Elevation with PV?

[Luthorville]

Has anybody heard comments on the impact of elevation with those with a PV? For example, is it safe to live at altitude (7,000 feet) or does that increase risk of thrombosis for those with PV? By extension stroke risks are certainly enhanced when traveling by plane. I have definitely travelled by plane plenty since I was diagnosed. But is there any data where a study has been done?

[EPguy]

I don't have specific info on that but can offer that planes have a "cabin altitude" of about 8000 ft. So the longest flight of ~18 hours is like being at that altitude for that long. An exception is the 787 which maintains 6000 ft. Its non-aluminum construction makes that possible. So if there is a choice booking a 787 will be a better air pressure experience. But blood clots can also be attributed to "economy class syndrome" where staying still for extended periods has added risk.

Living at 8000 is a much longer time period so adverse effects likely have different details.

[Luthorville in reply to EPguy]

Helpful, okay thanks!

[hunter5582]

Decreases oxygen levels causes the body to increase red blood cell levels. This can be an issue if you stay at higher elevations for extended periods of time. It could require higher dosing or more frequent phlebotomies to maintain HCT at target. As EPGuy indicates, the risk with flying is more about staying seated for extended periods of time. This increases everyone's risk of thrombosis. It is more of a risk with MPNs.

I travel a fair bit by plane. I make a point to get up and move about every hour. It is better for my back and joints too. I have never had an issue with flying, including on some longer trips.

Wishing you all the best and happy travels.

[EPguy in reply to hunter5582]

My plane travel ended with the Sjo, I can never see my husband's family again. Such freedom is to be treasured.

[Luthorville in reply to EPguy]

I’m really not familiar with the sjo and its impact. Inability to fly is definitely hard. Hopefully his family understands. Do you mind if I ask what is your background? You have such a scientific mind.

[EPguy in reply to Luthorville]

I am a tech sort, Chemical engineering at UCLA, 100+ US patents (mechanical stuff) and pleasure in connecting information to find a message. But I'm not so scientific, that requires procedural discipline I don't have.

I'm also lame at some stuff, my husband knows well.

[Luthorville in reply to EPguy]

Is it the dryness on the plane?

[EPguy in reply to Luthorville]

If flying were my main limitation I'd be thrilled, such loss is trivial in my current reference. But being unable to go outside some days is real issue. Being unable to stay vertical is another real issue. Sjo in moderate to severe form is a devastating disease that is way more than dryness which it self can be devastating. It's not the self correctable dryness most are familiar with.

I asked my Rhuem which common autoimmune is the worst option, he replied Sjogren's. It can go after every part of the body, debilitating fatigue (this is not about being tired) neuro, muscular, organ, GI, joint, weakness, mental health, major impacts on the autonomous nervous system (lung, heart, digestion), and on. Dryness gets a lot of attention because it is an unusual A-I complication, and advanced Sjo destroys the salivary glands similar to neck radiation treatments plus eye glands. It can lead to teeth falling out, chocking, eye damage, etc. But dryness is just one of that long list of evils. Sjo has no effective treatments and is progressive and irreversible. (5 new meds are in ph 3 trials that might change this) Most Rhuems and lay people know of Lupus but not the equally devastating close relative Sjo.

The wide suffering seen on the Sjo forum is heart breaking, a most different vibe than here. Being in the thick of it is sad.

Sjo is ~90% women while the small portion of males tend to a more severe form, on average. So far I'm the only male here with IFN induced Sjo.

I go on here because Sjo was a "common" adverse event in the Bes trials, and has afflicted real members right here. Hence my ongoing nag when a member indicates a risk.

[Luthorville in reply to EPguy]

Absolutely awful. I’m hopeful for the drugs at the stage 3 clinical point. That, at least, is something to be legitimately hopeful about and perhaps you have an opportunity to enroll in the trial? You are remarkable in the work and research you have done on all of these complex conditions.

[EPguy in reply to Luthorville]

Sorry I missed this one. There are 4 trials quite near me but among other things, one or both of the MPN and Rux exclude me. The current trial meds are immune suppressants to varying extents so adding Rux is a problem. I am willing to switch to HU if it would enable me to try.

The new cell therapies are most exciting. These are distant relatives to the exciting ones for CALR. But they are all going to Lupus since few "get" why Sjo is just as worthy.

