MuSK antibody screening is used to diagnose severe myasthenia gravis, mainly as a second test, when the first-line serological tests are negative.
Autoantibodies against the acetylcholine receptor (AChR) are present in 80 to 90% of patients with severe myasthenia (myasthenia gravis). About 45% of patients with generalized severe myasthenia who do not have antibodies against the acetylcholine receptor have antibodies against muscle-specific receptor tyrosine kinase (MuSK).
Patients negative for acetylcholine receptor antibodies and positive for MuSK antibodies tend to have a much lower incidence of thymoma and thymus hyperplasia. Patients with severe myasthenia and positive AChR antibodies do not have MuSK antibodies. MuSK antibodies generally do not occur in patients with ocular myasthenia.
Screening for MuSK antibodies may clarify the diagnosis of myasthenia gravis in patients who are negative for antibodies against AChR.
See also: Acetylcholine Receptor (AChR) Antibodies, LRP4 Antibodies
Important Note
Laboratory test results are the most important parameter for the diagnosis and monitoring of all pathological conditions. 70%-80% of diagnostic decisions are based on laboratory tests. The correct interpretation of laboratory results allows a doctor to distinguish "healthy" from "diseased".
Laboratory test results should not be interpreted from the numerical result of a single analysis. Test results should be interpreted in relation to each individual case and family history, clinical findings, and the results of other laboratory tests and information. Your personal physician should explain the importance of your test results.
At Diagnostiki Athinon we answer any questions you may have about the test you perform in our laboratory and we contact your doctor to get the best possible medical care.
