Session Time: 5:30pm-7:30pm
Presentation Time: 5:30pm-7:30pm
Location: Halls C&D
Introduction: Paired/pooled donation (PPD) facilitates transplantation between UK donor-recipient pairs who are either HLA or blood group incompatible, in whom transplantation is either contraindicated or considered 'high risk'. In the current era, allograft survival in ABOi transplantation is comparable with ABOc. Chronic AMR remains the leading cause of allograft failure in ABOc grafts with the risk of de novo DSA and rejection depending upon the degree of HLA mismatch (MM). The aim of this study was to determine the impact of HLA mismatch on the outcomes of ABOi and living donor ABOc grafts. This in turn will help inform patients considering entering the PPD system with a well HLA matched but blood group incompatibility donor.
Methods: We performed a retrospective analysis of ABOi and ABOc grafts transplanted between2005-2015. A low HLA MM was defined by a NHSBT MM level of 1 or 2, and a high MM as a level of 3 or 4. 55 high MM ABOi, 5 low MM ABOi, 428 high ABOc and 137 low ABOc were performed and all patients received a steroid sparing immunosuppressive protocol. Mean follow up was 5.3 ±2.8 yrs.
Results: Allograft outcomes are shown below.
|Event free survival||High ABOi||Low ABOi||High ABOc||Low ABOc||p value|
|Graft loss (GL)||80.1%||100.0%||77.4%||87.0%||0.68|
|De novo DSA||78.9%||100.0%||65.3%||92.2%||0.0001|
The mean time to rejection was shorter in the high ABOi [0.97 (0.6-6.3) months] compared with the high ABOc [5.8 (4.4-7.8) months] group, p=0.0065. Directly comparing high ABOi with high ABOc grafts; overall rejection was increased [HR 1.72 (0.97-3.0), p=0.03], however there was no difference in GL [HR 0.77(0.36-1.68), p=0.48], AMR [HR 0.52 (0.21-1.30), p=0.07] and DSA risk [HR: 0.72 (0.40-1.32), p=0.35].
Discussion: Small numbers in the low ABOi group preclude statistical analysis however extrapolation from the low ABOc group suggest that low ABOi patients may have better outcomes than high ABOc grafts. It is therefore important when considering entering ABOi patients into the PPD that HLA mismatch requirements are stipulated if the original ABOi donor is well HLA matched, otherwise the ABOi recipient may be disadvantaged if they receive a poorly matched ABOc graft.
CITATION INFORMATION: Willicombe M, Lawrence C, Charif R, McLean A, Galliford J, Taube D. Poor HLA Matching May Reduce the Beneficial Effect of ABOi Pairs Entering the Paired and Pooled Scheme. Am J Transplant. 2016;16 (suppl 3).
To cite this abstract in AMA style:Willicombe M, Lawrence C, Charif R, McLean A, Galliford J, Taube D. Poor HLA Matching May Reduce the Beneficial Effect of ABOi Pairs Entering the Paired and Pooled Scheme. [abstract]. Am J Transplant. 2016; 16 (suppl 3). https://atcmeetingabstracts.com/abstract/poor-hla-matching-may-reduce-the-beneficial-effect-of-aboi-pairs-entering-the-paired-and-pooled-scheme/. Accessed March 8, 2021.
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