Exogenous Insulin Requirements Research Articles

Autologous nonmyeloablative hematopoietic stem cell transplantion in newly diagnosed childhood type 1 diabetes mellitus: the first year report

Autologous nonmyeloablative hematopoietic stem cell transplantation (AHST) in newly diagnosed and young adult type 1 diabetes mellitus (T1DM) was reported. We report our first year AHST experience in newly diagnosed childhood T1DM. 7 patients with T1DM (HbA1c 11.7%-14%, 4 with diabetic ketoacidosis, aged 5.0-13.7 years) diagnosed within the previous 3 months by clinical findings and hyperglycemia and confirmed with positive antibodies against GAD65, IA2, ICA or insulin. Hematopoietic stem cells were mobilized with cyclophosphamide and granulocyte colonystimulating factor and then collected from peripheral blood by leukapheresis and cryopreserved. The cells were injected intravenously after conditioning with cyclophosphamide and rabbit antithymocyte globulin. Major side effects, changes in exogenous insulin requirements, HbA1c, C-peptide levels are analyzed. During a 12- to 18-month follow-up, 6 (6/7, 85.7%) patients became insulin free 1-3 months after AHST, 1 patients failed (5 year old) to acquire insulin free, all the patients resumed normal school study. The preprandial, predormital blood glucose were ranged from 3.9-6.0 mmol/L with the HbA1c level between 4.6%-6.1% in insulin-independent patients. Vomiting, anorexia, short-term fever, hair loss occurred in all the patients during AHST, convulsion occurred in 1 patients due to severe sodium water retention, leukocytopenia was evident in the first 1-3 months after AHST, one patients suffered from acute bronchitis 2 months after AHST. No other systemic organ lesions were found in all the patients. High-dose immunosuppression and AHST were performed with acceptable toxicity in 7 patients with newly diagnosed childhood T1DM. With AHST, beta cell function was improved and induced insulin independence in the majority of the patients.

Amniotic stem cell transplantation therapy for type 1 diabetes: A case report

This case report presents an evaluation of the clinical effects of an allogeneic amniotic cell transplant for the treatment of type 1 diabetes mellitus. A 26-year-old man with type 1 diabetes was treated with stem cells isolated from his neonatal son's amniotic membrane, collected at birth (2 × 10(7) cells). The cells, which expressed high levels of cluster of differentiation (CD) 133 and CD34 as assessed by flow cytometry, were infused into the pancreatic dorsal artery through the left femoral artery. The main study outcome was the change in exogenous insulin requirements, which began to decrease 3 days after transplantation. At 3 months post-transplantation, the patient was insulin independent and remained so for 6.2 months. During a 36-month follow-up, the patient's blood glucose remained under control and insulin treatment was readjusted to a dosage of 8 IU/day. These preliminary data suggest that amniotic membrane stem cell transplantation can improve islet-cell function in response to glucose in vivo, although an alternative explanation (such as a honeymoon period due to reduced glucose toxicity) also has to be considered.

Pancreas and Islet Transplantation

Pancreas and Islet Transplantation

Exogenous insulin requirements do not differ between youth and adults with cystic fibrosis related diabetes

To examine whether insulin requirements and diabetes control differ between adolescents and adults with cystic fibrosis related diabetes (CFRD). All CFRD patients on insulin therapy seen at the University of Minnesota outpatient clinic from 1 January 2011 to 1 June 2012 were identified. Hemoglobin A1c (HbA1c) levels obtained during this period were averaged for each patient, and the most recent outpatient insulin dose was obtained. In addition, retrospective chart review was performed in order to obtain longitudinal data on insulin requirements during the transition from adolescence to adulthood. Eighteen youth aged 14-19 yr and 137 adults aged 20-67 yr were identified to be currently on insulin therapy. The average insulin dose was 0.38 ± 0.29 units/kg/d for adolescents and 0.46 ± 0.30 units/kg/d for adults (p = 0.20). In adults, insulin doses were significantly higher in transplant recipients: Tx = 0.58 ± 0.29, no Tx = 0.43 ± 0.30 (p = 0.005). Average HbA1c was 6.9 ± 2.1% in youth and 6.9 ± 1.5% in adults (p = 0.35). There were no changes in the insulin dosage when adolescents transitioned to adulthood with diabetes were not on higher doses of insulin compared to when they were adolescents with diabetes. Modest insulin requirements suggest the persistence of endogenous insulin secretion in both youth and adults with CFRD. In adolescents, residual endogenous insulin secretion likely compensates for the insulin resistance during puberty, keeping insulin requirements low.

