Thymectomy in nonthymoma early-onset myasthenia gravis in correlation with disease severity and muscle autoantibodies

Eur Neurol. 2003;49(4):210-7. doi: 10.1159/000070185.

Abstract

Objective: To study the clinical effect of thymectomy in a well-defined early-onset MG subgroup and to correlate it to MG severity, the presence of circulating muscle autoantibodies, and the need for pharmacological treatment in a long-term setting.

Methods: Fifty-two consecutive AChR antibody-positive early-onset MG patients (34 thymectomized and 18 nonthymectomized) were included. Severity was assessed and the pharmacological treatment monitored on a yearly basis, starting from the year of MG onset, for 5, 10, 15, and 20 consecutive years; AChR, titin, and RyR antibodies were assayed.

Results: In the four follow-up groups, MG severity was significantly higher in nonthymectomized compared to thymectomized MG patients. The postthymectomy MG improvement was significant and persistent. There were 21/34 remissions in thymectomized patients and only 4/18 in the nonthymectomized group. Patients with initially high or low AChR antibody concentration had a similar thymectomy outcome. Only 6 patients had titin antibodies, and none had RyR antibodies.

Conclusion: The present study indicates a benefit of thymectomy in early-onset MG. The muscle autoantibody concentration does not influence the outcome of thymectomy in early-onset MG.

Publication types

  • Comparative Study

MeSH terms

  • Acetylcholine / blood
  • Acetylcholine / immunology
  • Adrenal Cortex Hormones / therapeutic use
  • Adult
  • Age of Onset
  • Autoantibodies / blood*
  • Cholinesterase Inhibitors / therapeutic use
  • Connectin
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Muscle Proteins / blood
  • Muscle Proteins / immunology
  • Muscle Weakness / etiology
  • Muscle Weakness / physiopathology*
  • Muscles / immunology
  • Myasthenia Gravis / blood
  • Myasthenia Gravis / therapy*
  • Plasmapheresis
  • Protein Kinases / blood
  • Protein Kinases / immunology
  • Pyridostigmine Bromide / therapeutic use
  • Remission Induction
  • Retrospective Studies
  • Ryanodine Receptor Calcium Release Channel / blood
  • Ryanodine Receptor Calcium Release Channel / immunology
  • Severity of Illness Index
  • Thymectomy*
  • Thymus Gland / pathology
  • Thymus Gland / surgery
  • Treatment Outcome

Substances

  • Adrenal Cortex Hormones
  • Autoantibodies
  • Cholinesterase Inhibitors
  • Connectin
  • Muscle Proteins
  • Ryanodine Receptor Calcium Release Channel
  • TTN protein, human
  • Protein Kinases
  • Pyridostigmine Bromide
  • Acetylcholine