Repeated human leukocyte antigen mismatches in lung re-transplantation

BackgroundThe role of HLA-sensitization in the absence of detectable DSA in lung re-transplantation is unclear. Antigens of the second donor matching the HLA typing of the first donor are considered 'unacceptable', by some tissue typing laboratories, especially in kidney re-transplantation.MethodsThus, we performed a retrospective analysis of all lung re-transplantations focussing on the impact of HLA-homologies between the first and the second donor ('unacceptable' antigens; repeated HLA mismatch) on patient and graft survival.ResultsA total of 132 lung re-transplantations were performed at our centre between 1985 and 2014, of which 120 with complete HLA data were analysed. 55.8% of the recipients received re-transplants with repeated HLA mismatched antigens whereas 43.2% of the re-transplants were transplanted without repeated HLA mismatched antigens.Postoperative survival showed no difference between re-transplant procedures with or without repeated HLA mismatches (p = 0.99). While neither homologies on the HLA-A, -B, -C, or -DR locus, nor the addition of several locus homologies (p = 0.72) had an impact on survival, unexpectedly, repeated HLA mismatching on the HLA-DQ locus was correlated with better survival. Re-transplantations with repeated HLA mismatches did not result in more development of CLAD as compared to recipients without repeated HLA mismatches (p = 0.99). Neither the number of repeated HLA mismatched antigens (p = 0.52) nor the HLA locus (HLA-A(p = 0.34), HLA-B(p = 0.97), HLA-C (p = 0.80), HLA-DR(p = 0.49) and HLA-DQ(p = 0.07)) had an impact on the development of CLAD after re-transplantation.ConclusionTransplantation with repeated HLA mismatches due to sensitization by a previous transplantation in the absence of detectable HLA-antibodies does not have a negative impact on patient or graft survival.