Diabetic Ketoacidosis at Diagnosis Influences Complete Remission After Treatment With Hematopoietic Stem Cell Transplantation in Adolescents With Type 1 Diabetes

OBJECTIVETo determine if autologous nonmyeloablative hematopoietic stem cell transplantation (AHSCT) was beneficial for type 1 diabetic adolescents with diabetic ketoacidosis (DKA) at diagnosis.RESEARCH DESIGN AND METHODSWe enrolled 28 patients with type 1 diabetes, aged 14–30 years, in a prospective AHSCT phase II clinical trial. HSCs were harvested from the peripheral blood after pretreatment consisting of a combination of cyclophosphamide and antithymocyte globulin. Changes in the exogenous insulin requirement were observed and serum levels of HbA1c, C-peptide, and anti-glutamic acid decarboxylase antibody were measured before and after the AHSCT.RESULTSAfter transplantation, complete remission (CR), defined as insulin independence, was observed in 15 of 28 patients (53.6%) over a mean period of 19.3 months during a follow-up ranging from 4 to 42 months. The non-DKA patients achieved a greater CR rate than the DKA patients (70.6% in non-DKA vs. 27.3% in DKA, P = 0.051). In the non-DKA group, the levels of fasting C-peptide, peak value during oral glucose tolerance test (Cmax), and area under C-peptide release curve during oral glucose tolerance test were enhanced significantly 1 month after transplantation and remained high during the 24-month follow-up (all P < 0.05). In the DKA group, significant elevation of fasting C-peptide levels and Cmax levels was observed only at 18 and 6 months, respectively. There was no mortality.CONCLUSIONSWe have performed AHSCT in 28 patients with type 1 diabetes. The data show AHSCT to be an effective long-term treatment for insulin dependence that achieved a greater efficacy in patients without DKA at diagnosis.

A clinical trial of xenotransplantation of neonatal pig islets for diabetic patients.

To ascertain the safety and function of the transplantation of neonatal pig islets (NPIs) for diabetic patients. 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. 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. Xenogenic islets can survive and function in the human body. No serious adverse events are noted.

Increased insulin sensitivity and insulin signaling protein content following regular exercise in T1‐diabetic rats

Type 1 diabetic (T1D) patients can develop insulin insensitivity due to the daily requirement of exogenous insulin. Regular exercise has been shown to improve insulin sensitivity (IS) through the increased expression of muscle Glut4 and insulin receptor (IR) content. This study examined the role of exercise on IS and Glut4 and IR expression in T1D rats. Thirty animals were randomly divided into 3 groups; control (C), diabetic sedentary (D), and diabetic exercised (DE). D and DE were injected with STZ and implanted with insulin pellets to maintain blood glucose levels between 9 and 15 mM. DE ran on a treadmill at 27m/min, 1hr/day, 5days/wk for 10wks. Compared to C, D demonstrate a significant decrease in Glut4 and IR protein content in the red (RV) and white (WV) vastus muscles (p<0.05), and a significant reduction in blood glucose clearance following an intravenous glucose challenge (p<0.05). DE demonstrated a significant increase in Glut4 protein in RV and WV (p<0.05), while IR protein content was elevated in the WV only (p<0.05). Also, blood glucose clearance rates were significantly increased in DE compared to D (p<0.05). To conclude, STZ-diabetic rodents exhibit insulin insensitivity which can be alleviated through regular exercise. These improvements in IS though exercise are concomitant with changes in Glut4 and IR protein content in a muscle-specific fashion. Supported by CIHR Grant #CCT- 83029.

The anterior chamber of the eye as a clinical transplantation site for the treatment of diabetes: a study in a baboon model of diabetes.

