Haematology Flashcards
What is microcytic anaemia?
Reduced MCV (<80)
What causes microcytic anaemia?
TAILS
Thalassemia/haemoglobinopathies Anaemia of chronic disease Iron deficiency anaemia Lead poisoning Sideroblastic anaemia
Hookworm infection (low/middle income countries)
What is the most common cause of anaemia?
Iron deficiency
What causes iron deficiency anaemia?
Low iron intake
Iron loss
Give examples of low iron intake that can cause iron deficiency anaemia.
Malabsorption and vegan diet
Give examples of iron loss that can cause iron deficiency anaema.
Menorrhagia, GI bleed, hookworm
Where is iron absorbed?
Duodenum
How is iron deficiency anaemia treated?
Treat cause
Iron supplements - ferrous sulfate/ferrous gluconate
What are the signs of iron deficiency anaemia?
Pale skin & mucous membranes Tachycardia Systolic flow murmur Brittle hair/nails Atrophic glossitis Angular stomatitis Koilonychia
What are the symptoms of iron deficiency anaemia?
Fatigue Lethargy Dyspnoea Palpitations Syncope Headache Tinnitus
What is normocytic anaemia?
Normal MCV
What causes normocytic anaemia?
Anaemia of chronic disease Acute blood loss Increased plasma volume (pregnancy, fluid overload) Haemoglobinopathies Aplastic anaemia Haemolysis Hypersplenism (destruction of RBCs)
What is macrocytic anaemia?
Increased MCV
What causes macrocytic anaemia?
B12/folate deficiency Toxins (alcohol, chemo) Liver disease Reticulocytosis Pregnancy Myeloma Hypothyroidism Myelodysplastic syndrome
What causes folate deficiency?
Low intake
Malabsorption
Pregnancy
Drugs
Who is at risk of folate deficiency?
Elderly, poverty, alcohol excess
What drugs can cause folate deficiency?
Trimethoprim, phenytoin, methotrexate
How does folate deficiency anaemia present?
Same as other anaemias
How do you investigate folate deficiency?
FBC
Blood film
Red cell folate
What does a blood film show for folate deficiency anaemia?
Macrocytic megaloblastic anaemia
What does red cell folate show for folate anaemia?
<160ug/ml
How do you treat folate deficiency anaemia?
Treat underlying cause
Folic acid supplement if certain of cause
Why should you be cautious of prescribing folic acid supplements for folate deficiency?
Can aggravate neuropathy associated with B12 deficiency
What causes pernicious anaemia?
Lack of intrinsic factor usually produced by parietal cells in the stomach which allow B12 absorption in the terminal ileum
What is the pathology of pernicious anaemia?
B12 and folate needed for DNA synthesis - RBC development arrested - large immature megaloblastic cells
How does pernicious anaemia present?
Same as other anaemias + neuropathy, depression and psychosis
How do you investigate pernicious anaemia?
FBC
Blood film
Serum antibodies - IF/parietal cell antibodies
Serum B12 <50ng/L
How do you manage pernicious anaemia?
B12 IM/PO (hydroxocobalamin)
What is sickle cell anaemia?
Inherited mutation of HbS leading to sickling of RBCs
What is the epidemiology of sickle cell disease?
More common in Afro-Carribeans
How is sickle cell disease inherited?
Autosomal recessive - 50% chance of being a carrier
What is the pathology of sickle cell disease?
Mutation of B globin (HbS)
Under stress this polymerises
RBCs become rigid and sickle shaped
Leads to intravascular haemolysis - obstruction of microcirculation - infarction
How does sickle cell anaemia present?
Anaemia symptoms (lethargy, syncope) Pain in hands and feet Jaundice Acute chest syndrome Dactylitis Stroke Priapism Nocturnal enuresis Thrombosis - ulcers/vascular necrosis
What are the key presentations of sickle cell anaemia?
Chest crisis
Sickle cell crisis
Splenic infarction/sequestration (main cause of death in children)
What is chest crisis in sickle cell anaemia?
Pulmonary infiltrate/infarct/infection - main cause of death in adults = PHTN/chronic lung disease
What is sickle cell crisis?
Acute bone pain
How do you investigate sickle cell disease?
