Help Understanding Test Results

[Brown42186]

I'm having a hard time understanding my blood test results. I've dealt with stomach issues for a few years and was tested for celiac but had not been eating much gluten if any at all around the date of my test. Could you help me interpret my results? Should I eat gluten consistently then have them redone? Thanks!

Deamidated Gliadin ABS, IGA - 4 units

Deamidated Gliadin ABS, IGG - 3 units

Endomysial Antibody IGA - Negative

Immunoglobulin A, QN, Serum - 211 mg

TTG IGA - <2 U/mL

TTG IGG - 9 U/mL

The bottom result for TTG IGG is the only one flagged as high, but does that mean I have celiac? Or is that just something else?

[Scott Adams]

Welcome to the forum, could you please include the reference ranges for each test, as they vary from lab to lab...thank you!

[trents]

The elevated TTG-IGG could be caused by celiac disease but it can be elevated for other reasons as well. The centerpiece of celiac blood antibody testing is the TTG-IGA and apparently that was not elevated. When you had the blood draw done for the testing, had you already been cutting back on gluten?

[Brown42186]

I added the normal ranges below. Yes, I had mostly quit eating gluten before the test was done last year. I have been consistently eating it since this past Christmas. I wasn't sure if the results could've been incorrect since I wasn't eating much if any at the time of the test. I have a GI appointment next week and was considering seeing if they'd retest me.

Deamidated Gliadin ABS, IGA - 4 units (0-19 range)

Deamidated Gliadin ABS, IGG - 3 units (0-19 range)

Endomysial Antibody IGA - Negative

Immunoglobulin A, QN, Serum - 211 mg (87-352 range)

TTG IGA - <2 U/mL (0-3 range)

TTG IGG - 9 U/mL (0-5 range)

[Scott Adams]

It looks like your tTG-IgA (tissue transglutaminase IgA) Blood Test for Celiac Disease was high, which could mean that you have celiac disease. Your doctor may want to schedule an endoscopy to confirm the results, and for this you would need to continue eating lots of gluten daily until that that is finished. Do you have any symptoms which led you to be tested? 

This article might be helpful. It breaks down each type of test, and what a positive results means in terms of the probability that you might have celiac disease:

Quote

The sensitivity of the tTG-IgG blood test is generally high, ranging from 85% to 98%. This means that the test can accurately detect celiac disease in a significant percentage of people who have the condition.

The specificity of the tTG-IgG blood test is also high, typically around 90% to 98%. This indicates that the test can effectively rule out celiac disease in individuals who do not have the condition.

 

 

[Brown42186]

Yes, I'm constantly bloated to the point it feels like my stomach will pop and have inconsistent bowel habits. I'm either constipated or have diarrhea, never really just normal. I sometimes have mucus in my poop. I get nauseous after I eat. My stomach never really feels good. I'm exhausted all the time and have started being anxious. I'm assuming maybe celiac or just a gluten sensitivity or IBS. I don't feel like the first GI I went to really wanted to do much. My primary care doctor did the celiac test and then it just went nowhere. I go to a different GI next week.

[Scott Adams]

At the very least this seems like it could be non-celiac gluten sensitivity.  Approximately 10x more people have non-celiac gluten sensitivity than have celiac disease, but there isn’t yet a test for NCGS. If your symptoms go away on a gluten-free diet it would likely signal NCGS.

If you want a formal diagnosis the next step would likely be an endoscopy, but again, this would reveal whether or not you have celiac disease, but you still could have NCGS.

 

 

[Brown42186]

Thanks for all the info! I'll see how my appointment next week goes. I think I'm going to push for having a blood test done again since I've been consistently eating gluten and go from there.

[trents]

Scott, am I missing something? For the TTG-IGA normal is anything 3 or less and his score less than 2. I think that one is in normal range. @Brown42186, if the GI doc is not interested in doing an endoscopy with biopsy of the small bowel lining based on the elevated TTG-IGG I would request a repeat on the bloodwork now that you have resumed gluten consumption again.

[Scott Adams]

This test was positive according to the original post, so the next normal step would be a biopsy:
TTG IGG - 9 U/mL (0-5 range)

@Brown42186 Here is more info about how to do a gluten challenge for a celiac disease blood panel, or for an endoscopy:

Quote

"...in order to properly diagnose celiac disease based on serology and duodenal histology, doctors need patients to be on gluten-containing diets, even if they are causing symptoms, and this is called a "gluten challenge."

• Eat gluten prior to celiac disease blood tests: The amount and length of time can vary, but is somewhere between 2 slices of wheat bread daily for 6-8 weeks and 1/2 slice of wheat bread or 1 wheat cracker for 12 weeks 12 weeks;
• Eat gluten prior to the endoscopic biopsy procedure: 2 slices of wheat bread daily for at least 2 weeks;

and this recent study recommends 4-6 slices of wheat bread per day:

 

 

[trents]

Yes, the TTG-IGG was positive but not the TTG-IGA.

[Scott Adams]

Understood, and with any positive blood test the usual next step is a biopsy to confirm celiac disease, and this would be true even if the tTg-IgA is negative.