So I recently posted about getting the intrinsic factor test and how long to stop injections before taking it. So had the test, and of course it has come back negative. Doctor originally was going to stop the injections, but after I protested and showed him current documentation he relented and is allowing the therapy to continue. He is also sending me back to a neurologist although I'm not sure why, just been diagnosed with mild bilateral carpal tunnel which they regard as not clinically significant. I think he is hoping they may know more about B12 deficiency than he does, although reading posts here I understand that may not necessarily be the case.
Anyway this has led me to dig through my previous blood tests and I have come across a few things that are confusing and beyond my understanding (and apparently my Doctors) so hoping that someone may have stumbled across similar circumstances before.
So beyond the B12 deficiency at 113pg/ml (ref 145-914) it seems that my folate is 8mg/ml (ref 4-20) and iron is at 18.6 umol/L (ref 12.5-32.2)
What is particularly confusing is my Mean cell volume shown in my FBC which is 82.8fL (ref 83-101) which would suggest I have microcytic cells, which would suggest iron deficiency but my iron seems to be in range. And also my Mean cell haemoglobin concentration is above the reference limit at 35.1g/dL (ref 31.5-34.5) although not sure of its possible significance, if any.
I know that the intrinsic factor test is inaccurate, but factoring in the lack of macrocytic red cells is it possible its not PA and if so what else could be the cause.
After being diagnosed with B12 deficiency and reading about PA so much made sense and so many of the stories here rang true with me. I really hoped it meant I'd be turning a corner, it seems however I've just turned the corner to hit another brick wall!
Any help gratefully received, thanks for reading.
Written by
Wolf79
To view profiles and participate in discussions please or .
Thanks for the reply, have had a good read of that info, only thing I can spot is the fact my Dr didn't order the total IgA test, and also failed to inform me of the need to up my gluten intake in the run up to the test. Will have to request a retest and the addition of the total IgA test.
Still a bit unsure as to why I would be showing microcytosis, can this be linked to being coeliac at all?
Some forum members have reported benefitting from going gluten free even if they are not coeliac. If you are waiting for more Coeliac tests it's probably better to wait until you've had them before contemplating going GF.
"So had the test, and of course it has come back negative"
You could pass this to GP which mentions when Antibody Negative PA can be diagnosed in UK.
Martyn Hooper, the chair of PAS had several IFA tests before one came back positive.
Other tests
Has GP given you basic tests to check liver function? I have read that liver problems may lead to raised MCHC and there are other conditions that can be associated with high MCHC.
The MCHC nowadays is really not much use for several technical reasons; some laboratories don't even report it because of this. The MCH is a better indicator.
Your MCV is normal; given that the range is almost certainly a 95% range then 2.5% of folks who are normal will be slightly below, and 2.5% will be slightly above the stated range.
Your serum B12 is low. Not every patient with PA has IF antibodies, [or detectable antibodies] but if oral B12 supplements are absorbed and reflected in the serum B12 level then PA is unlikely.
Measurement of iron is tricky. Ferritin is a popular test but needs treating with care because it's also an acute phase reactant, so in inflammatory conditions it can be raised, and therefore could mask a deficiency state. Serum Iron and Transferring Saturation Ratio can be helpful but isn't always available.
If your FBC reports RDW, then that can be interesting. If the RDW is significantly raised when your MCV is borderline then that would indicate some microcytes present.
I hope this isn't too confusing, but it's a complex subject and there aren't always easy answers.
Ferritin is a popular test but needs treating with care because it's also an acute phase reactant, so in inflammatory conditions it can be raised, and therefore could mask a deficiency state.
Made me laugh - I couldn't help thinking about X Factor or Strictly (or other TV programs with votes). The phone lines are now OPEN! Vote for your favourite blood test.
I was shocked some years ago when I found that several areas had abandoned all other iron tests (at least at GP level).
Ferritin is easy and cheap to measure, which is why we do it and most of the time it's OK. But it has its problems. In starvation states it's suppressed too.
Serum Iron is technically more troublesome, and TIBC [total iron binding capacity] is extra, so they tended to be dropped off when ferritin became easy to measure with automated immunoassay.
20% of patients with B12 deficiency present without any signs of macrocytic anaemia - macrocytic anaemia is one potential symtpom of B12 deficiency but it isn't a defining characteristic.
MCHC is a ratio between MCH and MCV. It will be raised if your MCH is raised or your MCV is low.
It is possible to microcytosis going on at the same time as macrocytosis and one can mask the other.
In his talk at the PAS conference yesterday Dr Hajo Auwerda gave lots of information about patients in his clinic. I didn't take proper notes at the time (technical problems at my end) but he did mention how many of his patients with low B12 had macrocytic anaemia.
I believe it was less than 3%!!
Waiting for the talks to be available online. I really recommend his one for some jaw-droppingness.
I relate to you very much. I was diagnosed with low b12 in August. I thought my intrinsic factor test would be positive... it too was negative. The process of navigating all the possibilities is so frustrating.
Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.
Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.
Diet related b12 deficiency 
B12 deficiency with High Serum B12?
B12 deficiency and b12 deficiency anemia
Functional B12 deficiency question 
