Intravenous immunoglobulin (IVIG) enhances immune homeostasis by modulating
expression and function of Fc receptors, interfering with activation of complement
and production of cytokines, providing anti-idiotypic antibodies, and affecting
the activation and effector functions of T and B cells. These mechanisms may
explain the effectiveness of IVIG in autoimmune neuromuscular disorders.
To systematically review the current status of the treatment of autoimmune
neuromuscular diseases with IVIG, with emphasis on controlled trials.
Peer-reviewed publications identified through MEDLINE (1966-2003), EMBASE
(1974-2003), and references from bibliographies of pertinent articles. Each
autoimmune neuromuscular disease term was searched in combination with the
term intravenous immunoglobulin.
Study Selection and Data Extraction
Criteria for selection of studies included controlled study design,
English language, and clinical pertinence. Data quality was based on venue
of publication and relevance to clinical care.
Outcomes of controlled trials indicate that IVIG at a total dose of
2 g/kg is effective as first-line therapy in Guillain-Barré syndrome,
chronic inflammatory demyelinating polyneuropathy, and multifocal motor neuropathy
and as second-line therapy in stiff-person syndrome, dermatomyositis, myasthenia
gravis, and Lambert-Eaton myasthenic syndrome. In other controlled studies,
IVIG produced a modest, variable, and transient but not statistically significant
benefit in patients with inclusion body myositis and paraproteinemic anti–myelin-associated
glycoprotein antibody demyelinating polyneuropathy. Intravenous immunoglobulin
is not effective in patients with multiple sclerosis who have established
weakness or optic neuritis. In myasthenia gravis, it should be reserved for
difficult cases or before thymectomy in lieu of plasma exchange.
Intravenous immunoglobulin is effective in many autoimmune neurologic
diseases, but its spectrum of efficacy, especially as first-line therapy,
and the appropriate dose for long-term maintenance therapy are not fully established.
Further controlled studies of IVIG, combined with a dose-finding effect, pharmacoeconomics,
and quality-of-life assessments, are warranted to improve the evidence base
for clinical practice.