P044 C1q status and titer of de novo donor specific antibodies are not predictors of allograft survival

Abstract

De novo donor-specific antibodies ( dn DSA) that develop after renal transplantation are independent predictors of allograft loss. However, it is unknown if dn DSA C1q status or titer at the time of first detection can independently predict allograft outcomes. In 70 renal transplant recipients who developed dn DSA we performed LABScreen single antigen bead assays using: neat, neat with ethylenediaminetetraacetic acid (EDTA), three dilutions after EDTA treatment (1:16, 1:64, 1:1024) and the C1q assay (neat sera). Histologic and clinical outcomes were correlated with the C1q assay or dn DSA titer. C1q positivity correlated with dn DSA titer (p dn DSA (p dn DSA development, but did not predict T-cell mediated rejection (TCMR) or antibody mediated rejection (ABMR). De novo DSA titer correlated with glomuerulitis, interstitial inflammation, tubulitis, peritubular capillaritis, and C4d scores, and predicted TCMR (p dnDSA development or other known predictors of post-dnDSA graft loss (i.e. clinical phenotype or non-adherence) neither C1q status nor dn DSA titer were independent predictors of a composite outcome of a 50% decline in eGFR or allograft loss (Fig. 1). Therefore, at present the additional cost and time associated with these approaches is not justified in routine practise. However, in cases where a renal biopsy is not possible dn DSA titer correlates with TCMR, and AMBR, and may assist in risk stratification. Download high-res image (239KB) Download full-size image