Haematology seminar 1 Flashcards
What are some examination findings of anaemia?
Pallor
Jaundice
Splenomegaly
Lymphadenopathy
Koilonychia
What is microcytic hypochromic anaemia?
When the red blood cells are small and pale in colour
Caused by iron deficiency and it’s a thalassaemia trait
How can anaemia arise?
Problems of synthesis
Over-consumption
Bleeding
What is thalassaemia?
When the body doesn’t make enough haemoglobin
What causes normocytic anaemia?
Its anaemia of chronic disease caused by bone marrow failure or bleeding
What causes macrocytic anaemia?
B12/folate deficiency
Myelodysplasia Haemolysis (reticulocytosis)
-Pregnancy
-Hypothyroidism
-Alcoholism
What is macrocytic anaemia?
The red blood cells are larger than normal
What is included in the haemolysis screen?
- Reticulocytes
- Direct anti-globulin test (DAT = Coomb’s test)
- Bilirubin
- LDH
- Blood film
Eg. Spherocytes, Sickle cells, RBC fragments
What are reticulocytes?
Immature red blood cells
What is Haemoglobinopathy?
Inherited disorders of globin, the protein component of haemoglobin
What are the different problems of synthesis causing anaemia?
Haematinic deficiency
- Iron deficiency (low ferritin)
- B12 (pernicious anaemia, gastrectomy or Crohn’s)
- Folate deficiency (diet, pregnancy or malabsorption e.g. coeliac)
Bone marrow failure
- Serum protein electrophoresis (myeloma?)
- Pancytopenia (bone marrow biopsy needed)
- Blasts (leukaemia)
- High MCV (myelodysplasia)
Renal failure
- Raised creatinine
- Low Epo levels
What is the treatment for iron deficiency?
Iron sulphate tablets 200mg TDS for 3 months
How is folate deficiency treated?
5mg oral OD for 3 months plus dietary advice
How is B12 deficiency treated?
Hydroxycobalamin 1mg IM injections for 5 alternating days then every 3 months
What is Hydroxycobalamin used for?
It’s a form of injectable B12
How does Erythropoeitin work?
It’s naturally produced by the peritubular cells of the kidney
It stimulates red blood cell production
What is hereditary spherocytosis?
Instead of being shaped like a disk, the cells are round like a sphere
These red blood cells (called spherocytes) are more fragile than disk-shaped RBCs
How does G6PD cause haemolytic disease?
Without Glucose-6-phosphate dehydrogenase to protect the RBC’s, they break apart
What is autoimmune haemolysis?
Premature destruction of healthy red blood cells
Warm (IgG-mediated): happens at room temperature
Cold (IgM): triggered by cold
What is valve haemolysis?
A complication of prosthetic heart valves
What are the 2 types of bone marrow biopsy?
Aspirate (marrow smears – haematologists)
Trephine (tissue sections – pathologists)
What is aplastic anaemia?
When the body doesn’t make enough RBC’s because the immune system attacking the stem cells in your bone marrow
Name some haematological marrow diseases
Leukaemia
Lymphoma
Myeloma
Myelodysplasia
Myelofibrosis
What is acute myeloid leukaemia?
- Mostly older adults (>60 yrs)
-25% of childhood cancers - Cure rate <50%, prognosis depends on cytogenetics and gene mutations
- Treatment with intensive chemotherapy (DA 3+10 regime)
- Allogeneic stem cell transplants is potentially curative
What is acute lymphoid leukaemia?
Commonest childhood cancer (mostly <10yrs)
-Cure rate >90%
- Treatment with chemotherapy for 2 years
What is chronic myeloid leukaemia?
High WCC (leucocytosis)
Massive splenomegaly
What is the Philadelphia chromosome?
Abnormal fusion protein = BCR-ABL tyrosine kinase
Causes CML
What is the treatment for CML?
Imatinib
It inhibits the ATP pocket of BCR-ABL
What is Myelodysplasia?
A group of cancers in which immature blood cells in the bone marrow do not mature or become healthy blood cells
Causes anaemia, neutropenia, thrombocytopenia
It can transform into AML
Treated with Azacytidine (elderly) or curative allografting (young)
What is Myelofibrosis?
