How Much Gluten Do I Need To Be Eating For The Blood Test?

[Notso]

Hi! I am new to this site, but very excited to find it. My daughter was diagnosed with celiac's four months ago. She had just turned one and we were still nursing, so I also went gluten free for the first three months. I didn't notice any change; but, since reintroducing gluten, I've been having explosive tummy troubles.

My daughter's GI recommended that I get tested since we know it runs in my family. I just had the blood test and it was negative, but it occurred to be that I may not be eating enough gluten. I maybe eat it once a day since we are gluten free at home for my daughter. Any ideas if I need to be eating more? My GI says he thinks I have it and wants to a biopsy, but I want to wait and do the blood work again.

Any thoughts or experiences would be appreciated! Thanks!

[GlutenFreeManna]

You need to be eating the equivalent of 3-4 slices orf bread per day for 3 months prior to the blood test or biopsy. If your symtpoms are too bad to do that however you may consider yourself to have it based on dietary response and genetics (your daughter got it from somewhere). The false negative rate on the blood tests even with a full gluten diet is around 30%. In other words about 30% of people with active celiac disease test negative no matter how much gltuen they ingest. You could be one of those 30%. It's actually good that your GI will do the biopsy with a negative blood test and is taking into account your family history.

[Notso]

You need to be eating the equivalent of 3-4 slices orf bread per day for 3 months prior to the blood test or biopsy. If your symtpoms are too bad to do that however you may consider yourself to have it based on dietary response and genetics (your daughter got it from somewhere). The false negative rate on the blood tests even with a full gluten diet is around 30%. In other words about 30% of people with active celiac disease test negative no matter how much gltuen they ingest. You could be one of those 30%. It's actually good that your GI will do the biopsy with a negative blood test and is taking into account your family history.

I am definitely not eating enough then. I'm still kind of hoping my symptoms are temporary from the diet change, and I don't have it. Better to know for sure, though.

[GlutenFreeManna]

I am definitely not eating enough then. I'm still kind of hoping my symptoms are temporary from the diet change, and I don't have it. Better to know for sure, though.

Normal people do not get sick from gluten when they go on a gluten-free diet and then add it back in. My husband went gluten-free with me for a month and then went back to eating gluten at work and restaurants without any problems. If you don't show up positive on the tests but still have symptoms when eating gluten you very likely have a gluten intolerance. You could be early enough celiac that it hasn't done enough damage to show up or you could have Non-celiac Gluten intolerance. Bottom line is no matter what the tests say, listen to your body.

[Austin Guy]

I am not getting tested. Eating gluten for more than a day would just kill me. I couldn't live with the sickness. Being healthy on a gluten free diet is enough of a diagnosis for me.

[gailc]

" In other words about 30% of people with active celiac disease test negative no matter how much gltuen they ingest. "

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I certainly believe you but I am going back to the doctor in a few days and I want to ask you where you found the 30% number. Do you have a reference?Since I wasn't allowed to speak with a doctor only a nurse practioner who stated the test (biopsy) would be accurate even though I had been gluten free for 4 months????

She also said Celiacs have diahreah, rather nastily under her breath, not so only 35% have diahreah according to my research.

I had biopsies yesterday, even though I tried to talk them out of the biopsies because I KNOW I was healed almost immediately on the diet and I'd heard 2 weeks gluten free voids the biopsies, he took the biopsies anyway.

I want to be able to say "about my blood tests-- 30% false negative " with more than saying I read it on the internet. Did Dr. Green's book say that? I returned it to the library and I don't remember.

By the way, all you folks out there getting colonoscopies, before you have them do it, ask them if they remove the air afterwards my previous GI doctor did remove the air. I spent all morning with the procedure and all afternoon and part of the evening in the ER(more $$$) with the side effects of leaving all that air in there. The pressure from the air gave me heart attack symptoms, they gave me ekgs, xrays, blood tests and I cannot remember if there were more things, and about to give me morphine and other drugs when this sweet young nurse came in and said 'this is your lucky day, I used to work in GI" Showed me how to quickly get rid of the air, I said hold off on the morphine and the rest then until I see if this helps(except I took the potassium) I wound up not needing the drugs.

As far as I am concerned, the doctor did not finish the procedure.

I have 6 holes in me now which will give false negative biopsies too, in addition to the blood tests a couple months ago --which, by the way I've never heard anything about.

No doctor ever commented on those blood tests, and they didn't show up online, I looked!

I wanted the endoscopy for my choking and swallowing problems anyway and the colonoscopy because I have put it off for too long--they did find a polyp as was expected after 65 years of being undiagnosed gluten intolerant/wheat allergy/Celiac.

gail

[gailc]

I tried for two weeks to eat gluten for the tests and gave up. Mostly mental, I could deal with the symptoms coming back, but mentally I could not cope with the damage I was doing to my body.

"FIRST, DO NO HARM" came to mind and I asked through a nurse if a gi doctor would convince me to continue eating gluten for the tests, and convince me it would be good for me then I would TRY. The answer was 'if you know it is bad for you , then don't eat it"

I am all for your decision, and I regret my 2 weeks of trying to eat gluten.

Everyone asks if I want to cheat, HUH, what?? The thought never entered my mind.

[GlutenFreeManna]

The 30% number is the often repeated number here. I'm sorry I can't remember where I first read it. I may be wrong and it may be that 30% of gluten intolerant people test false negative or something like that. I will try to find a reference for you.

[GlutenFreeManna]

Okay this may be where the 20-30% number came from: https://www.celiac.com/articles/57/1/Interpretation-of-Celiac-Disease-Blood-Test-Results/Page1.html

From that article:

"Both IgA and IgG anti-gliadin antibodies (AGA) are detected in sera of patients with gluten sensitive enteropathy (celiac disease). IgG anti-gliadin antibodies are more sensitive but are less specific markers for disease compared with IgA class antibodies. IgA anti-gliadin antibodies are less sensitive but are more specific. In clinical trials, the IgA antibodies have a specificity of 97% but the sensitivity is only 71%. That means that, if a patient is IgA positive, there is a 97% probability that they have celiac disease. Conversely, if the patient is IgA negative, there is only a 71% probability that the patient is truly negative for celiac disease. Therefore, a positive result is a strong indication that the patient has the disease but a negative result does not necessarily mean that they don not have it. False positive results are rather uncommon but false negative results can occur."

Bold is mine. So 29% percent of negatives are false negatives but that is only dealing with the IgA test. It gets more complicated (with differen false neg rates) when you add in the other tests which are talked about in the article. I'm not a scientist and it's a struggle for me to read these things due to poor short term memory so I may be reading it wrong...I also found a thread on the forums in which someone said the NIH had estimated 20% of negatives were false negatives but there was no link to those findings. You may be able to search the NIH publishings if you have access and find something.