Design and Methods of the Validating Injury to the Renal Transplant Using Urinary Signatures (VIRTUUS) Study in Children

Juhi Kumar; Kévin Contrepois; Michael Snyder; Paul C Grimm; Asha Moudgil; Jodi M Smith; Amy E Bobrowski; Priya S Verghese; David Hooper; Elizabeth Ingulli; Rachel Lestz; Patricia Weng; Janaiya L Reason; Tom D Blydt-Hansen; Manikkam Suthanthiran; Brendan Keating; Sandra Amaral

doi:10.1097/TXD.0000000000001244

Design and Methods of the Validating Injury to the Renal Transplant Using Urinary Signatures (VIRTUUS) Study in Children

Transplant Direct. 2021 Nov 17;7(12):e791. doi: 10.1097/TXD.0000000000001244. eCollection 2021 Dec.

Authors

Juhi Kumar¹, Kévin Contrepois², Michael Snyder², Paul C Grimm³, Asha Moudgil⁴, Jodi M Smith⁵, Amy E Bobrowski⁶, Priya S Verghese⁷, David Hooper⁸, Elizabeth Ingulli⁹, Rachel Lestz¹⁰, Patricia Weng¹¹, Janaiya L Reason¹², Tom D Blydt-Hansen¹³, Manikkam Suthanthiran¹⁴, Brendan Keating¹⁵, Sandra Amaral¹⁶

Affiliations

¹ Department of Pediatrics and Population Health Sciences, Weill Cornell Medicine, New York, NY.
² Department of Genetics, Stanford University School of Medicine, Stanford, CA.
³ Department of Pediatrics, Stanford University School of Medicine, and Lucile Packard Children's Hospital, Stanford, CA.
⁴ Division of Nephrology, Children's National Hospital, The George Washington University School of Medicine and Health Sciences, Washington, DC.
⁵ Seattle Children's Hospital, University of Washington, Seattle, WA.
⁶ Center for Pediatric Nephrology, Cleveland Clinic Children's, Cleveland, OH.
⁷ Ann and Robert H. Lurie Children's Hospital, Chicago, IL.
⁸ Cincinnati Children's Hospital, Cincinnati, OH.
⁹ Rady Children's, San Diego, CA.
¹⁰ Children's Hospital Los Angeles, Los Angeles, CA.
¹¹ Mattel Children's Hospital, University of California Los Angeles, Los Angeles, CA.
¹² University of Pennsylvania, Philadelphia, PA.
¹³ University of British Columbia, Vancouver, BC, Canada.
¹⁴ Department of Medicine, Weill Cornell Medicine, New York, NY.
¹⁵ Division of Transplantation, Department of Surgery, Perelman School of Medicine, Penn Transplant Institute, University of Pennsylvania, Philadelphia, PA.
¹⁶ Departments of Pediatrics and Biostatistics, Epidemiology and Informatics, Perelman School of Medicine, Children's Hospital of Philadelphia and University of Pennsylvania, Philadelphia, PA.

Abstract

Lack of noninvasive diagnostic and prognostic biomarkers to reliably detect early allograft injury poses a major hindrance to long-term allograft survival in pediatric kidney transplant recipients.

Methods: Validating Injury to the Renal Transplant Using Urinary Signatures Children's Study, a North American multicenter prospective cohort study of pediatric kidney transplant recipients, aims to validate urinary cell mRNA and metabolite profiles that were diagnostic and prognostic of acute cellular rejection (ACR) and BK virus nephropathy (BKVN) in adult kidney transplant recipients in Clinical Trials in Organ Transplantation-4. Specifically, we are investigating: (1) whether a urinary cell mRNA 3-gene signature (18S-normalized CD3ε, CXCL10 mRNA, and 18S ribosomal RNA) discriminates biopsies with versus without ACR, (2) whether a combined metabolite profile with the 3-gene signature increases sensitivity and specificity of diagnosis and prognostication of ACR, and (3) whether BKV-VP1 mRNA levels in urinary cells are diagnostic of BKVN and prognostic for allograft failure.

Results: To date, 204 subjects are enrolled, with 1405 urine samples, including 144 biopsy-associated samples. Among 424 urine samples processed for mRNA, the median A260:280 ratio (RNA purity) was 1.91, comparable with Clinical Trials in Organ Transplantation-4 (median 1.82). The quality control failure rate was 10%. Preliminary results from urine supernatant showed that our metabolomics platform successfully captured a broad array of metabolites. Clustering of pool samples and overlay of samples from various batches demonstrated platform robustness. No study site effect was noted.

Conclusions: Multicenter efforts to ascertain urinary biomarkers in pediatric kidney transplant recipients are feasible with high-quality control. Further study will inform whether these signatures are discriminatory and predictive for rejection and infection.

Abstract

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