroenterology for further investigation for coeliac disease
    • refer people with negative serological test results to a gastrointestinal specialist for further assessment if coeliac disease is still clinically suspected

Reference:

1. Scand. J. Gastro. 1994; 29(5): 452
2. Prescribers' Journal 1997;37(4): 206-12
3. Rostom A et al. The diagnostic accuracy of serologic tests for celiac disease: a systematic review. Gastroenterology 2005;128:S38-46.
4. NICE (September 2015). Coeliac disease: recognition, assessment Coeliac disease: recognition, assessment and management.