Low vitamin B12 levels and gastric parietal cell antibodies in patients with aquaporin-4 antibody-positive neuromyelitis optica spectrum disorders.

摘要

In up to 80 % of patients, neuromyelitis optica (NMO, Devic's syndrome), is associated with antibodies to aqu-aporin-4 (AQP4-Ab), the most abundant water channel in the central nervous system [2, 6-8, 10, 11]. However, AQP4 is also highly expressed in the basal cell membrane of gastric parietal cells (GPC) and, accordingly, serum AQP4-Ab from patients with NMO has been shown to bind to GPC [10]. The latter fact is of particular interest because humoral autoimmunity to GPC is a common cause of vitamin B12 deficiency and because low vitamin B12 levels can cause subacute combined degeneration of the spinal cord (SACD) as well as optic neuropathy and may thus aggravate neurological deficits in patients with NMO, a disease mainly characterized by spinal cord and optic nerve damage (Fig. 1) [14].