Reliable Food Intolerance Testing

[Celiacattack]

Hello!

This is my first post on the Celiac.com Forum. A few weeks ago my lab results (blood work) tested positive for Celiac Disease (or gluten-intolerance). My gastroenterologist has since scheduled me in mid-October to have an endoscopy for the purpose of taking a biopsy of the villi in my small intestines. Of course, I've been contending with many typical (and a some atypical) symptoms of celiac disease for many years.

I've been told that many people with Celiac disease also have intolerances to other foods as well.

Question: Are there any food-intolerance tests which are scientifically proven to be reliable?

It seems everything I read on the Internet suggests that the reliability of most food-intolerance tests is not very good. Incidentally, I live in Ontario, Canada. I'd be looking for some testing procedure which would be available locally.

Many thanks...

[shadowicewolf]

eh, not really. The best test is trial and error. You may have other intolerences or you may not.

[Skylark]

Question: Are there any food-intolerance tests which are scientifically proven to be reliable?

Yes. Eliminate the food from the diet for a few weeks and challenge. That is the ONLY reliable and accurate way to check for food sensitivities.

You will find a lot of people around here who swear by various lab tests, but as your research has indicated, none of the testing holds up to scientific scrutiny. RAST and skin prick are the most common, but you can have a fair amount of IgE to a food in blood or skin and not react when you eat it. Skin testing is quite accurate as far as what food will cause a problem when you prick your skin with it. MRT has never been scientifically validated and IgG4 is so bad the American College of Immunologists has published papers saying it's a scam. There is actually growing evidence that IgG4 to foods is protective against IgE reactions. Another popular test is sIgA measured in feces, but again it's never been clinically validated and the false positive rate is staggering. Some blood IgA food tests are starting to become available, but they aren't looking any better than RAST or IgG.

The big quagmire is that food reactions can be IgE, IgG, or IgA mediated, and that you can have blood antibodies but no reaction at all, or a reaction and no antibodies. (This may be due to how the food antigen is prepared.) False negatives are also possible, although my understanding is that false positives are more common. Most allergists will order RAST and maybe an IgG panel and use the results to guide an elimination diet.

[GottaSki]

I had many allergy and antibody tests over the years - both blood and patch tests - the ONLY test that was ever positive was my tTG IgA which came back only mildly positive at age 43.

I had been gluten-free for over two years when I recently eliminated all grains, dairy, legumes, nightshades, nuts, eggs and citrus. I am currently challenging food items one every three or four days -- it has been live altering! Within three days I was out of bed (at the time I had maybe two good hours in the morning if I was lucky). Each day and week of the past month I have gotten stronger and my mind is clear (have had severe brain fog for several years and had been losing my memory for the past year). I've got a way to go with challenging all food items, but would highly suggest eliminating all possible food intolerances if all your symptoms do not improve by going gluten-free. My docs and research told me that some with celiac disease take longer to improve than others because of the more severe damage to our gut. For over two years I struggled with trying to eliminate possible causes for my condition getting worse (my digestive symptoms initially improved after about 9 months gluten-free).

Very thankful to finally be improving -- I feel 46 again (if not younger) -- two months ago I felt 86 (if not older).

I hope gluten is your only intolerance, but if not - you are not alone.

Good Luck!

-Lisa

[Celiacattack]

Wow! Many thanks for the informative and helpful comments.

Question: If it is known to often require several months of a gluten-free diet before any noticeable health improvements are realized, how can an elimination and challenge diet involving some other (non-gluten) food yield any diagnostic results after a mere few weeks?

A few years ago I had a hair mineral analysis conducted by a reputable Canadian-based lab. Although I fully realize that even hair mineral analysis has dubious predictive validity (i.e., mineral concentrations in hair samples might not be indicative of body tissue mineral concentrations), nonetheless, the results were astounding. For almost every recorded mineral concentration, I was at least two standard deviations below the mean. Considered by itself, I probably wouldn't ascribe too much credibility to these lab results, but when the larger picture is taken into consideration, I have little doubt that I'm contending with chronic malabsorption - despite eating large amounts of assorted and nutritious foods.

I'd be curious to know if others have had a hair mineral analysis lab work conducted at some point. If so, in hindsight, do you believe the results to be indicative of your overall nutritional status and capacity to absorb nutrients from your food?

Reliability...

Can I assume that most gliadin-based blood tests are not really specific to gluten-intolerance? Could the antibodies be elevated due to other food intolerances?

Likewise, I'm scheduled to have an endoscopy next month. Hypothetically, if the villi in my duodenum are denuded, damaged, or exhibit significant atrophy, can I be reasonably certain that gluten is the main culprit? Or, is the only ironclad "acid test" a postoperative elimination & challenge food regime?

Thanks in advance for any responses...

