Abstract: FR-PO1001
Graft Survival Following Microvascular Inflammation: Effect of Donor-Specific Antibodies and Cross-Match Status in Kidney Transplant Recipients
Session Information
- Transplantation: Clinical - Pretransplantation, Living Donation, and Policies
November 07, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Transplantation
- 2102 Transplantation: Clinical
Authors
- Zahran, Somaya, McGill University Health Centre, Montreal, Quebec, Canada
- Balakrishnan, Suryanarayanan, Mayo Clinic Minnesota, Rochester, Minnesota, United States
- Gandhi, Manish, Mayo Clinic Minnesota, Rochester, Minnesota, United States
- Alexander, Mariam P., Mayo Clinic Minnesota, Rochester, Minnesota, United States
- Schinstock, Carrie A., Mayo Clinic Minnesota, Rochester, Minnesota, United States
Background
Microvascular inflammation (MVI) is a hallmark of antibody-mediated rejection (ABMR) and is linked to variable graft outcomes. The Banff 2022 classification recognizes MVI as a spectrum based on the presence or absence of donor-specific antibodies (DSA). We evaluated how DSA status and flow cytometric crossmatch (XM) affect graft survival in kidney transplant recipients with MVI.
Methods
We conducted a retrospective cohort study of kidney transplant recipients at Mayo Clinic Rochester (2010–2024) with at least one biopsy showing MVI. Indication and surveillance biopsies (4 months, 1-, 2-, 4-, and 7-yrs post-transplant) were included. Patients were categorized into four groups: de novo DSA, preformed DSA with positive or negative XM, and no DSA. DSA was defined using MFI >1000, and de novo DSA was newly detected 3 months post-transplant. Graft survival was assessed using Kaplan-Meier methods.
Results
Among 3,352 recipients, 410 (12%) had MVI with DSA data: 19% de novo DSA, 62% preexisting DSA, and 19% no DSA. Among DSA-positive patients, 72% had a positive XM. Mean follow-up was 4.5±3.2 years. Graft survival differed significantly by DSA group (p = 0.031), with the best outcomes in DSA-negative patients. Survival was similar in de novo and preformed DSA groups. Among DSA-positive recipients, those with a positive XM trended toward worse survival than those with a negative XM (p = 0.062).
Conclusion
In kidney transplant recipients with MVI, DSA and XM status predict graft survival. Absence of DSA was linked to better outcomes, while a positive XM identified a higher-risk group. Graft survival was similar in patients with de novo and preformed DSA, differing from prior studies—possibly due to the inclusion of surveillance biopsies, which may have enabled earlier detection. These markers can guide risk stratification and personalize post-transplant care.