What's The Likelihood For False Positives From Blood Test?

[kb27]

My 8-yr-old was recently diagnosed with "probable celiac" from a blood test. He's scheduled for a biopsy in February.

My question is, how likely is it that his positive blood test was false? Or is he pretty much positive for celiac and the biopsy is just to confirm?

Here are the tests they ran as best I can tell:

The ones they highlighted for me were:

Celiac gene pairs present? Yes

Tissue Transglut Ab IgA >100.0 (H) (<4 negative, >10 positive)

The other ones under the celiac comprehensive cascade were

Immunoglobulin A (IgA): 83 RAnge: 34-274 mg/dL

DQ Alpha 1 0.5:01,05

DQ beta 1 02:01,02:01

and the interpretation says "Celiac disease probable. Consider biopsy."

During the same exam, he also tested positive for H. Pylori and is on antibiotics for that. We scheduled a GI appt was to look in his stomach and see if there was any damage from that. That's being expanded to include the celiac biopsy.

I have 6 weeks to stew on this, and I've been preparing mentally for a switch to gluten-free for him. I just wonder how likely it is that he has it. He's not really sick. His main symptom that prompted the screening is anemia that won't go away with iron supplements. He's also a little short, and a little irritable (but I was blaming his age for both of those).

Thanks!

[sa1937]

My 8-yr-old was recently diagnosed with "probable celiac" from a blood test. He's scheduled for a biopsy in February.

My question is, how likely is it that his positive blood test was false? Or is he pretty much positive for celiac and the biopsy is just to confirm?

Here are the tests they ran as best I can tell:

The ones they highlighted for me were:

Celiac gene pairs present? Yes

Tissue Transglut Ab IgA >100.0 (H) (<4 negative, >10 positive)

The other ones under the celiac comprehensive cascade were

Immunoglobulin A (IgA): 83 RAnge: 34-274 mg/dL

DQ Alpha 1 0.5:01,05

DQ beta 1 02:01,02:01

and the interpretation says "Celiac disease probable. Consider biopsy."

During the same exam, he also tested positive for H. Pylori and is on antibiotics for that. We scheduled a GI appt was to look in his stomach and see if there was any damage from that. That's being expanded to include the celiac biopsy.

I have 6 weeks to stew on this, and I've been preparing mentally for a switch to gluten-free for him. I just wonder how likely it is that he has it. He's not really sick. His main symptom that prompted the screening is anemia that won't go away with iron supplements. He's also a little short, and a little irritable (but I was blaming his age for both of those).

Thanks!

Welcome to the forum!

False positives on the celiac panel would be exceedingly rare, if at all. I'd say he has it based on his blood work alone. Even if the biopsy would come in negative, damage is many times patchy and can be missed. I can't help you decipher the gene tests (have no clue what my genes are) and they are not diagnostic.

Whatever you do, don't have him go on the gluten-free diet until after the endoscopy/biopsy.

My adult daughter, also celiac and gluten-free since Aug. 2010, has been anemic for years in spite of being on iron supplements. She'll be having some follow-up testing soon, so hopefully she'll see improvement in those readings.

[divamomma]

I agree with the above poster! It is pretty rare to have false positive blood. I have never heard of anyone who did. There are also MANY symptoms associated with celiac including the ones you mentioned you see in your son. Not everyone has the "classic" symptoms or what people think are the classic symptoms.

[Skylark]

TTG is an autoimmune antibody that is usually caused by celiac, but it's not 100% specific by itself. With both DQ2.5 and positive TTG he definitely needs to be off gluten.

Even if the biopsy is negative damage can be patchy or partial and the biopsy can miss it. Celiac disease can also develop gradually in some people, where the biopsy isn't positive for a number of years after the TTG. You don't want to let your son get that ill if possible. After he is gluten-free for six months, request a follow-up TTG. If the TTG antibodies are caused by celiac and not another autoimmune condition, they will be falling if not gone.

[lovegrov]

"His main symptom that prompted the screening is anemia that won't go away with iron supplements."

This is a HUGE celiac symptom.

As others have said, false positives are rare. And do NOT have him go gluten-free before the biopsy.

richard

[kb27]

Thanks everyone. I thought there weren't many false positives, but I wasn't sure I was reading everything correctly.

He's staying on gluten until the biopsy and then we are going gluten-free. It would be nice to have a positive biopsy because that can help us get an official doctor's note with diagnosis for school/camp/etc. Even if it's indeterminate, I think we will go gluten-free and see if that helps with the anemia.

[kb27]

Just figured I'd follow up. He had a biopsy last week and it was positive. We cleaned all the gluten out of the house and went gluten-free a week ago. So far, so good. Thanks for the help. Knowing that the blood tests were pretty accurate for positives gave us 6 weeks to prep our son and get ready for the big gluten-free shift. It went pretty smoothly.

[Mom2Will]

I am where you were a few weeks ago. A few days ago we got the blood work back on my 8 year old son and he tested quite high for both tTG and gliadin IGA. His symptoms have been loose stools (for the past 5 years!) and recurrent stomach pains that are very sporadic. His ped never tested him because he's always been in the 60-70% for his height and 50% for weight. Since his growth was fine she assumed he couldn't have any intolerances and his loose stools were explained away first by "toddlers diarrhea" then as just being "normal" for him.

We have an appointment on the 28th with the gastro and I'm assuming he will want to schedule a biopsy. He's still on gluten right now awaiting our appointment, his stomach has been fine recently so this diagnosis seems so surreal. I'm sure once we have the biopsy and start the gluten-free diet it will really hit home. Now I feel so overloaded by information that I almost feel paralyzed.

Do you have other children? Have you gotten them tested, if you do? I have 2 other kids so one of my goals for tomorrow is to make an appt. for them to have blood tests done as well. I'm sure I'll get used to it and it will become our new normal but right now it feels like nothing will ever be the same.

Melissa

[kb27]

I am where you were a few weeks ago. A few days ago we got the blood work back on my 8 year old son and he tested quite high for both tTG and gliadin IGA. His symptoms have been loose stools (for the past 5 years!) and recurrent stomach pains that are very sporadic. His ped never tested him because he's always been in the 60-70% for his height and 50% for weight. Since his growth was fine she assumed he couldn't have any intolerances and his loose stools were explained away first by "toddlers diarrhea" then as just being "normal" for him.

We have an appointment on the 28th with the gastro and I'm assuming he will want to schedule a biopsy. He's still on gluten right now awaiting our appointment, his stomach has been fine recently so this diagnosis seems so surreal. I'm sure once we have the biopsy and start the gluten-free diet it will really hit home. Now I feel so overloaded by information that I almost feel paralyzed.

Do you have other children? Have you gotten them tested, if you do? I have 2 other kids so one of my goals for tomorrow is to make an appt. for them to have blood tests done as well. I'm sure I'll get used to it and it will become our new normal but right now it feels like nothing will ever be the same.

Melissa

We have one other son. We had him tested, and both my husband and I got tested. None of us had high tTG readings at all. I had the gene test run, and it was positive, so we know it came from my side of the family. A few of my relatives are getting tested, too - the ones with symptoms compatible with celiac.

Good luck with everything, Melissa! We had never even heard of celiac when we got the test results back - our son's problem was anemia, not any GI issues, so he was seeing a hematologist. I will say that for us the transition has been fairly smooth. I think my younger son is having the most trouble, because he doesn't understand why we don't have bagels and English muffins around the house any more. My celiac son is doing ok with it all.