[Skylark]

Question: If it is known to often require several months of a gluten-free diet before any noticeable health improvements are realized, how can an elimination and challenge diet involving some other (non-gluten) food yield any diagnostic results after a mere few weeks?

Celiac disease can require months or even years because auto-antibodies have to disappear, lymphocytes have to leave the intestine, and then the body has to repair all the autoimmune damage. This is very different from a food intolerance where the body is simply reacting to a food. It's like an animal allergy, where you get away from the cat and feel better fairly quickly. At worst you'll have some inflammation that has to resolve. Most people feel better eliminating problem foods including gluten after two weeks, or a month at most if they have a lot of inflammation. Even some celiacs feel noticeably better after a week or two off gluten, because most celiacs are also gluten intolerant.

Reliability...

Can I assume that most gliadin-based blood tests are not really specific to gluten-intolerance? Could the antibodies be elevated due to other food intolerances?

I'm not sure I understand your question. Gliadin-based blood tests detect anti-gliadin antibodies. If you have anti-gliadin antibodies, you may be intolerant to gluten, or you may even have celiac disease. On the other hand, some folks with anti-gliadin antibodies eat wheat just fine - this is the general issue with all antibody blood tests. A positive blood test does not reliably predict a reaction whent the food is eaten. If you have anti-deamidated gliadin antibodies, which is a newer test, you're celiac becasue deamidated gliadin is ONLY produced by the celiac intestine.

Likewise, I'm scheduled to have an endoscopy next month. Hypothetically, if the villi in my duodenum are denuded, damaged, or exhibit significant atrophy, can I be reasonably certain that gluten is the main culprit? Or, is the only ironclad "acid test" a postoperative elimination & challenge food regime?

You seem to have celiac disease and food intolerance confused. The villous atrophy is from the autoimmune attack of celiac disease. Other food intolerances don't trigger autoimmunity. They just make you feel ill after you eat the food. If you have a positive biopsy, with the positive blood test it is 100% certain that you are celiac. By the way, you must be eating gluten for an accurate biopsy.

[Bubba's Mom]

Thank you for that clarification SkyLark. My blood tests were negative, but my endoscope showed flattened villi. The GI said I had Celiac. Since going gluten-free I've noticed that soy gives me neurological symptoms, which has had me questioning if soy caused the damage...or is it gluten?

My allergist said that dairy can cause villi damage too, leaving me with even more questions!

[Skylark]

I'm a researcher, not a doctor, but I have never seen a study where a food other than gluten has caused villous atrophy. I think maybe there is one case history out there of villous atrophy to chicken. There is some fairly strong documentation of anti-gliadin antibody cross-reactivity to casein in many people with celiac disease, meaning that celiacs who are still eating wheat are often casein-sensitive. I would be really curious to know how well your allergist has documented these people where he thinks the dairy is causing villous atrophy. If it's documented and not clinical hunch he really should publish it. It could be a cure for some folks who are being told they have refractory celiac. (I suspect it's simply dairy cross-reactivity in people with celiac who are like you and don't have antibodies in the blood. The blood isn't the best place to look for gut antibodies!)

It is quite possible that you are also sensitive to soy and dairy but they wouldn't be causing the villous damage. I'm sorry to hear soy is causing you neuro troubles. That sounds like a real pain! I started out my own gluten-free diet reacting to both cow dairy and soy. They gave me stomach trouble much like gluten did. Eventually I healed and was able to go back to eating them, but I still cannot eat gluten.

[Bubba's Mom]

Very shortly after being DXed and going gluten-free I went to the grocery store. I had to walk through the bakery dept. to get to the special diet food section. I had a reaction like my throat closing as I went through. It concerned me so I asked my allergist for food allergy testing.

I told him I had just been diagnosed with Celiac, but it didn't show up in my blood tests. That's when he said dairy could cause flattened villi too.

He said it very "matter of factly" so I didn't question it.

I didn't get a reaction to anything from the skin prick testing which surprised me. I thought for sure I'd react to wheat? He said there's a kind of allergy that they don't have a good test for finding. He said my gluten "problem" was likely that kind of allergy. Apparently soy is one of those too?

I've heard some people can add back in dairy or soy after healing? I hope I'm one of those. Soy seems to be in even more foods than gluten! I sure would like to be able to have chocolate back again.

[Skylark]

Skin prick tests for true IgE mediated allergy. As we are well aware, IgE is not the only antibody that can cause reactions to foods.

I am very suspicious of the dairy causing villous atrophy. It seems to me that it would be in the medical literature if it were common and it's not. Doctors say a lot of dead wrong things very matter-of-factly.

I'm one who added dairy and soy back. Both gave me stomach trouble at first. Now I tolerate them fine, though I don't eat a LOT of soy like tofu because it slows thyroid function.

