Haematology Flashcards
What is haematopoeisis?
Manufacture of blood
What is the definition of anaemia?
Low haemoglobin
Symptoms of anaemia?
Shortness of breath, lethargy, headache and angina
Causes of anaemia?
Bleeding, dietary deficiency, haemolysis
Three classifications of anaemia?
Microcytic - Small cells
Normocytic - Normal sized red cells
Macrocytic - big red cells
Changes that occur when iron is in excess?
Transferrin receptors and iron uptake is reduced
How is transferrin involved in iron uptake?
Macrophages gain iron from old red cells and transferrin carries it in the blood
Common cause of microcytic anaemia?
Iron deficiency
Common cause of normocytic anaemia?
Chronic disease/infection
Common cause of macrocytic anaemia?
B12/folate deficiency
What can cause iron deficiency leading to microcytic anaemia?
Blood loss
Thalassaemia’s
Malabsorption in the gut
Poor dietary intake and increased demand e.g. pregnancy, children, menstruation
Features of microcytic anaemia?
General symptoms of anaemia
Nail deformity
Sore tongue
Pica (abnormal appetite)
Lab features of microcytic anaemia?
Low Hb
Pale/small cells
Low ferritin
Transferrin receptors increased
What is thalassaemia?
Heterogenous group of genetic disorders all resulting in globin chains not being produced (α and β chains)
What does folate do?
Is an essential coenzyme required to synthesise TMP, which is essential for the manufacture of DNA.
What does B12 do in the body?
Is an essential coenzyme to produce THF which synthesises DNA.
What do transcobalamins do?
Transport B12 to the liver and other tissues
What does B12 and Folate deficiency cause?
Gradual onset anaemia
Mild jaundice
Sterility
Neuropathy (only B12)
Blood clots
Causes of B12 deficiency?
Vegans
Infants born to B12 deficient mothers
Alcoholics
Pernicious anaemia
Crohns disease
Lab features of B12 deficiency?
Hyper segmented neutrophils
Macrocytic red cells
Bilirubin is raised
Cause of macrocytosis?
Anaemia related:
Alcohol
Liver disease
Thyroid disease
Non-anaemia associated:
Cytotoxic drugs
Aplastic anaemia
Some haematological malignancies
Pathogenesis causing normocytic anaemia in chronic disease?
Mild decrease in red blood cell lifespan
Disturbance in erythropoiesis
Interactions of cytokines
Low EPO and serum iron
What is haemolytic anaemia?
Shortened RBC lifespan below 15 days
Types of hereditary haemolytic anaemias?
Membrane affected
Metabolism affected
Haemoglobin synthesis affected
Types of acquired haemolytic anaemias?
Autoimmune anaemias
Infections
Red cell pigmentation syndromes
What is pancytopenia?
reduction in red and white cells as well as platelets
What can cause pancytopenia?
Bone morrow failure - chemotherapy, viral hepatitis
Peripheral consumption/destruction
