Work

Claims-Based Phenotyping of Acute Kidney Transplant Rejection in a National Medicare Cohort

Year: 2026

Type: article

Abstract: Introduction: National transplant registries record acute rejection (AR) without the granularity needed to study rejection heterogeneity and prognosis at scale. Whether AR can be stratified by type and severity in national claims data using a claims-based algorithm, and whether these phenotypes correlate with graft outcomes, remains unclear. Methods: We conducted a cohort study using the US Renal Data System (USRDS) data including adult kidney transplant recipients from 2012-2021. AR within 12 months posttransplant was identified using International Classification of Diseases codes for transplant complications with evidence of antirejection treatment within 2 weeks. Episodes were categorized by type and severity based on treatment regimen. Biopsy-associated AR was defined by renal biopsy within 14 days before the treatment. Death-censored graft survival was assessed using Kaplan-Meier methods and multivariable Cox proportional hazards models. Results: < 0.05]), with trends persisting after adjustment for recipient and donor characteristics. Conclusion: Claims-based phenotyping can identify clinically meaningful AR subtypes and prognostic gradients at national scale, enabling more granular national rejection surveillance.

Source: Kidney International Reports

DOI: 10.1016/j.ekir.2026.107060