I found out at the beginning of the pregnancy my platelets were about 470,000 consistently and decided to check it out. The hematologist sent me for a jak2 blood test...twice i got the same answer back: There is a suspicion of jak2, please retest again in a few months..(i sent the third one now) - which basically means..inconclusive.
I just did another blood count and my platelets were in the normal range! but borderline (446).
The weird thing is..i know for a fact my platelets were borderline 10 years ago but never gave it any thought...
I know ET is a progressive disease, so how is it possible that IF i have it - it didn't progress and even got better?
Please help...
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Winterella
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With ET not everyones platelet count increases over time. My sister was diagnosed with ET nearly 20 years ago now and her counts have always bounced around the 800 mark, up and down a little.
If yours have always been top end of normal, that they registered a different result during pregnancy is maybe not that unusual.
The Jak2 mutation only shows in 50-60% of ET cases, other mutations such as CALR can also be the cause.
Sounds like you are probably going to be closely monitored which is a good thing. Even at 800 my sisters blood tests where only once yearly.
Thanks for replying, this is interesting since i am reading ET progresses, so wondering how it is possible.
Also read a research on google scholar that said jak2 can be spontaneously reduce over time in healthy individuals, no idea how that happens and if maybe that's the case for me.
MPNs are a bit of an odd set of diseases. Although there are common symptoms and experiences everyone’s profile and journey is unique.
It’s not true that ET is a ‘progressive disease’ in the sense that you automatically go from one stage to another over a common timeframe.
Many people experience months, years or even decades when the disease plateaus and stabilises.
Some people are diagnosed when their platelet count is significantly elevated, they have many symptoms and they need immediate intervention (and they may also be older and / or had a thrombotic episode or similar). And once under control their platelets lower and stay lowered. Others are essentially asymptomatic at diagnosis and much younger and maintained on a ‘watch and wait’ basis. Very few people progress to more aggressive stages like MF or leukaemia. Added to which some people like me who were originally diagnosed as unclassified MPN / ET then turn out some years down the line to have PV. It’s unlikely that the disease ‘progressed’ just that it went in a roundabout way to show its true colours.
So bottom line, you’re young (yeah!), your numbers are low (yeah!), you’ve been pregnant (plays havoc with just about everything!) and your platelet count is now just about normal (double yeah!). If you’re also feeling generally good then that’s all positive news.
Platelet counts fluctuate for all kinds of reasons whether or not someone has an MPN. The key thing is the trend. Are they on an upwards climb? And in your case, they don’t appear to be. Hope this reassures you. Enjoy your baby.
I guess i will have to wait and see if i am a true ET or something reactive. I have the feeling i have ET since my platelets were for more than a decade normal borderline or just a little above it - i’m guessing that’s not really normal.
Nice to know it can not progress sometimes.
Am reading nonstop research data trying to understand ET.
Very interesting indeed, also jak2 capability of being naturally reduced (basically the mutation dies) before it reaches fenotip stage (expression=disease).
Some people just tend towards higher platelet readings without any concern about abnormalities. (Sounds like your haematologist is alert and being sensibly cautious.)
Good to be informed. Understanding of MPNs as well as the development of new interventions is moving at an astonishing pace so just be aware of this when you’re reading research material. Certainly views of progression and prognosis have changed beyond all recognition in the past decade to fifteen years.
The reality is a very small proportion of people with MPNs develop the more challenging stages of the disease. Added to which as awareness of the disease grows more people are being diagnosed at younger ages (and before they present with a major thrombotic episode) and so the traditional profile of, and outlook for, an MPN patient has also now changed. The overwhelming majority of MPNers will live out their normal lives and die of something other than their MPN (just to look on the bright side 🤣).
As I understand it (and I am just a patient who has read around the subject, not an expert), JAK2+ is a gene mutation so it is what it is, not something that changes. ET can progress into other diseases but not necessarily. Your platelets are not excessively high so at least at this stage, you can afford to not worry excessively. Best wishes to you.
It's always worth remembering that the risk with ET is Thrombosis and this risk is not necessarily only high with high platelet count figures. Other factors like the 'stickiness' of the plates increase the risk of thrombpsis to the point where counts of 550 can cause serious thrombosis.
Are you still pregnant? It often happens that with the increase in blood volume during pregnancy the platelet count will drop. After delivery the count will rise again.
Sounds like this is something to keep an eye on. Note: iron deficiency can cause secondary thrombocytosis. I would wonder a bit about your inconclusive JAK2 testing. Some people with ET have very low levels of the JAK2 mutation. Perhaps it is possible that you are hovering at the edge of detectable levels.
It sounds like you are on top of this. Continued monitoring and awareness make good sense. The doc may have recommended low-dose aspirin just as a precaution. FYI - I was diagnosed with ET over 30 years ago. It progressed to PV about 7 years ago. Most of the time with ET - I was aspirin-only. Never have had any incidents of thrombosis with platelet levels typically between 525 - 750.
