OBJECTIVE
The objective of this study was to evaluate the utility of urine CD163 for detecting disease activity in childhood-onset systemic lupus erythematosus (cSLE) patients.
METHODS
Sixty consecutive pediatric patients fulfilling ≥ 4 ACR criteria for SLE and twenty healthy controls were recruited for testing of urinary CD163 using enzyme linked immunosorbent assay. SLE disease activity was assessed using SLEDAI-2000.
RESULTS
Urine CD163 was significantly higher in patients with active lupus nephritis than inactive SLE patients and healthy controls, with ROC AUC values ranging from 0.93-0.96. Lupus nephritis was ascertained by kidney biopsy. Levels of CD163 significantly correlated strongly with SLEDAI, renal SLEDAI, urinary protein excretion, and C3 complement levels. Urine CD163 was also associated with high renal pathology activity index and chronicity index, correlating strongly with interstitial inflammation and interstitial fibrosis based on examining concurrent kidney biopsies.
CONCLUSION
Thus, urine CD163 emerges as a promising marker for identifying cSLE patients with active kidney disease. Longitudinal studies are warranted to validate the clinical utility of urine CD163 in tracking kidney disease activity in children with lupus.