Paroxysmal Nocturnal Haemoglobinuria

Key points

• Paroxysmal nocturnal haemoglobinuria (PNH) is an acquired disorder leading to haemolysis (mainly intravascular) of haematological cells.
• GPI can be thought of as an anchor which attaches surface proteins to the cell membrane
• complement-regulating surface proteins, e.g. decay- accelerating factor (DAF), are not properly bound to the cell membrane due a lack of GPI
• thrombosis is thought to be caused by a lack of CD59 on platelet membranes predisposing to platelet aggregation Features
• haemolytic anaemia