ASN's Mission

ASN leads the fight to prevent, treat, and cure kidney diseases throughout the world by educating health professionals and scientists, advancing research and innovation, communicating new knowledge, and advocating for the highest quality care for patients.

learn more

Contact ASN

1401 H St, NW, Ste 900, Washington, DC 20005

email@asn-online.org

202-640-4660

The Latest on Twitter

Kidney Week

Abstract: PO1766

Renal Activity Index for Lupus Nephritis Distinguishes Active Renal Disease Among Lupus Patients

Session Information

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