The aim of this study was to provide evidence that the anterior chamber of the eye serves as a novel clinical islet implantation site. In a preclinical model, allogeneic pancreatic islets were transplanted into the anterior chamber of the eye of a baboon model for diabetes, and metabolic and ophthalmological outcomes were assessed. Islets readily engrafted on the iris and there was a decrease in exogenous insulin requirements due to insulin secretion from the intraocular grafts. No major adverse effects on eye structure and function could be observed during the transplantation period. Our study demonstrates the long-term survival and function of allogeneic islets after transplantation into the anterior chamber of the eye. The safety and simplicity of this procedure provides support for further studies aimed at translating this technology into the clinic.

Characterization and validation of a streptozotocin-induced diabetes model in the vervet monkey

Introduction: Streptozotocin (STZ), preferentially toxic to pancreatic beta cells, is commonly used to model Type 1 diabetes mellitus (DM) in numerous species, including nonhuman primates. Methods: We induced DM in twenty vervet monkeys ( Chlorocebus aethiops) by intravenous administration of either 45 (n = 8, STZ-45) or 55 mg/kg STZ (n = 12, STZ-55); ten control (CTL) monkeys received saline. Results: Overall there was 15% mortality, likely secondary to renal toxicity. Twice-daily insulin therapy was initiated to maintain comparable glycemic control, confirmed by comparable glycated hemoglobin levels. Exogenous insulin requirements increased rapidly for 4 weeks; STZ-45 insulin doses stabilized thereafter while STZ-55 doses continued to increase through 16 weeks. Glucose tolerance testing and arginine-stimulated insulin secretion confirmed 80–90% reduction in pancreatic beta cell function in both groups. Body weight was reduced in all STZ monkeys, with return to baseline only in STZ-45 at 16 wks. Elevated blood urea nitrogen (BUN) and creatinine were noted in the STZ-55 group. Alkaline phosphatase (ALKP) was also increased with STZ-55 (p < 0.05 vs. CTL) whereas STZ-45 ALKP elevation resolved by study end. Red cell parameters were reduced in all STZ monkeys, but more severely in the STZ-55 group. Discussion: We have demonstrated that a model of DM can be induced and maintained in vervets with a single dose of STZ. The lower dose of STZ (45 mg/kg) significantly improved the toxicity profile without altering efficacy in inducing DM. Finally, sufficient time following induction is recommended to allow transient renal, hepatic and hematologic parameters to resolve.

Beta cell function during rapamycin monotherapy in long-term type 1 diabetes

Type 1 diabetes is considered non-reversible at end-stage disease when there is no measurable insulin production. However, there are indications that insulin-producing beta cells could be present or return if autoimmunity could be controlled. We therefore sought to determine whether immunosuppression therapy can reinstate beta cell function in patients with long-term type 1 diabetes. We examined pancreatic beta cell function in 22 patients with long-term type 1 diabetes (median disease duration 27 years), who had been receiving rapamycin monotherapy (0.1 mg/kg; target trough levels 8-10 ng/ml; 26-314 days) as pre-conditioning for islet transplantation. As control, beta cell function was measured in 14 patients (median disease duration 17 years) who were waiting for an islet transplant without rapamycin pre-conditioning. Fasting C-peptide increased from <0.03 nmol/l (0.0066 nmol/l, interquartile range [IQR] 0.0003-0.023) at baseline to 0.039 nmol/l (IQR 0.0066-0.096) at end of rapamycin monotherapy (p < 0.005). In 12 patients, fasting C-peptide increased to >0.076 nmol/l (C-peptide responders). Exogenous insulin requirement decreased from 0.64 U/kg daily (IQR 0.56-0.72) to 0.57 U/kg (IQR 0.45-0.70; p = 0.01), but this reduction was significant only in the 12C-peptide-responsive patients. Rapamycin monotherapy was also associated with a decrease in insulin antibody titre (median decrease 110 to 35.9 U/ml; p < 0.001) and fasting serum proinsulin (median decrease 0.51 to 0.28 pmol/l; p = 0.001). All variables remained unchanged in the 14 control patients. Therapies to reinstate beta cell function may be applicable to patients with long-term C-peptide-negative type 1 diabetes. ClinicalTrial.gov NCT01060605.

