Macrocytosis

[Pixielula]

Hey guys.... how do you know if you have macrocytosis, what part of the blood test?

[taka Administrator]

MVC (mean cell volume) is raised when you have macrocytosis. Each area has slightly differing cut offs but they mostly seem to be around 98-100fL as the upper limit for normal bloods. Numbers above this would indicate macrocytosis.

If iron deficiency anaemia is present then this has the opposite effect on MCV and makes the red blood cells smaller (microcytosis). The ranges for this mostly seem to be around 78-80fL as the lower MCV range. Numbers below this would indicate microcytosis.

If both B12 deficiency and iron deficiency anaemia are present then it is a bit more complicated. They sort of cancel each other out, since MCV is a measure of the mean (average) size present.

RDW (red cell distribution width) is a measure of how wide a range of sizes of red blood cells is present. This can be helpful to try to work out whether there is macrocytic or microcytic anaemia going on (RDW would be a higher % than normal) however again this may not be a helpful measure if you have both types of anaemia. RDW isn't measured everywhere - some areas don't measure it (like mine!)

Hope this helps.

[Pixielula in reply to taka]

Oh thank you for the reply, I have posted my daughters blood test in the next post her ferritin is low but there are no reference ranges. Would you be so kind as to have a look and see what you make of her bloods

[Pixielula in reply to taka]

Her MCV is 86!

[taka Administrator]

Hmmm normal MCV then. Off to look at your other post!