{beta}-Cell function following human islet transplantation for type 1 diabetes

Islet transplantation can provide metabolic stability for patients with type 1 diabetes; however, more than one donor pancreas is usually required to achieve insulin independence. To evaluate possible mechanistic defects underlying impaired graft function, we studied five subjects at 3 months and four subjects at 12 months following intraportal islet transplantation who had received comparable islet equivalents per kilogram (12,601 +/- 1,732 vs. 14,384 +/- 2,379, respectively). C-peptide responses, as measures of beta-cell function, were significantly impaired in both transplant groups when compared with healthy control subjects (P < 0.05) after intravenous glucose (0.3 g/kg), an orally consumed meal (600 kcal), and intravenous arginine (5 g), with the greatest impairment to intravenous glucose and a greater impairment seen in the 12-month compared with the 3-month transplant group. A glucose-potentiated arginine test, performed only in insulin-independent transplant subjects (n = 5), demonstrated significant impairments in the glucose-potentiation slope (P < 0.05) and the maximal response to arginine (AR(max); P < 0.05), a measure of beta-cell secretory capacity. Because AR(max) provides an estimate of the functional beta-cell mass, these results suggest that a low engrafted beta-cell mass may account for the functional defects observed after islet transplantation.     

Noninvasive diagnosis of recurrent autoimmune type 1 diabetes after islet cell transplantation

Islet cell transplantation is curative therapy for patients with complicated autoimmune type 1 diabetes (T1D). We report the diagnostic potential of circulating transplant islet–specific exosomes to noninvasively distinguish pancreatic β cell injury secondary to recurrent autoimmunity vs immunologic rejection. A T1D patient with hypoglycemic unawareness underwent islet transplantation and maintained normoglycemia until posttransplant day 1098 before requiring exogenous insulin. Plasma analysis showed decreased donor islet exosome quantities on day 1001, before hyperglycemia onset. This drop in islet exosome quantity signified islet injury, but did not distinguish injury type. However, analysis of purified transplant islet exosome cargoes showed decrease in insulin‐containing exosomes, but not glucagon‐containing exosomes, indicating selective destruction of transplanted β cells secondary to recurrent T1D autoimmunity. Furthermore, donor islet exosome cargo analysis showed time‐specific increase in islet autoantigen, glutamic acid decarboxylase 65 (GAD65), implicated in T1D autoimmunity. Time‐matched analysis of plasma transplant islet exosomes in 3 control subjects undergoing islet cell transplantation failed to show changes in islet exosome quantities or intraexosomal cargo expression of insulin, glucagon, and GAD65. This is the first report of noninvasive diagnosis of recurrent autoimmunity after islet cell transplantation, suggesting that transplant tissue exosome platform may serve as a biomarker in islet transplant diagnostics.     

Pancreas islet transplantation in patients with type 1 diabetes mellitus after kidney transplantation

Diabetic patients with end-stage renal disease have a high mortality rate. A combined kidney-pancreas transplant is associated with greater life expectancy. Pancreas islet transplantation is an alternative involving a lower degree of morbidity. We present two patients, of 41 and 37 years of age, with a long history of diabetes mellitus (C-peptide negative), both with a previous kidney transplant, who had been treated with 22 and 28 U of insulin/d, respectively. Both patients had frequent episodes of unawareness hypoglycemia. Pancreatic islets were infused to a total of 7809 and 19,180 IE/kg, respectively. Basal posttransplant C peptide levels were 2.9 and 1.3 ng/mL. After the implant, one patient required occasional doses of insulin, and the other patient more than 50% reduced dose. After the first implant neither patient had any episodes of unawareness hypoglycemia. HbA1c at 4 months were 6.2% and 6.9%. There were no transplant-related complications.     

Islet cell hormonal responses to hypoglycemia after human islet transplantation for type 1 diabetes

Islet transplantation can eliminate severe hypoglycemic episodes in patients with type 1 diabetes; however, whether intrahepatic islets respond appropriately to hypoglycemia after transplantation has not been fully studied. We evaluated six islet transplant recipients, six type 1 diabetic subjects, and seven nondiabetic control subjects using a stepped hyperinsulinemic-hypoglycemic clamp. Also, three islet transplant recipients and the seven control subjects underwent a paired hyperinsulinemic-euglycemic clamp. In response to hypoglycemia, C-peptide was similarly suppressed in islet transplant recipients and control subjects and was not detectable in type 1 diabetic subjects. Glucagon was significantly more suppressed in type 1 diabetic subjects than in islet transplant recipients (P < 0.01), although the glucagon in islet transplant recipients failed to activate as in the control subjects (P < 0.01). Pancreatic polypeptide failed to activate in both type 1 diabetic subjects and islet transplant recipients compared with control subjects (P < 0.01). In islet transplant recipients, glucagon was suppressed normally by hyperinsulinemia during the euglycemic clamp and was significantly greater during the paired hypoglycemic clamp (P < 0.01). These results suggest that after islet transplantation and in response to insulin-induced hypoglycemia, endogenous insulin secretion is appropriately suppressed and glucagon secretion may be partially restored.     

