I’ve been on HU for 7 months after being diagnosed with essential thrombocytopenia. Platelet count approached 1000 after open heart surgery. Docs thought it might be a “reactive” response to the surgery. Follow-up tests revealed JAK-2 mutation. Never had a blood (platelet) value issue prior to surgery.
My feeling is I acquired JAK-2 through blood transfusions received during bypass surgery. My hematologist doesn’t think so but didn’t say it was not possible. Anyhow, no side effects from HU except for late day fatigue.