In Cell treatments, the current trend is moving away from CAR-T toward iNK (Natural Killer). It's supposed to be safer and easier to do. Maybe we'll iNK our way out of our MPNs someday too. This is just one report of countless ones in the area discussing the shift (I've not tread it thru)

pmc.ncbi.nlm.nih.gov/articl...

[Luthorville in reply to hunter5582]

If someone is traveling to a higher elevation, this makes sense. But if it’s a permanent move, would the increase in HCT be temporary once the body adjusted?

[hunter5582 in reply to Luthorville]

The increase in red blood cell production would be permanent if you lived at higher elevations. This is the body's natural response to the lower oxygen levels. Lower O2 levels cause hypoxia which triggers the release of erythropoietin, the ligand that drives RBC production.

[Luthorville in reply to hunter5582]

If a person with PV already has elevated RBCs, they might naturally carry more oxygen, which could reduce the risk of hypoxia. On the other hand, if medications are keeping their RBC count at normal levels, then an induced hypoxic response might be acceptable and may not increase the risk. Lastly, if the person is undergoing phlebotomy to lower iron levels and limit RBC production, the body may find it difficult to produce more red blood cells due to the lack of available iron.

[hunter5582 in reply to Luthorville]

At higher elevations the lower oxygen will still trigger the release of erythropoietin, increasing production of RBCs. The body senses the lower oxygen level and responds in a normal way, which in the context of PV means an even higher level of erythrocytosis. If someone were so severely iron deficient that the body could produce inadequate RBCs, they would become anemic. That happened to me when I had too many phlebotomies.

Here is one study on the impact of altitude on PV.

ashpublications.org/blood/a...

[Luthorville in reply to hunter5582]

There was a study, okay thank you, Hunter.

Looks like 12% higher HCT. Though none of the patients were on Besremi or Jakafi. Hopefully another study will be done for people at elevation on those drugs if they have had CHR. Though Bogota is also extremely high in elevation. The impact from Denver should be meaningfully lower.

[ERei]

My MPN doc said it's fine - just take an extra dose of aspirin

[Luthorville in reply to ERei]

If you live there do you think your body is at increased risk or it just adjusts

[yibberat]

I live at altitude with PV. Denver at 5280. Often spend time in the mountains though I did stop skiing a few years ago (wrecked my knee - not PV). Have stopped climbing the 14k summits and sleeping/camping at over 9000 feet. That's where I get a bit breathless and don't get a good nights sleep - but that was the case before a PV diagnosis as well. Mostly hiking/walking now. For most people who live at sea level - including no PV - even going to Denver will result in at least a day or two of poor sleep before your system adjusts for altitude.

I have no doubt that PV will delay any altitude adjustment because you are likely iron deficient and the way your body adjusts to less O2 in the air is for your red blood cells to become more oxygen-efficient. That takes about three months for red blood to turn over which is why athletes who train at altitude spend time living at altitude as well. At least for me - my JAK2 mutation results in not merely more red blood cells but also crappier ones. More a quantity mutation than a quality mutation.

[Luthorville in reply to yibberat]

That’s really interesting. Hard to distinguish PV from just normal high altitude issues. Surprised you got a poor night of sleep at 9000 coming from Denver. I was at 14,000 last year and had to go down pretty quickly. It seemed meaningfully worse than before.

[yibberat in reply to Luthorville]

There is both an absolute and a relative issue re altitude. Living at Denver altitude, I get a mile high head start (so a relative issue) on exertion issues at higher altitude. But for stuff like sleeping, need to take a deep breath occasionally, I think those are 'absolute' issues related to basic respiration rate, cardio fitness, or genetics - not blood efficiency.

I will say that high altitude probably causes much higher hematocrit levels. Not just the potential of 'secondary polycythemia'. I was diagnosed with PV and my hematocrit was mid-70's. I'm sure had I had blood tests earlier, I would have been diagnosed earlier and I doubt the jak2 mutation was some sudden onset.

[Luthorville in reply to yibberat]

Mid 70s HCT is really high. My doctors flipped out when I was mid to upper 60s. Hmmm so maybe my dream to live in the mountains off of Salt Lake City need to be rethought…