Improved outcomes of islet autotransplant after total pancreatectomy by combined blockade of IL-1ß and TNFα.

The efficacy of islet transplant is compromised by a significant loss of islet mass posttransplant due to an innate inflammatory reaction. We report the use of a combination of etanercept and anakinra (ANA+ETA) to block inflammatory islet damage in 100 patients undergoing total pancreatectomy with islet autotransplant. The patients were divided into 3 groups: no treatment (control [CTL]), etanercept alone (ETA), or a combination of etanercept and anakinra (ANA+ETA). Peritransplant serum samples were analyzed for protein markers of islet damage and for inflammatory cytokines. Graft function was assessed by fasting blood glucose, basal C-peptide, secretory unit of islet transplant objects (SUITO) index, and hemoglobin A1c . Administration of both antiinflammatory drugs was well tolerated without any major adverse events. Reductions in interleukin-6, interleukin-8, and monocyte chemoattractant protein 1 were observed in patients receiving ANA+ETA compared with the CTL group, while also showing a modest improvement in islet function as assessed by basal C-peptide, glucose, hemoglobin A1c , and SUITO index but without differences in insulin dose. These results suggest that double cytokine blockade (ANA+ETA) reduces peritransplant islet damage due to nonspecific inflammation and may represent a promising strategy to improve islet engraftment, leading to better transplant outcomes.

Evidence for instant blood-mediated inflammatory reaction in clinical autologous islet transplantation.

A nonspecific inflammatory and thrombotic reaction termed instant blood-mediated inflammatory reaction (IBMIR) has been reported when allogenic or xenogenic islets come into contact with blood. This reaction is known to cause significant loss of transplanted islets. We hypothesized that IBMIR occurs in patients undergoing total pancreatectomy followed by autologous islet transplantation (TP-AIT) and tested this hypothesis in 24 patients and in an in vitro model. Blood samples drawn during the peritransplant period showed a significant and rapid increase of thrombin-anti-thrombin III complex (TAT) and C-peptide during islet infusion, which persisted for up to 3 h, along with a decreased platelet count. A concomitant increase in levels of inflammatory proteins IL-6, IL-8 and interferon-inducible protein-10 was observed. An in vitro model composed of pure islets plus autologous blood also demonstrated significantly increased levels of TAT (p<0.05), C-peptide (p<0.05), tumor necrosis factor-alpha (p<0.05) and MCP-1 (p<0.05), as well as strong tissue factor expression in islets. Islet viability decreased significantly but was rescued by the presence of low-molecular-weight dextran sulfate. In conclusion, AIT-induced elevation of TAT and destruction of islets suggests that IBMIR might occur during AIT. Modulating this process may help improve islet engraftment and the insulin independence rate in TP-AIT patients.

Withaferin A inhibits pro-inflammatory cytokine-induced damage to islets in culture and following transplantation.

AIMS/HYPOTHESIS: Beta cell death triggered by pro-inflammatory cytokines plays a central role in the pathogenesis of type 1 diabetes and loss of transplanted islets. The nuclear factor κB (NF-κB) signalling pathway is a key regulator of beta cell stress response, survival and apoptosis. Withaferin A (WA), a steroidal lactone derived from Withania somnifera, has been demonstrated to be a potent, safe, anti-inflammatory molecule that can inhibit NF-κB signalling. Therefore, we evaluated the ability of WA to protect mouse and human islets from the damaging effects of pro-inflammatory cytokines in vitro and following intraportal transplantation. METHODS: Mouse and human islets were treated with a cytokine cocktail, and NF-κB activation was measured by immunoblots, p65 nuclear translocation and chromatin immunoprecipitation of p65-bound DNA. Intraportal transplantation of a marginal mass of syngeneic mouse islets was performed to evaluate the in vivo protective effect of WA. RESULTS: Treatment with WA substantially improved islet engraftment of syngeneic islets (83% for infusion with 200 islets + WA; 0% for 200 islets + vehicle) in a mouse model of diabetes, compared with marginal graft controls with superior islet function in WA-treated mice confirmed by glucose tolerance test. Treatment of human and mouse islets with WA prevented cytokine-induced cell death, inhibited inflammatory cytokine secretion and protected islet potency. CONCLUSIONS: WA was shown to be a strong inhibitor of the inflammatory response in islets, protecting against cytokine-induced cell damage while improving survival of transplanted islets. These results suggest that WA could be incorporated as an adjunctive treatment to improve islet transplant outcome.