Abstract: SA-PO687
Biomarkers of Disease Activity in Childhood-Onset Lupus Nephritis
Session Information
- Pediatric Glomerular Disease
November 09, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Pediatric Nephrology
- 1700 Pediatric Nephrology
Authors
- Greco, Jessica M., Ohio State Wexner Medical Center, Columbus, Ohio, United States
- Zhang, Xiaolan, The Ohio State University, Columbus, Ohio, United States
- Sinclair, John, The Ohio State University, Columbus, Ohio, United States
- Mason, Sherene, Connecticut Children's Medical Center, New Haven, Connecticut, United States
- Greenbaum, Larry A., Emory University, Atlanta, Georgia, United States
- Kallash, Mahmoud, Nationwide Children's Hospital, Hilliard, Ohio, United States
- Wenderfer, Scott E., Baylor College of Medicine, Houston, Texas, United States
- Rovin, Brad H., Ohio State University Wexner Medical Center, Columbus, Ohio, United States
Background
Systemic Lupus Erythematosus (SLE) is a chronic autoimmune disease that affects children and adults, but is more severe and more often involves the kidneys in children. The traditional clinical signs of renal injury do not adequately reflect kidney histology in lupus nephritis (LN), but repeating biopsies frequently is not practical. In adults with LN urine levels of CD163 and epidermal growth factor (EGF) correlate with histologic activity and chronic damage, respectively. These putative biomarkers were examined in a cohort of SLE patients from the Midwest Pediatric Nephrology Consortium.
Methods
Urine was collected prospectively from 37 pediatric patients with active LN, 27 with active extra-renal lupus, and 34 with inactive SLE. Urine CD163 (uCD163) and urine EGF (uEGF) were measured by ELISA and analyzed using JMP14 Pro.
Results
uCD163 was higher in children with active LN compared to those with active non-renal lupus and inactive disease (p=0.0011, p=0.0004, respectively). uCD163 fell significantly in patients who had a complete renal response or in whom renal inflammation resolved on repeat biopsy after 6 months of treatment (328±350 ng/mg urine creatinine vs 15±31 ng/mg, P<0.03). uCD163 correlated with the biopsy NIH activity index (r2=0.452, p=0.002), and specifically capillary hypercellularity, WBC infiltration, hyaline deposits, karyorrhexis, and interstitial inflammation. uCD163 did not correlate with chronic damage. uEGF was significantly lower in children with active LN compared to those with active non-renal lupus and inactive disease (p=0.0008, p=0.0004, respectively). In patients with eGFR <60 ml/min/m2 uEGF was 24±8 ng/mg compared to 129±44 ng/mg in those with eGFR >60 (p<0.0001). In the patients with eGFR <60, the biopsy chronicity index (CI) was 0 (n=2), 2 (n=1), 3 (n=1). uEGF did not correlate with CI, interstitial fibrosis, or tubular atrophy. uEGF tended to increase in treated patients as eGFR improved (p=0.06).
Conclusion
uCD163 reflects histologic activity in pediatric patients with LN. In children uEGF does not reflect histologic chronicity, but appears to be a marker of acute kidney injury.