Anaemia Flashcards
What are the 4 mechanisms of anaemia?
reduced production of red cells/haemoglobin by the bone marrow
reduced survival of red cells in the circulation (haemolysis).
loss of blood from the body
pooling of red cells in a very large spleen.
What are the three classifications of anaemia? (size)
Microcytic
Normocytic
Macrocytic
What are reticulocytes?
Early red cells
What is ferritin?
Cellular store of iron
What is a classic form of microcytic anaemia?
Iron deficiency
What is ESR (process)?
Rate at which red cells fall in test tube
What does ESR stand for?
Erythrocyte sedimentation rate
Why do rouleaux develop?
Increased number of plasma proteins with positive charge
Attract red cells
Stacking of coins
What is anaemia of chronic disease?
Characterised by pattern of low-normal transferrin
No obvious cause except that the patient is ill
Diagnosis by exclusion
What is the issues with measuring
Not very sensitive measure of iron stores
What causes low MCV?
Iron deficiency
Alpha/Beta Thalassemia
Anaemia of chronic disease
What laboratory tests can be conducted to diagnose microcytic anaemia?
Iron screening
What comprises an iron screening
Ferritin Serum iron Transferrin Transferrin saturation Hb electrophoresis
What question should you ask in iron defficency?
Heavy menstrual blood loss Menopausal and bleeding? Diet - vegan/vegetarian GI symptoms: dysphagia Weight loss Medication e.g. NSAIDS, asprin
What are features of iron deficiency anaemia?
Glossitis
Angular stomatitis
Koilonychia
She reports weight loss, what investigations should you carry out?
Investigation for blood in the stool
GI investigations
Coeliac antibody testing
What is haemolysis?
Breakdown of red blood cells
Shortened lifespan
What are causes of inherited haemolytic anaemia?
Membrane abnormalities
Abnormal Hb
Metabolic pathways
Why is MCV raised in haemolytic anaemia?
Reticulocytes are larger
What are heinz bodies?
Precipitated oxidised haemoglobin
What is the cause of haemolytic anaemia on this case?
G6PD deficiency
What are those with a G6PD deficiency told to do?
Avoid oxidant drugs
Don’t eat broad beans
Avoid naphthalene
Be aware that haemolysis can result from infection
What is LDH?
Is an intracellular enzyme that is leaked into the plasma when cells breakdown
What are spherocytes?
Smaller RBC’s with loss of central pallor
What are the two types of haemolytic anaemia?
Inherited
Acquired (normal red cells but environment becomes toxic to the cell)
What are the two types of acquired haemolytic anaemia?
Non-immune
Immune mediated
What test do you do to look for auto-antibodies?
Direct antiglobulin test
DAT
How does DAT work?
Add rabbit antibody that is directed against human immunoglobulin
Binds human immunoglobulin together
What is AIHA?
Auto immune haemolytic anaemia
What causes hereditary spherocytosis?
Due to inherited defect in red cell membrane
What are polychromatic macrocytes?
Blue, large cells
Due to the presence of ribosomes they pick up blue dye
Young cells
What is treatment for hereditary spherocytosis?
Folic acid
Splenectomy
What is meant by inappropriately normal reticulocytes?
When Hb is so low you would expect reticulocytosis to compenstae
What is a neutrophil with many lobes known as?
hyper-segmented neutrophil
Why do you always have to check B12 and folic acid blood test?
Present exactly the same on blood films
Need to do both to differentiate
What is megaloblastic change?
Nucleocytoplasmic dissociation
What can cause megaloblastic change?
Drugs
Folate antagonists e.g. methotrexate
BM cancer
What does B12 require to be absorbed?
Intrinsic factor
What is pernicious anaemia?
Destroy cells in stomach
Cannot absorb B12
