That’s So Testing for Celiac
I wish this blog post was straight forward and did not have any grey areas, but unfortunately it does due to the topic of discussion. Also, please remember that I am not a healthcare professional, so I can’t provide healthcare advice and/or help diagnose you. However, I can provide insight from my own experiences and encourage each of you reading this to continue advocating for your own health & to seek out a professional healthcare team to help support you.
There is a blood test is available that can show indicators of celiac disease. These indicators are elevated Tissue Transglutaminase IgA antibodies and IgG antibodies. Why these indicators? Those living with celiac disease who eat gluten have higher than normal levels of these antibodies, which are produced by the immune system. They are produced by the immune system since the body sees gluten as a threat / invader of the body.
According to the Celiac Disease Foundation, Tissue Transglutaminase Antibodies (tTG-IgA) – the tTG-IgA test will be positive in about 98% of patients with celiac disease who are on a gluten-containing diet. The test’s sensitivity measures how correctly it identifies those with the disease. The same test will come back negative in about 95% of healthy people without celiac disease. The test’s specificity refers to how accurately it is able to identify those without the disease. The tTG test is the most sensitive test for celiac disease. Though rare, this means patients with celiac disease could have a negative antibody test result.
There is a margin of error for the blood test as you can receive a false positive test result, especially for people with other autoimmune diseases like:
Type 1 Diabetes
Hashimoto’s Thyroiditis
Psoriatic or Rheumatoid Arthritis
I mean there are over 300 symptoms of celiac disease and it tends to mimic quite a few different other possibly diagnosis – hello multiple misdiagnosis in my case (you can read about more of my celiac story here).
Personally, I never had a specific blood test done, but have had lots of blood work done. None of the healthcare professionals that reviewed my blood work mentioned anything of having higher than normal levels of these antibodies, but were consistently seeing ranges that were not “normal” like elevated liver enzymes. Something I have learned is that celiac disease may be the underlying cause of unexplained elevations of liver enzyme levels.
There are other antibody tests that can double-check the work of the first tests and confirm for potential false positives or false negatives, but because of this potential, a biopsy of the small intestine is the only way to diagnose celiac disease.
It is the biopsy of the small intestine that finally led to my celiac diagnosis after a few years of many other tests including many tests. An intestinal biopsy is considered the “gold standard” for diagnosis (this may be changing based on recent articles I have read – Simply Gluten Free – May-June 2021 has an article titled, “Confused About Celiac Test Results? What you Need to Know”), but I still tell others that this is the form of testing that finally gave me answers. This internal biopsy not only allows a GI specialist to tell you if you have celiac disease, but it allows them to tell you if you have something else going on like a GI disorder and/or a sensitivity.
What exactly does this internal biopsy consist of? This is an outpatient operation where the GI specialist will perform an endoscopy, so they can see what is going on inside your GI tract. The scope is inserted through the mouth and down the esophagus, stomach and small intestine, giving the GI specialist a detailed looked at your GI track and while also taking a sample of the tissue from your small intestine. Do not worry, you are “sleeping” during this short operation and will more than likely just wake up with a gas filled tummy that they have to pump in you for the GI specialist to do all the above. You get to go home and rest for the day while your biopsies are sent off to be reviewed under a microscope.
Personally, I do not respond well to anesthesia, so I cry then have to try and keep some liquid & food down, which typically takes a while. I then have a hard time releasing the gas which can be painful, but the procedure was worth it in my eyes as two weeks later I had the answers I had been looking for. The very nice nurse called to tell me that I did not have Chron’s (the GI specialist I was seeing recommended we test for that due to all the symptoms I was showcasing), but I 100% had Celiac Disease – I can vividly remember this phone call and instantly texting my now husband the news. This was the day my life changed in many, many ways.
A rather important note to end this blog post on is that you must be on a gluten-containing diet for antibody (blood) testing to be accurate.
Resources:
https://celiac.org/about-celiac-disease/screening-and-diagnosis/