OR13 C3D as a non-invasive tool for early prediction of Antibody Mediated Rejection (AMR) and renal allograft failure

Aim Complement fixation of donor-specific antibodies (DSA) is the hallmark of antibody-mediated rejection (AMR) and usually results in graft loss. However, many patients with DSA maintained a very stable graft function with no rejection, suggesting not all DSA are detrimental. Here, we tested different functional characteristics of DSA as predictors of AMR and graft failure. Methods 315 consecutive renal transplant patients were accrued in this study. Of these 315 patients, 39 patients had de novo DSA. Serum specimens were analyzed for three functional characteristics of DSA-C1q positivity, C3d positivity and type of IgG subtype using single antigen beads. Each functional characteristics was then assessed for its role as biomarker of AMR, graft failure and different histological characteristics associated with chronic allograft failure. Results Among 39 patients, who developed DSA, 19 were C1q+ and 16 were C3d+. Interestingly, 14 of the C3d+ patients had concomitant C1q/C3d positivity (P  Conclusions Early detection of C3d-DSA is an important tool for prediction of AMR, which aids in the identification of patients with high risk of renal allograft failure. The study elaborates the relevance of functional characteristics of DSA on the renal allograft outcome.