Analysis index

1 ml serum

< 0,4 nmol/l – 0,5 nmol/l

Suspicion of generalized or ocular myasthenia gravis

85 % of patients with generalized form of myasthenia gravis have AchR-antibodies. These bind to the nicotinic acetylcholine receptor of the neuromuscular end plate and not only hinder the ligand binding, but also lead to an internalization of the receptors and possibly to immune-mediated destruction of the end plate, which decreases the responsiveness of musculature and leads to exercise dependent muscle weakness. Patients with the ocular form of MG are more often seronegative. Children of mothers with active MG show a transient form of neonatal MG. Intra individually the determination of antibodies is also suitable for monitoring of disease-activity, as the serum concentration shows good correlation with the intensity of the muscle weakness.

Further autoantibodies: Anti-titin. Anti-titin positive patients more often have thymomas than patients who are only AchR-antibody positive. Differential diagnosis: Lambert Eaton syndrome and neurogenic myotonia, please also refer to VGCC-antibodies and VGKC-antibodies, antineural antibodies.