Diagnosis/Testing
By
Roxie Johnson
The following is from my own research, and is meant for educational
purposes only. Please consult a qualified medical physician concerning
your particular diagnosis and testing.
It is important to have a formal medical diagnosis of celiac disease as soon as possible for several reasons:
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The diagnosis will dramatically effect your diet for the rest of your life. It is a very stringent diet compared to a diet such as one for wheat intolerance. If you have any doubts about your diagnosis, you will be understandably tempted to not follow such a strict diet.
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Once you have modified your diet (i.e. if you are tempted to stop eating gluten for awhile to self-diagnose), it is very difficult to then get accurate testing for celiac disease.
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A confirmed diagnosis means that others in your immediate family should be screened for celiac disease. The potential serious health problems associated with undiagnosed celiacs should be a strong motivator to have them tested.
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There are implications for more complete yearly physical checkups and testing.
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Without the formal diagnosis, physicians will be less inclined to do family member testing and the more extensive medical follow-ups.
It is essential that the person seeking diagnosis be consuming gluten for a few of months before having either the blood screening tests and/or the biopsy of the upper intestine. The University of Chicago Celiac Disease Center recommends consuming at least "one serving of gluten (1/2 slice of bread or a cracker, for example) every day for 12 weeks prior to a blood test or biopsy".
The four primary considerations that lead to the diagnosis of celiac disease are briefly discussed below.
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Symptoms are one part of the diagnosis for the disease (listed in the About Celiac Disease section). The overt symptoms vary widely from person to person, but help to indicate when a blood screening test should be done. Basic blood work that evaluates iron, folic acid, calcium, the vitamins K, A, D, and E, and zinc levels may also be helpful.
- (serology)
Several different serology tests may be used for screening purposes for celiac disease. These include:
Anti-Endomysial Antibodies (EMA)
Anti-Tissue Transglutminase Antibodies (tTG)
Anti-Gliadin Antibodies (AGA)
Anti-Deamidated Gluten Peptide (DGP) (see below)
It is important to get these tests done at a laboratory that does celiac testing on a regular basis. This is due to the fact that reading the results of some of the tests requires a highly skilled and trained eye and, of necessity, is somewhat subjective. Remember - don't stop consuming gluten until these are done.
Low-cost local celiac screening program: The Warren Medical Research Center for Celiac Disease at U.C. San Diego is offering screening for Celiac Disease for only $29.25. No doctor appointment necessary. Available only to adults at this time. Read more.
New blood screening test: The anti-DGP (Anti-Deamidated Gluten Peptide) is a relatively new celiac serology test that is being used for those with questionable/unclear diagnosis of celiac disease. The Celiac Disease Center at the Harvard Medical School gives an explanation on when they feel it is appropriate to use this test. You must scan down the page to See New Celiac Antibody Lab Test . . . (you must scan down the page) on the Harvard Medical Scool Celiac Disease Center site.
In the GIG Quarterly magazine, Volume 4, 2009 it states: "There are a lot of exciting aspects of the anti-DGP test. First, most research shows that it has a very high sensitivity and specificity, comparable to the tTG and EMA tests. There is also evidence that anti-DGP antibodies show up in the blood before anti-tTg and anti-EMA antibodies. This may allow for earlier detection of CD in children. It may also be a better test to catch those with minor intestinal damge, which other tests may miss."
RJ's Note: The specific blood tests used for celiac disease screening keep evolving. The websites listed above get into more specifics on this and are recommended reading.
The biopsy of the upper (small) intestine is necessary to establish diagnosis. The confirmation of damaged villi in the intestine is considered the “Gold Standard” for diagnosing CD. This is usually done following a positive result in the antibody blood tests, but may be done even without a positive blood screening antibody result.
- after following the gluten-free diet.
For further information about testing, see the following:
http://www.americanceliac.org/diagnosis.htm (American Celiac Disease Alliance)
http://www.celiacdisease.net/testing (University of Chicago Celiac Center)
http://celiaccenter.ucsd.edu (The Warren Celiac Center at UCSD). There is testing information under "About CD for Patients" (both Adult and Children) and "About CD for Doctors".
- This is being explored as a possibility to be used for detection of celiac disease, but is not standard practice at this time. Read more.
- This testing is done by sending stool samples through the mail to EnteroLab. EnteroLab only claims that their testing determines gluten sensitivity, not celiac disease. This method is still controversial in the medical community as the data from the testing/research has never been published.
- Read an article about convincing family members to get tested at www.celiacdisease.net/newsletter. Then click on "Summer 2006".
Genetic testing only tells whether it is possible for you to develope celiac disease, not that you for sure have it. This testing is sometimes done by mail and uses a swab of the inside of the cheek. See What is genetic testing and who can benefit from it? on the University of Chicago Celiac Disease Center website. Also see the article on the Celiac.com site titled Ten Facts about Celiac Disease Genetic Testing by Dr. Scot Lewey.
There appears to be a very large group of individuals that do not test positive for celiac disease, but do respond very positively to the gluten-free diet. The medical community acknowledges the existence of this population of individuals, but do not have any tests beyond starting the GF diet and evaluating symptom results. Read more.
See "Follow Up Care" on the About Celiac Disease page.
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A small biopsy of the unaffected skin very close to an eruption or eruption site is taken by a physician and sent to a laboratory for analysis. The presence of IgA deposits confirms a diagnosis of DH. Sometimes the physician may also want blood work done for celiac disease (see above). A small intestine biopsy is not necessary for the diagnosis of celiac disease in persons with DH.
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The information, including opinions and recommendations, contained in this website
is for educational purposes only. Such information is not intended to be a substitute
for professional medical advice, diagnosis or treatment. No one should act upon
any information provided in this website without first seeking medical advice
from a qualified medical physician.
