Kidney Week

Abstract: SA-PO670

Utility of Adult-Derived Biomarkers for Assessment of Kidney Function in Pediatric ANCA-Associated Vasculitis

Session Information

• Pediatric Nephrology - 2
  October 26, 2024 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Pediatric Nephrology

• 1900 Pediatric Nephrology

Authors

• Brown, Kelly, The University of British Columbia Faculty of Medicine, Vancouver, British Columbia, Canada

Kelly Brown, PhD

• Mann, Simranpreet Kaur, The University of British Columbia, Vancouver, British Columbia, Canada

Simranpreet Kaur Mann

• Toor, Kirandeep, The University of British Columbia, Vancouver, British Columbia, Canada

Kirandeep Toor

• Bosman, Else S., BC Children's Hospital, Vancouver, British Columbia, Canada

Else S. Bosman, PhD

• Chen, Audrea, The Hospital for Sick Children, Toronto, Ontario, Canada

Audrea Chen, MD

• Mammen, Cherry, BC Children's Hospital, Vancouver, British Columbia, Canada

Cherry Mammen, MD

• Cabral, David A., BC Children's Hospital, Vancouver, British Columbia, Canada

David A. Cabral, MBBS

• Morishita, Kimberly, BC Children's Hospital, Vancouver, British Columbia, Canada

Kimberly Morishita, MD

Group or Team Name

• On behalf of the Pediatric Vasculitis (PedVas) Investigator Network.

Background

In adults with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), measures of ANCA positivity and antigen specificity, estimated glomerular filtration rate (eGFR), and urine proteins are informative of kidney function and aid treatment decisions. Despite aggressive therapy, two-thirds of pediatric AAV patients have persistently reduced renal function. The objective of this study is to evaluate the utility of adult-derived kidney markers in pediatric AAV.

Methods

Eligible participants < 18 yrs of age in the ARChiVe/PedVas initiative had a diagnosis of small vessel vasculitis including AAV, ANCA positive pauci-immune glomerulonephritis, and unclassified primary vasculitis. Kidney disease activity was defined by the renal component of the pediatric vasculitis activity score. Kidney function was categorized by eGFR into KDIGO stages. Predictive analysis of ANCA and baseline eGFR for 1- to 2-year outcomes were conducted using adjusted regression models and/or a proportional odds logistic regression model. Concentrations (ELISA) of MCP-1, sCD25, and sCD163 in time-of-diagnosis urine was measured for correlations with baseline and 1-year kidney state using R statistical language.

Results

At diagnosis, patients with MPO-ANCA had similar levels of overall disease activity to those with PR3-ANCA but had 2.4 times higher odds of kidney involvement (P = 0.008) and 6.0 times higher likelihood of worse kidney dysfunction (P < 0.001). Time-of- diagnosis eGFR was informative to future kidney function with the odds of worse kidney function at 1-year being 18.2 times higher for children with moderately-severely reduced function at onset. Urine proteins performed poorly as indicators of kidney disease activity at onset and follow up.

Conclusion

The results of this study show mixed utility of adult derived biomarkers for use in the pediatric population, with severe kidney disease at onset and function over the first 1-year being best informed, respectively, by MPO-ANCA seropositivity and baseline eGFR. The study illustrates the need for pediatric AAV-focused studies for novel kidney biomarker discovery.

Funding

• Government Support – Non-U.S.