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Kidney Week

Abstract: TH-PO0991

Artificial Intelligence (AI)-Based Quantification of Collagen Microarchitecture Across Serial Biopsies Reveals Longitudinal Remodeling Patterns After Kidney Transplantation

Session Information

Category: Transplantation

  • 2001 Transplantation: Basic

Authors

  • Subramanian, Ajay Rajaraman, Georgia Institute of Technology, Atlanta, Georgia, United States
  • Tokuyama, Naoto, Emory University, Atlanta, Georgia, United States
  • Abe, Yohei, Kagawa Daigaku, Takamatsu, Kagawa Prefecture, Japan
  • Krishnamoorthy, Anusha, Georgia Institute of Technology, Atlanta, Georgia, United States
  • Fan, Fan, Emory University, Atlanta, Georgia, United States
  • Pathak, Tilak B., Emory University, Atlanta, Georgia, United States
  • Taoka, Rikiya, Kagawa Daigaku, Takamatsu, Kagawa Prefecture, Japan
  • Madabhushi, Anant, Emory University, Atlanta, Georgia, United States
Background

Early interstitial fibrosis has been associated with long-term graft function after kidney transplantation. However, collagen microarchitecture may undergo longitudinal fibrotic changes in the early post-transplant period, and the trajectory of these changes between implantation and 3 months remains uncharacterized. We investigated whether AI-based quantification of longitudinal collagen microarchitectural changes across serial biopsies could predict early renal allograft function decline.

Methods

We analyzed 136 living-donor kidney transplant recipients at Kagawa University. Masson trichrome–stained implantation and 3-month biopsies were analyzed using a computational pipeline extracting 24 collagen features capturing fiber structure, spatial organization, and textural heterogeneity. Collagen changes were evaluated using Wilcoxon signed-rank tests with Bonferroni correction. Patients were divided into training (n=91) and test (n=45) cohorts. A delta-change model was evaluated for prediction of 2-year ≥20% eGFR decline using Cox regression and Kaplan–Meier analysis.

Results

Eighteen features changed significantly after Bonferroni correction (p<0.002), indicating reduced collagen organization and increased structural heterogeneity. Two prognostic delta features were identified: Haralick IMC1 (HR=1.328, 95% CI 1.091–1.617, p=0.005) and collagen contrast (HR=1.367, 95% CI 1.036–1.804, p=0.027), both reflecting greater textural complexity and spatial irregularity of collagen deposition at 3 months. A two-feature model stratified the held-out test cohort into high- and low-risk groups, with high-risk patients showing over twice the rate of ≥20% eGFR decline events (log-rank p=0.020, C-index=0.637).

Conclusion

Changes in collagen microarchitecture between implantation and 3-month biopsies are associated with subsequent renal allograft dysfunction, suggesting that the interval change between serial biopsies may provide useful prognostic information.