Is just an IgG test sufficient to rule out celiac?

[Sekhmet]

Hi everyone,

I am new here.  At my request, my doctor ordered a blood test to check for celiac disease.  A nurse told me my doctor said they would do a "celiac panel," so I expected that it would cover a few different measures. However, I went in this morning for the blood draw and noticed that the paperwork indicated only this test: Gliadin (Deamidated) Antibodies, IgG, Serum

From my reading, this is not the preferred test, although it may be done in conjunction with other tests.

If this single test comes back negative, can I be confident that I do NOT have celiac? Or would I need to push my doctor for a more comprehensive panel?

Thank you!

[cyclinglady]

That is really weird!  The standard, pretty much world-wide, to screen for celiac disease is to order the TTG.  Usually the TTG IgA and  IgA (Immunoglobulin A) test (which is used in the case of celiac disease testing as a control test to see if the TTG IgA works) is ordered.  This is one the most cost effective methods.  Often, the TTG IGA and TTG IgG test is ordered.  But the first option let’s a doctor know if you are low in Immunoglobulin A which  is common in celiacs and brings another set of health issues to the table.  

If negative, the doctor can order the DGP tests (IgA and IgG versions and the EMA IgA (most expensive, labor intensive) and very specific for celiac disease).  If that fails the doctor might still proceed with an endoscopy to obtain intestinal  biopsies (the gold standard in diagnosing celiac disease still....) because some celiacs are seronegative and the doctor needs to really see what is going on).  

Is your doctor a medical doctor?  Some NPs order the DGP IgG for gluten sensitivity.  Problem is there is no test for gluten sensitivity — at least recognized by any Celiac Research Center in the world.  Usually a sensitivity is determined by firmly ruling out celiac disease and trialing the diet.  I wish there was an easy accurate test.  

Now, your test. Consider asking for the rest of the panel.  If you are IgA deficient, ask for the TTG IgG test too.  Heck, if my GI had ordered just the DGP IgG, my diagnosis would not have been caught (but my Immunoglobulin A is not low/deficient).   

Research more, because your doctor does not sound celiac-savvy.  

 

 

[Sekhmet]

Thank you, cyclinglady!

Yes, she is an MD. This was my first visit to her, and I was really impressed during my visit - she seemed to really be on top of things (at least, relative to a string of mediocre doctors I have had previously), but at that time celiac was not a topic. So you may be right that she is not celiac savvy. ?

I am holding out a small hope that maybe what was on the paperwork is not what their lab will actually do??  The nurse had said "panel," after all. I'm hoping it'll end up magically including some of those others. Or... the doctor meant to order the full panel but like clicked the wrong one... Anyhow I will wait and see what this result looks like and go from there.

[Sekhmet]

Got the result today, and it is indeed the IgG only, and it is "negative" with a result of: <10.0 Units

I have sent a message to my doctor requesting that she at least also order the TTG IGA test.

However, I'm assuming that this result does at least significantly lower the likelihood that I have celiac?

This is all just a shot in the dark anyhow... but after 8 years of unsatisfactorily diagnosed mystery joint pain, I don't want to only half-explore an option and then abandon it without a reasonably definitive result.

[cyclinglady]

Why....why would your doctor not follow the standard of care for testing celiac disease?  I think you need to think about  finding another doctor.  If you are in the US, you can “walk” into a lab and order the test and pay cash:

https://labtestsonline.org/tests/celiac-disease-antibody-tests

No, your result does not significantly lower your odds of getting a celiac disease diagnosis.  She ordered the LEAST commonly used test, especially since she only ordered that one alone.  I think she thinks you do not have celiac disease, but that you may have a gluten sensitivity.  But that is wrong!  There is no test for gluten sensitivity. 

http://www.cureceliacdisease.org/screening/

https://www.mayocliniclabs.com/it-mmfiles/Celiac_Disease_Diagnostic_Testing_Algorithm.pdf

https://celiac.org/about-celiac-disease/screening-and-diagnosis/screening/

https://www.verywellhealth.com/celiac-disease-blood-tests-562694

https://www.niddk.nih.gov/health-information/diagnostic-tests/celiac-disease-health-care-professionals

I am not a doctor though.  Perhaps, you can ask her why she did not order the complete panel or at least the screening tests most often ordered for celiac disease.

Know that some celiacs are asymptomatic (no symptoms) Some just have one symptom.  Some have classic symptoms.  I presented with only anemia and no GI symptoms with only a positive on the DGP IgA.   

I hope this helps.

 

[Sekhmet]

Thank you so much, cyclinglady. Yes, very helpful!

I want to tell her the exact tests I want.  I am thinking I should request:

1. tTG-IgA
2. Total serum IgA

Do you agree? I am on a super high-deductible health plan, so I end up paying for all of these, so I don't want to go overboard while still being as sure as I can be.

