Table 3. APC Classification for Celiac Disease.

Age at diagnosis	A1: <18 yr of age
	A2: ≥18 yr of age
Presentation	P1: Classical. Chronic diarrhea, failure to thrive, malnutrition or malabsorption syndrome
	P2: Non-classical. Lack of features included in classical disease. Presentation with extraintestinal medical conditions like unexplained iron deficiency anemia, osteoporosis, short stature, infertility, cryptogenic liver disease, dermatitis herpetiformis, neurological disorders etc
	P3: Asymptomatic
Complications	C0: None
	C1: Present. Complications like refractory sprue, ulcerative jejunoileitis, celiac crisis or malignancy

APC, age at diagnosis, presentation and complications.