Confused - False Positive

[ccooper]

My 11 year old son seen the GI specialist yesterday. The GI said that he believed the blood test was a false positive. He had a score of 67(?). The 67 was high but the other two test were normal. The GI is now running a test for IgA only. What does this mean? If it's not celiac what is it? I was hoping that the celiac diagnosis was going to be our answer to his symptoms. He has a history of intestional issues (watery stools sometimes, cramping, short stature 5% range), canker sores, itchy skin and sores, fecal incontinence, IRRITABILITY (he doesn't get along with himself most of the time). Any ideas would be appreciated.

[WorryMom]

I have done a lot of research on false positives and weak positives in the last few months because my 9 year old son's tTg IGA was 4.3 on a scale where 0-4 negative, 4-10 weak positive.

What I found indicates that you are much more likely to have a false negative than a false positive. According to most of what I read, even if not all the tests are positive they should still do an endoscopy to check for damage especially if they are having symptoms such as your son is. Did they do the endoscopy yet? Some of the things that could cause a false positive on the tTg are cirrhosis of the liver, diabetes or heart failure but this is very rare. Given his symptoms it seems much more likely he has celiac. I hope they are able to figure it out soon so your son can start healing.

My son is seeing a specialist next week. He was tested due to family history and not really sick at the time but in the last few months he has started being tired all the time and complaining of stomach aches. He has occasional bathroom issues and has become whinier than usual. I'm hoping the doctor will agree to do the endoscopy so we can see if he has it or not.

[tarnalberry]

Most of us here "don't believe in" false positives. Why? Because your body is not going to produce an antibody to itself with no reason and without doing damage. It's kinda what autoimmune diseases are all about.

Do you know WHICH test came back "positive"? I'm assuming, from your comment about testing total IgA, that it was the anti-gliadin IgA test. About 10% of celiacs are IgA deficient, which means that they will always have low numbers, regardless of whether or not they are producing "more" anti-gliadin IgA. But that means they'll more likely get a false negative, not positive.

[ravenwoodglass]

Your son's symptoms and the postive test make it pretty certain that he is one of the 'family'. If you are going to have them do an endoscopic exam on him, which also has a risk of a false negative, you need to make sure to keep him on the full gluten diet. If you are not going to do an endoscopy then go ahead and put him on the diet.

[ccooper]

I called the pediatrician to get a list of actual scores - Here they are:

IgA - 64

Gliadian IgG - 67

TtG - 3

No biopsy has been scheduled. More blood test were ordered in order to check for IgA deficiency. Does the above mentioned scores mean anything to anyone? The doctor is calling it a false positive.

[ang1e0251]

Could you please put the lab's ranges with those numbers? Each lab is different.

Many, many people have false negatives but I have never heard of someone who actually had a false positive.

[ccooper]

Could you please put the lab's ranges with those numbers? Each lab is different.

Many, many people have false negatives but I have never heard of someone who actually had a false positive.

O.k, this is the best that I know:

IgA - 64 with range of 65 to 246

IgG - 67 range of 1 to 11 normal

TtG - 3 normal range 3 and below

Does this help?

[tarnalberry]

O.k, this is the best that I know:

IgA - 64 with range of 65 to 246

IgG - 67 range of 1 to 11 normal

TtG - 3 normal range 3 and below

Does this help?

As I suspected, the IgG test is positive, and the others negative. The tTg test being borderline just gives you an idea of how much damage is happening. (Still, why would he have any if there wasn't some response going on?) The IgA test being low tells you nothing if he's IgA deficient. The IgG test is QUITE DISTINCTLY POSITIVE. He is clearly have an immune reaction to gluten. (Most doctors *want more* because they so hate to put their patients on a gluten free diet. BAH!)

[ccooper]

As I suspected, the IgG test is positive, and the others negative. The tTg test being borderline just gives you an idea of how much damage is happening. (Still, why would he have any if there wasn't some response going on?) The IgA test being low tells you nothing if he's IgA deficient. The IgG test is QUITE DISTINCTLY POSITIVE. He is clearly have an immune reaction to gluten. (Most doctors *want more* because they so hate to put their patients on a gluten free diet. BAH!)

The GI acted like the IgG elevation wasn't anything if the other two areas weren't positive also. If he doesn't have celiac than I want to know why the levels were so high..... I guess I will have to wait and see what happens on Monday when I get the IgA deficiency results back. I don't mind the doctor wanting to know more, but I feel like I know less than I did before I went to the office.The GI stressed that grains are a very important part of ones diet and that no diet changes should be made unless something else shows up

[Jestgar]

***Personal opinion alert***

The GI stressed that grains are a very important part of ones diet and that no diet changes should be made unless something else shows up

That's complete and utter crap. The human race survived for thousands of years without grain.

Ask him to name you ONE essential nutrition that can only be found in grain.

[tarnalberry]

that might "just" be jestgar's opinion, but I think she's completely correct. in my opinion, anyway.

your doctor is full of crap if he thinks grains are a mandatory part of a diet, or even that you can't have any grains if you're gluten free. wrong and wrong.

[ccooper]

Maybe he's full of crap and being ignorant. On a positive note, maybe he just didn't want us to get to alarmed yet- so that's why he said the grain thing???? I don't know.

I have read some other post that says that an elevated IgG is sometimes something else. Any ideas?