Confused about IFA/PCA!

[ednotdave]

Can anyone please confirm that PA is diagnosed by EITHER intrinsic Factor antibodies OR Parietal cell antibodies? My tests show IFA neg, PCA pos. Thanks.

[Hidden]

Hi Ednotdave,

Being IF abs positive is a 100% diagnosis of PA, being IF Abs negative means you could still have PA because that test is so unreliable. Having Parietal cell antibodies does not automatically mean you have PA , as these antibodies occur with other conditions aswell (Thyroid) but they can cause altered stomach acidity (gastric acid achlorhydria ) in which IF can not survive and that can result in no uptake of B12 as it needs to be connected to IF before it can be taken up by the body.

Details here:

BSCH guidelines B12 and folate def‏

bcshguidelines.com/document...

(a) Anti-intrinsic factor antibody The finding of a low total serum cobalamin level may be further evaluated by testing for anti-intrinsic factor antibody (IFAB). If positive, the test has a high positive predictive value (95%) for the presence of pernicious anaemia (Toh, et al 1997), with a concurrent low false positive rate (1-2%) i.e. a high specificity. It identifies those patients with a need for lifelong cobalamin replacement therapy. IFAB is positive in 40-60% of cases(Ungar 1967) i.e. low sensitivity, and the finding of a negative intrinsic factor antibody assay does not therefore rule out pernicious anaemia (hereafter referred to as AbNegPA)

(b) Gastric anti-parietal cell antibody

Gastric parietal cell antibodies (GPC antibodies) have a low specificity for the presence of pernicious anaemia since, despite being positive in 80% of pernicious anaemia subjects, they are also positive in 10% of normal individuals. Positive gastric parietal cell antibodies may cause gastric acid achlorhydria and progression to pernicious anaemia may occur. However, a positive GPC antibody test is not definitive for pernicious anaemia (Khan, et al 2009).

So you could have PA with your results, as a negative for IF abs does not mean you do not have PA, and being positive for Gastric parietal cell antibodies (GPC antibodies) also means you could be getting B12 def if your stomach acidity is not right (achlorhydria), which also can interupt other vit/ min uptake like iron as it needs a certain PH for uptake etc.

To read up on achlorhydria, have a look at this:

emedicine.medscape.com/arti...

I hope this helps,

Kind regards,

Marre.

[Mrs_Somerset]

Hi ednotdave (interesting name BTW )

I think Marre has said it all, intrinsically your results are not 100% conclusive, however, it is the symptoms that matter.

Have you tried the symptoms checklist on the Pernicious Anemia society website:

pernicious-anaemia-society....

there is a link to the symptoms chekclist and also their mini test to see if you are liekly to have pernicious anemia.

you can still have a B12 dificiency, even if it is not pernicious anemia, the only difference is that your own body is not destroying the cells that transport / absorb B12, but you can still suffer from the symptoms.

in that case you need to look at resolving the issues you have with absorption / diet and see if once those are rectified, if you feel better.

you could try adding mre B12 to your diet and see if any of the symptoms lessen - this would suggest B12 deficiency, but not pernicious anemia ( as us PA's cannot get B12 from our food any more - this can happen at any time in your life - you can be fit and healthy and happy and then a gene turns on and bang - your body decides to attck itself, for no good reason)

just because you might not have pernicious anemia, does not mean your deficiencies should not be treated - they are just treated in a different way.

Big Hugs,

M

[ednotdave]

OK, thanks peeps.