celiac's disease

Question 1

What are the 4 take-home pts of celiac’s disease?

Answer 1

1. common
2. significant non-GI disease
3. commonly overlooked and under-diagnosed
4. diagnostic screening blood test

Question 2

classic celiac GI presentation

Answer 2

diarrhea, steatorrhea, bloat and flatulence, weight loss, failure to grow, muscle wasting, low serum proteins, ascites. maldigestive wasting disease from severe atrophy of the intestinal mucosal absorptive surface.

Question 3

common celiac GI presentation

Answer 3

episodic loose stool, bloat, vague abdominal discomfort. often labeled IBS. mean time to diagnosis 7-11 yrs

Question 4

non-GI presentations of celiac’s disease

Answer 4

aphthous stromatitis and excessive cavities
iron deficient anemia, rarely B12
osteopenia
neuro
secondary hyperparathyroidism, infertility, amenorrhea, impotence
dermatitis herptiformis
arthralgia
abnormal LFTs
hyposplenism
tetany

Question 5

most commonly associated conditions with celiac’s (not caused by celiac’s)

Answer 5

DM type I
auto-immune thyroiditis
Down’s
autoimmune hepatits

Question 6

normal gut immunity

Answer 6

intestine has a difficult job: must decide what is food, what is BAD bacteria that must be killed, and what bacteria shouldn’t be let through but is commensal.
this recognition is done via pattern recognition of key molecular sequences. PAMPS (pathogen associated molecular patterns) on bad bacteria interact with receptors on the surface of immune cells to cause an immune response with activated T cells and antibodies. Immune suppressors dampen these mechanisms when the antigen is just food. This process is complex and poorly understood.

Question 7

cereals in gut

Answer 7

cereals are hard for primates to digest. proline peptidase is necessary for wheat digestion but is only present at low concentrations.

Question 8

Celiac pathophysiology

Answer 8

HLA molecules DQ2 and DQ8 have the ability to develop into celiac’s disease. when wheat antigens are presented in celiac’s pts by DQ2 and DQ8, the inflammatory cascade is initiated. T cell derivatives cause cell and tissue injury resulting in shortened intestinal villi and reduced absorptive surface in the proximal intestine. Also results in the production of antibodies against tissue transglutaminase (which plays a role in antigen presentation and can be measured as a serum marker for celiac pathology).
Celiac pts also have some defect, either congenital or acquired, during the development of intestinal immune tolerance.

Question 9

histologic features of celiac’s disease

Answer 9

proximal intestinal lesion of flattened villi and crypt hyperplasia with an incr. pop of active intra-epithelial lymphocytes.

Question 10

What part of wheat is inflammatory in celiac’s disease? where else is this found?

Answer 10

gluten, more specifically gliadin. also found in barley and rye

Question 11

Why are most celiac’s lesions in the proximal gut?

Answer 11

there is lots of gluten antigen in the proximal gut. With time and gut enzymes, the antigent is eliminated in more distal gut tissue. Importantly, this means that most adults with celiac’s disease have enought distal gut to get enough macronutrient digestion (most adults don’t have symptoms from maldigestion of macronutrients). However, there isn’t always enough space for calcium and iron absorption –> osteoporosis and iron deficiency anemia

Question 12

Dx of celiac’s disease

Answer 12

antibodies to TTG (tissue transglutaminase) have high sensitivity and specifity. Good negative predictive value. if test is positive, do an upper endoscopy with biopsy for confirmation.

Question 13

Tx for celiac’s

Answer 13

gluten free diet