IVIG and TPE are Equally Effective for Myasthenia Gravis
For myasthenic crisis with respiratory compromise, both IVIG (2 g/kg over 5 days) and therapeutic plasma exchange (TPE) are equally effective treatments, but IVIG is generally preferred as first-line therapy due to easier administration, wider availability, and fewer complications requiring discontinuation. 1, 2, 3
Evidence for Equal Efficacy
A randomized controlled trial of 84 patients with moderate to severe myasthenia gravis demonstrated no statistically significant difference in functional outcomes between IVIG and TPE, with both groups showing a mean improvement of 4.0 points on the Quantitative Myasthenia Gravis Score at day 14. 3, 4
Both treatments showed comparable efficacy across multiple parameters including percentage of responders, persistence of treatment effect, and tolerability, with improvements accompanied by enhanced disease-specific quality of life. 4
The only factor predicting response to either treatment was baseline disease severity—patients with more severe disease demonstrated the largest clinical improvements regardless of which therapy was used. 4, 5
When to Choose IVIG Over TPE
IVIG should be the default first-line choice in most clinical scenarios for the following reasons:
IVIG is easier to administer without requiring specialized equipment or vascular access beyond standard IV lines, making it more widely available across different healthcare settings. 1, 2
Early studies demonstrated that TPE was more likely to be discontinued due to adverse events compared to IVIG, though both carry comparable overall risks. 6
IVIG is specifically preferred in pregnant women, as TPE requires additional monitoring considerations and complications during pregnancy. 1
For Grade 3-4 myasthenic exacerbations requiring hospitalization with respiratory compromise, IVIG at 0.4 g/kg/day for 5 consecutive days (total 2 g/kg) can be initiated immediately upon ICU admission. 1, 2
When TPE May Be Preferred
TPE remains the treatment of choice in true myasthenic crisis with severe respiratory failure requiring mechanical ventilation, as it may provide more rapid removal of pathogenic antibodies in life-threatening situations. 3
In resource-limited settings, TPE may be more cost-effective than IVIG, though this advantage is offset by the need for specialized equipment and trained personnel. 6
TPE should be considered when IVIG is contraindicated or when patients have failed to respond to IVIG therapy. 1
Critical Management Algorithm for Acute Crisis
For Grade 3-4 myasthenic crisis (dysphagia, respiratory weakness, rapidly progressive symptoms):
Admit immediately to ICU for close respiratory monitoring with frequent pulmonary function testing (negative inspiratory force and vital capacity). 1, 2
Initiate either IVIG 0.4 g/kg/day × 5 days OR TPE (5 sessions at 200-250 ml/kg). 1, 2
Continue or initiate corticosteroids (methylprednisolone 1-2 mg/kg daily or prednisone 1-1.5 mg/kg daily) concurrently during IVIG or TPE treatment. 1, 2
Maintain pyridostigmine therapy, adjusting dose based on improvement (can be withheld if intubation is required). 1, 2
Perform daily neurologic evaluations to assess treatment response. 2
Important Caveats
Sequential therapy (TPE followed by IVIG) is no more effective than either treatment alone and should be avoided. 1
IVIG should NOT be used for chronic maintenance therapy in myasthenia gravis—it is reserved specifically for acute exacerbations and crisis situations. 1
Before initiating either therapy, strictly avoid medications that worsen myasthenic symptoms including β-blockers, IV magnesium, fluoroquinolones, aminoglycosides, and macrolides, as these can precipitate crisis. 1, 7, 2
Treatment decisions may ultimately depend on presence of respiratory distress severity, medical comorbidities, institutional access to therapies, and cost considerations, but efficacy should not be the deciding factor as both are equivalent. 3