Polycythaemia Vera Flashcards
What is polycythaemia vera?
It is defined as a myeloproliferative disorder in which there is excess production of erythrocytes
What is the pathophysiological consequence of polycythaemia vera?
It results in raised haemoglobin concentration, increased red cell volume and haematocrit
What is the pathophysiological cause of polycythaemia vera?
JAK2 Mutation
What two risk factors are associated with polycythaemia vera?
Older Age, 60 -70 Years Old
Budd-Chiari Syndrome
What are the ten clinical features of polycythaemia vera?
Fatigue
Headaches
Ruddy Complexion
Erythromelalgia
Pruritis
Tinnitus
Abdominal Mass
Splenomegaly
Haemorrhage
Hypertension
What is erythomelalgia?
It is defined as burning pain, warmth and redness in the hands and feet
Describe the pruritus associated with polycythaemia vera
It tends to occur or worsen following hot showers/baths
What four investigations are used to diagnose polycythaemia vera?
Blood Tests
Arterial Blood Gases (ABG)
Abdominal Ultrasound
Bone Marrow Biopsy
What ten blood test results indicate polycythaemia vera?
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
What haemoglobin level result indicated polycthaemia - in males/females?
Males = > 185g/L
Females = > 165g/L
What haematocrit result indicates polycythaemia vera - in males/females?
Males = > 0.52
Females = > 0.48
What is secondary polycythaemia?
It is defined as increased erythrocytes due to physiological response to chronic hypoxia, local renal hypoxia or excess erythropoietin production
What investigation is used to differentiate between polycythaemia vera and secondary polycythaemia? Explain
Total red cell mass
In polycythaemia vera, the total red cell mass is > 35ml/kg in males and > 32ml/kg in females
What two ABG features indicate polycythaemia vera?
Decreased Oxygen Levels
Increased Carboxyhaemoglobin Levels
How are abdominal ultrasounds used to investigate polycythaemia vera?
They are used to identify splenomegaly and exclude secondary causes of polycythaemia, such as renal and hepatic pathology
How are bone marrow biopsies used to investigate polycythaemia vera?
They are used to distinguish polycythaemia vera from secondary polycythaemia
What are the five features of polycythaemia vera on bone marrow biopsies?
Hypercellularity
Erythropoiesis
Granulopoiesis
Megakaryopoiesis
Variable Megakaryote Size
What are the two diagnostic criteria of JAK-2 positive polycythaemia vera?
Increased Haematocrit (0.52 males, 0.48 females) OR Increased Red Cell Mass
AND
JAK2 Mutation
What are the nine diagnostic criteria of JAK-2 negative polycythaemia vera?
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
What is the conservative management option of polycythaemia vera?
It involves cardiovascular risk factor optimisation, due to the increased risk of arterial/venous thrombosis
What is the pharmacological management option of polycythaemia vera?
Aspirin
When is aspirin used to manage polycythaemia vera?
It is used to manage all polycythaemia vera patients
How is aspirin used to manage polycythaemia vera?
In order to reduces the risk of thrombotic events
When is venesection used to manage polycythaemia vera?
It is the first line management option of polycythaemia vera
What is venesection?
It involves withdrawing around 200-500mls of blood at intervals suitable to the patient
What is the aim of vensection in polcythaemia vera?
Haematocrit levels < 0.45
When is cytoreductive therapy used to manage polycythaemia vera?
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
How is cytoreductive therapy used to manage polycythaemia vera?
It is used to reduce the white cell and platelet count
What is the first line cytoreductive therapy used to manage polycythaemia vera?
Hydroxycarbamide
What is the second line cytoreductive therapy used to manage polycythaemia vera?
Interferon-alfa
What is the first line cytoreductive therapy agent in women of childbearing age? Why?
Interferon-alfa
This is due to its lack of teratogenic effects, compared to hydroxycarbamide
What are the six complications associated with polycythaemia vera?
Ischaemic Stroke
Myocardial Infarction
Pulmonary Embolism
Myelofibrosis
Acute Myeloid Leukaemia
Budd-Chiari Syndrome
