Haematology Profile (FBC/FBE)

• Should demonstrate an anaemia

• Schistocytes
  • Products of RBC breakdown
  • Suggests intravascular haemolysis (IVH)
• Microspherocytes
  • Intra/Extravascular haemolysis (IVH/EVH)
  • A hallmark of haemolytic anaemia (HA)
• Polychromasia (IVH/EVH)
• Nucleated Red Blood Cells (IVH/EVH)
• Erythroid hyperplasia is more pronounced than in HA than in non-HA (Dec. M:E)
• Noticeable that the lifespan of RBCs from a patient with an intrinsic RBC defect, when infused into a normal patient, are decreased. Normal RBCs infused into a patient with an intrinsic RBC defect do not haemolyse.

• A measure of the RBCs resistance to haemolysis by osmotic stress, depending primarily on the volume of the cell, the surface area and the cell's membrane function
• RBCs are incubated in varying concentrations of a hypotonic solution of sodium chloride (NaCl)
• As the concentration of NaCl decreases, cells take on water to produce osmotic equilibrium
• Normal cells begin to haemolyse at NaCl concentrations of approximately 0.50%
• Because of their Dec. surface area:volume, spherocytes can not expand as much as normal discoid cells, thus lysis is usually completed by 0.4-0.5%, starting at higher NaCl concentrations
• Incubation of blood overnight at 37^oC makes the OFT more sensitive
• A shift to the left of the normal range (NR) is a decreased OF (eg. HS)
• A shift to the right of the NR is an increased OF (eg. thalassaemia)
• Dec. cell stability occurs in thalassaemia, sickle cell anaemia and conditions associated with target cells

• EVH - Dec. due to destruction within the spleen
• IVH - Absent

• Monitoring an Inc./Dec. unconjugated bilirubin
• Also increased in liver disease