Haem - myeloproliferative disorders Flashcards
Which population tends to be affected by myeloproliferative disorders
Elderly
Why do myelproliferative disorders precipitate attacks of gout
Rapid cell turnover –> increased purine metabolism –> raised uric acid levels –> precipitate attacks of gout
What is relative polycythemia
Decrease in plasma volume leads to raised haematocrit giving the impression of increased RBCs
What is primary polycythaemia vera(PV)
Due to mutation in erythrocyte receptor(JAK-2) leading to increased RBCs
There will be low EPO due to negative feedback
What is secondary abnormal PV due to
EPO secreting tumour(RCC, HCC, phaeo)
What is secondary compensatory PV due to
Response to hypoxia
- COPD
- OSA
- High altitude
- CO poisoning
- Right to left cardiac shunt
Which syndrome can PV lead to
Hyperviscosity syndrome
Features of hyper viscosity syndrome
Tortuous retinal veins –> visual disturbance
Headaches
Dizziness
Tinnitus
Bleeding
Clinical features of PV
Easy bruising and bleeding due to thrombocytosis(sucky platelets)
Erythromelalgia
Aquatic pruritus
Gout
Hepatosplenomegaly
What is aquatic pruritus
Itching after hot shower(histamine release)
What is erythromelalgia
Paroxysmal dilation of small arteries in the feet and hands –> swelling, erythema and burning pain
Microvascular thromboses(due to increased number of platelets)
IX for PV
Increased Hb
Increased Hct, RBC count, Plt
Bone marrow biopsy - generalised hypercellularity, absence of bone marrow iron
EPO levels low
ABG - to rule out hypoxia as cause
JAK2 mutation test
Complications of PV
Budd-chiari syndrome
MI
Stroke
Treatment of PV
Phelbotomy(to reduce rbc count) Myelosuppressant(hydroxyurea) Aspirin(erythromelalgia and thromboses) Antihistamine(for aquagenic pruritus) Allopurinol(to decrease uric acid)
Presentation of essential thrombocytosis
Bruising Bleeding Erythromelalgia Headache and visual disturbance Gout Hepato-splenomegaly(rare in ET)
Diagnosis of ET
FBC - Plt
Peripheral smear
Bone marrow biopsy –> megakaryocytic hypertrophy and hyperplasia
JAK-2 kinase mutation test
Causes of secondary thrombocytosis
Iron deficiency Infection Inflammation Splenectomy Trauma Surgery Ischaemia
Management of ET
Hydroxyurea(reduce PLT)
Anegralide, pegylated interferon(reduce PLT)
Aspirin(anti-platelet - treatment of erythromelalgia)
What is anegralide
PDE inhibitor which blocks maturation of megakaryocytes into platelets
What is primary myelofibrosis
Clonal malignancy where there is atypical megakaryocytes –> monoclonal proliferation of fibroblasts
Ix - Primary myelofibrosis
Early panmyelosis - nucleated RBCs, pro-myelocytes, myeloblasts
Increased uric acid, LDH and ALP
X-ray - osteosclerosis
Clinical findings in primary myelofibrosis
Tear drop cells Anaemia symptoms Infections if leukopenia Pancytopenia Gout
Bone marrow aspiration - Primary myelofibrosis
‘Inaspirable marrow’
Increased reticulin
Treatment of primary myelofibrosis
Splenectomy Steroids --> inhibit fibroblasts Allopurinol(for gout) Chemotherapy Allogenic bone marrow transplant
Complications of primary myelofibrosis
Pancytopenia
Malignant transformation –> AML
Causes of secondary myelofibrosis
P vera
ET
Causes of secondary myelofibrosis
P Vera
ET
Metastasis to the bone marrow from other tumours
Effect of steroids on neutrophil count
Cause neutrophilia
