Negative blood test, positive biopsy

[Patremagne]

Hi,

Back in January I'd had the TTG blood test done and it came back negative (while still eating gluten). Fast forward to now, I had an endoscopy this month and last week the results came in positive for celiac, so I began going gluten-free. After seeing a dietitian, it was brought up that it was atypical to blood test negative and then have the biopsy be positive, and that I should ask my GI. I did that, and the GI said the biopsy is the gold standard, but that since I got the blood test at a different location, that I should schedule another blood test at the same location of the endoscopy, as well as checking "celiac genetics" - which I would need to resume consuming gluten for. 

Obviously my GI is a doctor for a reason and I should heed her advice, but if the biopsy is the gold standard, I'm curious as to whether or not it's even worth getting those other (re)tests, as I'm loath to start consuming gluten again to further delay my recovery. Anyone been in a similar situation?

Edited April 23, 2019 by Patremagne

[GFinDC]

Hi,

The gene testing does not require you to be on a gluten diet.  The blood test and the endoscopy do though.

You might be able to get a positive blood test if you've only been a couple weeks off gluten.  But you'd need to get your blood drawn right away.  Since medical tests are expensive it might be better to go ahead and start eating gluten again now for the testing to have the best chance of detecting a reaction.  The ttg is just one celiac test.  They also can do the DGP IgA, DGP IgG, EMA and total IgA tests.  That combination is sometimes referred to as a celiac panel.

[cyclinglady]

I only had a positive on the DGP IgA, even on repeated celiac panels.  I have NEVER had a positive on the TTG tests.  The TTG test is good and catches most celiacs, but not all (like me) and it is cheaper to do just one test instead of the complete panel. (It is always about the money.....)   My intestinal biopsies revealed some pretty severe damage.  And then there are some celiacs (about 10%) who never have a positive on ANY of the celiac blood tests.  The blood tests are great for screening, but intestinal biopsies remain the gold standard as your GI indicated.  

I guess you could have a repeat blood test, but insist on the complete panel: DGP, TTG and EMA (IgA and IgG versions).  Include the Immunoglobulin A test too which is used as a control test when trying to help diagnose celiac disease.  For example, if you are naturally low on Immunoglobulin A (IgA), then the TTG IgA, EMA IgA and DGP IgA tests are not going to work.  You would have to rely on the DGP IgG and TTG IgG tests provided you are not one of those 10% celiacs who do not have positives on the celiac panel.  Only you can decide if it is worth getting back on gluten because you and your GI have the whole health history.  

The genetic test?  What if you are one of the oddballs who do not have the common genes?  Researchers were so sure they had identified all the genes, but guess what?  They have not.  Kind of like when they thought only those of European decent could develop celiac disease and now it is found in many areas of the world.  

Need more proof?  Feeling better on the gluten-free diet.  Give it time though.......most of us took a year or longer to really feel normal.  

You might want to ditch the dietician.  Unless she or he has celiac disease, they should not question the GI’s diagnosis.  If she was wrong about being able to have celiac disease without a positive TTG, she might not know enough about the gluten-free diet.  Yikes!  She could keep you sick!  

Edited April 23, 2019 by cyclinglady