Prefibrotic Myelofibrosis: Diagnosis Favors Essential Thrombocythemia

Hi,
I know this is an old thread but I had not found it until today! I totally agree with the confusion that exists in diagnosis of ET and PMF having gone through that experience myself after routine physical in December 2024. In January2025 I was told I had ET by my assigned O/H and she prescribed 500 mg Hydrea twice per day which I never took as quite a strong dose for my size I read elsewhere. I was found to have CALR1 mutation so I asked her for bone marrow biopsy to confirm diagnosis. That annoyed my O/H but she ordered it and then she changed my diagnosis to PMF in February 2025. Then she sent a memo to my kp.org saying “you might be transitioning from prefibrotic phase now” and referred me to bone marrow transplant specialist. Kaiser’s are quite far away from where I live but I am just going to that appointment today in August 2025. It will be interesting to hear his opinion. My O/H said it was the best she could do as my O/H says Kaiser has no MPN specialists. I am thankful to God that I have no symptoms still, normal spleen size on CT pelvic scan done recently, but mildly enlarged liver. I do have high platelets so take low dose aspirin daily. I am 65 and blessed to have no health issues other than being told I have all of this now. I really do not get too concerned about it all and just try to learn as much about them all as I can while continuing to live my positive busy life as always. I have tons of energy ad always and exercise daily and eat healthy as I always have. Prayers and positive thoughts for all.

Good for you, it is behind you now! I was super anxious for that procedure as well. I just wanted to give you the heads up that the results will take up to four weeks. That was a very hard wait for me. Some results will appear in your portal in a short time and if you're handy with google you can sorta figure out what's going on. That was my experience, I started out with PV in 2016 however I now have myelofibrosis and getting prepped for a bone marrow transplant in September. I too live alone and care for my 2 horses and 3 dogs and the 12 acres we call home. Fortunately my sons are about 30 minutes away. We all have our struggles it is in the way we chose to handle them that really matters. I am the type that wants to know EVERYTHING there is to know. Have clarity can be very helpful. I wish you the very best.

Doctors and diagnoses are so confusing. I to have just recently been told I have myelofibrosis in July from MDS several years ago. I go back for more blood work in September. Speak more to her on how she derived at that from an old bone marrow biopsy . I would like to do another biopsy just to come to a clear diagnosis. I’m on no medication. Plates are steady at 72. Red and white blood low but steady and high B12. Other than the horrible bruising and fatigue hits I maintain a good diet too and do my daily chores as I call them ( house work and yard work). In 2 bible studies and complain to no one. I’ll be 77 in October. I made the switch in doctors hoping to get the info I wanted plus from a h/o to a blood h/o specialist. Grateful for this group. I read it daily.

Quite a spate of folks progressing to MF here. Sounds like docs are increasingly favoring BMT as treatment for MF? Wishing everyone who's moving to MF fortitude and caring helpers as they make new treatment decisions.

So far my ET (CALR+) has been stable x 17 years with help from HU x 6 years. Quarterly blood test today, so knock wood.

Hi@nohrt4me,

My O/H told me Kaiser does not have MPN specialists so she referred me to see a bone marrow transplant specialist as they do have those who work also at City of Hope alternating monthly where they work. I chose the one I wanted to see and waited to get appointment with him. The bone marrow transplant specialist I saw said CALR1 mutation is strong reason the pathologist gives diagnosis as primary myelofibrosis which I think you had mentioned. He also said I do not need a transplant now and may not need one or at least not for a very long time. He also informed me that age of 70 years old is not a reason to say person cannot do a bone marrow transplant. Lori had written that also and was entirely correct. He did say person needs to stay fit to have one if older. He informed me that Hydrea does not prevent fibrosis and only lowers cell counts which I already knew. He said cell counts can vary tremendously when I asked him why my platelets lowered 400 with me doing nothing differently and no meds. It is overall trend over time that is important. He was very happy to inform me that I do not need a bone marrow transplant and I was happy to hear that too.

So glad that you got some answers!

Yes, ET-CALR is suspected to be a somewhat different "animal" than ET-JAK2. The big difference now is that it keeps many of us CALRs in the low to moderate risk groups, which means we don't need to start HU as soon.

Age alone is not a reason to write off BMT. It's not something I would consider given other health conditions and low income, but it has clearly helped many folks here get a second chance!

Hi again @nohrt4me ,

I honestly don’t know if I would choose to do a bone marrow transplant even without having other health conditions because even with CALR mutation, the odds of being alive after five years is only estimated at 64%. Perhaps if the odds improve years from now, I might have a different opinion. MPNs to me are an evolving field with much still not known.

Diagnosed with prefibrotic myelofibrosis 7/25. 78 years old with JAK2, ASXL1, ZRSR2 & TET2 mutations. Platelets went to 1.355 million..now down to 527 with heavy Hydroxy. BMB confirmed by University of Virginia Cancer & Virginia Cancer Institute.
Trying to find my way through the available info.
Questions:
1. Can you measure the speed of progression by the speed the platelets initially increased?
2. How can you tell when moving from Pre to the next phase?

Welcome to Connect, @jtcat7. Looks like you have a full deck of mutations in your hand. Over our lifetime, we can develop some genetic mutations. Some of these may lead to various blood disorders such as myeloproliferative neoplasms (MPNs) which can cause issues with our bone marrow and its ability to produce healthy blood products. Many people with MPNs have either Polycythemia Vera (too many red blood cells) or Essential thrombocythemia (too many platelets). Both of these conditions may rarely progress to MF. MF (myelofibrosis) the normally spongy bone marrow can become filled with scar tissue or fibrotic tissue and interfere with blood cell production.

You’ve asked a couple of questions regarding the speed of progression and how you can feel if you’re moving from pre to the next phase. Those are great questions for your hematologist.

I did find a good series with videos from Patient Power with information about MPNs and prefibrotic primary myelofibrosis which might help in answering your questions.
https://www.patientpower.info/video/myeloproliferative-neoplasms/treatments/what-is-prefibrotic-primary-myelofibrosis
Was your high platelet level discovered during a routine exam or were you having any symptoms that to the discovery? How are you feeling with the HU? Any side effects?

Thanks for responding. I was in an ER in March as a result of a fall off my front porch which resulted in a compression fracture (L-2). The platelet count was 819 which they failed to mention. My diabetic endo got the report and figured it was a mistake so her CBC showed 1.04 million platelets. She then referred me to a hematologist at Virginia Cancer Institute.
As for side effects, when I was on 2,000 mg daily, I was REALLY fatigued, night sweats and my WBC took a nose-dive.
I'm still finding my way around. The fall from the porch and the discovery of diverticulitis all happened at the same time.
Jeez...