Antibodies and Allograft Outcomes (Videos Available)

Tuesday July 03, 2018 from 09:45 to 11:15

Room: N-117/118

425.2 Antibody-mediated rejection with and without HLA donor-specific antibodies in kidney-transplantation

Abstract

Antibody-Mediated Rejection With and Without HLA Donor-Specific Antibodies in Kidney-Transplantation

Marta Crespo1, Dolores Redondo1, Carrie Butler4, Javier Gimeno2, Carme Garcia3, Maria Jose Perez1, Carla Burballa1, Marisa Mir1, Anna Faura1, Nicole M Valenzuela4, Elaine F Reed4, Julio Pascual1.

1Nephrology Department, Hospital del Mar. Institute Mar for Medical Research, Barcelona, Spain; 2Pathology Department, Hospital del Mar. Institute Mar for Medical Research, Barcelona, Spain; 3Catalonian Reference Laboratory, Barcelona, Spain; 4UCLA Immunogenetics Center. Department of Pathology and Laboratory Medicine, University of California , Los Angeles, CA, United States

Background: Correlation between antibody-mediated damage (AMR) and HLA donor-specific antibodies (DSA) is strong but imperfect in kidney transplant (KT) recipients. We reviewed histopathology and HLA DSA in AMR patients and compared them with those with only interstitial fibrosis and tubular atrophy (IFTA) or no abnormalities.
Methods: Retrospective assessment of patients with biopsies (Banff’13) and serum samples (pre- and postransplant) tested for HLA antibodies.
Results: A total of 118 patients were studied. The diagnoses were normal biopsy (n=16), AMR (n=53) and IFTA (n=49). Death-censored graft survival was worse in patients with AMR than with IFTA or normal biopsies. Pre-transplant DSA were more frequent in AMR cases than IFTA or normal ones (46.3%, 20.5 and 6.3%, p=0.003). Differences were mostly due to pre-transplant DSA combined I&II (22 vs 2.3 and 0%, p=0.004) but not to isolated DSA class I or II. At biopsy, 75.5% AMR patients had HLA DSA (7.5% class I, 54.7% II and 13.2% combined I&II), but also 14.6% of IFTA and 6.3% of normals. Twelve AMR patients (22.6%) had no DSA pre-transplant or peri-biopsy. AMR patients with and without DSA were similar at baseline, except that more DSA+AMR patients were sensitized pretransplant and less well DR-matched, with no differences in graft function or immunosuppression. Patients with AMR with or without DSA showed similar microvascular inflammation and chronic changes.
Conclusions: 20% of patients with AMR do not show circulating HLA DSA. These patients are more frequently HLA unsensitized pre-transplant, without other differences at transplantation, in their biopsies or at follow-up.

 



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