Polycythaemia Vera Flashcards
Part of Myeoproliferative Neoplasms
What are myeloproliferative disorders?
Uncontrolled proliferation of a single type of stem cell in the bone marrow.
They are a form of cancer that progresses slowly and may transform into acute myeloid leukaemia
Name the key myeloproliferative disorders
- Primary myelofibrosis
- Polycythaemia vera
- Essential thrombocythaemia
Which cell line proliferates in polycythaemia vera?
Erythroid cells
What is the key blood finding in polycythaemia vera?
High haemoglobin
What is polycythaemia vera (PV)?
Clonal haematological malignancy with pronounced symptoms with an increased risk of thrombosis, and potential progression to myelofibrosis or secondary acute myeloid leukaemia
What is the median age of diagnosis for PV?
Around 65 years, though it can also affect younger individuals
What genetic mutation is present in over 95% of PV patients?
The JAK2 kinase mutation
How does the JAK2 mutation contribute to PV?
It leads to loss of autoinhibition, activating erythropoiesis in the absence of erythropoietin, causing an increased red cell mass
What are key clinical features of PV?
1 - Asymptomatic discovery on routine blood tests
2- Gout, fatigue, weight loss, and night sweats
3- Splenomegaly
4- Thrombosis
5 -Headaches, fatigue, and aquagenic pruritus (itching after hot water exposure).
How is PV diagnosed?
1 - Key findings
= High haemoglobin, high haematocrit, erythrocytosis (genuine red cell mass increase)
2 - JAK2 mutation status
= Present in most cases
3 - Additional tests
= Erythropoietin levels and bone marrow biopsy if JAK2 is negative.
What investigations are needed to rule out secondary causes?
(1) CXR
(2) O2 saturation/ABGs
(3) Drug history
(4) Check for secondary polycythaemia
What is the first-line treatment for PV?
(1) Venesection
= To reduce haematocrit to <0.45
(2) Aspirin
= To prevent thrombosis
(3) Cytotoxic chemotherapy
= For further management if needed.
Pathophysiology of polycythaemia vera
Raised red cell mass
Low serum erythropoietin
JAK2 mutation present
A 75-year-old male presents to his GP with headaches and dizziness. They have a red complexion and initial blood tests reveal a raised haemoglobin, haematocrit and platelet count.
Given the likely diagnosis, what treatment option would suppress erythropoiesis?
Hydroxycarbamide
A 50-year-old Caucasian male presents to his GP with headaches and dizziness. He has noted redness pain and swelling of his hands and legs. His wife complains that he is always itching after taking a bath.
On examination, he shows a facial plethora and a mass in the left upper quadrant. Given the likely diagnosis, what is the best diagnostic test?
JAK2 mutation screen
Hydroxycarbamide would be a therapy to consider here and would be the drug of choice if the patient was what?
(1) high risk of thrombosis
(2) or had marked thrombocytosis (platelets >1500).
A 52-year-old male was referred to the haematology clinic after his GP found his haemoglobin to be 182g/L on a routine blood test. He was diagnosed with polycythaemia rubra vera (PRV).
What known complications of this condition?
(1) Thrombosis
(2) Gout
(3) Splenomegaly
(4) Marrow failure
(5) Aquagenic pruritu - itch after hot water
(6) Fatigue and weight loss
(7) Headache and dizziness
What is the most appropriate management for those with polycythaemia?
Aspirin 75mg and Venesection
Is ESR raised in polycthaemia vera?
nope
When is hydroxycarbamide (hydroxyurea) used as first-line treatment in polycythemia vera?
(1) In high-risk patients
= history of thrombosis, over 60 years
(2) Those with intolerable symptoms
= pruritus, splenomegaly
(3) When phlebotomy(vansection) /aspirin alone is insufficient
What is the appropriate management for polycythemia in order?
- Phlebotomy
- Aspirin
- Hydroxycarbamide (hydroxyurea)
- JAK2 inhibitors
thrombocytosis means looking at what
Platelets (ensure its not >1500)
A 65-year-old woman presents to the emergency department with sudden onset left leg pain, redness and swelling. She has recently arrived in the country after a long-haul flight from Australia. She denies any history of trauma, and cannot recall any family history of similar symptoms.
Given the most likely diagnosis, which underlying risk factor may predispose her to this condition?
Polycythaemia increases the risk of venous thromboembolism
A 28-year-old male presents to the GP with fatigue. The GP arranges for a blood test to exclude anaemia as a cause. Where in the body are red blood cells normally broken down?
Spleen
