DDx erythrocytosis and polycythemia rubra vera

Question 1

Erthrocytosis

Answer 1

Increased RBCs - increased Ht and Hb

Or decreased volume of plasma = relative polycythemia

Question 2

Hb value

Answer 2

Men: 130 - 180 g/L
Women: 115 - 160 g/L

Question 3

Types of polycythemia

Answer 3

Relative: plasma volume decrease due to dehydration, burns

Absolute:
Primary - Polycythemia vera: decreased EPO in PCV due to negative feedback suppressing renal EPO production

Secondary - Appropriate absolute: lung disease, congenital hear disease, high altitude - increased EPO - hypoxemia

Inappropriate absolute: increased RBC mass and EPO - malignancy (RCC, hepatocellular carcinoma)

Question 4

Polycythemia vera cause

Answer 4

Malignant clonal proliferation of hematopoietic stem cells leading to excessive erythrocyte production - EPO independent!
JAK2 positive

Question 5

PCV symptoms

Answer 5

Hyperviscosity
- headache, dizziness, weakness, pruritus, visual impairment, dyspnea

Thrombosis
- DVT, MI, Portal vein thrombosis

Hepatosplenomegaly

Question 6

Diagnosis

Answer 6

Rule out other 2nd causes 
CBC - increased RBC count, Hb, Hematocrit > 50
Thrombocytosis, leukocytosis 
Decreased serum EPO 
BM biopsy - confirmation

Question 7

Treatment

Answer 7

Phlebotomy - major treatment for RBC overload
Hematocrit < 0.45
Aspirin - prevent arterial thrombosis
Hydroxyurea - 1st line treatment of myeloproliferative neoplasm
INFalpha is useful