Clinical aspects of Celiac disease Flashcards
What are the causes of malabsorption?
Luminal factors, mucosal factors: which can be absolute (resections) or mucosal diseases, or transport problems.
What are clinical signs of malabsorption?
Loss of calories (weight loss), diarrhea, flatulence, abdominal pain, or deficiencies.
What is the physiology of absorption?
Mechanical and enzymatic breakdown (luminal factors), absorption (mucosal factors), and transport (blood, lymphatics).
What is Celiac disease?
Celiac disease is an autoimmune disease that occurs in genetically predisposed people where the ingestion of gluten leads to damage in the small intestine.
What is gluten?
It’s a protein that is present in wheat, rye, and barley.
Why can gluten cause immune activation?
They have a high content of glutamine (Q) and proline (P) which are resistant to enzymatic digestion, so there will be large PQ peptides in the duodenum that can cause immune activation.
How does gluten cause immune activation?
Gluten will be broken down into gliadin proteins. The gliadin will be absorbed in the small intestine and deamidated by tissue transglutaminase.
In Coeliac disease, the deamidated gliadin peptide will be bound by HLA-DQ2 and HLA-DQ8 on antigen-presenting cells, which will subsequently present the deamidated gliadin to T-cells.
The T-cells will provide help to B-cells which will then produce anti-deamidated gliadin peptide antibodies, anti-endomysial antibodies, and anti-tissue transglutaminase antibodies.
How is Coeliac disease diagnosed?
By serology, genetics, endoscopy, and histology.
What serologic tests are there for Coeliac disease?
Anti-gliadin antibodies, anti-deamidated gliadin antibodies, anti-transglutaminase antibodies, and anti-endomysium antibodies.
What genetic tests are there for Coeliac disease?
HLA-DQ2 and DQ8 negative tests exclude Celiac disease, positive tests do not indicate the disease because 40% of the population is positive.
What do you see in the histology of Coeliac diseased patients?
The filli are disappearing and the mucosa becomes flattened.
What is the ‘treatment’ for Coeliac disease?
A ‘simple’ gluten-free diet. This is of course bothersome for patients.
What do you see in the endoscopy of Coeliac diseased patients?
Ulcers and swollen mucosa, no normal filli.
