How much of a risk factor is high white blood cell count with pv?

Welcome to Connect, @eferret. Polycythemia vera is from a group of blood conditions called myeloproliferative neoplasms. Most people with polycythemia vera have too many red blood cells. But it can also cause you to have too many white blood cells and platelets (ET). PV is frequently caused by a gene such as JAK2 that doesn’t work the way it should. Hydroxyurea is a medication used with Myeloproliferative disorders to help keep blood cell production levels at a normal level. So it’s not limited to just red blood cells as it can also lower white cells and platelets.

Doctors use statistics and trends to help make the determination about how well a medication is working or how a disease is potentially progressing. You’ve only been on HU for 6 weeks and that’s not very long in the world of medicine to make a fair assessment of your condition and its response to the meds. Your doctor will continue to monitor your lab results down to see if any changes in meds need to be made.

Do you know if you have a mutation with the JAK2 gene that caused your PV?

I was diagnosed with PV about 4 years ago and my white blood count has been in the 20,000’s since that time. I’ve also been on hydroxyurea since then and my doctor does seem concerned about the high readings .I really don’t have any symptoms but with all the excess blood cells that the condition generates, my spleen is now about 50% larger than normal.

( doctor does NOT seem concerned)

I found a website that discusses the implications of high white blood cell count.
myhematology,com

Complications of Leukocytosis
Leukocytosis itself isn’t necessarily a disease, but rather an indicator of an underlying condition. However, depending on the severity and type of leukocytosis, there can be potential complications.

Vascular Occlusion
• Hyperleukocytosis: Extremely high WBC counts (>100 x 109/L) can lead to a condition called hyperleukocytosis.
• Increased Blood Viscosity: In hyperleukocytosis, the massive number of WBCs can thicken the blood, increasing its viscosity. This can impair blood flow and potentially lead to:
o Ischemic Organ Damage: Reduced blood flow to organs like the brain, lungs, kidneys, or heart can cause tissue damage and organ dysfunction.
o Stroke: If blood flow to the brain is compromised, a stroke can occur.
o Pulmonary Edema (Fluid in the Lungs): In severe cases, impaired blood flow to the lungs can lead to fluid buildup.

Disseminated Intravascular Coagulopathy (DIC)
• This is a serious condition where abnormal blood clotting occurs throughout the bloodstream.
• Certain types of leukocytosis, particularly those associated with some cancers, can increase the risk of DIC.
• DIC can lead to:
o Bleeding complications
o Blockage of blood vessels by clots

Tumor Lysis Syndrome (TLS)
• In certain cancers, particularly leukemias, aggressive treatment can lead to the rapid death of a large number of cancer cells.
• The breakdown products can overwhelm the body’s ability to handle them, leading to:
o Electrolyte imbalances (e.g., high potassium, low calcium)
o Kidney failure
o Heart rhythm disturbances

Increased Risk of Infection (Paradoxical)
• While leukocytosis indicates the body’s attempt to fight infection, very high WBC counts can sometimes impair the function of certain white blood cells, making the body paradoxically more susceptible to opportunistic infections.

Organ Infiltration
• In some cases of leukemias, the abnormal white blood cells can infiltrate organs like the liver, spleen, and lymph nodes, causing:
o Enlargement of these organs
o Disruption of their normal function

PV allele burden (VAF) from quantitative test
I have had 2 JAK2 tests, one qualitative, that helped confirm I have PV, and a quantitative test that my PV ratio, called the allele burden, is 91%. Is there a different prognosis for people with a high percentage compared with a low percentage, and does it change the preferred treatment options?