Polycythaemia Vera

Question 1

What is polycythaemia vera?

Answer 1

It is defined as a myeloproliferative disorder in which there is excess production of erythrocytes

Question 2

What is the pathophysiological consequence of polycythaemia vera?

Answer 2

It results in raised haemoglobin concentration, increased red cell volume and haematocrit

Question 3

What is the pathophysiological cause of polycythaemia vera?

Answer 3

JAK2 Mutation

Question 4

What two risk factors are associated with polycythaemia vera?

Answer 4

Older Age, 60 -70 Years Old

Budd-Chiari Syndrome

Question 5

What are the ten clinical features of polycythaemia vera?

Answer 5

Fatigue

Headaches

Ruddy Complexion

Erythromelalgia

Pruritis

Tinnitus

Abdominal Mass

Splenomegaly

Haemorrhage

Hypertension

Question 6

What is erythomelalgia?

Answer 6

It is defined as burning pain, warmth and redness in the hands and feet

Question 7

Describe the pruritus associated with polycythaemia vera

Answer 7

It tends to occur or worsen following hot showers/baths

Question 8

What four investigations are used to diagnose polycythaemia vera?

Answer 8

Blood Tests

Arterial Blood Gases (ABG)

Abdominal Ultrasound

Bone Marrow Biopsy

Question 9

What ten blood test results indicate polycythaemia vera?

Answer 9

Increased Haemoglobin Levels

Increased Haematocrit

Increased Red Cell Mass > 25%

Increased Platelet Levels

Increased Neutrophil Levels

Increased Basophil Levels

Decreased ESR Levels

Increased ALP Levels

Normal/Decreased Ferritin Levels

Positive JAK2 Analysis

Question 10

What haemoglobin level result indicated polycthaemia - in males/females?

Answer 10

Males = > 185g/L

Females = > 165g/L

Question 11

What haematocrit result indicates polycythaemia vera - in males/females?

Answer 11

Males = > 0.52

Females = > 0.48

Question 12

What is secondary polycythaemia?

Answer 12

It is defined as increased erythrocytes due to physiological response to chronic hypoxia, local renal hypoxia or excess erythropoietin production

Question 13

What investigation is used to differentiate between polycythaemia vera and secondary polycythaemia? Explain

Answer 13

Total red cell mass

In polycythaemia vera, the total red cell mass is > 35ml/kg in males and > 32ml/kg in females

Question 14

What two ABG features indicate polycythaemia vera?

Answer 14

Decreased Oxygen Levels

Increased Carboxyhaemoglobin Levels

Question 15

How are abdominal ultrasounds used to investigate polycythaemia vera?

Answer 15

They are used to identify splenomegaly and exclude secondary causes of polycythaemia, such as renal and hepatic pathology

Question 16

How are bone marrow biopsies used to investigate polycythaemia vera?

Answer 16

They are used to distinguish polycythaemia vera from secondary polycythaemia

Question 17

What are the five features of polycythaemia vera on bone marrow biopsies?

Answer 17

Hypercellularity

Erythropoiesis

Granulopoiesis

Megakaryopoiesis

Variable Megakaryote Size

Question 18

What are the two diagnostic criteria of JAK-2 positive polycythaemia vera?

Answer 18

Increased Haematocrit (0.52 males, 0.48 females) OR Increased Red Cell Mass

AND

JAK2 Mutation

Question 19

What are the nine diagnostic criteria of JAK-2 negative polycythaemia vera?

Answer 19

The individual must meet A1 - A4 plus two other criteria…

A1 = Increased Haematocrit (0.60 males, 0.56 females) OR Increased Red Cell Mass

A2 = Negative JAK2 Mutation

A3 = No Secondary Erythrocytosis Cause

A4 = Bone Marrow Histology Positive

A5 = Palpable Splenomegaly

A6 = Acquired Genetic Abnormality In Haematopoietic Cells

B1 = Thrombocytosis > 550 x 109/L

B2 = Neutrophil Leucocytosis > 10 x109/L Non-Smokers, > 12.5 x 109/L Smokers

B3 = Radiological Splenomegaly

Question 20

What is the conservative management option of polycythaemia vera?

Answer 20

It involves cardiovascular risk factor optimisation, due to the increased risk of arterial/venous thrombosis

Question 21

What is the pharmacological management option of polycythaemia vera?

Answer 21

Aspirin

Question 22

When is aspirin used to manage polycythaemia vera?

Answer 22

It is used to manage all polycythaemia vera patients

Question 23

How is aspirin used to manage polycythaemia vera?

Answer 23

In order to reduces the risk of thrombotic events

Question 24

When is venesection used to manage polycythaemia vera?

Answer 24

It is the first line management option of polycythaemia vera

Question 25

What is venesection?

Answer 25

It involves withdrawing around 200-500mls of blood at intervals suitable to the patient

Question 26

What is the aim of vensection in polcythaemia vera?

Answer 26

Haematocrit levels < 0.45

Question 27

When is cytoreductive therapy used to manage polycythaemia vera?

Answer 27

It is the second line management option of polycythaemia vera, which is indicated in those who meet the following criteria…

• Age > 60 Years Old
• Progressive Leucocytosis > 15
• Progressive Thrombocytosis > 1500
• Progressive Splenomegaly
• Poor Venesection Tolerance
• Thrombosis History

Question 28

How is cytoreductive therapy used to manage polycythaemia vera?

Answer 28

It is used to reduce the white cell and platelet count

Question 29

What is the first line cytoreductive therapy used to manage polycythaemia vera?

Answer 29

Hydroxycarbamide

Question 30

What is the second line cytoreductive therapy used to manage polycythaemia vera?

Answer 30

Interferon-alfa

Question 31

What is the first line cytoreductive therapy agent in women of childbearing age? Why?

Answer 31

Interferon-alfa

This is due to its lack of teratogenic effects, compared to hydroxycarbamide

Question 32

What are the six complications associated with polycythaemia vera?

Answer 32

Ischaemic Stroke

Myocardial Infarction

Pulmonary Embolism

Myelofibrosis

Acute Myeloid Leukaemia

Budd-Chiari Syndrome