Histopathology at Diagnosis and One-Year Outcomes in Antibody Mediated Rejection in Pediatric Kidney Transplant Recipients: Preliminary Findings from the Paramour “Pediatric Renal AMR Outcomes” Study

R. Zahr¹, D. Puliyanda², I. Ashoor³, N. Hayde⁴, S. Solomon⁵, R. Engen⁶, L. Harshman⁷, C. Peterson⁸, S. McEwen⁹, A. Jain¹⁰, R. Garro¹¹, A. Mansuri¹², M. Kallash¹³, K. Twombley¹⁴

¹Pediatrics, University of Tennessee Health Science Center, Memphis, TN, ²Cedars-Sinai Med Ctr, West Hollywood, CA, ³Pediatrics, Lousiana State University, New Orleans, LA, ⁴Montefiore Medical Center, Bronx, NY, ⁵The Children's Hospital at Montefiore, New York, NY, ⁶Pediatrics, University of Wisconsin Madison, Madison, WI, ⁷University of Iowa Children's Hospital, Iowa City, IA, ⁸University of Utah, Salt Lake City, UT, ⁹University of Minnesota, Minneapolis, MN, ¹⁰Pediatrics, Wayne State University, Troy, MI, ¹¹Emory University, Atlanta, GA, ¹²Pediatrics, Augusta University, Augusta, GA, ¹³Pediatrics, The Ohio State Univesrity, Columbus, OH, ¹⁴Medical University of South Carolina, Charleston, SC

Meeting: 2022 American Transplant Congress

Abstract number: 407

Keywords: Biopsy, Histology, Rejection

Topic: Clinical Science » Kidney » 44 - Kidney Acute Antibody Mediated Rejection

Session Information

Session Name: Kidney Immunosuppression: Desensitization & Acute Antibody Mediated Rejection

Session Type: Rapid Fire Oral Abstract

Date: Tuesday, June 7, 2022

Session Time: 3:30pm-5:00pm

Presentation Time: 4:40pm-4:50pm

Location: Hynes Ballroom A

*Purpose: Antibody mediated rejection (AMR) is a major cause of kidney allograft dysfunction leading to graft loss. There is a paucity of data regarding how histopathology at diagnosis of AMR correlates with one year outcome in pediatric kidney transplant recipients.

*Methods: PARAMOUr is a retrospective cohort study of 127 pediatric transplant recipients from 14 centers within the Pediatric Nephrology Research Consortium with biopsy proven AMR between 12/31/2009-12/31/2019. This study examined histopathology scores at time of diagnosis with one year kidney function outcomes. Estimated glomerular filtration rate (eGFR) was obtained by the modified Schwartz formula.

*Results: Males (63%) were more likely to have AMR; with the median age at diagnosis of AMR being 15 years of age. Pure AMR was diagnosed in 54.3% (69/127) patients and in 45.7% (58/127) mixed AMR + TCMR (T-cell mediated rejection). Of 127 patients with AMR, only 87 patients had complete histopathology Banff scoring. The 87 patients were divided into 2 groups for comparison: >30% decrease in eGFR or eGFR <20 at one year (n=35); and <30% decrease in eGFR at one year (n=52). There was no difference in the microvascular injury, acute inflammation, chronic inflammation or interstitial fibrosis/tubular atrophy scores.

*Conclusions: Most AMR diagnoses occurred in adolescents and was most common in male pediatric transplant patients. Pathology scores at time of AMR diagnosis did not differ between our composite outcomes. Future exploration of potential biomarkers of transplant rejection may be important in predicting the prognosis of AMR in pediatric kidney transplant patients.

Histopathology Results in Pediatric Kidney Transplant AMR and One Year Graft Function Outcome
	>30% decrease in eGFR, or eGFR<20 N=35 (SD)	<30% decrease in eGFR N=52 (SD)	P value
Pathology Scores at diagnosis
Microvascular Injury Score	2.1 (+/-1.5)	2.5 (+/- 1.7)	0.23
Chronic inflammation	4.0 (+/- 2.7)	3.2 (+/- 3.2)	0.59
Acute Inflammation	4.5 (+/-2.0)	4.7 (+/-2.1)	0.79
Interstitial Fibrosis and Tubular Atrophy	2.5 (+/-1.8)	2.0 (+/-1.5)	0.13

To cite this abstract in AMA style:

Zahr R, Puliyanda D, Ashoor I, Hayde N, Solomon S, Engen R, Harshman L, Peterson C, McEwen S, Jain A, Garro R, Mansuri A, Kallash M, Twombley K. Histopathology at Diagnosis and One-Year Outcomes in Antibody Mediated Rejection in Pediatric Kidney Transplant Recipients: Preliminary Findings from the Paramour “Pediatric Renal AMR Outcomes” Study [abstract]. Am J Transplant. 2022; 22 (suppl 3). https://atcmeetingabstracts.com/abstract/histopathology-at-diagnosis-and-one-year-outcomes-in-antibody-mediated-rejection-in-pediatric-kidney-transplant-recipients-preliminary-findings-from-the-paramour-pediatric-renal-amr-outcomes/. Accessed November 21, 2024.

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