How Reliable Is A Blood Test?

[DonnaD55]

My daughter who is 12 has been dealing with abdominal cramping and diarrhea for about a year and a half. At first we thought it was lactose intolerance as taking her off of dairy helped a lot but not completely. We've rather loosely done a gluten free diet recently and she was better. But sometimes she can eat wheat products with no problems at all. She had a blood test for celiac last week and the test came back positive. Can i trust that it's correct or do we need more testing to confirm the diagnosis?

[Skylark]

Hi and welcome. There are multiple tests for celiac disease, some of which are more specific than others. Which test was positive?

It is possible for someone with celiac to eat wheat without immediate symptoms. The autoimmune damage is still being done. She also may find that she gets more sensitive to wheat once you get the diet going correctly and her immune system settles down from the constant assault.

[lemontree1]

Correct me if I'm wrong, but I've never heard of a false positive for a Celiac blood test. False negatives abound, but not false positives.

[mushroom]

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One negative aspect of the TTG antibody is that it can be falsely positive in a patient who has another autoimmune condition. TTG false positivity has been described in patients with both type I diabetes and autoimmune hepatitis. Theoretically, it can also be falsely positive in other autoimmune disease.

[rosetapper23]

I agree with Mushroom, but at celiac conferences the experts generally say that, while false negatives are common and should be questioned, false positives are rare and you can "take it to the bank" that you have celiac.

[Skylark]

Correct me if I'm wrong, but I've never heard of a false positive for a Celiac blood test. False negatives abound, but not false positives.

The blood tests that really leave no question are anti-EMA and anti-DGP. The old anti-gliadin test is notoriously inaccurate, although if you get a positive result you probably do need to have a biopsy and try the diet.

TTG is a sign of autoimmunity but not specific for celiac as Raven mentioned. As well as type 1 diabetes and autoimmune hepatitis, TTG is common in inflammatory bowel disease like Crohn's.

[DonnaD55]

Thank you so much for your thoughts. We go to the doctor on Tuesday to discuss the results of the test. I'll find out exactly what the test was. Meanwhile, we'll stay gluten free!

[tristonsdad]

With my daughter we did an upper endescopomy (probably spelled wrong) and they also took biopsy at same time to verify. This was recommend by our specialist after the positive blood test.

[Di2011]

Thank you so much for your thoughts. We go to the doctor on Tuesday to discuss the results of the test. I'll find out exactly what the test was. Meanwhile, we'll stay gluten free!

Get a COPY of the results. You will need them in coming years and she will need them as an adult.

[mushroom]

Thank you so much for your thoughts. We go to the doctor on Tuesday to discuss the results of the test. I'll find out exactly what the test was. Meanwhile, we'll stay gluten free!

If you are going to be referred to a GI you may want to continue eating a full gluten diet because he will probably want to do an endoscopy with biopsy to confirm the diagnosis, which requires a full gluten diet for acccurate results.

[sahm-i-am]

My daughter had tons of symptoms and yet her bloodwork came back negative. She did have the two genes for Celiac (forgot which ones) and both her dad and I tested positive for celiac disease. So, even though her tests came back negative she wanted to try the diet to see if it helped with her GI issues. A few weeks later she was right as rain! So, sometimes test results can be wacky, but listening to how your body responds is always a good way to go!