Transplanted functional islet mass: donor, islet preparation, and recipient factors influence early graft function in islet-after-kidney patients.

Background: The ability to predict clinical function of a specific islet batch released for clinical transplantation using standardized variables remains an elusive goal.

Methods: Analysis of 10 donor, 7 islet isolation, 3 quality control, and 6 recipient variables was undertaken in 110 islet-after-kidney transplants and correlated to the pre- to 28-day posttransplant change in C-peptide to glucose and creatinine ratio (ΔCP/GCr).

Results: Univariate analysis yielded islet volume transplanted (Spearman r=0.

Using HTK for prolonged pancreas preservation prior to human islet isolation.

Background: Histidine-tryptophan-ketoglutarate (HTK) has been established as an alternative to University-of-Wisconsin solution (UWS) for abdominal organ preservation, but data about HTK efficiency to preserve pancreata during prolonged cold ischemia time (CIT) are conflicting. In human islet transplantation, HTK provided similar isolation outcomes after short CIT. The present study aimed to investigate whether islets can be successfully isolated from HTK-preserved pancreata after prolonged CIT compared with UWS.

Operational tolerance in nonvascularized transplant models induced by AR-C117977, a monocarboxylate transporter inhibitor.

AR-C117977, a monocarboxylate transporter inhibitor, reduces immune responses both in vitro and in vivo, maintains long-term graft survival, and induces operational tolerance. To evaluate the immunosuppressive limitations of AR-C117977, this study was performed in nonvascularized transplant models noted for their refractive response to standard immunosuppressive agents. Rat skin was transplanted from DA(RT1avl) into PVG(RT1c) and the reverse.

Costimulation blockade-induced cardiac allograft tolerance: inhibition of T cell expansion and accumulation of intragraft cD4(+)Foxp3(+) T cells.

Background: Previous studies have demonstrated that anti-CD40L or anti-B7 requires the presence of CD4(+)CD25(+) regulatory T cells (Treg) to induce antigen specific hyporesponsiveness. Other tolerance strategies involving Treg have shown a dependency on interleukin (IL)-10. The objective of this study was to investigate the role of CD4(+)CD25(+) Treg and IL-10 when treating transplant recipients with cytotoxic T lymphocyte-associated antigen (CTLA)-4 immunoglobulin (Ig), anti-CD40L, and anti-lymphocyte function-associated antigen (LFA)-1.

CTLA4ig induces long-term graft survival of allogeneic skin grafts and totally inhibits T-cell proliferation in LFA-1-deficient mice.

Background: It was recently shown that some strains of mice are capable of rejecting transplants independently of B7 and CD40L signaling and that this rejection is mediated by CD8(+) T cells. LFA-1 is known to be important for CD8(+) T cell activation and cytotoxicity. Therefore, blockade of LFA-1 could be important in overcoming costimulation blockade, CD8(+) T-cell-mediated, resistant rejection.