[StephanieL]

A + skin prick test is about 50% accurate. A - skin prick test is about 92+% accurate. As stated, that is for "true" IgE allergies. For all the others, there isn't anything "reliable" out there. Hang in there!

[Celiacattack]

Thanks for the helpful clarifications, Skylark!

My recent IgA test was negative and my IgG test was positive (44 KEU/L), with any value exceeding 20 KEU/L apparently being flagged as abnormal.

That being said, I was essentially on a gluten-free (or minimal gluten) diet at the time of this blood test. Now I'm well over two weeks into eating a gluten-inclusive diet (as requested by my gastroenterologist), and my endoscopy is scheduled for mid-October. Apart from gastrointestinal problems, insomnia has become a huge problem. If I eat a sandwich, for example, I also have to lay down for awhile due to the pronounced mental and physical fatigue. There are a host of other noticeable problems as well... including elevated anxiety levels.

So, I am relieved to know that if my upcoming endoscopy establishes that the villi in my small intestines exhibit characteristic gluten related antibody damage, this per se is enough to confirm a diagnosis of celiac disease. In other words, I won't have to undergo a second endoscopy (at a later date) after having eliminated gluten from my diet - to confirm that the villi have since rejuvenated. One endoscopy is sufficient to establish a diagnosis. Is my understanding correct?

Thanks again...

[Bubba's Mom]

Yes..one endoscope should be enough to find villi damage. That being said...several samples should be taken for biopsy at that time. In some cases villi damage may occur beyond the reach of the scope. The small intestine is pretty long and has lots of turns. So, unfortunately if there is no visible damage it doesn't mean it isn't there.

A truly gluten free diet should have you feeling better if gluten is your problem.

Some Drs like to redo the scope at a later date if you still have symptoms to see if there are ulcerations, or other isssues, or to check for healed villi.

[Celiacattack]

A truly gluten free diet should have you feeling better if gluten is your problem.

Certainly my symptoms have become far more pronounced since I started a full gluten-inclusive diet, almost three weeks ago, in preparation for my upcoming endoscopy. That being said, at no point in my life have I been "entirely" gluten-free. Already I'm looking forward to going gluten-free... based on what I'm experiencing now.

A diagnosis of celiac disease would certainly explain a lot. For example, my blood work always exhibits anemia (decreased number of red blood cells). No physician has ever explained this anomaly, and I have (barring possible gluten issues) no diagnosable health problems.

Thanks!

[Celiacattack]

Hello again!

Well, today I had my endoscopy procedure done at the local hospital. Unfortunately, the gastroenterologist only took three (3) biopsy samples from my stomach (none from the small intestines). This physician looked to be under 40 years-old. So, he should be well-acquainted with the recent medical literature pertaining to celiac disease. Of course, I had deliberately been eating gluten for six weeks prior to this medical procedure. It will be awhile before I know the lab results of the biopsies.

Question #1: Are biopsy samples of the stomach also a reliable indicator of celiac disease?

Before I was anesthetized today, the gastroenterologist made a few disconcerting remarks while we were chatting. For example, he maintained that diarrhea must be present in every instance of celiac disease when gluten is being consumed. As well, he claimed there exist NO blood tests which mean anything in regard to celiac disease - due to the fact that false positive results are exceedingly common. Finally, he mentioned that it is unlikely that I have celiac disease since this condition is quite rare. All this being said, this was our first encounter. Prior to today, I had never met this gastroenterologist before. It was my family physician who requested the blood-work and made the referral. Although it is - of course - possible that I don't have celiac disease, my reading seems to be irreconcilable with the details mentioned by this physician.

Question #2: Is this physician correct? Am I mistaken?

Thanks!

[Skylark]

Oh, gosh. This guy is an idiot. Celiac cannot be diagnosed from stomach biopsies. The biopsies must be taken from the small intestine, and the state of the intestinal villi are diagnostic for celiac.

I can't understand how the estimated 1 in 133 Americans with celiac would be "exceedingly rare." If you are only diagnosing with Marsh 3 or 4 biopsy there are false positive blood tests, but experts are starting to demonstrate that people with positive blood tests and negative biopsy are simply in a latent period between seroconversion and intestinal damage. And no, diarrhea is not always present in celiac disease. Some celiacs don't even have GI symptoms - they have dermatitis herpetiformis or neurological symptoms.

I'm so sorry you wasted all your time and effort with this terrible doctor.

[Bubba's Mom]

A Dr. so mis-informed is scary..but unfortunately common.

My PCP is right out of medical school. I had hopes she would be better informed about Celiac but she's not. She questioned my Dx because I didn't fit into the narrow "frame" of symptoms she expected.

I feel so bad that the Dr. wasted your time. Go gluten-free and best of luck to you. If your symptoms persist find another GI.

