Abstract: PO1766
Renal Activity Index for Lupus Nephritis Distinguishes Active Renal Disease Among Lupus Patients
Session Information
- Glomerular Diseases: Lupus and Membranous
October 22, 2020 | Location: On-Demand
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1202 Glomerular Diseases: Immunology and Inflammation
Authors
- Aljaberi, Najla Fadl Jaafar Bader, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
- Mathur, Arjun, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
- Jose, Steffy, Baylor College of Medicine, Houston, Texas, United States
- Hennard, Theresa, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
- Merritt, Angela, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
- Ma, Qing, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
- Rose, James, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
- Sahay, Rashmi, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
- Liu, Chunyan, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
- Brunner, Hermine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States
- Wenderfer, Scott E., Baylor College of Medicine, Houston, Texas, United States
Background
Conventional tools to identify active nephritis in SLE (LN) fail to supersede invasive kidney biopsy. The renal activity index in lupus (RAIL) was developed using 6 urinary biomarkers to reflect disease activity (Brunner, et al. 2016). Our objective was to test RAIL for identifying active LN in childhood-onset SLE.
Methods
Urine samples obtained from cross-sectional sampling of 2 cSLE cohorts, classified as active LN, inactive LN or non-LN SLE. RAIL scores were calculated from ELISA or nephelometry data for six urine markers (NGAL-1, ceruloplasmin, MCP-1, adiponectin, hemopexin, kidney injury molecule-1). Data collected included ISN/RPS histologic classification and extra-renal component of SLE disease activity index (SLEDAI) score.
Results
Among 117 cSLE patients, 37 had active LN; 30, inactive LN; 50, no-LN. RAIL scores of inactive LN and no-LN group largely overlapped, so they were combined (Group 2) and compared to active LN (Group 1, Table). Group 1 had higher RAIL score (0.7 vs. -1.1). After adjusting for age and extra-renal SLEDAI score, RAIL score odds ratio was 2.16 (95%CI 1.4-3.3, p=0.001) for active LN. A receiver operating curve (ROC) for an adjusted RAIL cut-off score of 0.35 produced an AUC=0.9 (sensitivity 86%, specificity 84%) for active LN. Adjustment for urinary protein and creatinine did not influence results.
Conclusion
The RAIL score is highly accurate in distinguishing active from inactive LN and non-LN SLE. Scores >0.35 identify cSLE patients who very likely have active LN.
Clinical characteristics and distribution of RAIL scores among Group 1 (active LN) and Group 2 (inactive LN + active non-LN SLE) patients
| Group 1 Active LN N = 37 | Group 2 Inactive LN + Non-LN SLE N = 80 | p-value | |
| Age (y), median (IQR) | 15 (13-17) | 18 (16-21) | < 0.0001 |
| Extra-renal SLEDAI, median (IQR) | 9 (6-13) | 2 (0-4) | < 0.0001 |
| GFR, median (IQR) | 91 (60-129) | 108 (98-126) | 0.05 |
| Urinary creatinine, median (IQR) | 92 (61-191) | 134 (73-184) | 0.32 |
| Urinary protein, median (IQR) | 254 (98-404) | 21 (11-50) | < 0.0001 |
| Urinary microalbumin, median (IQR) | 254 (189-316) | 15 (9-43) | < 0.0001 |
| RAIL Score, median (IQR) | 0.7 (-0.1-1.6) | -1.1 (-2.5-0.3) | < 0.0001 |
| NIH-AI, median (IQR)¥ | 9 (4-13) | 0 (0-0) | < 0.0001 |
| NIH-CI, median (IQR)¥ | 1 (0-2.75) | 0 (0-0) | 0.11 |
¥ Includes only active (N=24) and inactive LN (N=4) patients with sampling performed within 30 days of kidney biopsy