Date: Sunday, April 30, 2017
Session Time: 6:00pm-7:00pm
Presentation Time: 6:00pm-7:00pm
Location: Hall D1
Aim: Characteristics of de novo donor-specific HLA antibodies (dnDSA) that are associated with C4d positive antibody-mediated rejection (C4d+ AMR) in kidney transplants have not been well defined. We determined the nature of dnDSA, their capacity to bind complement components (C1q and C3d), and their correlation with biopsy proven C4d+ AMR in kidney transplant recipients.
Methods: Sera from 120 kidney transplant recipients (68 males; 14 re-Tx; 43 LD), who had dnDSA (by One Lambda single antigen beads) at the time of a protocol or for-cause kidney biopsy (median 3.8 yrs post-tx), were tested for C1q (One Lambda) and C3d (Immucor) binding dnDSA. Results were assessed using two-tailed Fisher's exact probabilities.
Results: Most of the recipients had a single DSA (53.3%) while 23.3% had 2 DSAs and 23.3% had >2 DSAs. Most of the DSA were directed against HLA class II (103/120; 86%). The strongest DSAs in most patients were directed to DQ antigens (80/120; 67%) . Fifty-seven patients (48%) had C3d-binding dnDSA, and sixty-seven patients (56%) had C1q-binding DSA. Most of the C3d and C1q-binding dnDSA had high MFI (13932+5278 and 14144+5363, respectively) compared with the C3d/C1q-negative dnDSA (5970+3347).
Sixty-three patients (52.5%) were diagnosed with C4d+ AMR (Table). Most of the C4d+ AMR patients had C3d (63.5%) and C1q (66.7%) binding dnDSA compared to the AMR negative group, and the differences were statistically significant. Furthermore, the patients with C3d and C1q-binding dnDSA had higher C4d scores on their biopsy.
Conclusions: Most dnDSA in kidney tx are directed against DQ molecules. There is a strong correlation between dnDSA with MFI>10000 and C3d/C1q-binding. The presence of C3d/C1q-binding MFI>10000 dnDSA is associated with a greater incidence of AMR. In addition, kidney recipients with high MFI/C3d/C1q-binding dnDSA had higher score of C4d deposition on the biopsy.
CITATION INFORMATION: Rajalingam R, Kopchaliiska D, Buenaventura O, Singh M, Tomlanovich S. Characterization of De Novo Donor-Specific HLA Antibodies and Correlations with C4d+ Antibody-Mediated Rejection of Kidney Transplants. Am J Transplant. 2017;17 (suppl 3).
To cite this abstract in AMA style:Rajalingam R, Kopchaliiska D, Buenaventura O, Singh M, Tomlanovich S. Characterization of De Novo Donor-Specific HLA Antibodies and Correlations with C4d+ Antibody-Mediated Rejection of Kidney Transplants. [abstract]. Am J Transplant. 2017; 17 (suppl 3). https://atcmeetingabstracts.com/abstract/characterization-of-de-novo-donor-specific-hla-antibodies-and-correlations-with-c4d-antibody-mediated-rejection-of-kidney-transplants/. Accessed December 6, 2019.
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