Our observations in patients with type 1 diabetes indicate that islet transplantation can result in insulin independence with excellent metabolic control when glucocorticoid-free immunosuppression is combined with the infusion of an adequate islet mass.

Islet transplantation can restore endogenous ␤-cell function to subjects with type 1 diabetes. Sixty-five patients received an islet transplant in Edmonton as of 1 November 2004. Their mean age was 42.9 ؎ 1.2 years, their mean duration of diabetes was 27.1 ؎ 1.3 years, and 57% were women. The main indication was problematic hypoglycemia. Forty-four patients completed the islet transplant as defined by insulin independence, and three further patients received >16,000 islet equivalents (IE)/kg but remained on insulin and are deemed complete. Those who became insulin independent received a total of 799,912 ؎ 30,220 IE (11,910 ؎ 469 IE/kg). Five subjects became insulin independent after one transplant. Fifty-two patients had two transplants, and 11 subjects had three transplants. In the completed patients, 5-year follow-up reveals that the majority S ustained C-peptide production and successful insulin independence after pancreatic islet transplantation in type 1 diabetic patients was reported over 4 years ago by the Edmonton group (1). This reality became possible with the use of newer, more potent immunosuppressive agents, the avoidance of corticosteroids, and high-quality islet preparations, although typically two islet infusions were necessary to attain insulin independence. Over this period, other centers have been able to replicate the initial success of the Edmonton Protocol with further refinements in technique (2-5), and islet transplantation is increasingly being used (6 -8).However, the need for ongoing immunosuppressive therapy and the scarcity of donor islets have precluded the widespread adoption of islet transplantation. The main indications for solitary islet transplantation have been frequent recurrent hypoglycemia or labile glucose values that have defied optimization of medical therapy. An additional hoped for, but unproven, benefit has been stabilization or improvement of diabetes complications with the achievement of stable good glycemic control. Now, 5 years after the first islet transplant was performed with the Edmonton Protocol, we have had the opportunity to review the outcomes in terms of C-peptide secretion, insulin independence, correction of hypoglycemia and lability, acute complications encountered, chronic problems related to immunsuppressive therapy, and some assessment of the effect on diabetes complications. RESEARCH DESIGN AND METHODSAs of 1 November 2004, 65 patients have received islet transplants at the University of Alberta. Four other subjects were transplanted as part of the Immune Tolerance Network trial of islet transplantation and will be reported independently. One further subject was transplanted with a preparation from a pediatric donor that had many trapped islets. This subject had primary nonfunction of the graft, and the data from this patient are not included in this report. At the time of the transplant, the mean age of the 65 patients was 42.9 Ϯ 1.2 years, their duration of diabetes was 27.1 Ϯ 1.3 years, and 57% were women. Their median weight was 68.5 kg (interq...

A major problem in hepatitis C virus (HCV) immunotherapy or vaccine design is the extreme variability of the virus. We identified human monoclonal antibodies (mAbs) that neutralize genetically diverse HCV isolates and protect against heterologous HCV quasispecies challenge in a human liver-chimeric mouse model. The results provide evidence that broadly neutralizing antibodies to HCV protect against heterologous viral infection and suggest that a prophylactic vaccine against HCV may be achievable.

Lack of a small animal model of the human hepatitis C virus (HCV) has impeded development of antiviral therapies against this epidemic infection. By transplanting normal human hepatocytes into SCID mice carrying a plasminogen activator transgene (Alb-uPA), we generated mice with chimeric human livers. Homozygosity of Alb-uPA was associated with significantly higher levels of human hepatocyte engraftment, and these mice developed prolonged HCV infections with high viral titers after inoculation with infected human serum. Initial increases in total viral load were up to 1950-fold, with replication confirmed by detection of negative-strand viral RNA in transplanted livers. HCV viral proteins were localized to human hepatocyte nodules, and infection was serially passaged through three generations of mice confirming both synthesis and release of infectious viral particles. These chimeric mice represent the first murine model suitable for studying the human hepatitis C virus in vivo.

Islet transplantation offers the prospect of good glycemic control without major surgical risks. After our initial report of successful islet transplantation, we now provide further data on 12 type 1 diabetic patients with brittle diabetes or problems with hypoglycemia previous to 1 November 2000. Details of metabolic control, acute complications associated with islet transplantation, and long-term complications related to immunosuppression therapy and diabetes were noted. Insulin secretion, both acute and over 30 min, was determined after intravenous glucose tolerance tests (IVGTTs). The median follow-up was 10.2 months (CI 6.5-17.4), and the longest was 20 months. Glucose control was stable, with pretransplant fasting and meal tolerance-stimulated glucose levels of 12.5 ؎ 1.9 and 20.0 ؎ 2.7 mmol/l, respectively, but decreased significantly, with posttransplant levels of 6.3 ؎ 0.3 and 7.5 ؎ 0.6 mmol/l, respectively (P < 0.006). All patients have sustained insulin production, as evidenced by the most current baseline C-peptide levels 0.66 ؎ 0.06 nmol/l, increasing to 1.29 ؎ 0.25 nmol/l 90 min after the meal-tolerance test. The mean HbA 1c level decreased from 8.3 ؎ 0.5% to the current level of 5.8 ؎ 0.1% (P < 0.001). Presently, four patients have normal glucose tolerance, five have impaired glucose tolerance, and three have post-islet transplant diabetes (two of whom need oral hypoglycemic agents and low-dose insulin (<10 U/day). Three patients had a temporary increase in their liverfunction tests. One patient had a thrombosis of a peripheral branch of the right portal vein, and two of the early patients had bleeding from the hepatic needle puncture site; but these technical problems were resolved. Two patients had transient vitreous hemorrhages. The two patients with elevated creatinine levels pretransplant had a significant increase in serum creatinine in the long term, although the mean serum creatinine of the group was unchanged. The cholesterol increased in five patients, and lipid-lowering therapy was required for three patients. No patient has developed cytomegalovirus infection or disease, posttransplant lymphoproliferative disorder, malignancies, or serious infection to date. None of the patients have been sensitized to donor antigen. In 11 of the 12 patients, insulin independence was achieved after 9,000 islet equivalents (IEs) per kilogram were transplanted. The acute insulin response and the insulin area under the curve (AUC) after IVGTT were consistently maintained over time. The insulin AUC from the IVGTT correlated to the number of islets transplanted, but more closely correlated when the cold ischemia time was taken into consideration (r ‫؍‬ 0.83, P < 0.001). Islet transplantation has successfully corrected labile type 1 diabetes and problems with hypoglycemia, and our results show persistent insulin secretion. After a minimum of 9,000 IEs per kilogram are provided, insulin independence is usually attained. An elevation of creatinine appears to be a contraindication to this immunosuppressive regi...