Blood count management in ET

[neela2020]

I wanted to know in patients with ET , if they are on hydra , does it affect/suppress their red and white count as well? If the treatment is same for ET and PV , how the hydra targets on platelets and not red and white blood cell counts...I am so confused.

[Kari1961]

Hi neela2020 . I have Jak2+ PV and take Hydroxycarbamide/hydrea.

It lowers all blood counts. I was prescribed it due to high Haematocrit (HCT Levels).

It's one of the main reasons why you are monitored closely during the first few months of taking the medication. It's basically to see how you react to the medication and to adjust the dosage accordingly.

I began with taking 500mg x 7 days. Then a while later the dosage was changed to 500mg x 3 days, 1000mg x 4 days (my blood count plummeted on that dosage) So the dosage was changed again, and I now take 500mg x 4 days and 1000mg for 3 days and everything is within 'normal' range again. I now also see my haem every 3 months, whereas when I started taking hydroxy it was every 4 to 6 weeks.

Unfortunately, it's not just Hydroxycarbamide that does this. Before I was medicated, I was having venesections every 6 weeks or so and would suffer the same consequences. Taking the medication has actually helped me to feel a lot better. As my bloods are now all in 'normal' range.

[Arty16]

Hi. I have et calr. I was put on hydrox due to platelets at 1.2 million. But my red and white cells reduced when on it. The docs tried diff amounts of hydroxy but it still reduced red and white. Eventually I was taken off it as the levels were getting too low. After a break to allow levels to normalise I started anagralide. It has lowered my platelets and my red and white cells are fine. Everyone is diff make sure you have a good conversation with hymotoligist

[Solyesh]

Hi neela2020 - I have ET Jak2+ initially diagnosed via BMB last December although my platelets have been high since 2007. Was on aspirin only until March of this year when my platelets jumped form about 950 to 1.400. Started out on 500mg x day - that brought my platelets down to the mid 900's but specialist was not happy with that so dosage was increased to 1000mg x day - platelets dropped to mid 700's so increased again to 1000mg x 4 days a week and 1,500mg x day for 3 days - still stuck in mid 700's so increased again to 1,500 mg x day. Unfortunately, platelets stay stubbornly stuck in the mid 700's (now at 1,500 mg x day for past two months). During that time, my other RBC have also decreased (to below normal levels). They were always in normal ranges but now are all low (evidence that the HU is doing as much as it can). My WBC were persistently high (leukocytosis) and the HU also brought them down to normal ranges for the last few readings.

Unfortunately as the level of the Hydroxy has been ratcheted up, the side effects have increased as well (nail discoloraiton; rash (severe); fatigue; breathlessness during exercise (never had before). Given the increasing SEs and that the HU seems to be stalled at bringing down the platelets, we are changing from HU to pegylated interferon.

[hunter5582]

HU does not specifically target platelets. It decreases all hematopoiesis. HU works by inhibiting DNA activity and inhibiting the DNA self-repair function throughout the body, including hemopoietic stem cells. "Hydroxyurea selectively inhibits ribonucleoside diphosphate reductase, an enzyme required to convert ribonucleoside diphosphates into deoxyribonucleoside diphosphates, thereby preventing cells from leaving the G1/S phase of the cell cycle."en.wikipedia.org/wiki/Hydro....

HU is an effective agent at decreasing all blood cell production. It is non-selective in that it does not selectively target the mutated hemopoietic stem cells. The normal HSCs are also suppressed. PEGylated Interferon is the only agent that seems to more selectively target the mutated HSCs, but it is not understood why this happens.

Here is a bit of basic information on HU.

drugs.com/monograph/hydroxy...

online.epocrates.com/drugs/...

oralchemoedsheets.com/sheet...

Hope that answers your question.

[neela2020]

Thankyou everyone for sharing their own experiences, I was in a state as if it is unique to me.Yes, now I get that balancing all the three counts is key.