Objective: To ascertain the safety and function of the transplantation of neonatal pig islets (NPIs) for diabetic patients.
Methods: NPIs were injected into the hepatic artery of 22 patients. After the transplantation, the patients were treated with a multiple drug immunosuppressive regimens. The first 14 patients were treated with cyclosporine (CsA), mycophenolate mofetil (MMF) and prednisolon, and porcine C-peptide was not monitored, the following 2 patients were given cyklosporin and MMF only, while the next 6 patients were given a quadruple drug regimen consisting of OKT3, takrolimus, sirolimus and prednisolon. The blood glucose levels,exogenous insulin requirement,HbA1c, porcine endogenous retrovirus (PERV) and liver function were assessed before and after NPI transplantation. The serum porcine C peptide were monitored in last 8 patients.
Results: The first 14 patients required less insulin and the HbA1c dropped after the transplantation. In the 2 subsequent patients, the metabolic parameters remained unchanged and monitor of porcine C-peptide was negative. Insulin requirements were reduced in all 6 patients, and HbA1c was normalized 3 months after the transplantation. Significant levels of porcine C-peptide were detected in the patient serum. Two of the patients were given a second injection of NPIs, and one of them became insulin independent for 7 d. No serious adverse events were noted after the transplantation. There was no evidence of PERV transmission. Six out of the 22 patients were followed up for 4-6 years after the NPIs injection, immunosuppressive treatment was stopped 1 year after the transplantation. The patients started to take insulin at the time of follow up. Four patients restricted the intake of sugar, while the other 2 did not. One patient had ketoacidosis twice and slight diabetic retinopathy, and another patient had ketoacidosis induced by acute gastroenteritis. The remaining 4 patients did not have any complications. Assays for PERV were again negative.
Conclusion: Xenogenic islets can survive and function in the human body. No serious adverse events are noted.