mean corpuscular haemoglobin (MCH)

Last reviewed 01/2018

Mean corpuscular haemoglobin (MCH) = haemoglobin/RBC - represents weight of heamoglobin in average RBC - not as useful as MCHC

• limited value in the differential diagnosis of anaemias
• decreased in
  • microcytic and normocytic anaemias
• increased in
  • macrocytic anaemias
  • infants and newborn
  • conditions with cold agglutinins - due to methodologic interference
  • in vivo haemolysis - due to methodologic interference
  • monoclonal proteins in blood - due to methodologic inteference
  • high heparin concentration - due to methodologic interference

Mean corpuscular haemoglobin concentration (MCHC) (gm/dL) = haemoglobin/haematocrit; represents concentration of haemoglobin in average RBC

• MCHC is increased in
  • hereditary spherocytosis - should be considered whenever MCHC > 36 gm/dL
  • infants and newborn
  • in vivo haemolysis - due to methodologic interference
  • conditions with cold agglutinins or severe lipaemia of serum - due to methodologic interference
  • high heparin concentration - due to methodologic interference
• MCHC is not increased in pernicious anaemia
• MCHC is decreased in (<30.1 gm/dL)
  • microytic anaemias - normal value does not rule out any of these anaemias - low MCHC may occur in iron deficiency anaemia when performed with automated instruments
  • marked leukocytosis (>50,000/cu mm) - due to methodologic interference

   

• changes in MCHC occur very late in the course of any disease process