The C1q-Binding Assays and Clinical Outcomes in Kidney Transplantation
1Transplantation Immunology and Nephrology, University Hospital Basel, Basel, Switzerland
2Institute for Pathology, University Hospital Basel, Basel, Switzerland
3Department of Pathology and Laboratory Medicine, Dalhousie University, Halifax, Canada.
Meeting: 2015 American Transplant Congress
Abstract number: 373
Keywords: Antibodies, Kidney transplantation
Session Information
Session Name: Concurrent Session: Kidney: Antibodies and Allograft Injury
Session Type: Concurrent Session
Date: Tuesday, May 5, 2015
Session Time: 2:15pm-3:45pm
Presentation Time: 2:51pm-3:03pm
Location: Room 118-AB
Background: Contradictory conclusions have emerged from clinical trials when testing the predictive value of C1q-binding donor-specific HLA-antibodies (HLA-DSA). The aim of this study was to investigate the association between C1q-binding ability of HLA-DSA and the clinical outcome (i.e. antibody-mediated rejection (AMR) and long-term allograft survival).
Methods: Pretransplant sera of 64 patients known to possess preformed HLA-DSA were retrospectively analyzed by the standard and anti-globulin (AHG) enhanced C1q assay.
Results: The cumulative incidence of clinical/subclinical AMR within 6 months posttransplant was equal in recipients with and without C1q-binding HLA-DSA when using the standard C1q and the AHG C1q assay with the cut-offs MFI 300, 500, and 1000 for positivity (p=0.62, p=0.47, p=0.80 and p=0.58, p=0.40, p=0.42, respectively). The prevalence of subclinical AMR at 3 and 6 months posttransplant was also not different between the recipients with and without C1q-binding HLA-DSA: p>0.55, p>0.35, and p>0.35 for the standard C1q assay; p>0.20, p>0.20, and p>0.10 for the AHG C1q assay with the cut-offs MFI 300, 500, and 1000. At a median of 8 years posttransplant, allograft survival was equal in patients with/without C1q-binding HLA-DSA (p>]0.57 for the standard and p>]0.09 for the AHG enhanced C1q assay). The MFI was a strong and independent factor for C1q-binding in both C1q assays (OR>8.25 for standard and >4.33 for AHG enhanced C1q assay; p<0.0001).
Conclusion:Pretransplant C1q-binding HLA-DSA – either detected by the standard or the AHG enhanced C1q assay – were not predictive for any clinical outcome. The MFI of HLA-DSA was strongly influencing C1q-binding.
To cite this abstract in AMA style:
Amico P, Hönger G, Hopfer H, Liwski R. The C1q-Binding Assays and Clinical Outcomes in Kidney Transplantation [abstract]. Am J Transplant. 2015; 15 (suppl 3). https://atcmeetingabstracts.com/abstract/the-c1q-binding-assays-and-clinical-outcomes-in-kidney-transplantation/. Accessed May 9, 2025.« Back to 2015 American Transplant Congress