MuSK autoantibodies in myasthenia gravis detected by cell based assay--A multinational study
- Tsonis, AI1
- Zisimopoulou, P2
- Lazaridis, K2
- Tzartos, J2
- Matsigkou, E2
- Zouvelou, V3
- Mantegazza, R4
- Antozzi, C4
- Andreetta, F4
- Evoli, A5
- Deymeer, F6
- Saruhan-Direskeneli, G6
- Durmus, H6
- Brenner, T7
- Vaknin, A7
- Berrih-Aknin, S8
- Behin, A8
- Sharshar, T9
- De Baets, J10
- Losen, M10
- Martinez-Martinez, P10
- Kleopa, KA11
- Zamba-Papanicolaou, E11
- Kyriakides, T11
- Kostera-Pruszczyk, A12
- Szczudlik, P12
- Szyluk, B12
- Lavrnic, D13
- Basta, I13
- Peric, S13
- Tallaksen, C14
- Maniaol, A15
- Casasnovas Pons, C16
- Pitha, J17
- Jakubíkova, M17
- Hanisch, F18
- Tzartos, SJ19
- 1. Hellenic Pasteur Institute, Athens, Greece; University of Patras, Patras, Greece
- 2. Hellenic Pasteur Institute, Athens, Greece
- 3. Neurology Department, Aeginition Hospital, Athens, Greece
- 4. Neurological Institute "C. Besta", Milano, Italy
- 5. Institute of Neurology, Catholic University, Rome, Italy
- 6. Istanbul University, Istanbul, Turkey
- 7. Hadassah Hebrew University Medical Center, Jerusalem, Israel
- 8. UPMC and INSERM, Paris, France
- 9. Raymond Poincaré Hospital, Garches, France
- 10. School for Mental Health and Neuroscience, Maastricht University, The Netherlands
- 11. The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus; Cyprus School of Molecular Medicine
- 12. Department of Neurology, Medical University of Warsaw, Poland
- 13. Neurology Clinic, Clinical Center of Serbia, School of Medicine, University of Belgrade, Belgrade, Serbia
- 14. Norway Department of Neurology, Ullevaal University Hospital, Oslo, Norway; Faculty of Medicine, Olso University, Norway
- 15. Norway Department of Neurology, Ullevaal University Hospital, Oslo, Norway
- 16. Bellvitge University Hospital, Barcelona, Spain
- 17. Department of Neurology and Clinical Neuroscience Center, 1st Faculty of Medicine, Charles University and General Teaching Hospital, Prague, Czech Republic
- 18. Universitätsklinikum Halle, Germany
- 19. Hellenic Pasteur Institute, Athens, Greece; University of Patras, Patras, Greece; Tzartos NeuroDiagnostics, Athens, Greece
Description
Seronegative myasthenia gravis (MG) presents a serious gap in MG diagnosis and understanding. We applied a cell based assay (CBA) for the detection of muscle specific kinase (MuSK) antibodies undetectable by radioimmunoassay. We tested 633 triple-seronegative MG patients' sera from 13 countries, detecting 13% as positive. MuSK antibodies were found, at significantly lower frequencies, in 1.9% of healthy controls and 5.1% of other neuroimmune disease patients, including multiple sclerosis and neuromyelitis optica. The clinical data of the newly diagnosed MuSK-MG patients are presented. 27% of ocular seronegative patients were MuSK antibody positive. Moreover, 23% had thymic hyperplasia suggesting that thymic abnormalities are more common than believed.