title: Two-year outcome of thymectomy in non-thymomatous late-onset myasthenia gravis.
abstract: Thymectomy is an effective treatment for myasthenia gravis (MG). However, there is limited data on its effectiveness in non-thymomatous late-onset MG (LOMG). The aim of this study was to analyze the effects of thymectomy in LOMG. We retrospectively reviewed the 2-year post-thymectomy prognosis in 39 consecutive patients with non-thymomatous, anti-acetylcholine receptor antibody positive, and generalized LOMG (age at onset ≥ 50 years). The MG foundation of America (MGFA) classification, MGFA post-intervention status, dosage of prednisolone and pyridostigmine, and anti-acetylcholine receptor antibody titers were evaluated. Among the 39 LOMG patients, thymic hyperplasia was seen in 5 (12.8%). MGFA classification and prednisolone dosage before thymectomy were similar between the LOMG with thymic hyperplasia group (n = 5) and the LOMG with involuted thymus group (n = 34). Two years after thymectomy, the LOMG patients with thymic hyperplasia showed higher proportion of remission (60 vs. 26%) and received lower prednisolone dosage compared to patients with involuted thymus (0.8 vs. 4.0 mg/day). Notably, the proportion of patients with minimal manifestation or better status with receiving ≤ 5 mg/day prednisolone was much higher in the thymic hyperplasia group than in the involuted thymus group (100 vs. 62%). In conclusion, thymectomy could have beneficial effects in generalized LOMG, particularly in patients with thymic hyperplasia.
authors: Department of Neurology, Graduate School of Medicine, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba, 260-8670, Japan, auzawa@chiba-u.jp.
authors: Akiyuki
authors: A
authors: Uzawa
authors: Naoki
authors: N
authors: Kawaguchi
authors: Tetsuya
authors: T
authors: Kanai
authors: Keiichi
authors: K
authors: Himuro
authors: Fumiko
authors: F
authors: Oda
authors: Shigetoshi
authors: S
authors: Yoshida
authors: Ichiro
authors: I
authors: Yoshino
authors: Satoshi
authors: S
authors: Kuwabara
mesh_terms: D017668:Age of Onset; D000368:Aged; D001323:Autoantibodies / Q000097:blood; D002800:Cholinesterase Inhibitors / Q000627:therapeutic use; D005260:Female; D005938:Glucocorticoids / Q000627:therapeutic use; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000097:blood / Q000188:drug therapy / Q000601:surgery*; D011239:Prednisolone / Q000627:therapeutic use; D011729:Pyridostigmine Bromide / Q000627:therapeutic use; D011950:Receptors, Cholinergic / Q000276:immunology; D013934:Thymectomy / Q000379:methods*; D013950:Thymus Gland / Q000002:abnormalities / Q000187:drug effects / Q000601:surgery; D015898:Tomography Scanners, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D001323:Autoantibodies; D002800:Cholinesterase Inhibitors; D005938:Glucocorticoids; D011950:Receptors, Cholinergic; D011239:Prednisolone; D011729:Pyridostigmine Bromide