Corticosteroid-Refractory Juvenile Myasthenia Gravis: Treatment Responses and Prognosis in a Large Chinese Cohort.

INTRODUCTION/AIMS: Some patients diagnosed with juvenile myasthenia gravis (JMG) have corticosteroid-refractory myasthenia gravis (CRMG). The aim of this study was to evaluate the biomarkers of corticosteroid (CS) responsiveness and refractoriness in children, and the overall prognosis of patients after receiving nonsteroidal immunosuppressants (ISs).

METHODS

This cross-sectional study was conducted at the Department of Pediatrics, Xiangya Hospital, Central South University. Data of the patients diagnosed with JMG from 2010 to 2023 were collected and analyzed.

RESULTS

Two hundred and seventy-five patients were included in this study; 215 utilized CS, of whom 44.2% had CRMG. Ptosis only was an independent predictor of CS responsiveness (OR = 2.13, SE = 0.36, OR 95% CI = 1.05-4.32, p value = 0.003). The presence of acetylcholine receptor antibodies (AChR-Abs) was an independent predictor of CS refractoriness (OR = 2.78, SE = 0.48, OR 95% CI = 1.09-7.05, p value = 0.033). At last follow-up, 65.8% of the CRMG patients responded to ISs including tacrolimus, azathioprine, intravenous immunoglobulin, mycophenolate mofetil, and rituximab. About 71.0% of the patients that received ≤ 2 ISs were responders; however, only 14.3% of the patients that received subsequent ISs responded.

DISCUSSION: This study provides an approximate prevalence of CRMG in children, as well as predictors of CS responsiveness and refractoriness, which can guide clinicians in prescribing alternative ISs in a timely manner. It can also help researchers understand the burden of CRMG in children when developing promising new therapies.