Specific autoantibodies (AChR, MuSK, Lrp4) should not be required as a profile when myasthenia gravis is suspected, but the initial test is represented only by anti-AchR antibodies. The determination of anti-Musk antibodies should be reserved for anti-AChR negative patients, while that of anti-Lrp4 antibodies should be limited to anti-AChR and anti-MuSK negative patients.

Type of practice

Laboratory tests

Since the three autoantibodies are mutually exclusive, it is not useful to simultaneously request the determination of all three antibodies, because about 80% of patients with myasthenia have only anti-AChR, 16% only anti-MuSK and the remaining 4% only anti-Lrp4 antibodies.


1. Leite MI, Waters P, Vincent A (2010) Diagnostic use of autoantibodies in myasthenia gravis. Autoimmunity 43:371-379
2. Evoli A (2017) Myasthenia gravis: new developments in research and treatment. Curr Opin Neurol 30:464-470
3. Gilhus NE (2016) Myasthenia gravis. N Engl J Med 375:2570-2581
4. Zisimopoulou P, Evangelakou P, Tzartos J, Lazaridis K, Zouvelou V, Mantegazza R et al (2014) A comprehensive analysis of the epidemiology and clinical characteristics of anti-LRP4 in myasthenia gravis. J Autoimmun 52:139-145

Attention. Please note that these items are provided only for information and are not intended as a substitute for consultation with a clinician. Patients with any specific questions about the items on this list or their individual situation should consult their clinician.