Polycythemia Vera and Secondary Polycythemia Flashcards
What is erythrocytosis?
Red blood cell count above normal range
Define true/absolute erythrocytosis polycythemia.
Increase in red cells, which causes increased haematocrit and Hb concentration
What is apparent polycythemia?
Red cell numbers are normal but are more concentrated due to less plasma
True or False: Apparent polycythemia results in increased haematocrit and Hb concentration.
True
What characterizes polycythemia vera?
Rare myeloproliferative cancer originating in bone marrow due to JAK2 mutation
At what age is polycythemia vera typically diagnosed?
After 60 years old
Who is more likely to develop polycythemia vera?
More common in men than women
Individuals with Jewish ancestry
History of Budd-Chiari syndrome
What is secondary polycythemia?
Overproduction of erythrocytes due to chronic hypoxia triggering increased EPO synthesis
Can secondary polycythemia occur at any age?
Yes
What is the primary cause of polycythemia vera?
JAK2 point mutation causing neoplastic proliferation of hematopoietic progenitor cells
List some risk factors for secondary polycythemia.
- Generalised hypoxia due to smoking, lung/cardiac disease, CO poisoning, high altitudes
- Renal hypoxia due to CKD
- Increased EPO production due to tumours
- Doping/medication with anabolic steroids, EPO, testosterone, diuretics
- Genetic mutations that upregulate EPO or code for hemoglobin variant with higher oxygen affinity
What triggers increased EPO synthesis in chronic hypoxia?
Commonly due to conditions like chronic lung disease or living at high altitudes
What is physiological polycythemia?
Form of secondary polycythemia caused by living at high altitudes
Fill in the blank: Polycythemia vera is characterized by the overproduction of _______.
[erythrocytes]
What are the clinical features of Polycythemia Vera?
Facial plethora, splenomegaly, gouty tophi, pruritus after warm water contact, fatigue, dizziness, neurological symptoms, GI symptoms.
Examples include swelling and puffiness with red/brown discoloration, early satiety, and discomfort.
What are the complications associated with Polycythemia Vera?
Increased risk of thrombosis, major hemorrhage, progression to myelofibrosis or AML.
Thrombosis can lead to cardiovascular events such as stroke or heart attack.
Which 4 investigations are used for Polycythemia Vera?
Bone marrow biopsy, FBC, JAK2 mutation test, serum EPO level.
Bone marrow biopsy shows hyperplasia of erythroid, granulocytic, and megakaryocytic lineages.
What findings are expected in FBC for Polycythemia Vera?
Erythrocytosis, leukocytosis, thrombocytosis, high hematocrit.
What are the clinical features of Secondary Polycythemia?
Abdominal mass, hypertension, cyanosis, nail clubbing, fatigue, dizziness, neurological symptoms, GI symptoms.
Abdominal mass could indicate EPO-secreting tumors.
What investigations are used for Secondary Polycythemia?
FBC, LFTs, U&Es, serum EPO level, ECGs, chest X-ray.
FBC shows erythrocytosis and high hematocrit; serum EPO level is increased.
What is a common laboratory finding in Secondary Polycythemia?
Increased serum EPO level and elevated serum uric acid.
What is the first-line treatment for Polycythemia Vera?
Hydroxycarbamide/hydroxyurea or interferons (chemotherapy) and aspirin
What is the second-line treatment for Polycythemia Vera?
The alternate first-line drug and aspirin, e.g., interferon is better for younger patients and pregnant women
What are the third-line treatments for Polycythemia Vera?
Anagrelide (inhibits megakaryocyte maturation but increases risk of thrombotic and bleeding events) or ruxolitinib (JAK2 inhibitor)
What additional procedure can be added to the treatment of Polycythemia Vera?
Venesection/phlebotomy (removing ~0.5 litres blood from a vein in the arm)
How should secondary polycythemia be managed?
Treat the underlying cause
