5.2 Haempoeis Gone Wrong Flashcards
What clinical features present with myoloproliferative disorders that effect RBC count?
Hypercellular marrow/marrow fibrosis
Cytogenic abnormalities
Extramedullary haemopoiesis (liver/spleen)
What is polycythemic Vera?
Too many red cells, a myeloproliferative disorder
- diagnostic criteria = high haemocrit or raised red cell mass
- JAK2 mutation is present in most patient
- median age = 60
- some patients also have high platelets and neutrophils
What are the clinical features of polycythamic Vera?
- arterial thrombosis - more blood cells = more sticky blood
- venous thrombosis
- haemorrhage into skin or GI tract
- pruritis = itchy when wet
- splenomegaly
- gout
How is PCV managed?
- venesection to maintain haematocrit
- aspirin 75mg
- manage CV risk factors
What is polycythemia?
Increase in circulating red cell conc typified by a persistently raised haemocrit
Can be
- relative = normal red cells, decreased plasma volume
- absolute = increased red cell mass
Absolute can be
1) primary = polycythemia Vera
2) secondary = driven by erythropoietin EPO production (appropriate in tissues where there’s hypoxia)
How can central and renal hypoxia all make erythropoietin in absolute secondary polycythaemia?
Central
E.g training at altitude/ CO poisoning/ COPD = less o2 delivered to tissues = more erythropoietin made
Renal
E.g renal artery stenosis = less o2 = more erythropoietin made
Why do athletes dope?
Stimulates erythropoietin production
What would you look for when diagnosing thrombocythaemia?
Mutation in JAK2 and CALR
Large and excess megakaryocytes in bone marrow
Thrombotic events
Excess platelets in the blood
How is essential thrombocythaemia managed?
- any cardiovascular risk factor should be aggressively managed
- aspirin
- return platelet count to normal with a drug like hydroxycarbomide
What is myelofibrosis?
Haemopoetic stem cell proliferation which then progresses to pancytopenia due to bone marrow fibrosis and hypersplenism (leading to splenomegaly)
More fibre than empty space in bone, starts to ossify. Red cells are tear drop shaped due to squeezing through hardening tissue.
Get heptomegaly also
What are the clinical features of myelofibrosis?
- fatigue, sweats
- splenomegaly leads to pain, early satiety
- progressive marrow failure needing transfusions
- transformation to leukaemia
What’s chronic myeloid leukaemia?
- usually present with a v high wcc
- splenomegaly, hyperviscosity or bone pain
- disease of adults
- may be breathless and blood vessels of lungs clogged up
What’s pancytopenia?
Reduction in white cells, red cells and platelets. Caused by: - B12/folate deficiency - Bone marrow infiltration by malignancy - marrow fibrosis - radiation - drugs -viruses
What is aplastic anaemia?
Pancytopenia with a hypo-cellular bone marrow in the absence of any abnormal infiltrate and with no increase in fibrosis
How can you get thrombocytopenia ?
1) increased platelet destruction
- drug induced e.g pear in
- hypersplenism resulting in increased destruction and splenic pooling of platelets
2) increased platelet consumption
- e.g massive haemorrhage
- disseminated intravascular coagulation
3) decreased platelet production
- B12 or folate deficiency
- acute/aplastic anaemia
- liver failure
- sepsis
- cytotoxic chemotherapy
