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Blood test for PV - Polycythaemia - why?

Posted , 9 users are following.

MhairiP
MhairiP

Wise & wonderful people here - I have more questions! 

I had to go for blood tests today and now that I'm more jenned-up about PMR, blood tests, etc., I asked the nurse what my previous (first) blood test results were - fully expecting them to be for ESR & CRP. But apparently I was tested for PV (2.08mpa) and CRP (42mg). 

I have read a little about PV and can't understand why I was ever tested for this. I had none of the symptoms (or at least none of the symptoms listed on this site: https://www.nhs.uk/conditions/polycythaemia/

So, my questions are: what does 42mg in the CRP test mean - are the inflammation markers extremely high, or slightly? Any ideas why I had the PV blood test? Is 2.08mpa good or bad?

Today, the nurse would only do the same 2 tests again - she wouldn't do ESR, calcium or Vit D. Apparently only the doctor can request blood tests - the patient can't. 

0 likes, 4 replies

4 Replies

  • lynda62707
    lynda62707 MhairiP

    Posted

    Hey MhairiP....please excuse my ignorance re: your post, but I just don't understand all the dx. ie crp, esr etc. I'm sure someone on this site will as most are much more informed than I ! However, I too am having follow-up blood work done on Thursday to test for GCA as opposed to the PMR I've already been dx'sd with ( there's those darned letters again)! Anyway, I'm anxious about what's potentially around the corner. If you can, I'd love to hear a more "lay-man's" description of your concerns. In the meantime, take care.

    • MhairiP
      MhairiP lynda62707

      Posted

      No prob Lynda - 2 or 3 weeks ago it would all have meant nothing to me, too! 

      My understanding is that the 2 bloods tests that are normally done when someone might have PMR are to test ESR (erythrocyte sedimentation rate) and CRP (c-reactive protein); if these are raised, then it shows there is inflammation (the next step is usually to prescribe pred, and after a day or so, if the pain goes then you have PMR, if it doesn't go, then you have something else). I learnt today that I wasn't tested for ESR last time; instead I had a "PV" test and a test for CRP. As you'll see below (thank you, EileenH!) PV is another test for inflammation that is mainly done in Scotland. 

      EileenH replied to a query of mine a couple days ago explaining in great, easy to understand language what the ESR and CRP blood tests are all about. Sorry, but I don't know how to link to it here, but it was in the thread I started about "What exactly do bloodtests show?". Have a read - it's really useful! 

  • EileenH
    EileenH MhairiP

    Posted

    PV is just another indicator for inflammation - plasma viscosity, or how thick your plasma (the clear part of blood) is. Not polycythaemia. As the link tells you - water has a PV of 1, human plasma varies between 1.3 and 1.7 so yours is a bit raised or a lot raised depending on what YOUR normal is.

    https://labtestsonline.org.uk/tests/plasma-viscosity

    There are not many hospitals that use it - I suspect most of them are in Scotland. It is supposedly more reliable than ESR but opinions differ and the equipment required has to be purchased - they all have the ESR stuff!

    You also need to ask about the normal range figures - usually in brackets behind the result. However, 2.08 is raised - so an indication there is inflammation somewhere.

    I assume the CRP is 42 mg/litre - normal is up to about 3 so it is also fairly high. Again - just an indication of inflammation. Some people have very high levels but the symptoms aren't as bad as some people with low readings. What is more important in future will be what it does in response to your being on pred. It should fall. And these tests help distinguish between PMR (raised) and fibromyalgia (not raised) which can have very similar symptoms.

    • MhairiP
      MhairiP EileenH

      Posted

      Thanks, EileenH. That was a good example of "a little knowledge is a dangerous thing" - I just looked up PV then jumped to the wrong conclusion! How interesting that the PV test is mainly done in Scotland. 

      It will be interesting to get the results next week! I'm feeling so much better, so the pred is obviously working. 

       

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