Plasma Exchange

Key points

• Plasma exchange (therapeutic plasma exchange/plasmapheresis) removes circulating pathogenic antibodies, immune complexes or abnormal plasma proteins and replaces the removed plasma with an appropriate replacement fluid.
• Guillain–Barré syndrome is a recognised indication; IVIG is an effective alternative.
• Myasthenia gravis , particularly myasthenic crisis or severe deterioration, is a recognised indication; IVIG is an alternative in appropriate patients.
• ANCA-associated vasculitis: plasma exchange is not routine for every patient . Current guidance considers it in selected severe renal disease and/or severe diffuse alveolar haemorrhage with hypoxaemia, after specialist assessment; ANCA/anti-GBM overlap is a particularly important indication.
• Hyperviscosity syndrome due to monoclonal proteins, such as in Waldenström macroglobulinaemia or selected myeloma presentations, can require urgent plasma exchange alongside treatment of the underlying disorder.
• Complications: citrate-related hypocalcaemia , hypotension, allergic reactions, bleeding/coagulation-factor depletion and vascular-access/infection complications.
• MRCP discriminator: GBS/myasthenic crisis → IVIG or plasma exchange; hyperviscosity → urgent plasma exchange; ANCA vasculitis → selected severe cases, not routine.
• Classic complication: citrate anticoagulation → hypocalcaemia.