Muscle autoantibodies in myasthenia gravis: beyond diagnosis?

Abstract

Myasthenia gravis is an autoimmune disorder of the neuromuscular junction. A number of molecules, including ion channels and other proteins at the neuromuscular junction, may be targeted by autoantibodies leading to abnormal neuromuscular transmission. In approximately 85% of patients, autoantibodies, directed against the postsynaptic nicotinic acetylcholine receptor can be detected in the serum and confirm the diagnosis, but in general, do not precisely predict the degree of weakness or response to therapy. Antibodies to the muscle-specific tyrosine kinase are detected in approximately 50% of generalized myasthenia gravis patients who are seronegative for anti-acetylcholine receptor antibodies, and levels of anti-muscle-specific tyrosine kinase antibodies do appear to correlate with disease severity and treatment response. Antibodies to other muscle antigens may be found in the subsets of myasthenia gravis patients, potentially providing clinically useful diagnostic information, but their utility as relevant biomarkers (measures of disease state or response to treatment) is currently unclear.

Keywords::

• AChR
• biomarkers
• diagnosis
• MuSK
• myasthenia gravis

Financial & competing interests disclosure

MN Meriggioli is a consultant and serves on the speakers bureau for Athena Diagnostics. He receives funding from the NIH (grant no. K08NS058800; National Institute of Neurologic Disorders and Stroke), Gliknik Inc. and the Muscular Dystrophy Association (MDA 34545 and MDA 185924). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.