Weakly positive DGP IgA

[Cat M]

TTG IgA <2

Ttg IgG 3

DGP IgG 4

Total IgA was not performed. My GP thinks I am gluten sensitive and do not have celiac. I would like to consume gluten for a few weeks and retest, or consult a gastroenterologist now. I am symptomatic, which is why we tested. I do have the HLA DQ2.

Is it possible this is a false positive? What would cause that?

[trents]

Welcome to celiac.com, @Cat M!

Were you consuming generous amounts of gluten for a significant period of time (weeks/months) before the blood draw and test results you posted? I ask because you say you would like to be retested after consuming gluten for a few weeks. Current guidelines for the gluten challenge call for the daily consumption of at least 10g of gluten (the amount found in about 4-6 slices of wheat bread) for at least 2 weeks. But I would go for longer than that to be sure, say 4 weeks. Testing is invalid when people have been gluten free or even skimping on it.

[Cat M]

I ate two pieces of toast each morning for three weeks prior to testing. The rest of the day I ate whatever. I am going to increase the gluten for four weeks and ask my doc to retest. I did read that false positives are possible, so I think it’s reasonable to retest. But I am very new to this, so not feeling confident.

[trents]

By the way, you need to repost those numbers in your first post and add the reference ranges. Different labs use different reference ranges so the test scores by themselves aren't very helpful, especially when the values may be borderline positive. It would need to be in a new post window as the edit function times out quickly such that you can't go back and make changes to the original.

What symptoms do you have? What has led you to investigate the possibility of having celiac disease?

Edited July 30, 2025 by trents

[Cat M]

Ah ok, I just saw didn’t even post the DGP IgA at all. 😫

I started with itching and hives Jan 2024, been taking a ton of meds and on Xolair and even that is not providing total relief. The other primary symptoms: intermittent but worsening abdominal pain, diarrhea and bloating. This summer I am just exhausted.
I uploaded my 23andMe data to genetic lifehacks and discovered quite a few variations, including DQ2, MTHFR, VDR and I have always had very low ferritin, vitamin D and B12.
I still think that mast cell disease makes the most sense, but latest labs show I am barely in range for thiamine, zinc and vitamin A, so the GI stuff feels more important to figure out than the hives right now. I did SIBO testing this morning.

TTG IGA <2   0-3 is negative

TTG IGG  3   0-5 is neg

DGP IGA 21    20-30 is weak positive

DGP IGG 4    0-19 is negative

Although total IGA is not resulted, there is a footnote stating it was low and the reason they ran IGG.

 

[trents]

If your total IGA is low then the values for the other IGA tests cannot be trusted. They will be depressed.

Celiacs who have the DQ2 gene typically are on the more sensitive side as opposed to those who only have the DQ8. But keep in mind that having either or both of those genes does not equate to having celiac disease as 40% of the general population have one or the other and only about 1% of the general population develops active celiac disease. Genetic typing can be used for ruling it out, however.

Because of the low total IGA, symptoms and the possession of the DQ2 gene, my suggestion would be for you to go seriously gluten free for a few months and see if your symptoms improve. It may be the only way you can ascertain if you are gluten intolerant because of the low total IGA.

[knitty kitty]

Hello, @Cat M, welcome to the forum!

I noticed you are low in ferritin and thiamine as well as other nutritional deficiencies already.  Deficiencies in iron and thiamine affect your body's ability to make antibodies.  Since you do have symptoms, nutritional deficiencies evidence of malabsorption, MTHFR and one celiac gene,  I'm suspecting you do have Celiac disease.  

Can you consult a gastroenterologist?  Or ask your doctor to do so.  

Gluten Sensitivity can be a precursor of Celiac disease in people with Celiac genes.  Since you've already got symptoms of Celiac disease and evidence malabsorption, an endoscopy with biopsies would be beneficial.  

It's can be so frustrating getting a diagnosis because doctors are not familiar with Celiac disease.  Sending you encouragement!

Keep us posted on your progress!