Fibrosis of the bone marrow causing pancytopenia
- Typically JAK2+ve
- Transforms eventually into AML
Treated with hydroxycarbamide or JAK inhibitors or allografting
What is excess myelopoiesis in bone marrow?
Myelopoiesis: the production of myeloid cells by bone marrow hematopoietic stem and progenitor cells
Typically carry JAK2 V617F mutation
Excessive production causes a risk of thrombotic events
What is Polycythemia rubra vera?
High Hb and haematocrit
Treat with venesection
What is essential thrombocythemia?
High platelet count
Treated with hydroxycarbamide
How does hydroxycarbamide work?
It works by increasing foetal haemoglobin
What is myeloma?
Malignancy of plasma cells, it’s treatable but incurable
Treatment:
- Chemotherapy for 4-6 months (cyclophosphamide, Velcade/thalidomide, steroids)
- Autologous stem cell transplant if young and fit
When should myeloma be concidered?
Hypercalcaemia
Renal failure
Unexplained anaemia
Bone pain or pathological fractures
What is the CRAB acronym for end organ failure?
Hyperkalaemia
Renal failure
Anaemia
Bone disease
It most typical clinical manifestations of multiple myeloma
What is the work up for myeloma?
Blood tests
- Haematology: anaemia, rouleaux, viscosity, ESR
– Biochemistry: U+Es, Ca, Albumin, total protein, LDH, CRP, β2-M
Serum protein electrophoresis
- Paraprotein (Monoclonal M band)
- Immunoglobulin levels low (immune paresis)
Serum free light chain assay
- Abnormal κ/λ light chain ratio
- Staging investigations
What is ITP?
Immune thrombocytopenic purpura
A rare autoimmune disorder where the blood doesn’t clot properly because the immune system destroys the platelets
What are the symptoms of Immune thrombocytopenic purpura?
- Bruising
- Nose bleeds
- GI bleeds
- Major haemorrhage
Usually self-limiting in children
What is AIHA?
Autoimmune haemolytic anaemia
What are the symptoms of autoimmune haemolytic anaemia?
Pallor
Jaundice
Dark urine
How is autoimmune haemolytic anaemia treated?
Transfuse as required (but difficulty cross-matching)
– Warm AIHA – treat with steroids, splenectomy, Rituximab
– Cold CHAD – treat with immunosuppression
What are the causes of splenomegaly?
Haematological causes
- Myeloproliferative disorders
- Lymphoproliferative disorders
- Haemolytic states
Infective causes
- Viral illness – EBV, CMV, HIV
- Tropical (malaria, schistosomiasis)
Portal hypertension due to liver disease
Rheumatoid arthritis (Felty’s syndrome)
What is Haemophilia?
A = Factor VIII
B = Factor IX (Christmas disease)
Both cause prolonged APTT
X-linked recessive (males only affected)
Causes severe bleeding into joints and muscles
Treat with recombinant factor product (or DDAVP if mild)
Treat prophylatically if severe haemophilia (<1% factor levels)
What is von Willebrand’s disease?
Deficiency of von Willebrand factor (vWF)
Low factor VIII and platelet aggregation causing mild bleeding into mucous membranes
Treat with DDAVP or Haemate P
How does Warfarin work?
It prevents γ-carboxylation of factors II, VII, IX, X
Monitored by INR (based on prothrombin time) but watch drug interactions
Reversed by vitamin K or Octaplex (25-50 IU/kg) if major bleed
Teratogenic in pregnancy; safe in renal failure
How does Heparin work?
It blocks thrombin to prevent clotting
LMWH
- Dosed by weight, no monitoring required
- Safe in pregnancy
- Unsafe in renal failure
Unfractionated Heparin
- Safe in renal failure
- Reversed by protamine sulphate
What is anti-phospholipid syndrome?
An autoimmune disorder that causes abnormal blood clots to form
Treatment:
– Anticoagulation with warfarin
– LMW heparin and aspirin in pregnancy
