Evolving experience of treating antibody-mediated rejection following lung transplantation

Background: The importance of antibody-mediated rejection (AMR) following lung transplantation remains contentious. In particular, the diagnostic criteria suggested to define AMR, namely the presence of donor-specific antibodies (DSA), C4d immunoreactivity, histological features and allograft dysfunction are not always readily applicable or confirmatory in lung transplantation. Methods: In a retrospective single-center study of 255 lung transplant recipients (LTR), we identified 9 patients in whom a clinical diagnosis of AMR was made within 12. months of transplant, and define the immunological, histological, clinical features, as well as the therapeutic response of this cohort. Results: Nine LTR with AMR underwent combination therapy with high-dose intravenous corticosteroid, intravenous immunoglobulin, plasmapheresis and rituximab. Following therapy, while the total number of the original DSA dropped by 17%, and the median value of the mean fluorescence intensity (mfi) of the originally observed DSA decreased from 5292 (IQR 1319-12,754) to 2409 (IQR 920-6825) (p. <. 0.001), clinical outcomes were variable with a number of patients progressing to either chronic lung allograft dysfunction or death within 12. month. Conclusion: AMR in lung transplantation remains both a diagnostic and therapeutic challenge, but when clinically suspected is associated with a variable response to therapy and poor long-term outcomes.