1. Polycythemia Vera Bleeding Disorders
Dr. Meg-angela Christi Amores

2. Polycythemia Vera
phenotypically normal red cells, granulocytes, and platelets accumulate in the absence of a recognizable physiologic stimulus
2 per 100,000 persons, sparing no adult age group and increasing with age

3. Etiology Unknown Genetic mutation
loss of heterozygosity on chromosome 9p, due to uniparental disomy
leads to homozygosity for the mutant JAK2 V617F
JAK2 V617F is the basis for many of the phenotypic and biochemical characteristics of PV

4. Clinical features Spenomegaly – initial presenting sign
first recognized by the incidental discovery of a high hemoglobin or hematocrit
Uncontrolled erythrocytosis causes hyperviscosity :
vertigo, tinnitus, headache, visual disturbances, and transient ischemic attacks
Systolic hypertension
venous or arterial thrombosis

5. Clinical features Signs of vascular stasis: Thrombocytosis:
Digital ischemia, easy bruising, epistaxis, acid-peptic disease, or gastrointestinal hemorrhage
Thrombocytosis:
Erythema, burning, and pain in the extremities, a symptom complex known as erythromelalgia
hyperuricemia with secondary gout, uric acid stones, and symptoms due to hypermetabolism can also complicate the disorder

6. Diagnosis
erythrocytosis in combination with leukocytosis, thrombocytosis, or both
elevated hemoglobin or hematocrit alone, or with thrombocytosis alone, the diagnostic evaluation is more complex
Hemoglobin > 20 , hematocrit > 60%
red cell mass and plasma volume determinations

8. Diagnosis
To differentiate from hypoxia: O2 saturation

9. Treatment
Thrombosis due to erythrocytosis is the most significant complication
maintenance of the hemoglobin level at 140 g/L (14 g/dL; hematocrit <45%) in men and 120 g/L (12 g/dL; hematocrit <42%) in women is mandatory to avoid thrombotic complications

10. Treatment
Phlebotomy
initially to reduce hyperviscosity by bringing the red cell mass into the normal range
Periodic phlebotomies thereafter serve to maintain the red cell mass within the normal range and to induce a state of iron deficiency
once an iron-deficient state is achieved, phlebotomy is usually only required at 3-month intervals

11. Treatment
Anticoagulants are only indicated when a thrombosis has occurred
For pruritus:
hydroxyurea, interferon (IFN-), and psoralens with ultraviolet light in the A range (PUVA) therapy are other methods of palliation
Chemotherapy:
Hydroxyurea
never indicated to control the red cell mass unless venous access is inadequate

12. BLEEDING
Bleeding disorders