Not related to celiac (as far as I know) but I was also reminded that my sister has the MTHFR gene mutation (homozygous C variant), so I need to ask her to be tested for that as well... She is going to think I am nuts, and that is fine. ;)

[cyclinglady]

For like $100 more, add the DGP IgA test as well.  The EMA is expensive because it is labor intensive (lab), so consider skipping that test.  

Why find out if you have the MTHFR gene?    What is that knowledge going to do for you?  I have probably have the MTHFR gene.  My B-12 and Folate used to be off the chart when I was consuming soy milk that was fortified with cheap unmethylated forms of vitamins.    (I used soy milk before my celiac diagnosis because I was lactose intolerant).  I ceased all vitamin supplements and dropped any foods that were enriched  (or you can purchase more expensive methylated versions if you want to supplement) and those levels dropped down to normal levels.  I found that If I ate a normal healthy and varied diet and healed from celiac disease, I do not need supplements.   It appears that I was not able to process unmethylated vitamins because I might the MTHFR gene.  Just a theory.   Knowing I have the gene?  What is that going to do for me?  Will it change my behavior or save me from a new illness?  Can my doctor formulate treatments based on that knowledge?  Can he manipulate my genes?  NOT YET.  This might be beneficial in the future, but science is not there yet.  Just lots of websites trying to sell you vitamins.  Believe me, I have a family full of Autistic family members, so the MTHFR topic is of interest to me.

Consider ruling out celiac disease first, address other issues that can impact joints like RA or Crohn’s), then eat a healthy diet that may or may not include gluten or processed food.  I have a friend who is on week three of the Whole 30 diet.  She ruefully confessed that she is feeling so much better.  In a few weeks, she will add foods back in that might be giving her issues.  I think she realizes that her Standard American Diet is not the healthy way to go.  Although she is happy about feeling significantly better, she is sad because she knows that she is going to have to give up all that junk food which seems to be making her sick.  I hope she moves forward because good health is priceless.  

 

 

[Sekhmet]

Okay, thanks.

Re: MTHFR - I don't really know yet... I only started reading about it yesterday and it is pretty overwhelming. But it does seem to be common advice that if you have a close relative with it you should be tested, and I guess having 2 copies of the "C" variant, as my sister has, is the "worst" variety of it.  It came to light for her when she was going through infertility and miscarriages.  They discovered that her homocysteine was high, which led to the MTHFR testing.

So that is one thing I know I would then want to proceed to do, if I do have it - get my homocysteine tested. My dad died of early-onset Alzheimer's, and apparently there is a link between high homocysteine as well as the MTHFR mutation and Alzheimer's.

It also seems like it would be worth knowing if I have it since it could be the cause of my lower levels of B12.

And I guess maybe I would need to start taking methyl-folate?

I mean, to answer your question, I am not entirely sure what I will do if I do have it.   Probably read a lot more about it... and take supplements like methyl-folate if I really think I need to.  Check my homocysteine & control that if I need to, hopefully to lower my risk of Alzeheimer's.  It seems like a frustrating area because there appear to be limited official medical websites that really even talk much about it (so far).  I have found one article on the NIH that focuses on the link with high homocysteine.

I already eat a very healthy diet.  Whole grains, lots of fruit & veg, mostly organic.  I am a vegetarian except for very rare seafood. I avoid processed food and, above all, foods with added sugar...  To me, sugar is by far the worst culprit in the SAD. 

I think RA has been ruled out by my 2 negative Rheumatoid Factor tests (one done several years ago, one just this year at my physical).  Also, the way this started in my elbows, and was really only there for years, is just... weird... and definitely doesn't really fit with arthritis.  And there is no swelling to speak of, just mild pain - sometimes aching, sometimes burning, sometimes sharp...  It may or may not fit with any systemic diagnosis versus a mechanical one, but nowadays I do also have pain in my hands, feet, and knees.  So then I think, well maybe it is/was something systemic, but it was worse in my elbows for some mechanical reason but now has progressed elsewhere. 

I thought Crohn's was just digestive?  (Of course, many people think that of celiac.)  So I haven't really investigated that one much.

My ANA was retested and is back down to "negative," so I think that pretty much rules out lupus.  I believe fibromyalgia is still on the table.

Anyhow....  Your point is nonetheless taken.  I do want to rule out celiac and go from there.  At this point I'd sure love to find out it is something I could control through my diet!

