I have read on here of cases where the diagnosis of ET or PV isn’t always so clear cut or where ET becomes PV and I was interested to know what the key differences were for the blood test results for each diagnosis.
Although I have an ET JAK2+ve diagnosis, my platelet levels have never been as high as a lot of people report on here- generally around the 500ish mark and more recently being only 425 (despite only being on aspirin) . So I was wondering which blood test results would need to be considered high or low to suggest a PV diagnosis instead?
My HCT levels were around 0.44 at diagnosis and one At 0.46 resulted in a venesection , the last one was 0.43. Hb is usually around 140g/l, RBC around 4.5, and RBCDW around 14%. I haven’t had a BMB. I think my allele burden was either 14% or 17%
I think I do likely have ET but I wondered how common it is to change from ET to PV ?
Thank you
C
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Cb1001
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Your blood counts are mild compared to many here and allele is in the more common ET range. But there is plenty of overlap between the two MPNs various blood counts. Most experts will say you need a BMB to be sure esp if bloods are ambiguous. Are your WBC also ok?
My MPN specialist indicated the distinction does matter because he said with classic ET he does not require strict HCT control. I have PV Dx with ET features so the ambiguity means we are watching HCT.
If you were ET and progressing to PV you would tend to see increasing HCT over time. But as above there is ambiguity in many ways that often only a BMB can resolve, but even then not always as my experience.
Here is the WHO criteria that help determine the Dx. Note the reliance on BMB. Your most recent PLT does not even meet the ET Dx, but you say it's usually higher.
I am one of those who had ET that progressed to PV. I was diagnosed with ET anobout 30 years ago., It progressed to PV about 9 years ago. The progression was readily identified by the progression in erythrocytosis. That is the key difference between ET and PV. The WHO criteria for PV includes "Hemoglobin >16.5 g/dL in men and >16 g/dL in women, or hematocrit >49% in men and >48% in women, or red cell mass >25% above mean normal predicted value." As EPguy notes, there are additional criteria that distinguish PV and ET,
There is also the issue of masked PV, Sometimes, PV is misdiagnosed as ET. This is reported in the literature. Here are a few examples of what is available.
With ET, there would be no reason to do a venesection at HCT = 0.46, even though it is above reference range for a female. It it is not part of the treatment protocol for ET. If your care team thinks the diagnosis is unclear, that would be a reason to be more concerned. Suggest you take your question back to your MPN care team for a clear answer as to what they are thinking.
Hopefully, your care team includes as MPN Specialist. If not, now would be a good time for a consult with a MPN Specialist. mpnforum.com/list-hem./
My PV developed classically except for my not having had any thromboses- years and years of slowly progressively higher HGB and HCT, slow increasing RBC, treated by donating at the Red Cross blood bank- until COVID , and then in 4/22, for the 1st time, my RBC was actually high to the point of being significantly over the upper limits of normal- I think 6.75 [million], where the top of normal was 6.1 mil- but all my others [WBC/Platelets] were solidly normal.
I was referred to a local [generalist] Heme/Onc in 6/22, by which time my WBC's were like 15K, and my platelets were also sky-high, and of course my BMB was classic for PV with a Jak2 allele burden of 46%, which I think is in the lower 'normal' range for PV.
BTW, don't wait for them to mention the idea of BMB, suggest it yourself because in some ways, it's really the most set of data you can get all in 1 place.
Unfortunately I don't think my haematologist is an MPN specialist and he appears to be only focussed on my Jak2+ve result and not on the symptoms that I seem to be suffering from- since I actually received the diagnosis- prior to that I felt fine. I've not been offered a BMB, he seemed happy to go with ET based on the blood results.
The issue I have is that I think I may have a vitamin B12 deficiency. The issues with tingling, tinnitus, a constant feeling of vibration in my body, brain fog etc all seem to point to a possible problem with B12. But because of the range of B12 that is classed as 'normal' and the inability of the standard test to distinguish active and inactive B12, although I'm near the lower end of the scale, I've ended up being fobbed off with a functional neurological disorder diagnosis ('FND') diagnosis. I have been reading the pernicious anaemia forum on here and the symptoms some of the people describe are exactly how I feel. Given that a B12 deficiency can result in permanent neurological damage I really need to get it checked/sorted out. I've had some improvement with oral B12 supplements but would like to try and get some injections, but this is proving so slow and since I've been taking supplements this is likely to skew the blood test arranged this week
I have seen the papersreferenced on here like pubmed.ncbi.nlm.nih.gov/257... that indicates that patients who had MPNs can have vitamin B12 deficiency, despite high serum vitamin B12 levels. hence I was trying to work out if having an MPN (either ET or PV) could be masking the issue of a B12 deficiency. Maybe my platelets would be higher if I didn't also have something else going on ?- but then again my platelets seem to have been in the 480-520 range since 2006, so pretty stable.
