Haemolytic Anaemia

These normochromic and normocytic anaemias are caused by intrinsic (acting from within the RBC eg. a defective membrane protein) or extrinsic (acting upon RBCs from without) factors which result in the premature destruction of RBCs. In compensated haemolytic anaemia (HA), the bone marrow is able to maintain normal RBC numbers in the circulation by increasing its activity.
Anaemia will result when destruction outpaces production or when the bone marrow fails to maintain production.

Haemolytic Anaemia Classification:

Intrinsic Defects in the RBC

Defects in the RBC Membrane
  eg. Hereditary Spherocytosis
Abnormal Enzymes
  eg. Pyruvate Kinase Deficiency
Abnormal Haemoglobin
  eg. Thalassaemia

Extrinsic Defects in the RBC

Plasma Factors
  eg. Snake Venom
Cell Damage
  eg. March haemoglobinuria
Immune Destruction
  eg. Autoimmunity

Screening for Haemolytic Anaemias New look for June 2003