High HCT but everything in range

[mjn500]

Hi - I was diagnosed ET JAK2+ 3 years ago. I am well-controlled on Hydroxy with platelets 320-360.

At my most recent blood test 2 weeks ago, my HCT was 47.3 though everything is apparently within normal ranges (waiting for the full results so I can have a look).

I don't understand why my HCT is high if everything else is okay; I drink 2-3 litres of water a day so not dehydrated.

Any ideas / experience to explain this?

Thanks,

Mel.

[hunter5582]

It is really impossible to say what this one HCT value means in the absence of more information. The normal range for a female is around 34.1% - 44.9%. There are a number of reasons why HCT can be elevated. Some are quite normal (e.g. spending time at high altitude). webmd.com/a-to-z-guides/wha...

It is also very important to know that you can never tell anything from a single lab value. This may just be a temporary flux. It could also be a lab error. This is something to pay attention to. I would repeat the CBC in a couple of weeks to see if the HCT and other erythrocyte values change or stay the same. I would also get a CMP just to check on some other things that might be going on.

To the extent you can, suggest not worrying until you know there really is something to worry about. This may just be a blip and nothing but a tempest in a teapot. It does need follow up in a timely fashion to see what exactly is going on.

Please let us know what you learn and how you get on.

[mjn500 in reply to hunter5582]

Thanks - my HCT has been 43 +/-0.5% for 2.5 years, including at my last blood test 3 months ago. Nothing has changed in lifestyle or anything else that I can think of.

I have a venesection next week, one 2 weeks later and a CBC in 8 weeks to check the situation.

I will be interested to see the full CBC results which I have asked for.

Mel.

[hunter5582 in reply to mjn500]

I was thinking that you are diagnosed with ET. Venesections are the treatment for PV, which is treatment for erythrocytosis. Were you diagnosed with PV?

FYI - I had ET for about 22 years before it progressed to PV about 8 years ago. This does happen sometimes.

I hope your docs have given you a clear diagnosis if they are changing the treatment plan.

[mjn500 in reply to hunter5582]

No, diagnosis is ET, the venesections are just to reduce the HCT. If it remains high I imagine there will be more investigations.

[hunter5582 in reply to mjn500]

WIth ET there would not be an elevation in erythrocytosis. By definition, ET only involves thrombocytosis. Erythrocytosis that requires venesection would be by definition PV. PV can also include thrombocytosis and leukocytosis. There is also a condition referred to as MPN, Unclassifiable that is used at times.

At this point, there should be more investigations. You do need clarification of your diagnosis as it bears on your treatment plan.

If you have progressed to PV as I have, it is something you need to know. It is not a cause for panic. It happened to me 8 years ago. I am doing fine. It is certainly something I need to take into account in how I think about my treatment plan.

Venesection is certainly the best way to address the erythrocytosis initially. The venesections will over time induce iron deficiency (without anemia). This is what controls the erythrocytosis. Your body cannot make red blood cells without iron. Unfortunately, chronic iron deficiency can also have its own side effects. Do be aware that a common side effect of venesection/iron deficiency is to increase thrombocytosis.

After a few years, I found the iron-deficiency side effects more bothersome than the PV symptoms. Since I am also Hydroxyurea-intolerant, I opted to start on Pegasys. I switched to Besremi once it was FDA approved. This has been much easier to tolerate and far more effective than either venesetions or hydroxyurea.

You may find your own experience quite different. We each tolerate the treatment options quite differently. Our MPNs present differently as does our response to medications. That is why it is so important to consult with a MPN Specialist rather than a regular hematologist.

I hope you get clarification of your diagnostic status soon. This will allow you to work with your care team to devise an effective treatment plan.

All the best.

[Inca]

My H C T has been high always it was over 80 + when diagnosed,when it came down to 50 over 11 yrs ago the consultant was delighted & relieved,I had venesection for several weeks,then straight on to Hydrea,3 yrs ago I started Jakavi & now H C T is at last normal....all other counts have always been ok & Plaquetaire always good except for odd 'blasts' or 'macro' that doesn't seem to cause a problem .So don't worry ,if I have managed you will too,Very Best to you.

[EPguy]

As Hunter says, a single data point is not as meaningful. At the same time anything medical that changes much and suddenly without clear reason is interesting. You might ask your Dr about having more frequent CBCs for a bit to see if it is a trend.

I had high PLT (1000+) and sort of high HCT (~48-50) at Dx. My Dx is PV but with ET features. My Dr calls it generic MPN to be not exclusionary. You could have some mix of the two or possibly be progressing to PV, esp if venesection is suddenly required.