Intravenous immunoglobulin treatment of multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis.

Intravenous immunoglobulin (IVIG) is an established treatment of immune-mediated demyelinating neuropathy. Since IVIG possesses multiple immunomodulatory and anti-inflammatory properties, IVIG therapy may represent a way of interfering with the disease process in multiple sclerosis (MS). In the MS animal model experimental autoimmune encephalomyelitis (EAE), infusions of IVIG significantly reduced disease symptoms as well as the underlying CNS pathology. IVIG was only effective in EAE when administered in a prophylactic treatment protocol, since IVIG infusions during the established phase of EAE did not alter the disease course or the degree of inflammation found in the central nervous system. IVIG also has the potential to act through myelin repair mechanisms as evidenced by work done in the Theilers murine encephalomyelitis virus model of demyelination. Together these observations have led to certain expectations for IVIG as a treatment for MS, and have resulted in various clinical trials. Several controlled trials report beneficial effects of IVIG on relapse rate, new MRI lesions, and disease progression in relapsing-remitting MS, while a remyelinating effect of IVIG has not been documented. IVIG is, therefore, presently regarded as a second-line therapy of MS.