Table 3

Differential diagnosis of refractory coeliac disease type 1 and refractory coeliac disease type 2

Clinical criteriaDisease category
RCD type 1RCD type 2
Abnormal immunophenotype of IELs with loss of normal surface markers CD3, CD8, and T cell receptor: either >50% by immunohistochemistry or >20–25% by flow cytometryNoYes
T cell receptor chains (γ or δ) clonal rearrangement by molecular methodsNoYes
Clinical or histological response to steroids or other immunosuppressive drugs or biologicsYesVariable
Lymphomagenesis potential (especially EATL development)RareFrequent
  • EATL, enteropathy-associated T-cell lymphoma; GFD, gluten-free diet; IELs, intraepithelial lymphocytes; RCD, refractory coeliac disease.