Is there any value in a Reticulocyte blood test to evaluate B12 and Irons if taking B12 and B Complex supplements?

[Gillybean1]

Hello Everyone,

As usual I am a bit out of my depth, or clutching at straws possibly. But wondered on your thoughts about doing this test, and would appreciate any thoughts or experience please.

Kind regards, G

[wedgewood]

I’ve never had a reticulocyte test , but I believe it can be done with a full blood test . They are immature red blood cells which are larger than mature ones . They can be immature because of the lack of B12 . If the percentage is higher than about 2% , it can indicate B12 deficiency .

[Gillybean1 in reply to wedgewood]

Hello Wedgewood,

Lovely to hear from you again, I hope you are doing well now?

Thank you for replying.........do you know if being on B complex and B12 supplement though if that would scupper the test ?

G.

[wedgewood in reply to Gillybean1]

No not “scupper “ the test . If you are absorbing the B12 and B9 that you are taking , and you are not iron deficient , then your reticulocyte reading should be normal . I’m not medically qualified. , but that’s how I would interpret the situation .

[FlipperTD]

Scientist, not medic.

I did very many retic counts in my career. If they're an automated test from a good analyser then they're precise, whereas in the old days of manual counts then precision was considerably lower, but still useful. But in terms of actual retics:

When your bone marrow releases 'newborn' red cells, they 'come out' as reticulocytes. They stay as countable retics for around two days, give or take. A retic is a considerably more biologically active red cell than a mature erythrocyte. Red cells stay in circulation for around 100-115 days, before they go off to 'the scrapyard' [mainly the spleen] to be dismantled and recycled. So, a 'normal' range for retics would be around 2% of the total.

If you're anaemic [say, B12 and/or folate deficient and anaemic] once you get the replacement therapy, your bone marrow goes into overdrive and produces many more red cells to make up the difference and get your Hb back up into the reference range. The initial spike in retics can be seen in under a week. [In iron deficiency, it takes a bit longer, but it's still quick.] If you don't check the retic count promptly, then you can miss the peak, which can be disappointing and maybe misleading too.

Is it worth doing a retic when you're well into replacement therapy and your Hb is in range, then no, it probably isn't, although if you have a haemolytic process going on [destroying red cells early, before their 100 days or so] then this should be reflected with a raised retic count. If you have a haemolytic process going on and you run out of folate, then your Hb can drop alarmingly, and the retic count will be higher, as the retics are more resistant to destruction.

Retics are identified by a special staining technique.

Retics contain active mitochondria, so they're able to generate considerably more energy than mature red cells.

[I could go on, but I've gone on quite long enough for today!]

[Myoldcat in reply to FlipperTD]

No, that was fascinating!

[Cherylclaire Forum Support in reply to Myoldcat]

Yes, wasn't it ?

First time I have seen that explained.

Thanks FlipperTD

[Dance_queen in reply to FlipperTD]

Thank you for that FlipperTD. I wondered if you could help, my retic count was 20.40 10*9L(25.00-105.00) two months ago, and I was also slightly anaemic, but it has now increased to 39.80. I have been taking oral B12 supplements for two and a half months, so I assumed that was why it had increased. But my GP said it’s likely that it was low due to a viral infection at the time and nothing to do with the supplements, even though other symptoms have improved since taking them. Could this be true?

[FlipperTD in reply to Dance_queen]

Full marks to GP! Right first time. Absolutely right, and that's what we pay them for.

Any viral infection can cause suppression of your bone marrow for a few days. Parvo virus is good for that. [And not just in doggies!] Anything putting stress on you can cause further effects. I've seen someone go from coping very well with a Haemolytic Anaemia to 'crashing' spectacularly due to a virus. We didn't know about the Haemolytic Anaemia because he was compensating very well.

The bone marrow can cope with a huge amount of over-production until you run out of, usually, folate. Well done to the GP, and good to hear you're on the mend.

[Dance_queen in reply to FlipperTD]

Thanks FlipperTD