I saw this post and am just wondering if you’ve gained any new information? I am in a similar situation. I am a 30 year old male. Platelets have fluctuated 430-455 for the last 10 years. I was tested for JAK2, CALR, and MPL and all came back negative. My MPN specialist said given these test results, the odds are in my favor that I don’t have an MPN, but that the possibility still remains and that it cant be ruled out. He is not requiring a BMB since it would probably be non-diagnostic in my case since the disease would be so mild (how do you differentiate someone with mild ET from someone with a naturally high platelet baseline)?
talked to a topped specialist here. he does not want to do a bone marrow biopsy yet because he says it will be inconclusive or false positive..for him atm i'm not sick i should just do complete blood counts every few months to watch my platelets and a repeat of jak2 pcr test... he does not know if i will get sick or not. This other professor said that if i am positive for jak2 and not sick there is a high likelyhood i will get sick in the future but said i should not worry as this can take many years and there is therapy nowadays sooo i'm not worried about it... i just "let it go"..ya know? the stress would make be sicker
If i were you i'd be thrilled i am negative for all mutations. Then again i would repeat in a few years again, check my other complete blood count values (especially hemoglobin/iron).
Differentiate is all about platelets levels (lower the better), 450 is max but even that is great because still considered normal. people here have 800+ to 2 million...so u're in a good place i guess. Maybe u don't even have an mpn. The fact u are jak2 negative is a blessing, your risk for blood clots is basically very very low.
Yes, I’ve been on the forum for a few months now. It sounds like you and I have a similar situation.
There are pros and cons to my situation. Unfortunately, it is not that straight-forward. Being JAK2 negative does mean my risk of clots is lower. However, if I am truly triple-negative ET, I may never know if I have an MPN if my platelets never rise above 450, which means I may never be diagnosed and that would prevent me from taking advantage of meds that halt or slow progression (interferon).
I was only tested for the 3 driver mutations. 15% of ET patients have no detectable driver mutation. Also, triple-negatives tend to have more aggressive disease if they progress to MF or AML.
As of NOW - you do not classify as an MPN patient. You CAN know if you will start to develop one by tracking your plt levels - there needs to be a gradual elevation. That's what periodical CBC are for..so do them and you will be on the SAFE side of knowing your situation and if it worsens to "catch" it on time. Lets put the paranoia on the side atm - you are friggin' healthy and young - be happy!!!. You may not even have anything not now not in the future. My specialist said some ppl's PLT are just naturally on the high side. NOBODY knows what the future holds and you should deal with stuff one step at a time when and IF it comes since we can always cross the street tomorrow and get run over.
I am not worried about having an MPN. I might have it, I might not. I have accepted this and live my life fully each day regardless of the outcome. I was simply trying to share my situation with you and show how we are similar.
A couple points to make clear here...
It is not true that MPN patients have to have a gradual increase in platelet levels over time. Any trend can exist, including staying constant at the same level. Some people have increases over time, some stay the same forever. Some have counts in the millions and never progress. Others have counts in the high 400s and progress to AML. Any trend is possible, and everyone is different.
Some people with ET have counts between 400 and 450 at diagnosis. While 450 is the normal threshold as defined by WHO, this is a general value for large groups of people. Some people in this forum have reported diagnosis with platelets barely over 400. Especially for men, whose platelets tend to run lower (on average) than women, this applies more. Technically speaking, ET diagnosis does not require platelets over 450 anymore if you meet the other 4 criteria outlined by the WHO.
“Healthy” is the absence of disease, not simply living without symptoms or awareness of an underlying undiagnosed condition. So while I am not worried about having an MPN and recognize the odds are in my favor, I do not live in ignorance of the fact that an MPN cannot be ruled out and that my platelets were high enough to warrant testing accordingly to 3 different physicians, including an MPN specialist.
Hmm from what i'm seeing in the updated page of the WHO is that they still require above 450 PLT as a major criterion... my specialist said there needs to be an elevation above 450..one even said above 470, latest research has outlined the hematopoiesis of the cells = more and more of infected jak2 cells (growth rate +- 0.5% a year), hence they support the gradual elevation of plt as a jak2 growth outcome (a slowly one tho) - and that is in the jak2 positive case.
Happy you did the testing, and if i were you i'd do it periodically (as not to be ignorant), I still do not think you have an MPN now.
Yes, 450 is one of the major criteria, but many people are being tested below this threshold and found to have mutations between 400 and 450, receiving their diagnosis. WHO guidelines are exactly that: guidelines. They are not strict requirements, nor do all hematologists abide exactly by them. My specialist told me that there is also a push in the field to lower the ET threshold to 425 or 400 due to the fact that testing has improved so much to where they are catching people early in their disease
I don’t believe allele burden correlates linearly with platelet counts, nor does it increase at a constant rate per year. If that were the case, everyone would progress at the same rate. It is not that clear-cut. I wish it were though
I fully agree that my odds of not having an MPN are greater than my odds of having one based on my test results. My specialist also thinks my odds are better for not having one. Since he can’t rule it out, he is recommending testing platelets quarterly for the next couple years, as well as further genetic testing (looking for non-driver mutations common in triple-negatives).
I think your hematologist is wise, that is obviously the right thing to do. About the jak2 burden..time will tell. This field still needs much research.
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so..it's rly a roulette
ET diagnosis
Waiting for diagnosis: ET or Pre-pmf
New ET diagnosis
New ET diagnosis
ET diagnosis JAK2 positive 
