This review summarizes the current status of
intravenous immunoglobulin (
IVIg) in the treatment of autoimmune neuromuscular disorders and the possible mechanisms of action of the
drug based on work in vivo, in vitro, and in animal models. Supply of idiotypic
antibodies, suppression of antibody production, or acceleration of catabolism of
immunoglobulin G (
IgG) are relevant in explaining the efficacy of
IVIg in
myasthenia gravis (MG),
Lambert-Eaton myasthenic syndrome (LEMS), and antibody-mediated neuropathies. Suppression of pathogenic
cytokines has putative relevance in
inflammatory myopathies and demyelinating neuropathies. Inhibition of
complement binding and prevention of membranolytic attack complex (MAC) formation are relevant in
dermatomyositis (DM),
Guillain-Barré syndrome (GBS), and MG. Modulation of
Fc receptors or T-cell function is relevant in chronic inflammatory demyelinating
polyneuropathy (
CIDP), GBS, and
inflammatory myopathies. The clinical efficacy of
IVIg, based on controlled clinical trials conducted in patients with GBS,
CIDP, multifocal motor neuropathy (MMN), DM, MG, LEMS, paraproteinemic
IgM anti-
myelin-associated glycoprotein (anti-MAG) demyelinating
polyneuropathies, and
inclusion body myositis is summarized and practical issues related to each disorder are addressed. The present role of
IVIg therapy in other disorders based on small controlled or uncontrolled trials is also summarized. Finally, safety issues, risk factors, adverse reactions, spurious results or serological tests, and practical guidelines associated with the administration of
IVIg in the treatment of neuromuscular disorders are presented.