Celiac Disease
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Contents |
Background
Celiac Disease is commonly misdiagnosed. It is an immune-mediated small bowel enteropathy (involving largely IgA and IgG class antibodies), in which sufferers form antibodies to the gliadin component of gluten. Gluten is in the grains wheat, barley, rye, and to an arguable extent in oats. This results in small bowel inflammation (jejunum especially), gradually flattening and destroying the villi, which finally causes diarrhea and malabsorbtion. Celiac Disease has many clinical manifestations, many of which may not be in the face of notable diarrhea or weight loss at all. Extragastrointestinal manifestations often predominate, leading to delayed and misdiagnosis. Some manifestations (including the gastrointestinal ones) are:
General
- Behavioural changes
- Fatigue, malaise
- Growth delay
- weight loss (explained and unexplained)
Hematological
- anemia
- hematologic diathesis
Skin/Mucous Membrane
- dermatitis herpetiformis
- alopecia (both universalis and areata)
- aphthous ulcers
- abdominal or generalized swelling
- epistaxsis
- easy buisability
- cheliosis, stomatitis
- scaly dermatitis
Musculoskeletal
- non-specific bone and/or joint pain
- osteopenia
- tetany
Neurological
- peripheral neuropathy
- seizures
Gastrointestional
- Abdominal pain
- Anorexia
- Diarrhea
- Flatulence, distention
- hepatic disease
- hypoglycemia
- malabsorbtion
- steatorrhea and greasy, bulky stools
Prevalence
Celiac Disease is more prevalent than previously thought. Prevalence has been shown to be as high as 1:250 [1] ). The prevalence may be as high as 1:133 in the general population.
Diagnosis
Diagnosis can be made reliably with blood testing, but the "gold standard" is still small bowel intestinal biopsy (obtained via EGD). Ideally, a small bowel biopsy should be taken while the patient is on a gluten diet and then checked against a follow-up biopsy after 12 weeks on a gluten-free diet. IgA anti-endomysial antibody (EmA) is at least 99% specific, and about 93% sensitive, but some studies show it to be nearly 100% specific and sensitive. Tissue anti-transglutaminase (tTG) antibody is similarly accurate. Total serum IgA is usually normal, but may be low to undetectable in a small percentage patients. If total IgA is very low, EmA and tTG will not be accurate and a small bowel biopsy should be considered. IgA anti-gliadin antibody (AGA) is more useful as a screening test, and neither anti-gliadin IgA or IgG antibodies are as specific or sensitive as anti-endomysial antibodies or anti-transglutaminase antibodies.
- Sumarizing Lab Tests for Celiac Disease
- AGA is more useful as a screening test
- EmA and tTG are very sensitive and specific
- EmA and tTG will not be accurate if total serum IgA is low
- Small bowel biopsy is still the "gold standard"
Lab Links
I have listed the links to lab pages we use in our area to order the tests discussed above. This may help you to decide how to obtain these tests in your area. The lab comments can also be helpful. (| Quest Diagnostics) below has some celiac panels (and your lab may as well).
Anti-gliadin antibodies, IgA & IgG
(| Pathology Associates Medical Laboratory) (Quest Diagnostics)
EmA (IgA, reflexive)
(| Pathology Associates Medical Laboratory) (Quest Diagnostics)
tTG, IgA
(| Pathology Associates Medical Laboratory) (Quest Diagnostics)
tTG, IgG
(| Pathology Associates Medical Laboratory) (Quest Diagnostics)
References
- ↑ Detecting Celiac Disease in Your Patients", American Family Physician, Vol. 57/No. 5, Pruessner, Harold T., M.D. http://www.aafp.org/afp/980301ap/pruessn.html
