What it is
Plasma exchange (plasmapheresis) removes the patient's plasma — and with it pathogenic antibodies, immune complexes, cryoglobulins or paraproteins — replacing it with albumin or fresh frozen plasma (FFP). It is used when rapid removal of a circulating factor will alter the disease course.
Indications
- Anti-GBM (Goodpasture) disease — remove anti-GBM antibody
- ANCA-associated vasculitis with rapidly progressive renal failure or pulmonary haemorrhage
- Thrombotic thrombocytopenic purpura (TTP) — with FFP replacement (replaces ADAMTS13)
- Cryoglobulinaemia and hyperviscosity syndromes (e.g. Waldenström)
- Neurological: Guillain–Barré syndrome, myasthenic crisis
Complications
- Hypocalcaemia — from citrate anticoagulation (paraesthesia, tetany)
- Bleeding — removal of clotting factors (when albumin is the replacement)
- Infection — removal of immunoglobulins; line-related sepsis
- Removal of protein-bound drugs; allergic/anaphylactoid reactions to replacement fluid
MRCP-specific traps
- Anti-GBM disease is the classic renal indication — plasma exchange plus immunosuppression.
- In TTP the replacement fluid is FFP (it supplies ADAMTS13), not just albumin.
- Watch for citrate-induced hypocalcaemia during and after treatment.
Summary
Plasma exchange removes pathogenic plasma constituents (antibodies, immune complexes, cryoglobulins), replacing them with albumin or FFP. Key indications: anti-GBM disease, severe ANCA vasculitis, TTP (FFP replacement) and cryoglobulinaemia. Watch for citrate hypocalcaemia, bleeding and infection.
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