Negative Blood Test...but I Dunno...

[elye]

Upon my urging, my dad had the blood work done for celiac. I have suspected since my diagnosis that he also has it, as he's always had some of the classic symptoms. I haven't talked to him yet about this, but he called last night to tell us that the test was negative. Now, I've been hearing that false negatives are possible. Can someone explain this a little for me? If there are no antibodies in the blood, doesn't that mean there is no autoimmune response? Is it something else they are looking for? I want to know exactly how celiac can be missed through the blood test (and I am assuming he got the cadillac test--the glutaminase(?) I believe it is called). Maybe someone can also remind me of the name of that test that is the most thorough. I need this info before I talk to my dad and say, "Actually, a negative result may mean nothing. And here's why..."

Thanks, guys!

[Guest nini]

Anti-Gliadin (AGA) IgA

Anti-Gliadin (AGA) IgG

Anti-Endomysial (EMA) IgA

Anti-Tissue Transglutaminase (tTG) IgA

Total Serum IgA

Here is the complete panel that should have been run, so if they did not do ALL of these in the panel, the results can be less accurate.

Many Celiacs are also IgA deficient and therefore show up as negative on the tests...

Also, if he hasn't been able to eat, or has been on a gluten-free diet or low gluten diet for a while, the results can be skewed as well.

Another way you can have a false negative is if the lab reading the results isn't familiar with Celiac and reads the results incorrectly, Also, many Dr's will say that a borderline or low positive result is negative when in fact it is really positive.

These are the only reasons I can think of at the moment. The dietary response is the most valid indicator in my opinion. It never hurts to try the diet and see if symptoms improve because positive dietary response is the best indicator of a problem with gluten.

[elye]

Thanks so much, Nini...excellent info. I'm copying it off to go over with the family, as there may be more questionable "negatives" when others eventually get tested.

[hungryforlife]

Hi Elye

I also wanted to throw in here that my brother was diagnosed with celiac disease through biopsy, but his bloodwork was negative. His body didnt make any AGA IgG/IgA antibodies. It is very possible.

Good luck to your dad. I agree with Nini.. If he has a positive dietary response then why go back?