OBJECTIVE: Porcine islets of Langerhans for xenotransplantation into humans have been proposed as a solution to the shortage of human donors. Rejection is one of the main constraints. This study presents the results of a clinical trial using a novel method for transplanting and immunoprotecting porcine islets in type 1 diabetic patients. DESIGN: A 4-year follow up of a clinical trial involving 12 patients, with no immunosuppressive drugs at any point. Eleven age matched untransplanted diabetics served as controls. METHODS: We have developed a procedure for protecting neonatal porcine islets by combining them with Sertoli cells and placing them in a novel subcutaneous autologous collagen-covered device. RESULTS: In the patients in the treatment group, no complications arose and no porcine endogenous retrovirus infection was detected. Half of the patients showed a significant reduction in insulin requirements compared with both their pre transplant levels and controls, and this reduction was maintained for up to 4 years. Two patients became insulin-independent for several months. Porcine insulin was detected in three patients' sera following glucose stimulation up to 4 years post transplant. Three years post transplant, one of four devices was removed from four patients, and the presence of insulin-positive cells in the transplant was demonstrated by immunohistology in all 4 patients. CONCLUSIONS: Long-term cell survival with concurrent positive effects on metabolic control are possible by this technique.
OBJECTIVE:Porcine islets of Langerhans for xenotransplantation into humans have been proposed as a solution to the shortage of human donors. Rejection is one of the main constraints. This study presents the results of a clinical trial using a novel method for transplanting and immunoprotecting porcine islets in type 1 diabeticpatients. DESIGN: A 4-year follow up of a clinical trial involving 12 patients, with no immunosuppressive drugs at any point. Eleven age matched untransplanted diabetics served as controls. METHODS: We have developed a procedure for protecting neonatal porcine islets by combining them with Sertoli cells and placing them in a novel subcutaneous autologous collagen-covered device. RESULTS: In the patients in the treatment group, no complications arose and no porcine endogenous retrovirus infection was detected. Half of the patients showed a significant reduction in insulin requirements compared with both their pre transplant levels and controls, and this reduction was maintained for up to 4 years. Two patients became insulin-independent for several months. Porcineinsulin was detected in three patients' sera following glucose stimulation up to 4 years post transplant. Three years post transplant, one of four devices was removed from four patients, and the presence of insulin-positive cells in the transplant was demonstrated by immunohistology in all 4 patients. CONCLUSIONS: Long-term cell survival with concurrent positive effects on metabolic control are possible by this technique.
Authors: R Valdes-Gonzalez; A L Rodriguez-Ventura; D J G White; E Bracho-Blanchet; A Castillo; B Ramírez-González; M G López-Santos; B H León-Mancilla; L M Dorantes Journal: Clin Exp Immunol Date: 2010-10-21 Impact factor: 4.330