Kidney Week

Abstract: SA-OR059

Percentage of Glomerular Crescents Predicts Renal Outcomes in Children with IgA Vasculitis – A Midwest Pediatric Nephrology Consortium Study

Session Information

• IgA Nephropathy and Lupus Nephritis
  October 27, 2018 | Location: 6E, San Diego Convention Center
  Abstract Time: 04:42 PM - 04:54 PM

Category: Glomerular Diseases

• 1203 Glomerular Diseases: Clinical, Outcomes, and Trials

Authors

• Wenderfer, Scott E., Baylor College of Medicine, Houston, Texas, United States

Scott E. Wenderfer, MD, PhD, FASN



Dr. Wenderfer is a pediatric nephrologist and immunologist with expertise in lupus and autoimmune kidney diseases. The primary goal of his research program at Baylor College of Medicine (BCM) is to improve the diagnosis and outcomes of glomerular diseases in children. He is Director of the Renal Laboratory at Texas Children’s Hospital (TCH) and Assistant Director for the Departmental Research Resource Office. He co-chairs the Glomerular Working Group for the Midwest Pediatric Nephrology Consortium (MWPNC) and the Lupus Nephritis Working Group at the Childhood Arthritis and Rheumatology Research Alliance (CARRA). His research has been funded by the National Institutes of Health, the National Kidney Foundation, and the Lupus Foundation.

• Rheault, Michelle N., University of Minnesota, Minneapolis, Minnesota, United States

Michelle N. Rheault,

• Selewski, David T., University of Michigan, Ann Arbor, Michigan, United States

David T. Selewski,

• Tran, Cheryl L., Mayo Clinic, Rochester, Minnesota, United States

Cheryl L. Tran,

• Pan, Cynthia G., Medical College of Wisconsin, Milwaukee, Wisconsin, United States

Cynthia G. Pan,

• Seamon, Meredith, The University of Utah, Salt Lake City, Utah, United States

Meredith Seamon,

• Nelson, Raoul D., The University of Utah, Salt Lake City, Utah, United States

Raoul D. Nelson,

• Twombley, Katherine, Medical University of South Carolina, Charleston, South Carolina, United States

Katherine Twombley,

• Onder, Ali Mirza, University of Tennessee, Memphis, Tennessee, United States

Ali Mirza Onder,

• Flynn, Joseph T., Seattle Children's Hospital, Seattle, Washington, United States

Joseph T. Flynn,

• Maliakkal, Joseph George, Saint Louis University School of Medicine, St. Louis, Missouri, United States

Joseph George Maliakkal,

• Smoyer, William E., Nationwide Children's Hospital, Columbus, Ohio, United States

William E. Smoyer,

• Hidalgo, Guillermo, Eastern Carolina University, Greenville, North Carolina, United States

Guillermo Hidalgo,

Background

While crescents on kidney biopsy predict poor outcome for children with IgA vasculitis, evidence-based thresholds for %crescents most predictive of renal risk are not established. The International Study of Kidney Disease in Children (ISKDC) used 50% and 75% thresholds to grade severity of crescentic glomerulonephritis. MEST-C scoring for IgA nephropathy has also been proposed for IgA vasculitis: 1 point for any glomerular crescent and 2 when crescents involve >25% of glomeruli.

Methods

To test the validity of 25, 50, and 75% thresholds for crescents in IgA vasculitis, we identified 62 patients (13 centers) in the IRB-approved Midwest Pediatric Nephrology Consortium Glomerulonephritis with Crescents Registry (18% of total). Enrollment included patients <21 yo with >1 crescentic glomerulus on biopsy from 2004-16. Primary outcome was end stage kidney disease (ESKD) at 1 year. Secondary outcomes included estimated glomerular filtration rate (eGFR) at 1 year and change in eGFR over time. Crescents were defined by local renal pathologist.

Results

The cohort was 47% female, 53% white, 3% black, 18% Hispanic, and 3% Asian. Median age at biopsy was 8 years (range 6-11) with 2.6 years median follow-up (IQR 1.7-4.8). A median of 36 glomeruli were sampled per biopsy (IQR 27-57). The median %crescents was 10.8 (IQR 7-18%, max 83%). Cellular crescents were seen in 95% of biopsies; fibrous crescents in 27%; both in 23%. Only 2% of children had crescents in >50% of glomeruli, and only one in >75% of glomeruli. One child with 13% cellular and 3% fibrous crescents advanced to ESKD at 26 months post-biopsy. Median change in eGFR was +2.8 mL/min/1.73m²/year (IQR -20 to +24) at 1 year and -1.5 (IQR -7 to +6) at latest follow-up. Change in eGFR was 2-fold greater for children with >25% crescents (-3.6) vs. those with <25% (-1.6).

Conclusion

Children with higher %crescents present with lower GFRs but most have significant recovery of eGFR at 1 year. Utility of the ISKDC thresholds for grading crescents in IgAV is limited, due to low prevalence of biopsies with crescents >50%. Long term, the 25% threshold for cellular crescents appears to predict worsening GFR decline.