Islet Transplantation Using Donors After Cardiac Death: Report of the Japan Islet Transplantation Registry

This report summarizes outcomes of islet transplantation employing donors after cardiac death (DCD) between 2004 and 2007 as reported to the Japan Islet Transplantation Registry. Sixty-five islet isolations were performed for 34 transplantations in 18 patients with insulin-dependent diabetes mellitus, including two patients who had prior kidney transplantation. All but one donor (64/65) was DCD at the time of harvesting. Factors influencing criteria for islet release included duration of low blood pressure of the donor, cold ischemic time, and usage of Kyoto solution for preservation. Multivariate analysis selected usage of Kyoto solution as most important. Of the 18 recipients, 8, 4, and 6 recipients received 1, 2, and 3 islet infusions, respectively. Overall graft survival defined as C-peptide level more than or equal to 0.3 ng/mL was 76.5%, 47.1%, and 33.6% at 1, 2, and 3 years, respectively, whereas corresponding graft survival after multiple transplantations was 100%, 80.0%, and 57.1%, respectively. All recipients remained free of severe hypoglycemia while three achieved insulin independence for 14, 79, and 215 days. HbA1c levels and requirement of exogenous insulin were significantly improved in all patients. Islet transplantation employing DCD can ameliorate severe hypoglycemic episodes, significantly improve HbA1c levels, sustain significant levels of C-peptide, and achieve insulin independence after multiple transplantations. Thus, DCD can be an important resource for islet transplantation if used under strict releasing criteria and in multiple transplantations, particularly in countries where heart-beating donors are not readily available.

Mesenchymal Stem Cells Enhance Allogeneic Islet Engraftment in Nonhuman Primates

OBJECTIVETo test the graft-promoting effects of mesenchymal stem cells (MSCs) in a cynomolgus monkey model of islet/bone marrow transplantation.RESEARCH DESIGN AND METHODSCynomolgus MSCs were obtained from iliac crest aspirate and characterized through passage 11 for phenotype, gene expression, differentiation potential, and karyotype. Allogeneic donor MSCs were cotransplanted intraportally with islets on postoperative day (POD) 0 and intravenously with donor marrow on PODs 5 and 11. Recipients were followed for stabilization of blood glucose levels, reduction of exogenous insulin requirement (EIR), C-peptide levels, changes in peripheral blood T regulatory cells, and chimerism. Destabilization of glycemia and increases in EIR were used as signs of rejection; additional intravenous MSCs were administered to test the effect on reversal of rejection.RESULTSMSC phenotype and a normal karyotype were observed through passage 11. IL-6, IL-10, vascular endothelial growth factor, TGF-β, hepatocyte growth factor, and galectin-1 gene expression levels varied among donors. MSC treatment significantly enhanced islet engraftment and function at 1 month posttransplant (n = 8), as compared with animals that received islets without MSCs (n = 3). Additional infusions of donor or third-party MSCs resulted in reversal of rejection episodes and prolongation of islet function in two animals. Stable islet allograft function was associated with increased numbers of regulatory T-cells in peripheral blood.CONCLUSIONSMSCs may provide an important approach for enhancement of islet engraftment, thereby decreasing the numbers of islets needed to achieve insulin independence. Furthermore, MSCs may serve as a new, safe, and effective antirejection therapy.

A Selective Peroxisome Proliferator-Activated Receptor α Agonist, CP-900691, Improves Plasma Lipids, Lipoproteins, and Glycemic Control in Diabetic Monkeys

