Abstract: FR-PO1181
Beyond Microvascular Inflammation: Banff Activity Index Trajectories Improve Risk Stratification After Antibody-Mediated Rejection
Session Information
- Transplantation: Clinical - Rejection, Biomarkers, and Pharmacology
October 23, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Transplantation
- 2002 Transplantation: Clinical
Authors
- Zuñiga Gonzalez, Erick Yasar, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Mexico City, CDMX, Mexico
- Camacho Murillo, Luis Agustín, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Mexico City, CDMX, Mexico
- Uribe-Uribe, Norma O., Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Mexico City, CDMX, Mexico
- Morales-Buenrostro, Luis E., Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Mexico City, CDMX, Mexico
Background
Antibody-mediated rejection (ABMR) represents a dynamic immune process, yet risk stratification relies mainly on cross-sectional microvascular inflammation (MVI) scoring. Whether longitudinal Banff Activity Index trajectories offer superior prognostic value over MVI-based trajectories remains unknown.
Methods
Single-center retrospective cohort of kidney transplant recipients with biopsy-proven ABMR and longitudinal surveillance biopsies, reclassified per Banff 2022 criteria. MVI (g+ptc) and Banff Activity Index were each modeled as longitudinal trajectories using latent class mixed models (LCMM). Primary outcome was death-censored graft loss; Cox models were adjusted for age, baseline eGFR, and chronicity burden.
Results
Among 166 recipients (median follow-up 56 months; 547 biopsies, median 3/patient), 33 graft losses occurred. LCMM identified two phenotypes for both Banff Activity Index and MVI: high-risk persistent and resolving trajectories (Figure 1A,C). Both models showed good discrimination: Activity Index C-index 0.82 (bootstrap 95%CI 0.73–0.90), MVI C-index 0.80 (95%CI 0.71–0.88); difference not significant (ΔC=0.019, p=0.227). Activity Index trajectory remained associated with graft loss after adjustment for age, baseline eGFR, and baseline chronicity burden (aHR 0.34, 95% CI 0.13–0.91, p=0.031), whereas MVI trajectory showed a clinically meaningful but non-significant association (aHR 0.45, 95%CI 0.20–1.05, p=0.064) (Figure 1 B,D). Baseline eGFR remained independently associated with graft loss.
Conclusion
Activity Index and MVI trajectories showed equivalent overall discrimination, yet Activity Index–based trajectories appeared to provide additional risk stratification beyond MVI alone. These findings support follow-up histologic surveillance after ABMR for dynamic risk assessment.
Figure1