I meant- Are HYPERsegmented neutrophils significant?

[Btab]

How significant are hypersegmented neutrophils in the diagnoses of pernicious anemia? Do the show up at commonly at other times such as during a mild bacterial infection ?

[Gambit62 Administrator]

diagnosis of PA usually focuses on red blood cells - and neutrophils are white blood cells. Not heard of using white blood cells in diagnosing

[Btab in reply to Gambit62]

Thank you for replying

[fbirder]

Hypersegmentation of neutrophils is very common in macrocytic anaemia caused by B12 and/or folate deficiencies. The same problems with the making of DNA that produce large red cells also interferes with the production of normal white cells.

Long-term infections can also cause hypersegmentation. But I get the impression that it's not common.

[Btab in reply to fbirder]

Thank you. I have seen a few articles regarding this and wondered as we are working on getting a diagnosis for my son.

[helvella]

Of possible interest - a paper about hypersegmented neutrophils and cobalamin status:

pubmed.ncbi.nlm.nih.gov/870...

[Foggyme Administrator]

Batak. Here's some links to information about hypersegmented neutrophils...together with some potential causes (macrocytic anaemia associated with B12 /folate deficiency, included):

en.m.wikipedia.org/wiki/Hyp...

sciencedirect.com/topics/bi...

Neutrophils can be raised during infection and hypersegmentation can (apparently) be associated with chronic infection.

👍

[FlipperTD]

I apologise if this gets a bit long and technical but some of you might find it helpful. I will use some gross over-simplifications but the principles remain sound.

Macrocytosis [raised MCV] and hypersegmented neutrophils generally reflect the same root cause; asynchrony between nuclear and cytoplasmic maturation. Both cell lines [red cells and white cells] require adequate levels of B12 and folate to produce mature cells. If the body 'runs out' of either B12 or folate then the mature cells end up bigger because they've missed out on one cell division; they have more nuclear material. The mature red cell has lost its nucleus before it enters the circulation, but the mature neutrophil still has the nucleus, and it is segmented. There are typically 2 to 5 segments. Typically, in normals, fewer than 5% of cells have 5 segments, and none would be expected with 6 or more. Neutrophils have a much shorter lifespan than red cells. So, when the bone marrow 'runs out' of B12 or folate, then larger red cells start being released, and the MCV slowly rises. Likewise, when the B12 or folate supplies are replaced, the MCV slowly falls. However, as the neutrophils are replaced much more quickly, then the hypersegmentation will appear far more quickly, and it's easily spotted. So, hypersegmentation will appear [and disappear] far more rapidly than macrocytosis. The hypersegmented netruophils tend to be larger also.

Neutrophil segmentation will alter in the presence of an infection, because production increases rapidly, and the early released cells show fewer segments. [Nothing is ever simple.]

The appearance of cells with fewer segments historically was described as a 'left shift' and an increase in segments a 'right shift'. Historically, a 'right shift' could be recognised easily from a stained blood film and microscope, whereas macrocytosis requires an analyser. Modern analytical technology is able to recognise the size of both red cells and white cells, but the stained blood film is still a useful adjunct.

[helvella in reply to FlipperTD]

How is the functionality of neutrophils affected by hypersegmentation?

[FlipperTD in reply to helvella]

This is getting way beyond my expertise, so this is largely guesswork, but I'll give it a go... I'm a retired scientist, and I'm much more familiar with counting and classifying them than what they're doing at a cellular level.

The hypersegmentation is unlikely to affect functionality; the segmented nucleus has 'done its job' by now because the neutrophil is an 'end cell'; it is past the stage where it could divide to provide more cells, much as red cells are 'end cells' and do what they do with what's present in their cytoplasm and membrane.

Even macrocytic red cells do their job in oxygen and carbon dioxide transport. The hypersegmented neutrophil is biologically active and capable of engulfing bacteria etc, doing what neutrophils do best.