Intravenous immunoglobulin for myasthenia gravis

Background Myasthenia gravis is an autoimmune disease in which autoantibodies interfere with neuromuscular transmission. As with other autoimmune diseases, people with myasthenia gravis would be expected to benefit from intravenous immunoglobulin (IVIg). This is an update of a review first published in 2003 and last updated in 2007. Objectives To examine the efficacy of IVIg for treating exacerbations of myasthenia gravis or for chronic myasthenia gravis. Search methods We searched the Cochrane Neuromuscular Disease Group Specialized Register (11 October 2011), CENTRAL (2011, Issue 3), MEDLINE (January 1966 to September 2011) and EMBASE (January 1980 to September 2011) using 'myasthenia gravis' and 'intravenous immunoglobulin' as the search terms. Selection criteria All randomised controlled trials (RCTs) or quasi‐RCTs in which IVIg was compared with no treatment, placebo or plasma exchange, in people with myasthenia gravis. Data collection and analysis One review author extracted the data and two others checked these data. For methodological reasons, no formal meta‐analysis was performed. Main results We identified seven RCTs. These trials differ in inclusion criteria, comparison with alternative treatment and outcomes. In a trial comparing IVIg with placebo, including 51 participants with myasthenia gravis worsening, the mean difference (MD) in quantitative myasthenia gravis score (QMGS) (MD 95% CI) after 14 days was: ‐1.60 (95% CI ‐ 3.23 to 0.03) this result being borderline statistically significant in favour of IVIg. In an unblinded study of 87 participants with exacerbation comparing IVIg and plasma exchange there was no difference in myasthenic muscle score (MMS) after 15 days (MD ‐1.00; 95% CI ‐7.72 to 5.72). In a study of 84 participants with worsening myasthenia gravis there was no difference in change in QMGS 14 days after IVIg or plasma exchange (MD ‐1.50; 95% CI ‐3.43 to 0.43). In a study of 12 participants with moderate or severe myasthenia gravis, which was at high risk of bias from skewed allocation, the mean fall in QMGS both for IVIg and plasma exchange after four weeks was significant (P < 0.05). A study with 15 participants with mild or moderate myasthenia gravis found no difference in change in QMGS 42 days after IVIg or placebo (MD 1.60; 95% CI ‐1.92 to 5.12). A study included 33 participants with moderate exacerbations of myasthenia gravis and showed no difference in change in QMGS 14 days after IVIg or methylprednisolone (MD ‐0.42;