Pathophysiologic function of B cells in graft rejection has been well recognized in transplantation. B cells promote alloantigen-specific T-cell response and secrete antibodies that can cause antibody-mediated graft failures and rejections. Therefore, strategies targeting B cells, for example, B-cell depletion, have been used for the prevention of both acute and chronic rejections. Interestingly, however, recent mounting evidence indicates that subsets of B cells yet to be further identified can display potent immune regulatory functions, and they contribute to transplantation tolerance and operational tolerance in both experimental and clinical settings, respectively.

Transplantation is the ideal therapy for end-stage organ failure, but outcomes for all transplant organs are suboptimal, underscoring the need to develop novel approaches to improve graft survival and function. The complement system, traditionally considered a component of innate immunity, is now known to broadly control inflammation and crucially contribute to induction and function of adaptive T-cell and B-cell immune responses, including those induced by alloantigens.

Posttransplantation lymphoproliferative disorder (PTLD) is a potentially life-threatening complication after solid organ transplantation (SOT) or hematopoietic cell transplantation. PTLD is a heterogeneous group of lymphoid proliferations with a broad spectrum of diseases ranging from benign hyperplasia to aggressive lymphomas. It is a result of immunosuppression, and it is associated with significant morbidity and mortality in transplant recipients.1 Epstein-Barr virus (EBV) is implicated in the development of PTLD in most cases. EBV-induced PTLDs occur mostly in a relatively early period after transplantation. However, there are an increased number of reports of late EBV-negative PTLD.

Normothermic machine perfusion (NMP) is used to preserve and test donor livers before transplantation. During NMP, the liver is metabolically active and produces waste products, which are released into the perfusate. In this study, we describe our simplified and inexpensive setup that integrates continuous renal replacement therapy (CRRT) with NMP for up to 7 d. We also investigated if the ultrafiltrate could be used for monitoring perfusate concentrations of small molecules such as glucose and lactate.