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Positive Home Test, Negative Lab Test - Manufacturer's Response

Slr38

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Slr38 Apprentice
Slr38
Posted

Hello Everyone,

A few weeks ago I received a positive result from a Biocard home celiac test. I then received a negative lab result (they only ran one test). I emailed the company to ask them about the different results. This is the response I received:

In clinical studies in the EU where the Biocard has been used and there has been a discrepancy between the equivalent Elisa lab test and the Biocard (Biocard “+” and Labe “-“), over time the “-“ lab tests become “+”. This has been explained by the sensitivity, specificity and cut-off limit of the Biocard relative to lab testing. The cutoff for the Biocard is 5u (international units). Many laboratory tests are between 10 and 20u.

So should I wait to see if I eventually get a positive blood test? Will my doctor even consider retesting? Should I just go ahead and try a gluten free diet?

I have an appointment with a Naturopathic Doctor next week. I'll see what she has to say.

Thanks for listening.

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ravenwoodglass Mentor
ravenwoodglass
Posted

What was the one test your doctor ordered? The doctor really should have done a full panel. Can you see if you can get the doctor to order a full panel or perhaps the naturopathic doctor could order it?

If you can you should wait until all celiac related testing is done to start the diet. However if your doctor won't order more testing for you then you really don't need a doctor's permission to go gluten free. Just make sure you are strict with the diet when you do your trial. Being gluten free will not impact testing for any other issues you might have.

Slr38 Apprentice
Slr38
Posted
  • Author

What was the one test your doctor ordered? The doctor really should have done a full panel. Can you see if you can get the doctor to order a full panel or perhaps the naturopathic doctor could order it?

If you can you should wait until all celiac related testing is done to start the diet. However if your doctor won't order more testing for you then you really don't need a doctor's permission to go gluten free. Just make sure you are strict with the diet when you do your trial. Being gluten free will not impact testing for any other issues you might have.

The only tests that I had were Tissue Transgluaminase Iga and Immunoglobulin A. I was under the impression that they were going to do the whole panel. Apparently the labs here in Calgary only run the other tests if the TTg Iga come back positive. This really does not make sense to me! I would think that they would especially run the other tests if the first was negative.

Thanks for your advice!

I will see if the Naturopathic doctor says.

guest134 Apprentice
guest134
Posted

In clinical studies in the EU where the Biocard has been used and there has been a discrepancy between the equivalent Elisa lab test and the Biocard (Biocard “+” and Labe “-“), over time the “-“ lab tests become “+”. This has been explained by the sensitivity, specificity and cut-off limit of the Biocard relative to lab testing. The cutoff for the Biocard is 5u (international units). Many laboratory tests are between 10 and 20u.

That response does not make sense. Each machine has different methods, even the ELISA based tests will vary from lab to lab. Each lab will come up with appropriate negative values based on several factors. It is important to remember that if a normal test is under 30 and you have a reading of 25 it is not because you have some antibodies, it is against dilutions and any number below the limit means a negative reading upon first dilution.

I for example tested 30 on a test were below 35 is negative for TPO ab's. I went to another lab that uses a cutoff value of 25 and my value came back at 14. It is all relevant to the labs specific tests and methods used.

If I were you I would ask for the research supporting their hypothesis, you have to remember they are a business and will say whatever they legally can to get your repeat patronage.

nvsmom Community Regular
nvsmom
Posted

Hello Everyone,

A few weeks ago I received a positive result from a Biocard home celiac test. I then received a negative lab result (they only ran one test). I emailed the company to ask them about the different results. This is the response I received:

In clinical studies in the EU where the Biocard has been used and there has been a discrepancy between the equivalent Elisa lab test and the Biocard (Biocard “+” and Labe “-“), over time the “-“ lab tests become “+”. This has been explained by the sensitivity, specificity and cut-off limit of the Biocard relative to lab testing. The cutoff for the Biocard is 5u (international units). Many laboratory tests are between 10 and 20u.

So should I wait to see if I eventually get a positive blood test? Will my doctor even consider retesting? Should I just go ahead and try a gluten free diet?

I have an appointment with a Naturopathic Doctor next week. I'll see what she has to say.

Thanks for listening.

If I understand that statement correctly, Biocard is saying that they have a lower sensitivity levels so their test will read positive at a lower level of ttg Iga in the blood. I suppose that makes sense... you had a really low ttg Iga through Calgary labs though, didn't you? My guess is that CLS tested wrong somehow. Since they are currently being investigated for messing up hundreds of labs (I didn't hear all the details of what they did wrong) it doesn't seem so far fetched.

I just don't know how the Biocard test could come up positive unless ttg Iga was there in a measurable amount. :huh: I really wonder if ttg iga levels can wax and wane based on how overactive our immune system is at the time. I know this happens with other autoimmune disorders so it would make sense if it did with celiac too...but I have no info to back that theory.

I hope the naturopath can help you with some answers. If you can't get a definitive answer, I guess you have two options:

1. Contune to eat gluten and test periodically. This gives you the benefit of possibly getting a positive quantifiable test result but if you do have issues with gluten, you'll have to continue to live with the symptoms it could be causing.

2. Go gluten free, which could relieve the symptoms but you will not test positive for celiac in the future.

At this point if I was you, I would continue eating gluten until the New Year (I remember you said going gluten-free would be tricky over the holidays) and then retest. Perhaps you could get the naturopath to order the ttg Igg and the DGP IgA and IgG for you on top of the ttg IgA; or maybe you could order some labs through the mail... I have no idea if that's done up here like it is in the states. After this final try of testing, I would then go gluten-free for a minumium of 3 months; 6 would be better. See if it helps. Cut out dairy too if you think it's an issue; if a glass of milk on am empty stomach bothers you (like it did me) then I would cut it out too.

I really hope that naturopath can help you out. I know how frustrated you are by this. (hug) Let me know what the nauropath says, okay?

Best wishes to you.

  • 1 month later...
Newfiegirl Newbie
Newfiegirl
Posted

Wow this is me! I did two biocard tests and both came back positive. I had blood work done and got the negative results yesterday. Only one test was completed, Anti Transglutaminase and it was negative. I'm up in Edmonton. Keep me updated if you can on your results :D

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