Clinical characteristics of children with membranous lupus nephritis: the Childhood Arthritis and Rheumatology Research Alliance Legacy Registry.

Objective The objective of this article is to describe and compare clinical features, treatment, and renal outcomes of children with membranous lupus nephritis (MLN), through analysis of a national multicenter registry. Methods Patients with pediatric systemic lupus erythematosus (SLE) and MLN from the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Legacy Registry were included. Demographic, disease and medication-related data were collected between 2010 and 2014 from 59 CARRA Legacy Registry sites. Results A total of 132 individuals had MLN, either in isolation or in combination with proliferative LN. Seventy-four patients had pure MLN. The proportion of patients with daily corticosteroid treatment was similar among groups (96%, 91%, and 96%, for class III+V, IV+V, and V, respectively, p = 0.67). Proportion of individuals exposed to any disease-modifying antirheumatic drug (DMARD) or biologic was similar among the three groups (83%, 91%, 95% for class III+V, IV+V, and V, respectively, p = 0.189). Proportion of patients with decreased glomerular filtration rate (less than 90 ml/min/1.73 m2) was significantly different among groups (4%, 38%, and 4%, for class III+V, IV+V, and V, respectively, p < 0.0001). Conclusion This is the largest reported cohort of children with MLN. More research is needed to understand treatment practices for pediatric MLN, particularly decisions related to pharmacologic treatment of pure MLN. More work is also needed to identify prognostic factors and predictors of outcome for pediatric MLN. Future observational studies will be a first step toward understanding and formulating a standardized approach to treatment of pediatric membranous LN and allowing for the initiation of prospective comparative effectiveness studies and interventional trials.