B12 level 364pmol/l two months after ... - Pernicious Anaemi...

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B12 level 364pmol/l two months after loading doses - Low or normal level?

Rippers101 profile image
7 Replies

My GP has said that my B12 is normal now and no more treatment is needed after loading doses in April. I did have a B12 level of 80pmol/l before loading doses and intrinsic factor was negative. I eat a varied diet with meat and eggs so shouldn't be low. Iron has historically been very low and folate at bottom of reference range.

I'd expect the B12 level to be higher after injections. I'm trying to arrange private active B12 and MMA tests but very wary of approaching this with a dr as last time the dr's I was with removed me from their patient list when I asked for their decision to not treat at 130 with neurological symptoms to be recorded in my notes.

I'm happy to start self injecting at some point but would like to evidence that I'm not absorbing vitamins as this will help me get treatment for my anemia which is always put down to me being a woman and having periods.

I did start to feel so much better on the injections and my iron levels have stabilised for the two months. I would expect levels to be much higher. Any pointers on next steps to respectfully challenge?

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Rippers101
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wedgewood profile image
wedgewood

Did you and your doctor know that a negative Intrinsic Factor antibodies test does NOT mean that you don’t have P.A. ? The Schilling test which was a much more satisfactory test was discontinued unfortunately, and the IFAB test shows up negative in about 50% of Pernicious Anaemia patients . Symptoms are of the essence in diagnosing P.A. So the loading doses helped with your symptoms, and are now returning.? Do try and get B12 injections from your GP . If you fail , then I suggest self-injections , which is what most of us in this forum have been forced to do . . It’s easy and cheap . You can get all the information you need here . I will send you information ,in case you need it .

Rippers101 profile image
Rippers101 in reply to wedgewood

I know about intrinsic factor but the practice says a negative result proves I don’t have PA (and therefore take tablets to supplement).

I’d like to respectfully challenge this as I think the b12/folate/iron issues I have are all related. I have another autoimmune disease and my maternal grandfather had PA.

I hoe to convince the dr to take me seriously and test privately to know myself that I don’t absorb b12 very well

wedgewood profile image
wedgewood in reply to Rippers101

Your practice should know that a negative IFAB test is not proof of no P.A. THEY SHOULD LOOK UP THE INFORMATION . Also there is definitely a genetic link , which you have . The antibodies come and go . Some patients test a few times before the antibodies appear .Our chairman had to test about 3 times before they showed up . You can get private IFAB tests but they are expensive .

Litatamon profile image
Litatamon

Your doctor is a dodo head. My Lord. The same thing happened to my sister. Oh you're low - shots - oh you're normal no shots. Rinse and repeat. Oh your test came back clear so no Pernicious Anemia.

Sigh

Sigh

Sigh.

You need your shots!

Litatamon profile image
Litatamon

And then when he or she gives you more BS, throw in this one -

stichtingb12tekort.nl/engli...

Gambit62 profile image
Gambit62Administrator

reference on IFAB test being prone to false negatives can be found in the BCSH guildelines available hereonlinelibrary.wiley.com/doi...

in the section on tests for the aetiology (cause) of B12 deficiency.

Anti-intrinsic factor antibody (anti-IFAB)The finding of a low total serum coamin level may be further evaluated by testing for anti-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 et al, 1967), i.e., low sensitivity, and the finding of a negative IFAB assay does not therefore rule out pernicious anaemia (hereafter referred to as AbNegPA). In addition, the positivity rate increases with age (Davidson et al, 1989) and in certain racial groups [Latino-Americans and African-Americans; (Carmel, 1992)].

The incidence of pernicious anaemia in the UK population is estimated [extrapolated from National Health and Nutrition Examination Survey (NHANES) reports in the United States] to lie between 1–5/100 000 per annum, i.e., a rare disease. Reflex testing of all low cobalamin samples in a routine diagnostic laboratory is therefore expensive with a low detection rate. A history of other autoimmune disease e.g. hypothyroidism, and family history (Banka et al, 2011) increases the pre-test probability of pernicious anaemia.

High titre IFAB may interfere with assays of cobalamin, leading to a false normal serum cobalamin level. Testing for IFAB is therefore advised in patients with strong clinical features of deficiency, such as megaloblastic anaemia or sub-acute combined degeneration of the cord, despite a normal serum cobalamin level. In these cases, pre-treatment serum should be stored for investigation with an alternative assay (HoloTC or MMA) to confirm the presence of a severe deficiency.

IFAB assays, based on automated chemiluminescence cobalamin binding, are vulnerable to give false positive IFAB results if the patient has had a recent cobalamin injection. Manufacturer product literature warns that these assays are only suitable for samples with a specified upper limit of serum cobalamin levels, and laboratories must comply with this advice. Results of assays using these methods should not be reported if the serum cobalamin is >295 pmol/l (400 ng/l) based on UK NEQAS survey data. True immunoassays for IFAB, based on porcine or recombinant intrinsic factor binding, can be used for post-treatment samples.

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