Several reports have already shown that intrahepatic transplantation of purified islets can replace the pancreatic endocrine function in diabetic patients without major side effects for either the patients or their liver function [1][2][3][4][5]. Despite these encouraging results, the data of the International Islet Transplant Registry [6] are not as encouraging: in the 1989-1994 period only 28 out of 180 patients (16 %) maintained insulin independence for more than one week.This paper reports the experience at one institute (San Raffaele Scientific Institute, University of Milan) with 21 cases of islet/kidney transplantations in insulin-dependent diabetic (IDDM) patients. The roles of islet mass and quality, immunosuppressive therapy and post-implantation management on the final outcome of fresh islet transplantation in IDDM patients are considered. Diabetologia (1997) Summary This single-centre study investigated parameters that positively correlated with the success rate after islet allotransplantation in insulin-dependent diabetic (IDDM) patients. Twenty-one intrahepatic, fresh islet transplantations were performed in 20 IDDM patients (one patient had two transplants), after or simultaneous with kidney transplantation. The correlation between number and purity of transplanted islets and final outcome was investigated. One patient died of a cardiac arrest several hours after islet transplantation; this patient was not included in the follow-up analysis. Three patients (15 %) experienced acute, irreversible, early failure of islet function, which was considered as a 'presumed rejection'. Nine patients (45 %) achieved either complete insulin-independence (seven cases) or a reduction (> 50 %) of exogenous insulin requirement (two cases), with sustained serum C-peptide secretion (0.89 ± 0.04 nmol/l; duration: 21 ± 7 months, range 2-58 months). Liver biopsy, performed 3 years after transplantation in one successful case, showed normal islets within the hepatic parenchyma. Eight cases (40 %) did not show any metabolic effect of islet transplantation, with low serum C-peptide levels ('presumed function exhaustion'). Metabolic investigations performed in successful cases showed an early phase of insulin release after arginine, mild and reversible postprandial hyperglycaemia and normal HbA 1c levels. Success of islet transplantation positively correlates with the number (p < 0.05) of the transplanted islets. Islet transplantation is a safe procedure, with 45 % success rate, in terms of insulin-independence or relevant reduction of exogenous insulin requirement, although success can be transient. [Diabetologia (1997) 40: 225-231]