It couldn't hurt to print out a little more updated symptoms/side effects to take to your Dr. so he is made more aware.

Please ask your PCP to do a blood panel to test your vitamin/mineral levels. It's scary that theseguys are in charge of our medical care and we know more than them!

[Celiacattack]

Thanks for your replies.

Next month I have a follow-up appointment with this GI specialist. I'll be sure to ask him many questions. Maybe he used the term "stomach" in a colloquial fashion (like "tummy"). Until I get more information, I'd like to give him the benefit of the doubt.

Sometimes I wonder if these physicians consider themselves too busy to keep abreast of topical medical literature. Although this is not a legitimate excuse, it might characterize their own perspectives.

Curiously, the constant cramping in my left side simply vanished while I was fasting for approx. 36 hours prior to the endoscopy. The postoperative consumption of a bowl of cereal and light soup seemed to bring this symptom back in full force. As suggested, I guess I'll simply have to go gluten-free and see what happens.

Thanks again... This discussion forum is a real blessing to me!

[Skylark]

HMO physicians do NOT have the time to stay abreast of literature. They work 10-hour days and come home exhausted. They take their required CME credits and most wish they had time and energy to read literature but they don't. HMO patient loads are too extreme. When doctors get time off, many are like you and me. They want to go do something unrelated to unwind (like golf) rather than hit the books.

Your doctor is most likely practicing on what he got in med school, and when he was in school celiac was "rare", and his textbook probably had a picture of an emaciated child with a bloated belly. It wasn't fair of me to call him "terrible". He is most likely doing what all doctors do to survive in a broken health care system.

I hope gluten-free helps you, no matter what the tests say. That's the important thing anyway!

[srall]

To the OP...it sounds like you are planning on going gluten free no matter what the test results are. My poor brother went through everything you're going through, after battling depression and severe stomach pains for years, only to be told by his GI that he did not have Celiac, so go ahead and keep eating gluten. Now years later he's still on meds for his stomach and his depression, and was diagnosed with diabetes at 39. My mom and I (and my daughter under my supervision) went ahead and went gluten free on our own. My mom tried to reintroduce gluten to do the gluten challenge but lasted 24 hours and couldn't get out of bed. I know from one accidental glutening that I would never survive until the testing. And I will not put my child through that. So, not everyone here has a diagnosis, but we have learned to listen to our bodies wisdom rather than doctors who, as has been pointed out, are too busy with their patient load to keep up with current research.

[Celiacattack]

Yes, I guess that's the most important detail... If our health improves when we are gluten-free, it doesn't really matter what the medical profession tells us. The proof is in the pudding!

Thanks again, guys!

[T.H.]

Hello again!

Question #1: Are biopsy samples of the stomach also a reliable indicator of celiac disease?

Nope, not in any way, shape, or form. Whatever he's looking for, it ain't celiac disease, or he's so ignorant it's appalling.

He maintained that diarrhea must be present in every instance of celiac disease when gluten is being consumed. As well, he claimed there exist NO blood tests which mean anything in regard to celiac disease - due to the fact that false positive results are exceedingly common. Finally, he mentioned that it is unlikely that I have celiac disease since this condition is quite rare.

Question #2: Is this physician correct? Am I mistaken?

Wow...he's batting 1000 on the 'ignorant' front.

Years ago, docs thought that all celiac disease patients had diarrhea. ABSOLUTELY wrong, and that's no longer in the medical texts (although it's only, oh, 10 years since that's the case, I think?). I have 4 celiacs in my family (blood and biopsies positive) and NONE of us had diarrhea going into this. I still don't get any gut issues at all from ingesting gluten, although it makes me sick in other ways.

It can be silent celiac disease or asymptomatic celiac disease, or just have other gut issues without diarrhea. Although in some recent research, they are finding at least as many people presenting with this 'silent' celiac disease as those with the gut issues!

With re: to blood tests: false negatives are more common than false positives. Biopsies, especially those with only three samples, are just as often false negative, too.

Rarity-wise? They used to think celiac disease affected maybe one in a few thousand. Now, they've found out it's 1 in 133 people.

Your doc sounds completely, utterly celiac ignorant. The new rules that informed celiac specialists seem to adhere to is to get 3 out of 4 tests positive for a diagnosis: blood work, biopsy, gene test, and symptom elimination on the gluten-free diet. You've got 2, plus one useless non-test (incorrect biopsy). If you get a gene test, most good docs will consider that a diagnosis.

[Celiacattack]

Hi T.H.,

Would you mind sharing what sort of (non-gastrointestinal) symptoms you typically experience when you're exposed to gluten? I'd simply be curious to know which of my own symptoms might be related to the ingestion of gluten.

Thanks!