Patients:

Eighty-three consecutive pediatric patients (≤18 years of age) fulfilling ≥4 of the 1997 American College of Rheumatology (ACR) classification criteria for SLE ¹³ were enrolled into this cross-sectional study from the Pediatric Nephrology Research Consortium (PNRC) LN-Autoantibodies study cohort, including patients recruited from pediatric clinics at Texas Children’s Hospital (TCH), Connecticut Children’s Medical Center, and Children’s Healthcare of Atlanta. The study was approved by the institutional review boards (IRBs) at Baylor College of Medicine (H-35050), the University of Connecticut, Emory University, and the University of Houston. Full protocol for the LN-autoantibody study is available upon request. All enrolled patients completed an IRB-approved informed consent form based on good clinical practice and the Declaration of Helsinki. Demographic, clinical data and conventional measures of disease activity, including anti-dsDNA (ordinal variable, based on Crithidia titer), complement C3 and C4 levels (continuous variable, in mg/dL), spot urinary protein-to-creatinine ratio (uPCR), serum creatinine levels, and eGFR (estimated by Bedside Schwartz equation) were collected prospectively. Demographics and clinical characteristics are summarized in Table 1. As controls, healthy individuals of comparable sex and age were enrolled from the Gynecology and Adolescent Medicine Clinic at TCH.

Patient demographics and clinical characteristics:

Interquartile range.