Real-world application of the pediatric Glucocorticoid Toxicity Index in childhood-onset lupus.

Objectives: The pediatric Glucocorticoid Toxicity Index (pGTI) is a new, pediatric-specific tool to quantify glucocorticoid (GC)-related morbidity in children. We evaluated the feasibility and construct validity of retrospective pGTI scoring in patients with pediatric-onset systemic lupus erythematosus (pSLE) and identified risk factors for cumulative toxicity.

Methods: We conducted a retrospective cohort study of patients with pSLE treated with GCs at two pediatric centers (1999-2023). GC exposure was estimated using interval-averaged oral prednisone-equivalent dose and cumulative prednisone-equivalent dose. We scored change in GC toxicity every 6 months (±2) using a modified pGTI including 7 of 10 domains. We calculated the Cumulative Worsening Score (CWS), a continuous summation of toxicity accrued. Mixed effects linear regression was used to identify factors associated with CWS.

Results: There were 126 patients with pSLE, including 88 with nephritis, with a median of 6 visits/patient. Nearly half (47 %) experienced toxicity in the Blood Pressure domain. Other common toxicities were mood disturbance (25 %), followed by increased body mass index (BMI), striae, and sleep disturbance (21 % each). Decreased growth velocity was observed in 18 %. There was modest correlation between cumulative GC dose and CWS (rho 0.3; p < 0.01). Greater cumulative toxicity was associated with younger age, elevated BMI, and rituximab use at the time of GC initiation, albeit indications for the latter were not captured.

Conclusions: Patients with pSLE experience a high burden of GC toxicity, particularly related to blood pressure, BMI, sleep, and growth. Standardized, pediatric-specific GC toxicity assessment is feasible in real-world settings and can facilitate evaluation of strategies to reduce morbidity in children requiring chronic GC treatment.