Is it possible I may have celiac, even though blood test came back negative?

[Catv25]

I got tested for celiac a few years ago. I was on a gluten-free diet at the time (didn't know I wasn't supposed to be) and the lab results came back negative. My doctor mentioned my levels were close to the celiac cutoff line, so I may be gluten intolerant. I have many of the symptoms, and feel significantly healthier and better, my symptoms go away when I stick to a gluten-free diet. 

I've recently fallen off the bandwagon but want to start again. Should I stick to a gluten-free diet? Or wait until lockdown lifts and get re-tested for celiac? Is that even necessary? Or should I just cut out gluten entirely? Sorry for the wall of text, would appreciate any insight 

[Scott Adams]

You could do another blood test, there are mail order ones, for example https://www.imaware.health/

I do wonder what exact criteria were used to create the current cut off lines. Why would one person who scores 1 single point below a cut off not have celiac disease, while another person would? Both people are having an inappropriate response to gluten, their immune system is responding exactly the same way, yet doctors often tell the person one point below the line that they can continue eating gluten (your doctor at least gave you a heads up about being gluten intolerant--when exactly this happened to my brother the doctor said "good news, you can continue eating gluten!").

In your case it seems like you already know that going gluten-free is the best path, so perhaps you would only need a formal diagnosis to keep you on that path? If not, just go gluten-free.  

[RMJ]

  On 10/14/2020 at 5:52 PM, Scott Adams said:

I do wonder what exact criteria were used to create the current cut of lines. Why would one person who scores 1 single point below a cut off not have celiac disease, while another person would?

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I am a scientist and used to develop this type of test for other health issues. The cut off between positive and negative is chosen to give the most correct answers when compared to either biopsy results, or an already approved blood test. Sometimes the dividing line is chosen to be lower if it is a disease where you don’t want to risk missing people who are positive, and sometimes it is chosen to be higher if you don’t want false positives.

So I think you are correct that someone just below the positive level very likely has an inappropriate immune response to gluten, especially if the person was on a gluten free diet.

To the original poster: if you’re having trouble staying on the gluten free bandwagon, it might be wise to repeat the blood test while you’re eating gluten.  If it is a definite positive this time it could convince you to stay on that gluten free diet.