Clueless-- What's Positive About These Labs?

[Avalon451]

Hi, my family and I are all new to this. DH and I have 3 daughters, 16, 13 and 9. The 16 y.o. was seeing a dermatologist for acne when, as an aside, she showed the doctor "this rash that's driving me nuts" on elbows, knees and back. You guessed it-- dermatitis herpetiformus diagnosed by biopsy. She is now seeing a GI doc at Seattle Children's hosp. It was confirmed by blood test (though I don't yet have a copy of those results) and she's getting an endo next Friday to check the internal damage and biopsy to confirm it (though I know that it's a positive celiac dx with the DH biopsy-- just checking to see what kind of damage she has internally).

Meanwhile! The rest of us got bloodwork done. Mine came back, and also my two younger daughters'. (DH just had his done yesterday, so not back yet.) I am so confused as to what the numbers mean. I have read the linked articles, googled it, tried to find what it is about these tests that are positive. Add in confusing comments by my doctor and my girls' pediatrician, and I really don't know why it's positive.

My doc said (via email) "It's not foolproof but I bet you're celiac. Try the diet." I replied that I'd like a referral to the GI doc and an endoscopy to confirm, he immediately gave me a referral but commented, "I'd hesitate to do the invasive procedure, since you're planning on going gluten-free anyway" But he's really cool with me exploring options for myself. Very supportive and generally knowlegable.

It looks like my test was kind of minimal compared to my daughters' more complete panels. Mine says:

Tissue transglutinase antibody <3

IgA serum 77

Here's my daughters':

13 year old: (comments: R's labs for celiac are positive. Follow up with Children's GI re their recommendations.)

TTG Antibody, IgG <3

TTG Antibody, IgA 31

Endomysial AB Screen NEGATIVE

Gliadin Antibody (IgA) 29

9 year old: (comments: F's lab results positive for a reaction to gluten. Follow up with GI (etc) )

TTG Antibody, IgG <3

TTG Antibody, IgA 33

Endomysial AB Screen POSITIVE

Gliadin Antibody (IgA) 27

So the one whose labs say positive, the comment is "reaction to gluten" and the one who says "negative" says she's celiac. And I don't know what makes my own doc think "I bet you have celiac."

Help interpreting these numbers, please? Thank you!

[Skylark]

You didn't include the normal ranges for the labs. Do you have them? Every lab is different.

Yours is a positive TTG test, which is an autoimmune antibody usually caused by celiac. (I'm guessing the <3 is the normal range on the lab slip?) There are other autoimmune diseases that can cause TTG, but with the celiac girls your doctor is making a reasonable assumption that your positive test is also from celiac. He's doing good medicine to diagnose from TTG, your genetics, and a trial of the diet rather than requiring you to get an endoscopy. You can obviously get one from the GI if you want to go that direction.

For the 9-year old, she is celiac. Endomysial AB is an autoimmune antibody only made by folks with celiac and the result is positive. I don't understand the comment either. I wonder if the wrong comments got on the wrong chart? Like a dictation error?

For the 13-year old, is there a normal range on the tests? Is the TTG for her also supposed to be <3 for normal?

[Takala]

Did the printed results you have there, have a range of numbers, as it can be a different scale used from different labs ?

hypothetical example:

"test result is > greater than 20 on a scale of 1 to 30. 1 to 15 is negative, 16 to 30 is positive" therefore the result for that one test done out of the four tests run, was positive.

The reason your doctor is saying "try the diet" is that if you have 3 kids with positive test results, one with a DH biopsy positive already, they had to be inheriting the genes for this from somebody.... and that would be... you.

[Avalon451]

Thanks for the replies!

The "range" is part of the problem, I think, of what was confusing me.

On mine it says

Your Value Standard Range Units

Tissue Transgluaminase Antibody <3 U/mL

Reference range:

Negative <5

Equivocal: 5-8

Postive: >8

IgA Serum 77 80-463 mg/dL

So it looks to me like I was negative for TTG. And that the IgA serum was just below normal (meaning... what?)

On my daughters: no range given. I mean, it says "range" but underneath that for each of the tests it just says (U/mL), which I think is just the units measured, not the range, right? Weird.

I'm absolutely cool with going gluten-free. I love to cook, and while I know it'll be a challenge, there's so much good info out there. Lots of our favorite foods are gluten-free anyway. I know there'll be times that we are in mourning for the hamburgers from our favorite stand.. but.. we will survive and thrive, and feel better. I will be happy to be free of 7 straight years of diarrhea, for sure.

Love what I'm seeing on this board, too-- such a supportive and info rich community!

[Skylark]

Your TTG test is negative because you have low total IgA. It's not something that affects your health much but it is a risk factor for celiac and means IgA testing will come back false negative. (Can't look for something that isn't there.) You need the IgG version of the celiac panel. Ask if you can get deamidated gliadin IgG too. It's a very sensitive test.

It is confusing that the reference range isn't given on the girls' test. If the girls were tested at the exact same lab as you were, they may both be positive for TTG. Is there a phone number to call on the lab slip to find out if a result >8 is positive?