[cyclinglady]

Just know that I am not a doctor or a dietitian, but since you are vegan/vegetarian, that could be the reason why you are B-12 borderline low.  My B-12 was high and the  dropped after I stopped drinking that fortified soy milk.  It is well known that vegans can be B-12 deficient.  My daily consumption of eggs, fish, and meat  insures (for now) that I do not need a B-12 supplement.  However, celiac disease or any GI issues can cause deficiencies.  Chances are I will need to supplement  since I also have autoimmune Gastritis and eventually, I will not be able to absorb iron or B-12 from supplements or food.  If you can absorb your nutrients from food, it is best.  The MTHFR gene allows you to process natural in-food nutrients.  Abou 40% of the population has the MTHFR genes, so it is not uncommon!  

https://www.healthline.com/health/mthfr-gene

Crohn’s can affect your joints.  If you end up with a Fibromyalgia diagnosis,  look to diet (autoimmune Paleo) and gentle exercise.  I have family members who have Fibromyalgia and even am a long-term Fibromyalgia study participant at local university.  Both diet and exercise can help.

Looks like you are researching all possibilities.  Just share those with your doctor.   I wish you well!   

 

 

[Sekhmet]

I've been lacto-ovo vegetarian for... going on 30 years. I was vegan for about 1 year, but that was ~20 years ago.  And I do know that veganism can result in a B12 deficiency, but not lacto-ovo vegetarianism.  I eat plenty of eggs & dairy, daily (probably too much dairy, in fact).

I don't have any real GI issues to speak of, so that is why I doubt Crohn's.

I really appreciate your advice and well wishes!  I will update once I get further testing done.

[Sekhmet]

So... I went back for another blood draw yesterday.  The doctor ordered:

1. TGG IgA Ab
2. IgA
3. Endomysial antibody, IgA titer (I think this is the one you warned can be expensive...)
4. ANA (for the 3rd time, I assume because I had 1 positive result & 1 negative result)
5. MTHFR mutation
6. Homocysteine

So this morning, in the clinic's web portal, 1 of the test results was already available.  It is my IgA, and it is flagged as "low" at a value of 42 mg/dL; the normal reference range is given as 70-400 mg/dL.

[cyclinglady]

I have not researched the cut off for IgA in regards as being used as only a control test in celiac disease (mine is the opposite and is very high), but it indicates that you should see a GI because any IgA related test (TTG IgA) might be inaccurate.  

Others on the forum have researched low IGA (which on its own is a separate issue), I thought it needed to be closer to zero, but I am not sure.  

Keep reporting!  I am curious.  Also, be persistent.  My niece went through four GIs before she finally received her Crohn’s diagnosis.  Damage was found with a pill camera and out of reach of both scopes.  We knew something was wrong and her parents did not give up.  

[Sekhmet]

So, I have spent the last hour researching it. The most useful information I am finding is in medical journal articles, because most websites just lump "low IgA" into the "IgA deficient" category and make blanket statements about it.  However, looking more deeply, there is common agreement that there is "severe" IgA deficiency, which is defined as <7 mg/dL, and there is "partial" IgA deficiency (defined as below the normal range I cited above).  So I fall into that "partial deficiency" camp. 

The latest article I was reading is here: http://clinchem.aaccjnls.org/content/54/7/1203 This study agrees with a couple others I have read that assert that a patient with "partial" IgA deficiency will still get positive results on the IgA-EMA test and I believe also the TTG-IgA test, apparently on a frequency that matches that of non-IgA deficient patients.  However, there are just a handful of studies that have been done on this, and I guess it hasn't been unanimously accepted that this is the case... It remains a bit of an unknown.

Still, I feel like if all of my blood tests were to come back negative, it probably would not really make sense to push for a biopsy because I do not have typical celiac symptoms to begin with??  As much fun as that sounds like...

[Sekhmet]

So, my TTG-IgA came back negative (< 0.5). 

EMA IgA isn't back yet, but I'm guessing it will corroborate the above.

I'm being referred for an immunology consult, because of my low IgA level.  ?

[jean9v]

Sekmet... Cyclelady is correct... I have showed a false negative on my IgA and IgG testing... for celiac.. but, it was a god sent.. Finding out that I was low... almost Nothing of IgA in my blood... I have IgA Deficiency, explains why it takes me 3 time a long to get rid of a common cold..you have nothing to defend it.   Long story short, because of that I went on the gluten-free diet anyway, severe skin rash, brain fog, stomach and digestive issues... within 3 days of the diet the severe itch was gone and within days my digestive pain and issues were receding.  I went to a IG Doctor and told him my story, I was going to have a biopsy taken to confirm, his question was... well it walks like a duck, if you are feeling so much better... the odds are you are sensitive.  That was 10 years ago, and it was my Dermatologist who diagnosed me... only after seeing so many other Drs. for 40 years to take care of my rash and that explained why I always had a head cold, I was told it was Hayfever and dust.. maybe a little bit... Anyway... go on the diet... for two weeks... write down all of your issues on day one... on day 5 write down how you feel, not looking at day one... then on the 12th day... write down how you feel... you will be shocked, that in that small bit of time how much better you are feeling... It is worth a try...