Intravenous immunoglobulin as treatment for myasthenia gravis: current evidence and outcomes

Abstract

We examined the current evidence for the efficacy of IV immunoglobulin (IVIG) in myasthenia gravis (MG) and the outcomes used to demonstrate this efficacy. There is class 1 evidence for the use of short-term IVIG in MG patients worsening MG and also good evidence for IVIG use in myasthenic crisis. For long-term maintenance therapy, controlled studies are lacking and the evidence is limited to class III retrospective studies. The clinical scales, serological, electrophysiological, and patient-reported quality of life outcomes with IVIG have been assessed. At this time, the quantitative myasthenia gravis score, a functional scale, remains the preferable outcome measure as it has demonstrated responsiveness in the clinical trial setting, but a scale incorporating patient-reported outcomes and the patients complaint of fatigue is likely to be preferable. The MG-composite is such a scale, but has measurement limitations that may reduce its sensitivity. Across trials, IVIG has generally been well tolerated.

Keywords::

• IVIG
• myasthenia gravis
• outcomes
• response
• treatment

Financial & competing interests disclosure

V Bril and H Katzberg both act as consultants for Grifols and CSL and have received research funding from both. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Key issues

• Class 1 evidence shows that IV immunoglobulin (IVIG) is an effective treatment for patients with worsening moderate-severe myasthenia gravis (MG).

• Treatment with IVIG or plasmapheresis produces similar outcomes in MG patients at 14 days after treatment as demonstrated by class 1evidence.

• The quantitative myasthenia gravis score is a useful scale to demonstrate improvement in MG patients after treatment and reflects disease severity as shown by clinical, eletrophysiological, and laboratory parameters. Improvement in the quantitative myasthenia gravis score is reflected by improved quality of life measures.

• Baseline disease severity in MG patients is the only factor that reliably predicts the results of treatment, so that those with more severe disease are more likely to respond to treatment.

• The use of IVIG as maintenance treatment in MG patients requires further study.