Am J Transplant 2019 May 6. Epub 2019 May 6.
Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium.
In this cohort study (N=924), we investigated the evolution and clinical significance of pretransplant donor-specific HLA antibodies (preDSA), detected in the single-antigen beads assay but CDC-crossmatch-negative. Donor specificity of the preDSA (N=107) was determined by high-resolution genotyping of donor-recipient pairs. We found that in 52% of the patients with preDSA, preDSA spontaneously resolved within the first 3 months posttransplant. PreDSA that persisted posttransplant had higher pretransplant MFI values and more specificity against DQ. Patients with resolved and persistent DSA both had a high incidence of histological picture of antibody-mediated rejection (ABMR ; respectively 54% and 59%). Patients with preDSA that persisted posttransplant had worse 10-year graft survival compared to resolved DSA and preDSA-negative patients. Compared to cases without preDSA, Cox modeling revealed an increased risk of graft failure only in the patients with persistent DSA, in the presence (HR=8.3) but also in the absence (HR=4.3) of ABMR . In contrast, no increased risk of graft failure was seen in patients with resolved DSA. We conclude that persistence of preDSA posttransplant has a negative impact on graft survival, beyond ABMR . Even in the absence of antibody-targeting therapy, low-MFI DSA and non-DQ preDSA often disappear early posttransplantation and are not deleterious for graft outcome. This article is protected by copyright. All rights reserved.