Log in
Pernicious Anaemia Society
17,169 members β€’ 11,882 posts

Further tests

Hi. Me again.

I've had a phone call from the hospital asking me to come in for further tests tomorrow, my little boy was crying at the time so all I got from the woman on the phone was a blood film test, she did say 3 things though and I thought I'd remembered what she'd said then I wrote down where to go and couldn't remember the rest, by this point the phone call had come to an end. (I'm not thinking very clearly at the minute & very forgetful) Writting it down I've realised it was another FBC so it's just one I'm not sure on.

I'm waiting on results from MMA & intrinsic factor and wondering whether the results of these would prompt the above tests?

I've been told to fast for the tests tomorrow.


5 Replies
oldest β€’ newest

I rang my gp to ask about the results as I don't have a contact at the hospital and they hadn't received them yet, they said it usually takes a week or so for them to get them.


Hi KJP723. First, this is not something you should worry about.

A blood film is a more precise way of looking at and identifying immature and abnormal white blood cells, red blood cells and platelets. I'm just going to focus on the red blood cell element because that's what's most closely associated with B12, folate, and iron deficiency (they usually tend to go together in us deficients πŸ˜–).

When a patient has symptoms of both iron deficency anaemia and B12/folate deficiency, the different elements of an FBC can often be difficult to interpret properly because the smaller microcytic red blood cells associated with iron deficiency anemia make the blood cells smaller and can 'mask' or hide the presence of the large microcytic red blood cells that can (but not always) be associated with B12 deficiency (amongst other things). (Simplified explanation so I hope you get what I mean)

In these cases, the guidelines state that a blood film should be performed to gain more accurate information about the size, shape, and maturity of the red blood cells to enable a more accurate picture of what's happening at a blood cell/platelet level. Most GP's don't bother to do this test so its good news that it's being done...it will help your GP to make a more accurate diagnosis. And if macrocytosis is identified on the blood film, it will make it easier for you to get treatment for B12 deficiency since this is what GP's (mistakenly) tend to look for. (You can still have PA and or B12 deficency even if macrocytosis is not present - your GP may not know that, but that's another story).

They'll do a new FBC at the same time since the blood film is a sort of snap-shot in time, an extension of the FBC, so they'll need to read each test against the other.

The blood film will have been requested in light of your original FBC test - to provide more information about that.

The results of the MMA test will stand alone as a marker of B12 deficiency, or not.

Likewise the IF test (if positive you definitely have PA, if negative you could still have PA since 50% of the time the test returns a false negative result).

So...calling you back to re-test your FBC and add in a blood film means that they're doing what all doctors should (but rarely) do...good news from where I'm sitting πŸ˜€.

So worry not, and let us know how it goes...and post your results if you want help with interpretation.

Good luck πŸ‘

1 like

Thank you for your reply. It's hard not to worry but I'm glad they are looking in to it properly. I'll post again when I find out more.

1 like

I've had the tests this morning and one of them was for kidney function so I'm assuming my MMA came back with increased levels? I asked the nurse about the results for MMA & intrinsic factor but she didn't have them. They also did I test for functional b12? Along with a FBC and blood film. Hopefully I'll have some answers soon.


Hi KJP723.

The kidney function test is one of the most commonly performed screening tests. If your FBC returned either a high or low RBC count or a high MCV count then the most likely cause is either iron, B12 or folate deficency. However, another less common cause could be renal insufficiency - so,it's possible that your doctor is taking a best practice approach and doing the renal function test to rule this,out as a possibility - as they should πŸ˜€.

Also - if you happened to be dehydrated when the blood tests was taken, this could also show changes in the FBC which would again lead to this best practice approach (rule everything out and see what's left).

No way of knowing if the kidney function tests was due to high MMA levels - but think it's more likely to be based on your FBC results (which are being repeated, together with the blood film.

Incidentally, high MMA results can be caused by B12 deficiency (including functional deficency), intestinal bacterial overgrowth, hypovolemia (caused, for instance, by dehydration or blood loss), or renal insufficiency...so if these do return a high result at least the renal insufficiency aspect will have been covered by liver function tests.

So...please don't be worrying that you have something wrong with your kidneys. The most likely reason for the additional tests is because they're taking the right best practice approach and ruling everything out.

Of how I wish more doctors would do the same πŸ˜€.

Good luck with the results...try not to worry, and let us know how it goes πŸ‘


You may also like...