24. Gluten Sensitivity Flashcards
What is the presentation of classic celiac disease?
Diarrhea
Bloating
Abdominal pain
Weight loss
What are the components of atypical sprue?
Iron deficiency Osteoporosis Dermatitis herpetiformis IBS DM type I Elevated LFTs
What is the prevalence of CD in people of Northern European descent?
1 in 100
What is the prevalence of CD in the following at-risk populations:
- With first degree relative with CD
- Second degree relative
- Monozygotic twin
- HLA id sibling
1 in 10
1 in 39
70-80%
40%
What is the area of the bowel that is most commonly affected by celiac disease?
duodenum
proximal jejunum
What vitamin deficiencies are often seen with celiac disease?
Iron deficiency
Folic acid deficiency
B12 deficiency
Why is reduced serum albumin seen with celiac disease?
Chronic malnourishment
What are other auotimmune disorders are associated with celiac disease?
Type I DM (2-15%) * Thyroid dysfunction (2-7%) * Addison disease PBC Sjogren's AI hepatitis
What two genetic defects are associated with celiac disease?
Down syndrome
Turner syndrome
Patients with celiac disease often have selective deficiency of what Ig?
IgA
**9% of all IgA deficient patients have CD
What is dermatitis herpetiformis?
Pruritic papulovesicles on the extensor surfaces of the extremities and trunk
What is the most common non-GI presentation of CD?
Osteopenia in 70% of patients with untreated CD
Osteoporosis in 25% of all CD patients
**all patients with CD should have bone density scan
What are the neurologic sx of CD?
Ataxia (B12 def) Night blindness (vit A) Seizures Headaches Epilepsy Mood disturbances Peripheral neuropathy
Gyneocologic and fertility problems with CD
- Amenorrhea in 1/3 untreated CD
- Infertility common in untreated CD
- Spontaneous abortions
- Intrauterine fetal growth retardation
What happens to gluten in the intestines?
Degraded into gliadin
Tissue transglutaminase deaminates gliadin
HLA DQ2 or DQ8 presents deaminated gliadin to T cells
B cells make anti-gliadin, anti-endomysium, anti-tTG antibodies
What are the most powerful and clinically useful tests for suspected celiac disease?
IgA endomysial antibody (EMA)
IgA tissue transglutaminase (tTG)
IgA and IgG DEAMINATED gliadin antibodies
If a small intestine biopsy is done in an adult with suspected CD, what will be seen?
- Scalloping or notching of the small bowel folds
- Villous atrophy
- Intraepithelial lymphocytosis
- Crypt hyperplasia (deepening)
What are two main reasons that one might get false negatives for CD serologic testing?
- Antibody levels fall on a gluten-free diet: may fall within a day with mild disease, usually 6-8wk
- Celiac patient that is IgA deficient
What is the best way to assess CD in a celiac patient that is IgA deficient?
IgG deaminated gliadin antibody
*can also look at biopsy
Pitfall of looking for villous atrophy for CD dx is that other things cause it:
NSAIDs
Infections
IBD
What HLA is CD associated with?
DQ2 heterodimer (95%) DQ8 heterodimer (5%)
What is HLA DQ2/8 useful for?
40% people with european descent have the genes, but it is useful in ruling out CD
**if someone doesn’t have DQ2/8, the don’t have CD
Rules for the gluten free diet
Avoid foods with wheat, rye, barley gluten
Avoid malt
Read labels, look for gluten in meds
What malignancy is most commonly associated with CD?
High-grade T cell NHL: entropathy associated T-cell lymphoma
