Sep

19

2021

What are the 3 different red cell types seen in flow cytometry of patients with suspected paroxysmal nocturnal hemoglobinuria (PNH)?

By William Aird

Type I cells – red blood cells (RBCs) express GPI-APs (for example, CD59) at normal density

  • RBCs express normal amounts of GPI-anchored proteins (GPI-AP), such as CD59
  • Full protection against complement-mediated lysis
  • Normal RBC lifespan of about 120 days

Type II cells – red cells partly deficient in GPI-APs;

  • RBCs partly deficient in GPI-APs
  • Partial protection against complement-mediated lysis
  • Lifespan intermediate between type1 and type 3 cells

Type III cells – red cells completely deficient in GPI-APs.

  • RBCs completely deficient in GPI-APs
  • No protection against complement-mediated lysis
  • RBC lifespan 10-15 days