Chronic Myeloproliferative disorders Flashcards
What are chronic myeloproliferative disorders?
Clonal stem cell disorders of the bone marrow
Are chronic myeloproliferative disorders malignant?
Yes, although there is much debate surrounding this
In what percentage of patients do CMDs transform into acute leukaemia?
around 10%
Name 3 CMDs?
1) Polycythaemia vera
2) Essential thrombocytosis
3) Idiopathic myelofibrosis
According to the environment and hormones they are exposed to bone marrow stem cells can differentiate into 1 of what 3 kinds of cells in the bone marrow?
1) Granulocytes
2) Erythrocytes
3) Megakaryocytes
Which organ is involved in removing old red blood cells?
Spleen
What are reticulocytes?
Immature red blood cells
Are reticulocytes normally present in the blood?
No - indicates some pathology
ie. if there is a bleed somewhere the bone marrow expels all the RBCs it has
this includes these immature RBCs
What is polycythaemia vera?
Increased red cells +/- neutrophils, +/- platelets
NB. it should be distinguished from secondary polycythaemia and secondary polycythaemia
What is essential thrombocytopenia?
Body produces too many platelets
NB. it should be distinguished from reactive thrombocytosis
What is myelofibrosis?
Variable cytopenias with a large spleen
Should be distinguished from other causes of splenomegaly
Define cytopenia?
Reduction in the number of blood cells
In what condition will a lay down of fibrosis be seen in the bone marrow?
Myelofibrosis - all 3 conditions are related and can turn into one and other, myelofibrosis is often an end stage where you get a reduction in the number of cells
In what age group does the incidence of polycythaemia vera peak?
50-70
What are the 8 symptoms of polycythaemia vera?
Insidious onset
1) Itching (aquagenic - happens in hot baths)
2) Plethoric face (characterised by an abundance of blood - red)
3) Headache
4) General malaise
5) Tinnitus
6) Peptic ulcer
7) Gout
8) Gangrene
What are the 3 signs of polycythaemia vera?
1) Plethora
2) Engorged retinal veins
3) Splenomegaly
What is haematocrit - what is a normal value for it?
The ratio of the volume of RBCs to the total volume of blood - normally less than 50%
What is the other name for polycythaemia vera?
Primary polycythaemia
What is relative polycythaemia?
Not enough plasma leads to an increase in haematocrit without an actual increase in the volume of RBCs- eg. seen in very dehydrated people
How is a diagnosis of polycythaemia made?
Persistent increased Hb/hct >0.5
Haematocrit over 50%
After a detailed history and examination what are the 4 first line tests in polycythaemia to distinguish primary from secondary?
1) FBC
2) Ferritin
3) Epo level
4) UE/LFT (used to evaluate kidney and liver function)
What is secondary polycythaemia?
Something is causing the polycythaemia rather than a problem in the bone marrow - ie. being at altitude or reduced oxygen level in COPD
Why can renal disease cause secondary polycythaemia?
Kidneys may produce too much Epo
Epo is:
a hormone that your kidney makes to trigger your bone marrow to make red blood cells.
A normal EPO level means that your body can make healthy red blood cells.
What are the 5 possible central hypoxic processes which can lead to secondary polycythaemia?
1) Chronic lung disease
2) Right to left shunts heart disease
3) Carbon monoxide poisoning
4) Smoker
5) Altitude
What are the 6 causes of secondary polycythaemia?
1) Central hypoxic process
2) Renal disease
3) EPO producing tumours
4) Drug associated
5) Congenital
6) Idiopathic eryhtrocytosis
What 2 drug treatments can lead to secondary polycythaemia?
1) Treatment with androgen preparations
2) Postrenal transplant erythrocytosis