Classical CD

Symptoms and signs of malabsorption including diarrhea, steatorrhea, weight loss; in children growth failure is required

Nonclassical CD

CD presenting with extraintestinal symptoms but without symptoms of malabsorption

Symptomatic CD

Clinically evident GI and/or extraintestinal symptoms attributable to gluten intake

Asymptomatic CD

Lack of GI or extraintestinal symptoms at diagnosis

CD autoimmunity

Increased antibodies to tTG2 or EMAs on ≥2 occasions (if biopsy is negative, it is “potential CD”; if positive, it is CD)

Subclinical CD

CD below threshold for clinical detection without symptoms or signs sufficient to trigger CD-testing in routine practice

Potential CD

Positive CD serology with normal small intestinal mucosa

Genetically at risk for CD

Family members of patients with CD who test positive for HLA-DQ2 and/or HLA-DQ8

Refractory CD

Persistent villous atrophy and malabsorptive symptoms and signs of active CD despite strict gluten-free diet for >12 months