How long before testing becomes negative?

Blood under a microscope.

I found something today. I was looking at the American College of Gastroenterology because that is what I do for fun – not really, but I was looking at it for something else.

It is commonly held within the gluten free community that you must be eating gluten for the blood tests to be accurate – which is really true! According to the American College of Gastroenterology standards for diagnosis and management of celiac disease published in 2013, ” While little is known about the precise dynamics of the reduction, a weakly positive individual may become negative within weeks of strict adherence to GFD.” They further say, ” After 6–12 months of adhering to a GFD, 80% of subjects will test negative by serology. By 5 years, more than 90% of those adhering to the GFD will have negative serologies.”

For me, it took a little over 2 years for my serology to come back into the normal ranges. Was I perfect in the first year? Heck no, I made a ton of mistakes which might be why it took so long for my blood tests to return to normal.

That’s the first thing.

The second interesting tidbit in this was, ” Unless all patients who test positive in the panel undergo histological confirmation of CD, this practice may lead to incorrect and over diagnosis followed by unnecessary treatment with GFD.” I argued with someone that today said that blood tests are enough to diagnose celiac disease. They are enough, but only in certain circumstances.

Now, there is an update. In December 2018, the ACG updated their standards and monitoring of celiac. They gave 11 key points.

  1. TTG IGA is the preferred method for screening for celiac, rather than EMA- IGA.
  2. Good biopsies are vital for diagnosis and important to ensure the issue really is celiac rather than something else.
    • Positive TTG IGA (>x10 upper limit) and positive EMA in a second blood sample is virtually 100% predictive of celiac. This is different than the European standard.
  3. If there is an IGA deficiency, then using DGP IGG and TTG IGG is recommended for initial screening.
  4. TTG IGG is not specific in celiac screening unless there is an IGA deficiency.
  5. If celiac is found first in biopsy, blood tests should be taken to confirm diagnosis.
  6. If CD is strongly suggested in the face of negative biopsies, repeat TTG IGA and repeat biopsies should be considered.
  7. A normal diet should be maintained throughout both blood and biopsy testing for celiac disease. Reduction or exclusion of gluten consumption may reduce the sensitivity of all tests.
  8. If a patient has already started a gluten free diet, it is recommended that they consume at least 3 slices of wheat bread daily for 1 to 3 months.
  9. Genetic testing is used to rule out those that might have celiac rather than confirm those that do.
  10. Negative celiac blood tests do not predict healed intestines. But continued positive blood tests indicate ongoing intestinal damage.
  11. Patients with persistent or relapsing symptoms, regardless of blood tests, should undergo repeat endoscopic biopsies to ensure healing.

We probably all knew these guidelines, but it is nice to see it in writing. I also think the more we know about what doctors are thinking about our disease the better off we will be.

I wish I had more news on the drug fronts, but I haven’t seen anything lately. And being the dork I am, I look.

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