myeloproliferative disorders Flashcards
what are myeloproliferative disorders
clonal proliferation of bone marrow stem cells excess production >1 haemopoietic lineage
what mutation is present in nearly all cases of PRV, 50% ET or primary myelofibrosis
mutation in JAK2
what is polycythaemia
increase in Hb above normal
what is true polycythaemia
red cell mass increased.
what is pseudo/relative polycythaemia
elevated Hb concentration due to reduction in plasma volume
causes true polycythaemia primary
primary- PRV. congenital- Hb variant with increased O2 affinity.
causes true polycythaemia secondary
high altitude, cyanotic congenital heart disease, chronic lung disease, renal disease,
causes relative polycythaemia
stress polycythaemia, dehydration, diuretics
what is thrombocytosis
elevation platelets
primary causes thrombocytosis
essential thrombocythaemia, part of another MPV- PRV, CML
reactive causes thrombocytosis
iron def, haemorrhage, severe haemolysis, trauma, infection, inflam, malignancy
what happens in polycythaemia rubra vera
bone marrow erythropoiesis increases, incr thrombopoiesis, incr granulopoiesis
what are the levels of erythropoietin in PRV
low
how present is JAK2 mutation in PRV
> 95%
features PRV
> 55yrs M=F. ruddy complexion- plethora, conjunctival suffsion, hyperviscosity- headaches and visual disturbances, thrombosis, pruritis, haemorrhage, enlarged spleen, gout
lab findings PRV
incr Hb, Hct and RCC. 75% incr WCC and platelets. uric acid raised, LDH raised, EPO low
bone marrow appearance PRV
hypercellular with prominent megakaryocytes
is JAK2 present in all types JAK2
no only PRV
treatment PRV
aspirin, multiple venesections, chemo- hydroxycarbamide. allopurinol
prognosis PRV
median survival- 16 years. 30%- myelofibrosis, 5%- AML
what is pseudo polycythaemia
in young male adults, especially smokers.
test for congenital polycythaemia
Hb O2 dissociation curve to look for Hb variant with increased oxygen binding affinity
what is essential thrombocythaemia
persistent elevation peripheral blood platelet count due to increased marrow production
what % patients have jak2 mutation in ET
50%
features ET
thrombosis, headaches, visual disturbance, excessive haemorrhage, splenomegaly 30%
lab findings ET
platelet count persistently raised, often >1000, uric acid raised
blood film ET
platelet anisocytosis (RBCs are different sizes) with circulating megakaryocytes
treatment ET in patient
aspirin alone
treatment ET
chemo- hydroxycarbamide, interferon, aspirin
prognosis ET
median survival >20 years. thrombosis and haemorrhage main causes morbiditiy/mortality. 1-5% to AML, higher to myelofibrosis
what is primary myelofibrosis
excessive scar tissue forms in bone marrow
what is primary myelofibrosis characterised by
haemopoiesis in the spleen and liver- hepatosplenomegaly
presentation myelofibrosis
hypermetabolic symptoms, night sweats, weight loss, fever, abdominal discomfort, Hb decr, infections, bleeding
what is the blood film myelofibrosis
tear drop RBCs
treatment myelofibrosis
marrow support- red cell transfusion, platelets, neutrophils. allogeniec stem cell transplant. chemo. thalidomide. splenectomy
prognosis myelofibrosis
4-5 years, 20% to AML
