Ocular MG an Independent Predictor of MG Responsive to Corticosteroids

Almost half of young patients with myasthenia gravis (MG) were refractory when they received corticosteroids (CS), whereas more than half responded well. A new study published in Muscle & Nerve1 found that the addition of other immunosuppressants (IS) led to more than two-thirds of patients with corticosteroid-refractory MG (CRMG) becoming responsive.

A total of 7.7% of the patients with MG in China were 19 years and younger, according to a recent population-based study.2 Ocular MG is milder in these younger patients compared with adult patients. Chinese guidelines indicate that CS should be used as a first-line immunotherapy in young children with MG.1 However, responses to CS in young patients have not been well studied. This study aimed to assess which biomarkers can predict CRMG and the overall prognosis of children with MG when they receive first, second, and successive IS to treat their MG.

MG that is responsive to corticosteroids was predicted through ocular MG symptoms. | Image credit: Kamitana - stock.adobe.com

All patients diagnosed with MG between June 2010 and January 2023 at the Department of Pediatrics in Xiangya Hospital of Central South University had their medical records collected for this retrospective study. Patients who only received CS for at least half a year and patients who received IS when symptoms were not controlled with CS alone were considered as having CRMG. Patients were excluded if there was insufficient data on treatment or if improved status or better was not reached due to an insufficient amount of CS. Patients who were 14 years or younger, had clear treatment information, and had a follow-up period of more than 1 year were included in the study.

There were 3 groups that patients were divided into: CS-free patients, CS-responsive patients, and patients with CRMG. The first group includes patients who achieved complete stable remission, pharmacologic remission, minimal manifestation, or improved status without the use of CS or IS.

There were 275 patients included in this study, of which 60 were in the CS-free group. A total of 78.2% of the 275 patients had used CS, with 55.8% responsive to CS vs 44.2% who had CRMG. Abnormal repetitive nerve stimulation and being positive for acetylcholine receptor (AChR) antibodies were associated with CRMG based on a univariate analysis.

An independent predictor of CS-responsive MG was ptosis (OR, 2.13; 95% CI, 1.05-4.32), but this association only remained when AChR antibody–positive status was an independent predictor of CRMG (OR, 2.78; 95% CI, 1.09-7.05).

A total of 76 patients with CRMG were given IS, with about a third receiving more than 1. Patients responded in 65.8% of the cases at the last follow-up. Proportion of responders decreased as more IS were given. No patient stopped taking tacrolimus due to adverse effects.

There were some limitations to this study. The retrospective design could have introduced information bias, and all data were collected from a single center, which could bias the results.

The researchers concluded that young patients with MG overall responded well with CS, with more than half having some response. CS-responsive MG was predicted through patients with ocular MG who had ptosis alone. “Prospective multicenter studies and clinical trials are needed to provide more CRMG predictors and better treatment options,” the authors wrote.

References

1. Kessi M, Huang X, Wang G, et al. Corticosteroid-refractory juvenile myasthenia gravis: treatment responses and prognosis in a large Chinese cohort. Muscle Nerve. Published online February 2, 2026. doi:10.1002/mus.70171
2. Chen J, Tian DC, Zhang C, et al. Incidence, mortality, and economic burden of myasthenia gravis in China: a nationwide population-based study. Lancet Reg Health West Pac. 2020;5:100063. doi:10.1016/j.lanwpc.2020.100063