Peroxisome proliferator-activated receptors (PPARs) are involved in the regulation of lipid and glucose metabolism. PPARgamma agonists improve insulin sensitivity and hyperglycemia and are effective in treating type 2 diabetes mellitus (T2DM), whereas PPARalpha agonists are used to treat dyslipidemia and atherosclerosis. The goal here was to examine the efficacy of a selective PPARalpha agonist {(S)-3-[3-(1-carboxy-1-methyl-ethoxy)-phenyl]-piperidine-1-carboxylic acid 4-trifluoromethyl-benzyl ester; CP-900691} on lipid, glycemic, and inflammation indices in 14 cynomolgus monkeys with spontaneous T2DM maintained on daily insulin therapy. Monkeys were dosed orally with either vehicle (n = 7) or CP-900691 (3 mg/kg, n = 7) daily for 6 weeks. CP-900691 treatment increased plasma high-density lipoprotein cholesterol (HDLC) (33 +/- 3 to 60 +/- 4 mg/dL, p < 0.001) and apolipoprotein A1 (96 +/- 5 to 157 +/- 5 mg/dL, p < 0.001), reduced plasma triglycerides (547 +/- 102 to 356 +/- 90 mg/dL, p < 0.01), and apolipoprotein B (62 +/- 3 to 45 +/- 3 mg/dL, p < 0.01), improved the lipoprotein index (HDL to non-HDLC ratio; 0.28 +/- 0.06 to 0.79 +/- 0.16, p < 0.001), decreased body weight (p < 0.01) and C-reactive protein (CRP) (1700 +/- 382 to 304 +/- 102 ng/ml, p < 0.01), and increased adiponectin (1697 +/- 542 to 4242 +/- 1070 ng/ml, p < 0.001) compared with baseline. CP-900691 treatment reduced exogenous insulin requirements by approximately 25% (p < 0.04) while lowering plasma fructosamine from 2.87 +/- 0.09 to 2.22 +/- 0.17 mM (p < 0.05), indicative of improved glycemic control. There were no changes in any of the aforementioned parameters in the vehicle group. Because low HDLC and high triglycerides are well established risk factors for cardiovascular disease, the marked improvements in these parameters, and in glycemic control, body weight, and CRP, suggest that CP-900691 may be of benefit in diabetic and obese or hyperlipidemic populations.

Kidney-Pancreas Transplantation Does Not Improve Retinal Arterial Flow Velocities in Type 1 Diabetic Uremic Patients

Kidney-Pancreas Transplantation Does Not Improve Retinal Arterial Flow Velocities in Type 1 Diabetic Uremic Patients

Cotransplantation of Adipose Tissue-Derived Insulin-Secreting Mesenchymal Stem Cells and Hematopoietic Stem Cells: A Novel Therapy for Insulin-Dependent Diabetes Mellitus

Aims. Insulin dependent diabetes mellitus (IDDM) is believed to be an autoimmune disorder with disturbed glucose/insulin metabolism, requiring life-long insulin replacement therapy (IRT), 30% of patients develop end-organ failure. We present our experience of cotransplantation of adipose tissue derived insulin-secreting mesenchymal stem cells (IS-AD-MSC) and cultured bone marrow (CBM) as IRT for these patients. Methods. This was a prospective open-labeled clinical trial to test efficacy and safety of IS-AD-MSC+CBM co-transplantation to treat IDDM, approved by the institutional review board after informed consent in 11 (males : females: 7 : 4) patients with 1–24-year disease duration, in age group: 13–43 years, on mean values of exogenous insulin requirement of 1.14 units/kg BW/day, glycosylated hemoglobin (Hb1Ac): 8.47%, and c-peptide levels: 0.1 ng/mL. Intraportal infusion of xenogeneic-free IS-AD-MSC from living donors, subjected to defined culture conditions and phenotypically differentiated to insulin-secreting cells, with mean quantum: 1.5 mL, expressing Pax-6, Isl-1, and pdx-1, cell counts: 2.1 × 103/μL, CD45−/90+/73+:40/30.1%, C-Peptide level:1.8 ng/mL, and insulin level: 339.3 IU/mL with CBM mean quantum: 96.3 mL and cell counts: 28.1 × 103/μL, CD45−/34+:0.62%, was carried out. Results. All were successfully transplanted without any untoward effect. Over mean followup of 23 months, they had a decreased mean exogenous insulin requirement to 0.63 units/kgBW/day, Hb1Ac to 7.39%, raised serum c-peptide levels to 0.38 ng/mL, and became free of diabetic ketoacidosis events with mean 2.5 Kg weight gain on normal vegetarian diet and physical activities. Conclusion. This is the first report of treating IDDM with insulin-secreting-AD-MSC+CBM safely and effectively with relatively simple techniques.

