Neuropsychiatric SLE in children with childhood-onset lupus nephritis: a 20-year retrospective cohort study

Neuropsychiatric systemic lupus erythematosus (NPSLE) and lupus nephritis (LN) are two major, life-threatening complications in childhood-onset SLE (cSLE). Data regarding the epidemiology and prognosis of children with concurrent NPSLE and LN remain scarce. This study aimed to investigate the clinical characteristics, associated factors, and outcomes of NPSLE in Chinese children with LN.

A retrospective cohort study was conducted at the Paediatric Nephrology Centre of Hong Kong Children's Hospital, including 95 Chinese children with biopsy-proven cLN. Comparisons were made between children with and without NPSLE.

Of 95 Chinese children with cLN, 11 (12%) developed NPSLE, and 31 NPSLE events were reported. Estimated glomerular filtration rate < 30 mL/min/1.73 m² at diagnosis of LN (OR_adj 6.7, 95% CI 1.29-35.1) and higher maximal proteinuria during the observation period (OR_adj 1.07, 95% CI 1-1.13) were predictive of NPSLE upon multivariable analysis. Compared to children with LN who did not develop NPSLE, significantly more children who developed subsequent NPSLE flare following initial kidney involvement had a history of medication non-adherence (100% vs. 25%, p < 0.001), higher degree of proteinuria at the diagnosis of LN (urine protein/creatinine ratio, 5.7 vs. 2.4 mg/mg, p = 0.04) and during the entire observation period (urine protein/creatinine ratio, 13.2 vs. 3.3 mg/mg, p = 0.004). Patients with NPSLE had significantly lower complete remission rates for LN at 6- and 12-month post-induction (27.3% vs. 70.2%, p = 0.014; 45.5% vs. 83.3%, p = 0.01, respectively). Kaplan-Meier analysis showed that patients with NPSLE had worse kidney and patient survivals (log-rank test, p < 0.001, 0.0014, respectively) than those without NPSLE.

Worse kidney and patient survivals are observed in cLN patients with NPSLE. Severe LN manifestation and medication non-adherence are associated with the development of NPSLE.