title: Response of thymectomy: clinical and pathological characteristics among seronegative and seropositive myasthenia gravis patients.
abstract: OBJECTIVE
  To identify the response to thymectomy in patients with seronegative and seropositive myasthenia gravis (SPMG). We analyzed the associated diseases, thymus histology, and the severity of symptoms between the two groups. MATERIAL AND METHODS - DESIGN: Descriptive, comparative.
  
  
  METHODS
  Fourteen patients with seronegative myasthenia gravis (SNMG) and 57 patients with SPMG who had a thymectomy between 1987 and 1997, with at least 3 years of follow-up. The patients were divided into four groups; (1) Remission, (2) Improvement, (3) No change and (4) Deterioration.
  
  
  RESULTS
  Fourteen patients (20%) were seronegative and 57 were seropositive (80%). In the group of patients with SNMG, three patients were in remission (21%), five with improvement (36%), five with no change (36%) and one with worsening (7%). In the group of patients with SPMG, 12 were in remission (21%), 17 with improvement (30%), 25 with no change (44%) and three (5%) with worsening. The patients with SNMG were older, with less associated diseases and with a lower frequency of thymomas.
  
  
  CONCLUSIONS
  The response to thymectomy was similar between the two groups. It has been suggested that seronegative patients have a better prognosis, but our results show no differences.
authors.affiliation: Departament of Neurology, Instituto Nacional de Ciencias Médicas y Nutrición 'Salvador Zubirán', Mexico City, Mexico. liztellez@correo.unam.mx
authors.forename: G R
authors.initials: GR
authors.lastname: Guillermo
authors.forename: J F
authors.initials: JF
authors.lastname: Téllez-Zenteno
authors.forename: N
authors.initials: N
authors.lastname: Weder-Cisneros
authors.forename: A
authors.initials: A
authors.lastname: Mimenza
authors.forename: B
authors.initials: B
authors.lastname: Estañol
authors.forename: J M
authors.initials: JM
authors.lastname: Remes-Troche
authors.forename: C
authors.initials: C
authors.lastname: Cantu-Brito
mesh_terms: D000328:Adult; D001323:Autoantibodies / Q000097:blood*; D018450:Disease Progression; D004491:Edrophonium; D004576:Electromyography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008297:Male; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000276:immunology / Q000473:pathology / Q000601:surgery*; D009460:Neurologic Examination; D011183:Postoperative Complications / Q000175:diagnosis*; D011950:Receptors, Cholinergic / Q000276:immunology*; D013934:Thymectomy; D013945:Thymoma / Q000276:immunology / Q000473:pathology / Q000601:surgery*; D013952:Thymus Hyperplasia / Q000276:immunology / Q000473:pathology / Q000601:surgery*; D013953:Thymus Neoplasms / Q000276:immunology / Q000473:pathology / Q000601:surgery*; D016896:Treatment Outcome
chemical_list: D001323:Autoantibodies; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D011950:Receptors, Cholinergic; D004491:Edrophonium