B cell-targeted therapy with rituximab and autoimmune neuromuscular disorders.

B lymphocytes play a central role in the pathogenesis of autoimmunity, so that B cell suppression is considered a potential treatment option for immune-mediated diseases. Rituximab, a chimeric anti-human CD20 antibody, is the only anti-B cell biological agent presently under study for the treatment of autoimmune neuromuscular diseases. Isolated case histories and series, pilot and retrospective studies report on the experimental administration of rituximab as treatment of a variety of immune-mediated neuropathy syndromes, treatment-refractory myasthenia gravis and inflammatory myopathies. Rituximab was used as monotherapy or in combination with other types of immunomodulation, and was well tolerated. The mechanism whereby B cell depletion shows benefit is uncertain and may vary depending on the inherent differences in the pathogenesis of various autoimmune neuromuscular disorders.