FBC
Blood film
Hb electrophoresis
Heel prick test
What is the supportive management of sickle cell disease?
Folic acid
Analgesia (start with opiates)
Abx
Fluids
What is the disease modifying therapy for sickle cell disease?
Hydroxycarbamide (increase HbF)
Transfusion
Stem cell transplant
What is the hyposplenic treatment for sickle cell disease?
Prophylactic abx
Vaccinations
What are complications of sickle cell disease?
Mesenteric ischaemia
Renal impairment
Pulmonary HTN
Joint damage
What causes malaria?
Protozoa P. falcirum P. vivax P. ovale P. malariae
Vector = female mosquito
What are the risk factors for malaria?
Poor Young Pregnant Elderly Recent travel abroad
How does malaria present?
Fever Chills Rigors Cough Myalgia Splenomegaly Hepatomegaly Jaundice
How is malaria investigated?
Travel history - where, when, stopovers Thick and thin blood film Diagnostic tests for plasmodium antigens Pregnancy test Rule out meningitis
How is falciparum malaria managed?
Quinine sulfate/IV quinine dihydrochloride
How is non-falciparum malaria managed?
Chloroquine
How is malaria prevented?
Chemoprophylaxis
Nets
Long clothes
What is polycythaemia?
Increase in Hb, packed cell volume and RBCs
What causes primary polycythaemia?
Increased sensitivity to EPO
JAK2 mutation
EPO receptor gene mutation
What causes secondary polycythaemia?
Increased EPO
Chronic hypoxia
EPO producing tumour
High altitude
What is the pathology of polycythaemia?
Impaired blood flow due to sludging
Haemostat mechanisms disrupted
How does polycythaemia present?
Red face Hepatosplenomegaly (PRV only) Easy bleeding/bruising Fatigue Dizziness Headache Sweating Pruritus Thrombosis
How is polycythaemia investigated?
FBC - raised Hb
Secondary polycythaemia - low EPO
BM biopsy - hypercellularity
Testing for JAK2 gene
How do you manage polycythaemia?
Venesection (400-500ml removed) Aspirin Treat cause if secondary Hydroxyurea Splenectomy if required Monitor haematocrit
What are the complications of polycythaemia?
Thrombosis
Can transform into myelofibrosis or AML
What do lymphoid stem cells become?
T and B cells
What do myeloid stem cells become?
Erythrocytes Platelets Mast cells Eosinophils Neutrophils Basophils etc.
What is leukaemia?
Cancer of blood cells in bone marrow
What are the symptoms of leukaemia?
Fatigue Night sweats Weight loss Bleeding/bruising Pain or swelling in abdomen
What are the features of chronic myeloid leukaemia?
Rare in children
Philadelphia chromosome
Blood smear resembles bone marrow aspirate
Affects one or all three of erythroid, platelet and myeloid cell lines
Chronic > accelerated > blast crisis
Tyrosine kinase inhibitors +/- stem cell transplant
What are the features of acute myeloid leukaemia?
Most common adult leukaemia Exposure to chemo/benzene Gum hypertrophy Auer rods in blast cells Chemo +/- stem cell transplant
Who does chronic lymphocytic leukaemia typically affect?
Older people
What are the symptoms of acute lymphoid leukaemia (ALL)?
Bruising, bleeding, fatigue, malaise
What is myeloma?
Malignancy of plasma cells
What causes myeloma?
Non-malignant > pre-malignant (smouldering) > malignant
How does myeloma present?
CRAB
Calcium
Renal
Anaemia
Bone
How does myeloma present (calcium)?
Hypercalcaemia - confusion
How does myeloma present (renal)?
Nephrotic syndrome
Renal failure
How does myeloma present (anaemia)?
Thrombocytopoenia - bleeding
Leukopenia - infections
How does myeloma present (bone)?
Spinal cord compression
Osteolytic lesions - fractures and bone pain
How is myeloma investigated?
FBC (low WBC, RBC, platelets)
U+Es (high Ca2+)
Serum protein electrophoresis - paraprotein
Urine protein electrophoresis - Bence Jones protein
X-ray
MRI
What is the gold standard investigation for myeloma?
Bone marrow biopsy
Immunofixation of serum and urine - paraprotein
How is myeloma managed in older patients?
Chemo