title: Clinical outcome of generalized myasthenia gravis in Hong Kong Chinese.
abstract: BACKGROUND
  Myasthenia gravis (MG) is an organ-specific autoimmune disease characterized by autoantibody-mediated impairment of skeletal muscle neuromuscular transmission. MG causes significant morbidity and even mortality. We studied the long-term clinical outcome of generalized MG (gMG) patients.
  
  
  METHODS
  Records of Chinese gMG patients managed in Queen Mary Hospital from 1997 to 2012 were reviewed. Clinical, serological and radiological characteristics were studied for independent predictors of good long-term clinical outcome.
  
  
  RESULTS
  A total of 123 Chinese gMG patients were studied. Their mean onset age was 44.8 years (range 7-83 years), 87 (70.7%) were female, and median follow-up duration was 114 months (interquartile range 67-188 months). Thymoma were detected in 45 patients (36.6%). Acetylcholine receptor autoantibodies were detected in 99 patients (87.6%). Ninety-three patients (75.6%) received immunosuppressant therapy (corticosteroid 75.6%, azathioprine 58.5%, mycophenolate mofetil 5.7%, cyclosporin 5.7%) and 77 (62.6%) received thymectomy. Thirty-five (28.5%) patients experienced MG crisis and two died. Ninety-six (78.0%) patients had good outcome defined by Myasthenia Gravis Foundation of America (MGFA) post-intervention status (PIS) of complete stable remission (CSR), pharmacological remission (PR) or minimal manifestation (MM) at latest follow-up, whereas 24 patients (19.5%) had intermediate outcome defined by MGFA PIS of Improved (I); 3 patients (2.4%) had poor prognosis defined by MGFA PIS of unchanged (U), worse (W), exacerbation (E) or died of MG (D). Azathioprine therapy was the only independent predictor of good outcome (OR 3.57, 95% CI 1.05-12.10, p=0.042).
  
  
  CONCLUSIONS
  78.0% of gMG patients had good long-term clinical outcome. Azathioprine therapy independently predicted good clinical outcome.
authors.affiliation: University Department of Medicine, Queen Mary Hospital, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong.
authors.forename: C Y
authors.initials: CY
authors.lastname: Lee
authors.affiliation: University Department of Medicine, Queen Mary Hospital, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong.
authors.forename: C L
authors.initials: CL
authors.lastname: Lam
authors.affiliation: University Department of Medicine, Queen Mary Hospital, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong.
authors.forename: S Y Y
authors.initials: SY
authors.lastname: Pang
authors.affiliation: University Department of Medicine, Queen Mary Hospital, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong.
authors.forename: K K
authors.initials: KK
authors.lastname: Lau
authors.affiliation: University Department of Medicine, Queen Mary Hospital, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong.
authors.forename: K C
authors.initials: KC
authors.lastname: Teo
authors.affiliation: University Department of Medicine, Queen Mary Hospital, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong.
authors.forename: R S K
authors.initials: RS
authors.lastname: Chang
authors.affiliation: University Department of Medicine, Queen Mary Hospital, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong; Neuroimmunology and Neuroinflammation Research Laboratory, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong; Research Center of Heart, Brain, Hormone and Healthy Aging, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong. Electronic address: koonho@hkucc.hku.hk.
authors.forename: K H
authors.initials: KH
authors.lastname: Chan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People; D016009:Chi-Square Distribution; D047630:Depsipeptides / Q000627:therapeutic use*; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000188:drug therapy* / Q000453:epidemiology*; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D047630:Depsipeptides; C517593:azathiocoraline
keywords: Acquired myasthenia gravis; Autoimmune; Azathioprine; Clinical outcome; Immunosuppressant therapy