From the Research
Plasma exchange should be considered for myasthenia gravis after IVIG when the patient shows inadequate response to IVIG therapy, experiences rapid clinical deterioration, or is in myasthenic crisis requiring immediate intervention, as it has been shown to have a faster efficacy compared to IVIG in the first two weeks of treatment 1.
Key Considerations
- Plasma exchange (PLEX) works more rapidly than IVIG, often showing improvement within days by directly removing autoantibodies from circulation.
- When transitioning from IVIG to PLEX, it's advisable to wait at least 24-48 hours between treatments to minimize complications.
- Important considerations include ensuring adequate venous access (often requiring central venous catheterization), monitoring for hypotension, electrolyte disturbances, and coagulation abnormalities during treatment, and implementing appropriate replacement fluids (typically albumin or fresh frozen plasma).
Patient Selection
- PLEX is particularly beneficial in antibody-positive patients and those with bulbar or respiratory involvement.
- The mechanism of action differs from IVIG, as PLEX physically removes pathogenic antibodies rather than modulating the immune response, which may provide benefit even when IVIG has failed.
Treatment Protocol
- A course of 5-6 exchanges performed every other day is recommended, with each exchange removing approximately 1-1.5 plasma volumes.
- The latest study 1 demonstrated a tendency indicating faster efficacy of PLEX in the first two weeks of treatment, which may be clinically meaningful in critical clinical conditions.
Evidence Base
- The most recent and highest quality study 1 compared the efficacy of PLEX and IVIG in patients with moderate-to-severe myasthenia gravis, showing a faster improvement with PLEX.
- Other studies 2, 3, 4, 5 also support the use of PLEX in myasthenia gravis, but the latest study 1 provides the most up-to-date and relevant evidence.