成人胰岛细胞移植治疗1型糖尿病

目的 探讨新型成人胰岛细胞分离、纯化技术分离的成人胰岛细胞移植治疗1型糖尿病的安全性与有效性.方法 采用全氟化碳液(PFC)和UW液双层冷藏胰腺,Liberase酶消化,COBE 2991型专用胰岛细胞分离机分离及连续密度梯度纯化,获取高纯度与高活性的胰岛细胞.通过上腹部小切口,胃右静脉或脐静脉插管,将经短期培养的胰岛细胞经门静脉移植到11例1型糖尿病患者肝脏内.采用达利珠单抗或阿来佐单抗进行诱导,西罗莫司和他克莫司联用的方案预防排斥反应,术后观察胰岛素使用情况,监测血糖、G-肽与糖化血红蛋白水平以及肝功能、肾功能.结果 45个胰腺中,42个成功分离出胰岛细胞,其数量平均为28.5×104胰岛当量(IEQ)/个,纯度为95.7%,活率为93.2%,胰岛素释放试验刺激指数为2.43.11例1型糖尿病患者共行胰岛细胞移植20次,其中移植1次4例,2次5例,3次2例,每次移植胰岛细胞数平均为11 200 IEQ/kg.术后随访6个月至4年,6例完全撤除胰岛素,2例胰岛素用量较术前减少80%,3例减少50%.术后血糖稳定维持在正常水平,C-肽均超过0.166 nmol/L,糖化血红蛋白基本正常,肝、肾功能正常,未发生与胰岛细胞输注相关的并发症.结论 新型成人胰岛细胞分离、纯化方法可靠,采用该技术分离、纯化的成人胰岛细胞移植治疗1型糖尿病临床效果较好.     

Autoantibody response to islet transplantation in type 1 diabetes.

Islet allotransplantation into patients with autoimmune type 1 diabetes represents a reexposure to autoantigen. Here, measurement of antibodies to GAD and IA-2 autoantigens before and after islet transplantation in 36 patients (33 receiving islet plus kidney grafts with cyclosporin and steroid-based immunosuppression, and 3 receiving solitary islet transplants with mycophenolate but cyclosporin-free immunosuppression) demonstrated marked rises in GAD antibodies within 7 days posttransplantation in 5 patients (3 receiving islet after kidney transplants, and 2 receiving solitary islet transplants) and within 30 days in the third patient receiving solitary islet transplantation. GAD antibodies were of the IgG1 subclass, against major autoantigenic epitopes, and in cases of islet after kidney transplants, the responses were short-lived and not accompanied by HLA antibodies. Two of these patients had subsequent marked rises of IA-2 antibodies, and an additional patient had a marked rise in IgM-GAD antibodies 3 years after transplantation. Insulin independence was not achieved in patients with autoantibody elevations and was significantly less frequent in these patients. These data are consistent with a reactivation of autoimmunity that may be dependent on immunosuppression therapy and is associated with impaired graft function.     

胰岛移植治疗1型糖尿病的现状和未来

1型糖尿病是一种全球性的慢性自身免疫疾病,会造成机体一系列代谢紊乱综合征,严重危害人类健康。胰岛移植可以通过增加1型糖尿病患者体内胰岛细胞的数量,减少患者对外源性胰岛素的依赖、有效控制血糖以及防治长期并发症,是一种安全可靠的治疗方法,这都是外源性胰岛素治疗和移植风险极高的全胰腺移植无法实现的。本文就胰岛移植供受体选择、胰岛细胞的分离纯化及胰岛移植、胰岛移植后的免疫抑制治疗、胰岛移植后的监测指标、胰岛移植临床应用的现状以及面临的挑战做一综述。     

Nutritional status and behavior in subjects with type 1 diabetes, before and after islet transplantation

