title: Thymectomy and anti-muscle autoantibodies in late-onset myasthenia gravis.
abstract: Thymectomy is still widely carried out in myasthenia gravis (MG) patients, but its role, especially in late-onset MG patients, is not established. These patients are immunologically heterogeneous, some with thymoma-like and others with early onset-like features. We evaluated whether any therapeutic effects of thymectomy correlate with the presence of non-acetylcholine receptor (AChR) muscle antibodies. The severity of MG, and titin and ryanodine receptor (RyR) antibodies, were assessed yearly starting from MG onset in 21 thymectomized and 22 non-thymectomized AChR antibody positive late-onset MG patients, who were followed for 2, 3 and 5 years. Clinical or pharmacological remission were seen in six of 11 titin antibody negative but none of the 10 titin antibody positive thymectomized patients, however, the non-thymectomized cases showed an opposite trend. The three MG-related deaths were all in patients with titin antibodies. There was no significant difference in MG severity between thymectomized and non-thymectomized patients; 2 years after MG onset, both groups were significantly improved. This study showed no dramatic benefit from thymectomy in late-onset MG in general. Any limited improvement appeared less likely in cases with titin and/or RyR antibodies.
authors.affiliation: Department of Neurology, Haukeland University Hospital, Bergen, Norway. fredrik.romi@haukeland.no
authors.forename: F
authors.initials: F
authors.lastname: Romi
authors.forename: N E
authors.initials: NE
authors.lastname: Gilhus
authors.forename: J E
authors.initials: JE
authors.lastname: Varhaug
authors.forename: A
authors.initials: A
authors.lastname: Myking
authors.forename: G O
authors.initials: GO
authors.lastname: Skeie
authors.forename: J A
authors.initials: JA
authors.lastname: Aarli
mesh_terms: D017668:Age of Onset; D000368:Aged; D001284:Atrophy; D001323:Autoantibodies / Q000276:immunology*; D015331:Cohort Studies; D064211:Connectin; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009124:Muscle Proteins / Q000276:immunology; D018908:Muscle Weakness / Q000209:etiology / Q000503:physiopathology; D018482:Muscle, Skeletal / Q000276:immunology*; D009157:Myasthenia Gravis / Q000276:immunology* / Q000473:pathology / Q000628:therapy*; D011494:Protein Kinases / Q000276:immunology; D011950:Receptors, Cholinergic / Q000276:immunology; D019837:Ryanodine Receptor Calcium Release Channel / Q000276:immunology; D013934:Thymectomy; D013950:Thymus Gland / Q000473:pathology
chemical_list: D001323:Autoantibodies; D064211:Connectin; D007166:Immunosuppressive Agents; D009124:Muscle Proteins; D011950:Receptors, Cholinergic; D019837:Ryanodine Receptor Calcium Release Channel; C577285:TTN protein, human; D011494:Protein Kinases