Pernicious Anaemia Society

Clutching at straws with haptocorrin?

This is probably one for the scientists: haptocorrin seems to be 1st phase binder to B12 and comes from the salivary glands and then on to the stomach, where haptocorrin's main task seems to be to protect B12 from hydrochloric acid produced by parietal cells. Am I right? If this is so, can a saliva gland infection and blockage and deformation of saliva ducts eventually become a B12 problem?

As you can see, still trying to find a reason, and perhaps solution. Don't want to bark up any more trees particularly with Dr, unless there could be something here?

5 Replies

This is very interesting stuff indeed. I also guess that's why it's really important to chew food properly so it gets coated in haptocorrin/saliva. Any link in the chain that's broken has to have some effect.


I think it is unlikely that problems with saliva glands would produce a deficiency. The binding with haptocorrin separates B12 from other proteins but then needs to be separated from, B12 needs to be separated from haptocorrin by higher acidity in the duodenum so it can be bound with IF and absorbed in the ileum and a failure in this part of the system seems to be much more significant.

This is an article that looks at whether holoT/active B12 is a more specific (and hence a better test) for diagnosing B12 deficiency ... the process for absorption is discussed in the section 'Why Herbert's model is flawed' - there is quite a good diagram showing the process

however, also have to admit that I am not a biochemist.


....nor me, Gambit, and this makes heavy reading. Could not understand purpose of first haptocorrin -from saliva glands (mine are known to be faulty), and then Holohaptocorrin (HoloHC) -presumably then B12-haptocorrin mix- which seems to be what is stored in liver but also in plasma? Confusing. Part of argument seems to be a comparison between effectiveness of measuring plasma HoloTC and HoloHC -which has a far greater half-life (?)

Still doing my own dysfunctional head in looking for reasons ! Gives me something to do while waiting for pre-op for shoulder on Feb. 3rd. anyway-

thanks for that, Gambit.


fbirder has just pointed out that acidity in duodenum is much lower than that in the gut - not really sure that would necessarily mean that low saliva would be a contributory factor to a B12 deficiency though. I couldn't find a reference to impaired saliva production leading to B12 deficiency which was how I ended up looking at the above.

I used to have problems with saliva glands and still do when B12 gets low - though in my case it tends to be the glands firing at odd times. May be that the link between saliva gland probs and B12 is the other way round.


May well be, Gambit, because working out exactly when the problems started- with the B12 deficiency or the gland- is not easy. Certainly, by the time I was getting hamster-faced every time I went to a restaurant, the gland thing was fairly advanced !


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