Oligodendrocytes are damaged by neuromyelitis optica immunoglobulin G via astrocyte injury.

Devic's neuromyelitis optica is an inflammatory demyelinating disorder normally restricted to the optic nerves and spinal cord. Since the identification of a specific autoantibody directed against aquaporin 4, neuromyelitis optica-immunoglobulin G/aquaporin 4 antibody, neuromyelitis optica has been considered an entity distinct from multiple sclerosis. Recent findings indicate that the neuromyelitis optica-immunoglobulin G/aquaporin 4 antibody has a pathogenic role through complement-dependent astrocyte toxicity.

Regional variations in the prevalence of multiple sclerosis in French farmers.

Background: Studies on the prevalence of multiple sclerosis have been carried out worldwide, showing a heterogeneous distribution between countries and even between the different regions of the same country.

Methods: We estimated the regional and national prevalence of multiple sclerosis in France on 1 January 2003, based on the computerised database of the national farmer health insurance system ("Mutualité Sociale Agricole").

Results: There were 2667 cases of multiple sclerosis registered on the prevalence date, out of 4,098,477 affiliates.