What do my test results mean?

[jmiller93]

Hello!

I just was notified of my test results of my celiac reflex panel. The ttg-iga was <2, but the iga was high-366. 

[trents]

Welcome to the forum, @jmiller93!

What was the range used by that lab to establish positive vs. negative? Different labs use different ranges. There is no industry standard. But the number is low enough to suggest a negative test result for the tTG-IGA. That one is actually an antibody test used to detect celiac disease. The other one, the "IGA" at 366 is what we commonly call "total IGA". It is not a test for celiac disease per se but is used to check for IGA deficiency. If there is IGA deficiency, the individual IGA antibody tests can give falsely low, results, and even result in false negatives.

Obviously, you are not IGA deficient. A high total IGA is of no particular consequence with regard to indicating other health issues not related to celiac disease as far as I know but check with your physician to be sure.

It needs to be pointed out that if you had already been withholding gluten from your diet prior to the blood draw done for celiac antibody testing, that would invalidate the testing.

It also needs to be said that testing negative for celiac disease does not rule out the possibility of having NCGS (Non Celiac Gluten Sensitivity). What caused you to see celiac disease testing? What are your symptoms?

[jmiller93]

My physician messaged and said I had a negative panel. I was diagnosed with IBS as a teenager and have had GI issues ever since. I have chronic diarrhea, abdominal pain, chronic fatigue, nausea.

I am adopted and didn’t know my medical history, so I took a dna test a few years ago. I had tested positive for one of the markers, so said I was at increased risk of developing. The panel was to rule out, so I guess it’s been ruled out. 

[trents]

You still may have NCGS. NCGS shares many of the same symptoms of celiac disease but does not damage the lining of the small bowel as does celiac disease. There is no test for it. A diagnosis for NCGS depends on first ruling out celiac disease. It is 10x more common than celiac disease. Some experts feel it can be a precursor to the development of celiac disease. Eliminating gluten from your life is the antidote for both.

You would do well to consider trialing the gluten free diet to see if your symptoms improve.

[jmiller93]

Thank you! I might give it a try.

[knitty kitty]

@jmiller93,

Some of us are seronegative and don't test positive on tTg IgA tests.  Anemia, diabetes, and Thiamine deficiency can cause false negatives on Celiac panels.  Have you been checked for nutritional deficiencies?  Iron? Thiamine?  Vitamin B12?  Vitamin D? 

Only one Celiac markers is needed to develop the active disease.  

I agree a gluten free diet trial is worth a try.

[jmiller93]

I’m have a vitamin D deficiency. I’m still waiting on a qualitative fat test to see if I have malabsorption. 

[trents]

knitty kitty, are you IGA deficient? I'm wondering if seronegative IGA celiacs will also be necessarily IGA deficient.

[knitty kitty]

There's different reasons why one may be seronegative.

Some Seronegative Celiacs may be genetically encoded to be IgA deficient.  But, they may still make IgG antibodies, hence both IgA and IgG antibodies are tested for in the full Celiac Panel of blood tests.  Instead of IgA and IgG antibodies, some Seronegative Celiacs may make other types of antibodies, like IgM antibodies, which aren't usually tested.  Some may make antibodies, not against Gliadin, but other immunogenic peptides in wheat, barley and rye.  

The immune system can respond to gluten by sending in different types of protective immune cells, which don't result in IgA production, but result in changes in the types of immune cells in the intestinal tissues may be seen. 

There's also the possibility that in some seronegative Celiacs the production of antibodies in the gastrointestinal tract is so poor and limited in number that sufficient antibodies don't get into the bloodstream where they can be measured.  Chronic Inflammation and Villous Atrophy may result in anemia and thiamine deficiency that can result in poor antibody production.  However, healing of the intestinal lining and villi may restore the ability to produce IgA and IgG antibodies.  They may test positive on serology at a future time.

I believe I'm of the last group.  I know at one point my doctor said I had high antibody levels, but the doctor refused to do further testing for specific antibodies found in Celiac Disease.  He laughed at me for suggesting Celiac because I was not the "Classic Celiac", all skin and bones, wasting away from malnutrition.  I was obese, bloated, and prediabetic, all symptomatic of Thiamine deficiency (High Calorie Malnutrition), and also Celiac Disease.  By the time I found a new doctor who would test for Celiac antibodies, my health was so poor from nutritional deficiencies and intestinal damage, I wasn't producing antibodies.  I was seronegative.  I was dismissed as being a hypochondriac, a mental case.  They did not connect my mental health issues with nutritional deficiencies (Wernicke's Encephalopathy, Pellagra, B12 Deficiency Dementia, Scurvy).  Will I undergo a gluten challenge to test for tTg IgA antibodies?  Absolutely not.  I have two genes for Celiac Disease and improvement on a gluten free diet.  That's plenty enough for me.  

Interesting Reading:

Seronegative Celiac Disease and Immunoglobulin Deficiency: Where to Look in the Submerged Iceberg?

https://pmc.ncbi.nlm.nih.gov/articles/PMC4586545/

Clinical profile of patients with seronegative celiac disease

https://pmc.ncbi.nlm.nih.gov/articles/PMC10404820/