Acquired neuromyotonia in thymoma-associated myasthenia gravis: a clinical and serological study
Articolo
Data di Pubblicazione:
2019
Abstract:
Background and purpose: Acquired neuromyotonia can occur in patients with
thymoma, alone or in association with myasthenia gravis (MG), but the clinical
prognostic significance of such comorbidity is largely unknown. The clinico-
pathological features were investigated along with the occurrence of
neuromyotonia as predictors of tumour recurrence in patients with thymomaassociated
myasthenia.
Methods: A total number of 268 patients with thymomatous MG were studied
retrospectively. Patients with symptoms of spontaneous muscle overactivity were
selected for autoantibody testing using immunohistology for neuronal cell-surface
proteins and cell-based assays for contactin-associated protein 2 (CASPR2),
leucine-rich glioma inactivated 1 (LGI1), glycine receptor and Netrin-1 receptor
antibodies. Neuromyotonia was diagnosed according to the presence of typical
electromyography abnormalities and/or autoantibodies against LGI1/CASPR2.
Results: Overall, 33/268 (12%) MG patients had a thymoma recurrence. Five/
268 (2%) had neuromyotonia, four with typical autoantibodies, including LGI1
(n = 1), CASPR2 (n = 1) or both (n = 2). Three patients had Netrin-1 receptor
antibodies, two with neuromyotonia and concomitant CASPR2+LGI1 antibodies
and one with spontaneous muscle overactivity without electromyography evidence
of neuromyotonia. Thymoma recurrence was more frequent in those with
(4/5, 80%) than in those without (28/263, 10%, P < 0.001) neuromyotonia.
Neuromyotonia preceded the recurrence in 4/5 patients. In univariate analysis,
predictors of thymoma recurrence were age at thymectomy [odds ratio (OR)
0.95, 95% confidence interval (CI) 0.93–0.97], Masaoka stage ≥IIb (OR 10.73,
95% CI 2.38–48.36) and neuromyotonia (OR 41.78, 95% CI 4.71–370.58).
Conclusions: De novo occurrence of neuromyotonia in MG patients with previous
thymomas is a rare event and may herald tumour recurrence. Neuronal autoantibodies
can be helpful to assess the diagnosis. These observations provide pragmatic
risk stratification for tumour vigilance in patients with thymomatous MG.
thymoma, alone or in association with myasthenia gravis (MG), but the clinical
prognostic significance of such comorbidity is largely unknown. The clinico-
pathological features were investigated along with the occurrence of
neuromyotonia as predictors of tumour recurrence in patients with thymomaassociated
myasthenia.
Methods: A total number of 268 patients with thymomatous MG were studied
retrospectively. Patients with symptoms of spontaneous muscle overactivity were
selected for autoantibody testing using immunohistology for neuronal cell-surface
proteins and cell-based assays for contactin-associated protein 2 (CASPR2),
leucine-rich glioma inactivated 1 (LGI1), glycine receptor and Netrin-1 receptor
antibodies. Neuromyotonia was diagnosed according to the presence of typical
electromyography abnormalities and/or autoantibodies against LGI1/CASPR2.
Results: Overall, 33/268 (12%) MG patients had a thymoma recurrence. Five/
268 (2%) had neuromyotonia, four with typical autoantibodies, including LGI1
(n = 1), CASPR2 (n = 1) or both (n = 2). Three patients had Netrin-1 receptor
antibodies, two with neuromyotonia and concomitant CASPR2+LGI1 antibodies
and one with spontaneous muscle overactivity without electromyography evidence
of neuromyotonia. Thymoma recurrence was more frequent in those with
(4/5, 80%) than in those without (28/263, 10%, P < 0.001) neuromyotonia.
Neuromyotonia preceded the recurrence in 4/5 patients. In univariate analysis,
predictors of thymoma recurrence were age at thymectomy [odds ratio (OR)
0.95, 95% confidence interval (CI) 0.93–0.97], Masaoka stage ≥IIb (OR 10.73,
95% CI 2.38–48.36) and neuromyotonia (OR 41.78, 95% CI 4.71–370.58).
Conclusions: De novo occurrence of neuromyotonia in MG patients with previous
thymomas is a rare event and may herald tumour recurrence. Neuronal autoantibodies
can be helpful to assess the diagnosis. These observations provide pragmatic
risk stratification for tumour vigilance in patients with thymomatous MG.
Tipologia CRIS:
1.1 Articolo in rivista
Keywords:
autoantibodies; DCC antibodies; myasthenia gravis; neuromyotonia; paraneoplastic neurological syndrome; thymoma; UNC5A antibodies
Elenco autori:
Gastaldi, M.; De Rosa, A.; Maestri, M.; Zardini, E.; Scaranzin, S.; Guida, M.; Borrelli, P.; Ferraro, O. E.; Lampasona, V.; Furlan, R.; Irani, S. R.; Waters, P.; Lang, B.; Vincent, A.; Marchioni, E.; Ricciardi, R.; Franciotta, D.
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