Therapeutic Advances in Neurological Disorders (Jan 2025)

Short-term and long-term prognoses in AChR-Ab positive very-late-onset myasthenia gravis patients

  • Nairong Xie,
  • Qing Liu,
  • Qi Wen,
  • Yaye Wang,
  • Haoran Liu,
  • Yuting Jiang,
  • Yan Lu,
  • Li Di,
  • Min Wang,
  • Wenjia Zhu,
  • Xinmei Wen,
  • Xuxiang Zhang,
  • Xin-Ming Shen,
  • Yuwei Da

DOI
https://doi.org/10.1177/17562864241309793
Journal volume & issue
Vol. 18

Abstract

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Background: Very-late-onset myasthenia gravis (VLOMG) refers to myasthenia gravis (MG) with onset at age 65 or older. Current research on VLOMG prognosis remains limited, especially regarding factors influencing outcomes. Objectives: To identify the clinical factors that affect the short- and long-term prognosis of MG patients with an onset age ⩾65 years. Design: This was a single-center, retrospective cohort study of AChR-ab positive VLOMG patients, classified into two subgroups based on age of onset: sub-very-late-onset MG (S-VLOMG, onset age ⩾65 and <75 years), and super-late-onset MG (SLOMG, onset age ⩾75 years). Methods: A total of 93 patients were included, including 75 in the S-VLOMG group and 18 in the SLOMG group. Clinical, therapeutic, and prognosis data were reviewed, and the Cox regression model was used to identify factors influencing short- and long-term prognosis. Results: Patient characteristics were well balanced between the groups. Overall, 49.5% of patients achieved minimal symptom expression (MSE) within 6 months and 86% within 24 months. There was no significant difference between the groups in the proportion achieving MSE at 6 months ( p = 0.635) or 24 months ( p = 0.714). The median time to achieve MSE was also comparable between the S-VLOMG and SLOMG groups (199.0 days vs 280.5 days, p = 0.463). Low baseline MG-ADL score and steroid therapy were associated with better short-term prognosis ( p = 0.007 and p = 0.002, respectively). For long-term prognosis, baseline bulbar and limb involvement, time to treatment initiation, and use of immunosuppressants were significant factors ( p = 0.025, p = 0.004, p = 0.025, and p < 0.0001, respectively). There were no significant differences in side effects or drug withdrawal rates between two groups. Conclusion: This study demonstrated that AChR-ab positive VLOMG patients have a favorable prognosis and responded well to medication, with age and comorbidities showing no significant impact.