Myeloproliferative disorders - Polycythaemia vera

Question 1

What can cause increased erythropoiesis?

Answer 1

Physiological reaction

Myeloproliferative disorders

Question 2

What are myeloproliferative disorders known as?

Answer 2

Myeloproliferative neoplasms

Question 3

What are the different types of myeloproliferative neoplasms?

Answer 3

Essential thrombocytosis

Polycythaemia vera

Myelofibrosis

Question 4

What are the genetic defects in myeloproliferative neoplasms? What are the consequences?

Answer 4

Point mutation in Janus kinase 2 gene

Produces tyrosine kinase
that gives increased proliferation and survival of haematopoietic precursors

Question 5

How do the genetic defects of myeloproliferative neoplasms affect treatment?

Answer 5

Give drugs targetting the abnormal protein

Question 6

How is haematopoiesis affected in myeloproliferative neoplasms?

Answer 6

Overproduction of a certain cell, or few cells

cells are abnormal

Question 7

How is the bone marrow affected in myeloproliferative neoplasms?

Answer 7

Hypercellular bone marrow

Marrow fibrosis

Question 8

How are organs affected in myeloproliferative neoplasms?

Answer 8

Extramedullary haematopoisis in liver, spleen

Question 9

What can myeloproliferative neoplasms develop into?

Answer 9

Acute leukaemia

Question 10

How is polycythaemia vera diagnosed?

Answer 10

High haematocrit
or
Raised red cell mass

Question 11

Is polycythaemia vera more common in younger or older people?

Answer 11

Older people

Question 12

Is polycythaemia vera more common in males or females?

Answer 12

Neither!

equally common in both

Question 13

What is erythrocytosis?

Answer 13

Increase in conc. of red blood cells

Question 14

What are the types of erythrocytosis?

Answer 14

Relative

Absolute

Question 15

What is relative erythrocytosis?

Answer 15

Normal red cell mass, but decrease in plasma volume gives increase in red blood cell conc.

Question 16

What is absolute erythrocytosis?

Answer 16

Increase in red cell mass gives increase in conc. of red blood cells

Question 17

What are the types of absolute erythrocytosis?

Answer 17

Primary

Secondary

Question 18

What is primary absolute erythrocytosis?

Answer 18

Polycythaemia vera

Question 19

What is secondary absolute erythrocytosis?

Answer 19

Increased erythropoietin production gives increased red blood cell mass

Question 20

What are the types of causes of increased erythropoietin production?

Answer 20

Physiological

Pathological

Question 21

What are some examples of physiological causes of increased erythropoietin production?

Answer 21

Hypoxia

• right to left shunts
• chronic lung disease
• renal artery stenosis
• high altitude

Question 22

What are some examples of pathological causes of increased erythropoietin production?

Answer 22

Cancers

Question 23

What are the signs and symptoms of polycythaemia vera?

Answer 23

Arterial thrombosis
Venous thrombosis

Splenomegaly

Haemorrhage into skin, GI tract

Gout

Pruritis

Question 24

What can polycythaemia vera develop into?

Answer 24

Acute leukaemia

Question 25

How is polycythaemia vera managed?

Answer 25

Venesection to reduce haematocrit Aspirin to reduce risk of blood clotting Maybe use drugs to reduce overproduction of red blood cells

Question 26

When are drugs used to treat polycythaemia?

Answer 26

Poor tolerance to venesection Worsening symptoms e.g. progressive splenomegaly