Endoscopic Gastric Submucosal Transplantation of Islets (ENDO-STI): Technique and Initial Results in Diabetic Pigs

The results of transplantation of human donor islets into the portal vein (PV) in patients with diabetes are encouraging. However, there are complications, for example, hemorrhage, thrombosis and an immediate loss of islets through the 'instant blood-mediated inflammatory reaction' (IBMIR). The gastric submucosal space (GSMS) offers potential advantages. Islets were isolated from adult pigs. Recipient pigs were made diabetic by streptozotocin. Donor islets were injected into the GSMS through a laparotomy (Group 1A, n = 4) or endoscopically (Group 1B, n = 8) or into the PV through a laparotomy (Group 2, n = 3). The pigs were followed for a maximum of 28 days. Monitoring of C-peptide in Group 1 indicated that there was minimal immediate loss of islets whereas in Group 2 there was considerable loss from IBMIR. In Group 1, there were significant reductions in mean blood glucose and mean exogenous insulin requirement between pretransplantation and 20 days posttransplantation. In Group 2, there was no significant reduction in either parameter. Insulin-positive cells were seen in the GSMS in Group 1, but not in the liver in Group 2. Endoscopic gastric submucosal transplantation of islets (ENDO-STI) offers a minimally invasive and quick approach to islet transplantation, avoids IBMIR and warrants further exploration.

Marked improvement in glycaemic control in a type 2 diabetes patient following a liver transplant for cirrhotic steatohepatitis

AbstractWe present the case of a 58‐year‐old woman with poorly controlled, insulin‐treated type 2 diabetes mellitus who underwent a liver transplant for cirrhosis due to non‐alcoholic fatty liver disease complicated by encephalopathy and portal hypertension. Within four months of surgery she exhibited marked improvement in insulin sensitivity, as evidenced by reduced exogenous insulin requirement, with cessation of insulin therapy at 11 months and a consequent dramatic improvement in glycaemic control, eventually achieving an optimal glycosylated haemoglobin concentration on no specific diabetes treatment aside from dietary advice. This was despite a standard regimen of immunosuppressive treatments including prednisolone, tacrolimus and sirolimus which all have the propensity to induce insulin resistance. This case provides an interesting insight into the cause and effect of insulin resistance in the setting of non‐alcoholic fatty liver disease. Copyright ©2009 John Wiley &amp; Sons.

Alleviation of exogenous insulin requirement in type 1 diabetes mellitus after immunoablation and transplantation of autologous hematopoietic stem cells

An essential component of type 1 diabetes mellitus is autoaggression of the immune system against insulin-secreting pancreatic cells. It is thought that early destruction of the autoaggressive mechanism prior to the complete damage of beta cells should halt this process. In a 28-year-old male patient with a 4-week history of type 1 diabetes mellitus, three courses of plasmapheresis had been performed before cyclophosphamide, 2 g/m2 body surface area, was administered and hematopoietic cells were obtained. Six weeks after the diagnosis, 4 doses of cyclophosphamide 50 mg/kg body weight were again administered together with antithymocyte globulin, and autologous hematopoietic cells were transplanted. The procedure was associated with no significant side effects. Insulin requirement started to drop from the first course of plasmapheresis, and the patient has remained normoglycemic with no need of exogenous insulin or other hypoglycemic agents since the third week after the procedure, which has been 5 months until publication of this report. Independence from exogenous insulin is associated with the implemented therapy (a gradual decrease in insulin requirement has been observed after consecutive stages of the immunosuppressive treatment, with total discontinuation after bone marrow transplantation). The course of the disease and the type of treatment may suggest that such medical procedures could eliminate autoaggressive mechanism in diabetes and prevent further degeneration of insulin-producing cells, thus becoming a new therapeutic option for patients with type 1 diabetes mellitus.

