Test Results

[AndyKay]

I was diagnosed with ET in January. My doctor is concerned because my platelets are not going down, started out at over 600, went down to 400 but now going back up to 437. I received the results of my blood work today and don't understand what is happening. My RBC is 3.44 and normal is 4.01 to 5.47. MCV is 116 and Platelets are 437. The blood test also shows that Macrocytosis is present and Ovalocytes is present. Can anyone explain this so that I can understand what is going on? I do take Hydro 500 twice a day. Thank you.

[EPguy]

In posts here you can see discussions of PLT levels, variations are normal and yours is still below the common 450 limit. So unless it starts a steady and larger increase it's usually not be a big worry. Has your Dr discussed why this is a worry? Have you several higher PLT results lately? Some Drs use a limit high as 600, this was a standard in the past, but it seems your Dr is using a less than 450 limit. My provider uses about 370, so it is quite variable.

We can know your HCT from the MCV and RBC you have (116*3.44/10)= 39.9. That means the Hydrea is working since your HCT is under 43 as should be for female.

Do you have your Hb results?

Macrocytosis is common with Hydrea:

<<Hydroxyurea, an agent ... interferes with DNA synthesis, causing macrocytosis by which compliance with therapy may be monitored.>>

emedicine.medscape.com/arti...

macrocytosis is high MCV. You can see its effect on my MCV here, the times where it's over the limit are when I was on HU (I'm now on Besremi and it's returned to normal) My Dr is not concerned with this value. But it is used to calculate HCT.

I'm not familiar with Ovalocytes. From:

biron.com/en/glossary/ovalo...

Ovalocytes relate to anemia and cancers (we on this forum all have that 2nd one)

Has your Dr discussed the ovalocytes?

MCV with HU

[AndyKay in reply to EPguy]

Thank you for responding. My doctor seems to be very concerned with my blood pressure. He is afraid I will have a stroke or heart attack. This is the first time that the ovalocytes have shown up in my blood tests.

[EPguy in reply to AndyKay]

Your Dr should be able to discuss the ovalocytes with you. Anything that is new or changed is worth understanding.

A bit more searching suggests it's worth asking some questions. Myelodysplasia seems possibly related to ovalocytes. More generally it seems less connected to classic MPN conditions than it is to other blood disorders, including MDS and anemia. This may be why I'm not familiar. It is mentioned re primary MF in one of these refs. But if you have confirmed ET that is distinct from Primary MF.

But these complex issues are questions for your Dr.

--

surgpathcriteria.stanford.e...

For Myelodysplasia <<Poikilocytosis Varying shapes, frequently macro-ovalocytes>>

sciencedirect.com/topics/bi...

<<Elliptocytes and ovalocytes are among the poikilocytes that may be present when there is dyserythropoiesis; they are often present in megaloblastic anaemia (macro-ovalocytes) and in iron deficiency anaemia (‘pencil cells’), but they may also be seen in myelodysplastic syndromes and in primary myelofibrosis (Fig. 5-8).>>

--

For your BP, are the regular meds not working for that? I take a mild BP med along with my MPN treatments. Unlike MPN, there many types of long proven meds for BP. Has Dr said they won't or aren't working?

[AndyKay in reply to EPguy]

I think one of my doctors worries is that my blood won't clot and he is afraid I will get a cut and bleed too much. I could be wrong, but he has told me to be very careful.

[EPguy in reply to AndyKay]

Your PLT value at low/mid 400's should not by itself cause such risks from what we see here. Much higher PLT values are known to be a risk. But you have other possibly more relevant and complex things happening, and if your Dr cannot give you detailed discussion on it, you might want a 2nd opinion.

[hunter5582]

It is normal for platelets to cycle up and down in response to what is going on in your body. PLT can cycle by as much as 100K in a single day. We never take a single lab ready as being too significant. it is always the trend over time that matters. PLT at 437 is not a concern for most people with ET. The thing to know is that there is not a linear relationship between platelet levels over 400 and risk of thrombosis.

Macrocytosis is an expected side effect of HU. It is so common that doctors use it to monitor patient compliance with taking HU. It is not something to worry about.

Anemia is another well known side effect of HU. The thing to understand is that HU reduces all hematopoiesis (PLT, RBC, WBC). It is an antimetabolite (cytotoxin) that interferes with DNA activity in all hemopoietic stem cells and other DNA-active cells in the body. Here is a bit of information about HU that you may find helpful.

online.epocrates.com/drugs/...

drugs.com/monograph/hydroxy...

oralchemoedsheets.com/sheet...

It is important to consult with a MPN Specialist regarding your care. Most doctors, including hematologists, have little experience with MPNs. Optimal care is achieved through expert consultation. These two lists can help identify a MPN-expert doc.

mpnforum.com/list-hem./

pvreporter.com/mpn-speciali...

I would not sweat a fluctuation up to 437. I cycled between the 500s - 700s for the better part of 30 years. Most of the time I was diagnosed with ET but it progressed to PV about 8 years ago. To date, I have never had a single incident of thrombosis. I have had a tendency to hemorrhage (bleeding/bruising) when my PLT levels were higher. That is something to watch for. With MPNs/thrombocytosis we are at risk for thrombosis, hemorrhage and microvascular symptoms. ET is an odd condition is a variety of ways.

All the best.

[Anag]

Everyone PLT May change from 9am to 5pm. Depends on many factors. We keep my thrombocytes no more than 780. They can be as low as 345 a month ago and as high as 1100 just a year ago on the same amt of Anagrelide. Causes:stress, too much vitamin K, sleeplessness, with Covid (they dropped like cracy).