Da, Yuwei

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.

AbstractObjectiveUse of tacrolimus in mild to moderate myasthenia gravis (MG) is generally limited to glucocorticoid‐refractory cases; the advantage of mono‐tacrolimus over mono‐glucocorticoids is unknown.MethodsWe included mild to moderate MG patients treated with mono‐tacrolimus (mono‐TAC) or mono‐glucocorticoids (mono‐GC). The correlation between the immunotherapy options and the treatment efficacy and side effects were examined in 1:1 propensity‐score matching. The main outcome was time to minimal manifestations status or better (MMS or better). Secondary outcomes include time to relapse, the mean changes in Myasthenia Gravis‐specific Activities of Daily Living (MG‐ADL) scores and the rate of adverse events.ResultsBaseline characteristics showed no difference between matched groups (49 matched pairs). There were no differences in median time to MMS or better between the mono‐TAC group and mono‐GC group (5.1 vs. 2.8 months: unadjusted hazard ratio [HR], 0.73; 95% CI, 0.46–1.16; p = 0.180), as well as in median time to relapse (data unavailable for the mono‐TAC group since 44 of 49 [89.8%] participants remained in MMS or better; 39.7 months in mono‐GC group: unadjusted HR, 0.67; 95% CI, 0.23–1.97; p = 0.464). Changes in MG‐ADL scores between the two groups were similar (mean differences, 0.3; 95% CI, −0.4 to 1.0; p = 0.462). The rate of adverse events was lower in the mono‐TAC group compared to the mono‐GC group (24.5% vs. 55.1%, p = 0.002).InterpretationMono‐tacrolimus performs superior tolerability with non‐inferior efficacy compared to mono‐glucocorticoids in mild to moderate myasthenia gravis patients who refuse or have a contraindication to glucocorticoids.