GPC test

[chloe2124]

Had GPC test today, what's s normal result?

[LtAngua52]

This is another poor and flawed test. The National institute of clinical excellence, NICE, no longer recommend doctors use this as a test for PA. It's in their guidelines, unfortunately, they still do. They don't give a result as a level just positive or negative. That is the situation in the UK anyway. I'm assuming you are. A lot of people with PA test negative for GPC, so it's not helpful really. Did you have intrinsic factor antibodies test too? Although that's flawed too as people can have PA and still be negative.

[fbirder in reply to LtAngua52]

Actually, according to the NICE document the anti-GPC antibodies are found in 80% of people with PA. The reason it's not recommended is that it is also found in 10% of people without PA, rising to 16% of women over 60.

It's my opinion, and that of my GP, that a positive for anti-GPC, combined with low B12, is a very good indication of PA.

[LtAngua52 in reply to fbirder]

'It's my opinion, and that of my GP, that a positive for anti-GPC, combined with low B12, is a very good indication of PA.'

Despite this, the BCSH, not NICE, made the decision not to recommend this test for PA. They said that despite the 80% statistic it has low specificity for PA. As Martyn Hooper says, the members of the BCSH are 'highly skilled, experienced and esteemed professionals, and I'm sure there was considerable deliberation and discussion before they made their recommendation.' 

[fbirder in reply to LtAngua52]

Yes, that is true. But, in the absence of a useful test for PA, we both think that, while the anti-GPC test alone is not specific for PA, in combination with low B12 it's better than the anti-IF test.

With the anti-GPC a negative result means the patient almost certainly does not have PA. A positive result means that they may have PA.

With the anti-IF a negative result means the patient may not have PA but the odds are equal that they do have it. A positive result almost certainly means that the do have PA.

I think of the anti-GPC test being like testing an animal for whether it is a zebra or not by seeing if it has hooves. A positive result means it might be a zebra, but there are a lot of other animals that also have hooves. But add in the results from another test - is it stripy (is the B12 level low) - gives you a damn good idea when both are positive. Yes, it may be a quagga, but it's most likely to be a zebra.

The anti-IF test is like testing to see if an animal is a narwhal by seeing if it has a long single spiral tusk. A positive result means it's almost certainly a narwhal. The only problem is that 50% of narwhals don't have long tusks.

[Galixie in reply to fbirder]

I love your colorful analogy, fbirder.

I tested positive for paretial cell antibodies once when my B12 was first found to be low and was told, based on that, that I had PA. A year later the test was done again and it came back negative so I was then told I couldn't have PA after all. Apparently I'm a quagga! lol

The sad truth is that we don't really have any reliable tests.

Btw, they do sometimes provide a range along with whether the result is positive or negative. But the range varies depending on the lab doing the testing.

The one time I tested positive, the lab results showed this set of ranges but the unit of measure was not included:

0.0-20.0 Negative

20.1-24.9 Equivocal

>24.9 Positive

(my level had been 37.1)

[Richardthelionheart in reply to LtAngua52]

Hi LtAngua52, (are you a Pratchett fan?)

I agree, opinions should not be used to push a particular view. Facts are more reliable, while opinion is subjective and dubious. I have started to examine many documents referred to on this forum and I am more likely to use them as guidance than the opinion of another member.

Unfortunately, I come across many people in my work, (I am a psychologist) who have an inflated opinion of themselves and forums are a great way for them to feel more important than they are. They are generally lonely and isolated and if they are no longer working have no one to use as a sounding board for their own opinions. The Internet has unfortunately, given them a global platform in which they can be heard. I often help these clients to understand why they have a desperate need for attention. The best thing for anyone to do, on the Internet is ignore them. Once they are not getting 'fed' they will lose interest and go on to someone else.

I will probably contact Martyn Hooper if my GP does not continue with the injections after the loading doses, or if I don't get them as frequently as I need. I'm sure, like many other members on this forum, I will end up self-medicating. I would rather not but I will if necessary.

thank you

[LtAngua52 in reply to Richardthelionheart]

Yes Richard, I am a Pratchett fan. It was a sad day when he died last year.

I do ignore those members. I rarely reply and don't even read replies from them. I've discovered there is no question that hasn't already been asked on here, so just put any query in the sites search engine. So no longer post.

Good luck.

[chloe2124]

That's everyone, no results yet but I will post them when I do if that's ok 

[chloe2124]

Results only just come back. I tested negative so no further action needed. Also had nerve conduction years in my feet for my numbness/tingling and they came back normal too. B12 214 so been told no action. Feel like I'm going mad, maybe it's ms or something more sinister