laboratory features

Last reviewed 05/2021

  • anaemia:
    • this is variable - an iron deficiency anaemia may occur due to chronic intravascular haemolysis and loss in the urine
    • the blood smear is not characteristic; features may include polychromasia and reticulocytosis

  • urine:
    • haemosiderin
    • haemoglobin
    • increased urobilinogen

  • serum haptoglobin - decreased or absent

  • serum LDH - raised

  • serum iron - may be decreased

  • white cell count:
    • usually low
    • leukocyte alkaline phosphatase (LAP) may be decreased

  • platelet count may be decreased

  • negative Coomb's test

  • bone marrow - variable; either hypoplasia or erythroid hyperplasia