Myasthenia gravis (MG) and Lambert-Eaton myasthenic
syndrome (LEMS) are autoimmune ion channel disorders mediated by
antibodies to postsynaptic acetylcholine receptors and
presynaptic voltage-operated calcium channels, respectively. MG
and LEMS are currently treated with corticosteroids and
immunosuppressive drugs with a positive clinical outcome. Since
both diseases are mediated by circulating autoantibodies, they
are good candidates for immunomodulation by intravenous
immunoglobulins (IVIG). Standardized controlled studies are
lacking in this field, but there is general agreement that IVIG
are effective. They can be used as an acute treatment to control
temporarily the most severe forms of these diseases, as well as
a chronic immunomodulating therapy in addition to standard
pharmacological treatment. Several aspects of IVIG
administration, cost benefit-analysis, and comparison to
plasmapheresis are still needed.