Embryonic pig pancreatic tissue for the treatment of diabetes in a nonhuman primate model

Xenotransplantation of pig tissues has great potential to overcome the shortage of organ donors. One approach to address the vigorous immune rejection associated with xenotransplants is the use of embryonic precursor tissue, which induces and utilizes host vasculature upon its growth and development. Recently, we showed in mice that embryonic pig pancreatic tissue from embryonic day 42 (E42) exhibits optimal properties as a beta cell replacement therapy. We now demonstrate the proof of concept in 2 diabetic Cynomolgus monkeys, followed for 393 and 280 days, respectively. A marked reduction of exogenous insulin requirement was noted by the fourth month after transplantation, reaching complete independence from exogenous insulin during the fifth month after transplantation, with full physiological control of blood glucose levels. The porcine origin of insulin was documented by a radioimmunoassay specific for porcine C-peptide. Furthermore, the growing tissue was found to be predominantly vascularized with host blood vessels, thereby evading hyperacute or acute rejection, which could potentially be mediated by preexisting anti-pig antibodies. Durable graft protection was achieved, and most of the late complications could be attributed to the immunosuppressive protocol. While fine tuning of immune suppression, tissue dose, and implantation techniques are still required, our results demonstrate that porcine E-42 embryonic pancreatic tissue can normalize blood glucose levels in primates. Its long-term proliferative capacity, its revascularization by host endothelium, and its reduced immunogenicity, strongly suggest that this approach could offer an attractive replacement therapy for diabetes.

C-Peptide Levels and Insulin Independence Following Autologous Nonmyeloablative Hematopoietic Stem Cell Transplantation in Newly Diagnosed Type 1 Diabetes Mellitus

In 2007, the effects of the autologous nonmyeloablative hematopoietic stem cell transplantation (HSCT) in 15 patients with type 1 diabetes mellitus (DM) were reported. Most patients became insulin free with normal levels of glycated hemoglobin A(1c) (HbA(1c)) during a mean 18.8-month follow-up. To investigate if this effect was due to preservation of beta-cell mass, continued monitoring was performed of C-peptide levels after stem cell transplantation in the 15 original and 8 additional patients. To determine C-peptide levels after autologous nonmyeloablative HSCT in patients with newly diagnosed type 1 DM during a longer follow-up. A prospective phase 1/2 study of 23 patients with type 1 DM (aged 13-31 years) diagnosed in the previous 6 weeks by clinical findings with hyperglycemia and confirmed by measurement of serum levels of anti-glutamic acid decarboxylase antibodies. Enrollment was November 2003-April 2008, with follow-up until December 2008 at the Bone Marrow Transplantation Unit of the School of Medicine of Ribeirão Preto, Ribeirão Preto, Brazil. Hematopoietic stem cells were mobilized via the 2007 protocol. C-peptide levels measured during the mixed-meal tolerance test, before, and at different times following HSCT. Secondary end points included morbidity and mortality from transplantation, temporal changes in exogenous insulin requirements, and serum levels of HbA(1c). During a 7- to 58-month follow-up (mean, 29.8 months; median, 30 months), 20 patients without previous ketoacidosis and not receiving corticosteroids during the preparative regimen became insulin free. Twelve patients maintained this status for a mean 31 months (range, 14-52 months) and 8 patients relapsed and resumed insulin use at low dose (0.1-0.3 IU/kg). In the continuous insulin-independent group, HbA(1c) levels were less than 7.0% and mean (SE) area under the curve (AUC) of C-peptide levels increased significantly from 225.0 (75.2) ng/mL per 2 hours pretransplantation to 785.4 (90.3) ng/mL per 2 hours at 24 months posttransplantation (P < .001) and to 728.1 (144.4) ng/mL per 2 hours at 36 months (P = .001). In the transient insulin-independent group, mean (SE) AUC of C-peptide levels also increased from 148.9 (75.2) ng/mL per 2 hours pretransplantation to 546.8 (96.9) ng/mL per 2 hours at 36 months (P = .001), which was sustained at 48 months. In this group, 2 patients regained insulin independence after treatment with sitagliptin, which was associated with increase in C-peptide levels. Two patients developed bilateral nosocomial pneumonia, 3 patients developed late endocrine dysfunction, and 9 patients developed oligospermia. There was no mortality. After a mean follow-up of 29.8 months following autologous nonmyeloablative HSCT in patients with newly diagnosed type 1 DM, C-peptide levels increased significantly and the majority of patients achieved insulin independence with good glycemic control. clinicaltrials.gov Identifier: NCT00315133.