Effect of lowered blood counts on blood pressure?

[RoundTheWorld]

Hello. I will ask the haematologist but wondered if anyone of you had experience?

As the meds reduce hct, rbc, wbc, platelets is there usually a notable effect on blood pressure readings (and perhaps an opportunity to reduce blood pressure meds accordingly)?

Thank you.

[mhos61]

That’s a reasonable question.

I’m convinced there is some connection. I do not have high blood pressure, but I do have a story. My average BP reading is 110/70. However, the years leading up to my diagnosis of ET my systolic reading was increasing to around 130, which was really unusual for me. I thought it must be age related.

Then along came my ET diagnosis and successful treatment and hey presto, back down to 110/15. It took sometime for me to make the connection. I believe the heart has to work harder to drive the thicker blood, just my theory.

There was a discussion on this a few years back and someone else had the same ‘systolic’ issue.

[RoundTheWorld in reply to mhos61]

Thanks mhos61. You have great blood pressure!

For me diastolic is more consistently high than systolic (can sometimes be both). I've been kept in low end of stage 1 hypertension for a few years via BP meds (took a while to work out which suited me). Very recently my (previously stubborn) HCT dropped markedly after a few months of interferon and several venesections and I've noticed my BP has also dropped and is usually in mid-low normal range in the last week or two. All of which I'm obviously pleased about, but I've been feeling a little light-headed / dizzy. I was wondering if this is a permanent change (which hopefully my body will quickly accept as the new norm) , a temporary result of venesection, side effect of interferon, or something else. I imagine only careful recording of symptoms and changes in meds over time will tell (or at least give clues).

Thanks for pointing out there has been a discussion previously - I'll search for that a bit more.

[mhos61 in reply to RoundTheWorld]

Good luck finding that conversation, I tried to find it and couldn’t. It was a young man from Texas who started the conversation.

[mhos61 in reply to RoundTheWorld]

Although my diagnosis is ‘likely ET’ after seeing an MPN Specialist. I did have borderline haematocrit levels at diagnosis (47.9). All counts reduced on hydrea, but haematocrit took a lot longer to respond than platelets.

[Inca in reply to mhos61]

You are right Mary,I remember that a short time after dx with PV I had to have a stent in an artery as blood was still thick tho I was at the time having blood taken out every week & just started taking Hydrea. ,Got sorted very quickly .Keep well🥰💕

[mhos61 in reply to Inca]

You keep well too Sally! X

[hunter5582]

Platelets and WBCs comprise less than 1% of total blood volume. Reducing thrombocytosis/leukocytosis will not affect blood pressure but does have other clinical benefits. RBCs comprise about half of total blood volume.. Erythrocytosis increases the viscosity of the blood which does increase blood pressure. I was in Stage 1 hypertension when my HCT was elevated. BP is now normal with the erythrocytosis under control.

Depending on what other factors are contributing to hypertension, reducing erythrocytosis may reduce or eliminate your dependence on BP medications. I was on the lowest dose of losartan (25mg). We made the decision to cut this dose in half (12.5 mg) as a precautionary measure even though my BP is in the normal range now.

It is worth noting that the elevation in inflammatory cytokines that is part of what happens with MPNs can also contribute to elevated blood pressure. The elevation in inflammatory cytokines also contribute to other secondary/constitutional symptoms people with MPNs experience.

Wishing you all the best.

[RoundTheWorld in reply to hunter5582]

Thanks Hunter - that's a clear explanation. It raises a few more questions that I hope you might be able to help me answer? (I’m encouraged that there may be scope to reduce some of the BP meds in the future).

In my last 20ish blood tests HCT has been raised ~ 75% of the time, but RBC only out of bounds ~ a third of the time. What other factors contribute to HCT? Blood plasma? Large RBCS? Sorry if these are daft questions - I just realise I don't understand HCT at all well.

Any beginner level resources overviewing inflammatory cytokines and the role of inflammation also v welcome (your info re. MPNs and iron having been v helpful in the past).

Thanks in advance for any info.

[Exeter21 in reply to hunter5582]

Great information put in an easier way to understand . Thanks Hunter for your knowledge 👌

[hunter5582]

Those are simple questions with complicated answers.

There are a number of factors that contribute to HCT (the % of total blood volume that is comprised of RBCs). Plasma volume is one of the factors since HCT = the ratio of plasma to RBCs-PLTs-WBCs. That is part of why staying well hydrated is important. The very short version is that the JAK2 mutation causes hematopoietic stem cells to produce RBCs even when there is no need for them. The "on switch" is always "on". Normally, RBCs are produced when EPO (the ligand that flips the on switch on) is produced. Iron is needed to produce RBCs. Reducing iron to sub-normal levels reduces the number of RBCs. Cytoreductive medications like HU, Besremi, Jakafi inhibit the production of all types of blood cells through different mechanisms of action. It helps to understand the rather complex process of hematopoiesis to better understand HCT.

Better understanding the role of inflammation in MPNs is emerging. Systemic inflammation is thought to play a significant role in the secondary and constitutional symptoms people with MPNs experience. It may also play a role in disease progression.

Here are some presentations on these topics.

youtube.com/watch?v=acGNCef...(Not working as expected?)

youtube.com/watch?v=qmykl0X...(Not working as expected?)

[RoundTheWorld in reply to hunter5582]

Perfect - thanks Hunter. I'll digest these and come back with questions for all you good folk if needed! Much appreciated.

[saltmarsh in reply to hunter5582]

Hunter - many thanks for that paragraph explaining the nature of this disease. For whatever reason, it really came together for me. Your input on this website greatly appreciated. Thanks and be well.

[katiewalsh]

Hi. You need to let your doctors (internist, primary care) know that you’re experiencing some lightheadedness or dizziness. That can become serious. Do you have an MPN specialist? It’s extremely helpful to have one. Good luck Katie

[RoundTheWorld in reply to katiewalsh]

Thanks Katie. My haematologist is aware and it’s not new, just intermittently quite noticeable recently (mild, but v tiring) so could be linked to Besremi or lowering counts, ferritin etc. Will discuss at haemo. appt. next week - I'm not regularly seen by MPN specialist but haematology liaises with one and I have met him once.