Polycythemia Vera Bleeding Disorders Dr. Meg-angela Christi Amores

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

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

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

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

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

Diagnosis To differentiate from hypoxia: O2 saturation

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

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

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

BLEEDING Bleeding disorders