The report you note shows up in a few posts, I finally checked it out, thanks for the good context.
It focused on MPN patients and suggests we get holoTC test, and/or MMA rather than regular B-12 to check for active B-12 levels.
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This reference on pernicious anemia says " High MMA levels confirm vitamin B12 deficiency." So seems either holoTC or MMA are good.
In this same ref "Numbness and tingling in your hands and feet" is a symptom. That does overlap with MPN in general so the improved B-12 test would be the way to know if B-12 is part of it.
"... in women <50 years and in (all) men, HoloTC, MMA, or Hcy do not appear superior to B12 for the detection of B12 deficiency. For women 50 years and older, HoloTC seems to be the preferred first-line marker for the detection of subclinical B12 deficiency.
You're not just wandering out in the woods with your concerns about possible B12 deficiency, they are valid and could be spot on.
That said, there is now some really good evidence that B12 injections are almost never really necessary- even in those cases which are diagnosed as having true pernicious anemia, which by the way, are very very few and far between- I've seen maybe 1 or 2 in 30 years of [family] practice.
If you think that you are still possibly deficient despite taking 1000mcg orally daily, you might try taking it twice daily, which may well overcome any absorption issues you might otherwise have.
Please note, I said taking it twice daily, and not 2 once daily- there are active transporters [not Jason Statham unfortunately] involved, which can become saturated and then any excess is out with the poo. By dividing it into 2 dosing intervals, you may be able to get more absorbed- but it takes a while to get to repletion, so give it at least a few weeks before deciding whether or not it's working.
You might also consider taking it with something acidic to drink- OJ comes to mind, or in my case, V8 [low sodium] is a go-to, because they help with absorption.
Also, if you might be B12 deficient, it's possible that you're also either just getting by with barely adequate folate/folic acid levels, or are deficient in that too- in which case, your symptoms might just improve slightly and then stall, as the increased B12 metabolism depletes the barely sufficient folate, or if you are also folate-deficient, you won't see much, if any change at all because they're co-factors and enough of both are needed for use of either.
BTW, unlike the fat soluble vitamins like A, D, and E, you cannot really hurt yourself by taking 'too much' B12 and folate- your kidneys won't mind excreting any surplus- but you have to have enough in the first place, in order to function normally.
From your comment here, I understand that we have nothing to lose by adding some b-12, esp in context of the MPN B-12 report here. It should help with a masked deficiency, and won't hurt if active B-12 is already ok.
Be careful about ever depending on RDA's to tell you anything useful [even when the margin is >1000% of same] because they're really just intended to be about the minimum standards meant to prevent obvious deficiency from occurring; and they in no way reflect what amounts might provide additional benefit- e.g., in a chronic disease state, i.e., an MPN.
"Multivitamin/mineral supplements typically contain vitamin B12 at doses ranging from 5 to 25 mcg"
My pills have 25mcg so it's at the high end. But level is "typically 500–1,000 mcg, in supplements containing only vitamin B12"
Further, absorption goes way down with higher doses "(Absorption) rates are about 50% at doses (less than 1–2 mcg) that do not exceed the cobalamin-binding capacity of intrinsic factor and are substantially lower at doses well above 1–2 mcg [23,24]. For example, absorption is only about 2% at doses of 500 mcg and 1.3% at doses of 1,000 mcg"
But the report says the very high, if inefficient, doses are used for B12 deficient pts. And as you said oral is fine vs injections.
-My take is a B12 deficient pt needs a very high oral dose of maybe 500-1000 mcg while others are fine on 25 or less if taking this vitamin. The question remains, for MPNs should we get the alternate B12 tests to find out?
...and to EPguy- thanks that's interesting research,.
In my case I was started on B12 supplementation because of a low B12 level, and [apparently unrelated] peripheral neuropathies long before any MPN reared its ugly head in my life- most likely because of avoiding red meat for health concerns.
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