Preformed donor specific antibodies in CDC-XM negative living unrelated male to female spousal kidney transplantations are associated with an increased risk of acute antibody-mediated rejection

F.H.J. Claas, J.W. de Fijter, K.E. Groeneweg, S. Heidt, M.E.J. Reinders, D.L. Roelen, D. Soonawala, F. van der Toorn

Wednesday 4 march 2020

16:00 - 16:10h at Joep Nicolas zaal

Parallel session: Parallel sessie VII – Basale- en Klinische abstracts

Background: Shortage of deceased donor kidneys has led to increased numbers of living unrelated kidney, in particular spousal, donors. Female recipients of a spousal kidney have an increased risk for pre-immunization and acute antibody-mediated rejection (ABMR). The aim of this study is to assess the incidence of ABMR and preformed donor specific antibodies (pDSA) in living unrelated donors (LURD) and to identify risk factors for acute ABMR.

Methods: We identified all 349 ABO compatible, CDC-crossmatch negative, LURD transplants performed at our transplant center between 1997 and 2015. All for-cause biopsies were classified according to the BANFF 2017 classification. All patients with ABMR were retrospectively tested for the presence of pDSA with multiplex and single antigen tests. Risk factors for immunization were extracted from personal health records and questionnaires.

Results: The overall incidence of biopsy-proven acute rejection in the first 6 months was 20% (TCMR: 85%; ABMR: 15%); median time to onset of ABMR was 8 days (range 5-75 days). Outcome was poor in ABMR as compared with patients with TCMR or those w/o rejection (graft loss or eGFR <30ml/min at month-6: 36%, 12% and 2% respectively). Eight patients with ABMR were female (73%) and six of these (75%) were recipients of a spousal kidney. Of these spouses four had given birth to a child of their kidney donor and 2 received blood transfusions prior to transplantation. Retrospectively 80% of spousal recipients with ABMR had pDSA in single antigen test, of which 67% had a negative multiplex initially.

Conclusions: Female spousal kidney recipients have a relatively high risk of ABMR. Traditional methods for detecting pDSA are not sensitive enough to rule out pDSA. Multiplex and single antigen should be included in the standard work-up of potential female spousal kidney transplant recipients to prevent ABMR and guide the option of indirect (cross-over) donation.