Pathogenesis of Celiac disease

Question 1

When are small bowel biopsies taken?

Answer 1

In adults, not in children. And after serology.

Question 2

What is sensitivity?

Answer 2

Sensitivity is the ability to detect the disease if it is really present.

Question 3

What is specificity?

Answer 3

Specificity is the ability to exclude persons who do not have the disease.

Question 4

When can you get false negative serology in CD?

Answer 4

IgA-deficiency, low gluten intake, and inadequate test systems.

Question 5

How do you diagnose Coeliac disease in individuals on a gluten-free diet?

Answer 5

• The gluten challenge, a 2 week GC is sufficient to elevate antibody titers if evaluated after 4 weeks.
• Measuring gliadin specific T-cells in peripheral blood.

Question 6

What is refractory celiac disease (RCD)?

Answer 6

persisting villous atrophy, crypt hyperplasia, and intraepithelial lymphocytosis despite a strict gluten-free diet (GFD) of >12 months.

Question 7

What is the difference between RCDI and RCDII?

Answer 7

In type 1 there are no aberrant IEL and there is a higher survival risk, in type 2 there are aberrant IEL and a high risk to develop T-cell lymphoma.

Question 8

What are aberrant IEL?

Answer 8

aberrant intraepithelial lymphocytes have loss of CD8 expression and surface CD3 expression.

Question 9

How can you identify aberrant IEL?

Answer 9

TCR clonality analysis (hypervariation VDJ junction), immunohistochemistry, and flow cytometry (most sensitive).