Neuromyelitis optica in patients with myasthenia gravis who underwent thymectomy.
BACKGROUND
Myasthenia gravis (MG) and neuromyelitis optica (NMO, also known as Devic disease) are rare autoimmune disorders, with upper-limit prevalence estimates in the general population of 15 per 100,000 and 5 per 100,000, respectively. To our knowledge, an association between these diseases has not been previously reported.


OBJECTIVE
To describe 4 patients with MG who developed NMO after thymectomy and to analyze possible causes of apparent increased prevalence of NMO among patients with MG.


METHODS
Case series.


METHODS
Four patients with MG who underwent thymectomy.


METHODS
None.


RESULTS
The prevalence of MG within the published cohort of patients with NMO is more than 150 times higher than that in the general population.


CONCLUSIONS
Dysregulation of B-cell autoimmunity in myasthenia, possibly exacerbated by loss of control over autoreactive cells as a result of thymectomy, may predispose patients to the development of NMO.
Kister
Ilya
I
Department of Neurology, Albert Einstein College of Medicine, Bronx, NY 10467, USA.
Gulati
Sandeep
S
Boz
Cavit
C
Bergamaschi
Roberto
R
Piccolo
Giovanni
G
Piccolo
Guiseppe
G
Oger
Joel
J
Swerdlow
Michael L
ML
D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D009157:Myasthenia Gravis / Q000150:complications / Q000473:pathology / Q000601:surgery*; D009471:Neuromyelitis Optica / Q000150:complications / Q000473:pathology / Q000601:surgery*; D013934:Thymectomy / Q000379:methods*; D016896:Treatment Outcome