BACKGROUND: To investigate whether changes of nutritional status and behavior are associated with islet transplantation (ITx) and to assess their possible mechanisms. METHODS: In this observational study, 52 subjects with type 1 diabetes, 30 of whom received ITx, underwent nutritional assessments. The study consisted of questionnaires complemented by a dietary intake recording, anthropometric measurements, and body composition analysis. Laboratory tests were also reviewed as part of the follow up. RESULTS: After ITx, significant reductions in body weight (3.7 kg; P<0.0001), body mass index (1.39 kg/m2; P<0.0001), waist circumference (3.96 cm; P=0.006), and fat weight (3.28 kg; P<0.01) were observed. The average consumption of carbohydrate and protein were also lower than pretransplant, together with some micronutrients (vitamins B12 and B6, zinc, and phosphorus). Insulin administration and changes in A1C were not associated with a significant change in anthropometric measurements. Subjects on exenatide after ITx showed significantly lower weight and body mass index than those not taking exenatide. CONCLUSIONS: ITx is associated with modifications in nutritional behavior and status. Drugs and health conditions are likely to be at least in part responsible for these changes, but a voluntary modification of eating habits by the patients also plays a role. Strict monitoring of nutritional parameters, counseling by experts in nutrition, and multivitamin/mineral supplement after ITx could be of benefit to the patients.     

Immunosuppression and procedure-related complications in 26 patients with type 1 diabetes mellitus receiving allogeneic islet cell transplantation

BACKGROUND: The success of sirolimus and low-dose tacrolimus in islet cell transplantation has influenced many transplant centers to utilize this novel regimen. The long-term safety and tolerability of this steroid-free immunosuppressive protocol for allogeneic islet transplantation has yet to be determined. METHODS: We transplanted 26 adult patients with long standing type 1 diabetes mellitus between April 2000 and June 2004. Immunosuppression consisted of induction with daclizumab and maintenance therapy with tacrolimus and sirolimus. Adverse events (AEs) in patients were followed and graded using the Common Terminology Criteria for Adverse Events, version 3.0 (National Cancer Institute). RESULTS: To date, the majority of patients were able to remain on the immunosuppression combination for up to 22+/-11 months. Four patients were successfully converted to Mycophenolate Mofetil due to tacrolimus-related toxicity. Withdrawal from immunosuppression was decided in four patients due to hypereosinophilic syndrome, parvovirus infection, aspiration pneumonia, and severe depression, respectively. Six patients required filgrastim therapy for neutropenia. Transient elevation of liver enzymes was observed in most patients early after islet infusion. Increased LDL in 20 patients required medical treatment. CONCLUSION: There was a varying range of AEs, most of them mild and self-limiting; however, some required urgent medical attention. The majority of patients were able to tolerate and remain on this effective regimen. To date, no deaths, cytomegalovirus disease, graft-versus-host disease, or posttransplant lymphoproliferative disease has been observed.     

Comparative evaluation of simple indices using a single fasting blood sample to estimate beta cell function after islet transplantation

Six single fasting blood sample–based indices—Secretory Unit of Islet Transplant Objects (SUITO), Transplant Estimated Function (TEF), Homeostasis Model Assessment (HOMA)2‐B%, C‐peptide/glucose ratio (CP/G), C‐peptide/glucose creatinine ratio (CP/GCr), and BETA‐2 score—were compared against commonly used 90‐minute mixed meal tolerance test (MMTT) serum glucose and beta score to assess which of them best recognizes the state of acceptable blood glucose control without insulin supplementation after islet allotransplantation (ITx). We also tested whether the indices could identify the success of ITx based on the Igls classification of beta cell graft function. We analyzed values from 47 MMTT tests in 4 patients with up to 140 months follow‐up and from 54 MMTT tests in 13 patients with up to 42 months follow‐up. SUITO, CP/G, HOMA2‐B%, and BETA‐2 correlated well with the 90‐minute glucose of the MMTT and beta‐score (r 0.54‐0.76), whereas CP/GCr showed a modest performance (r 0.41‐0.52) while TEF showed little correlation. BETA‐2 and SUITO were the best identifiers and predictors of the need for insulin support, glucose intolerance, and ITx success (P < .001), while HOMA2‐B% and TEF were unreliable. Single fasting blood sample SUITO and BETA‐2 scores are very practical alternative tools that allow for frequent assessments of graft function.

     

2型糖尿病患者骨钙素水平及其与胰岛素抵抗和胰岛β细胞功能相关性分析

目的探讨2型糖尿病(type 2 diabetes mellitus,T2DM)患者血清骨钙素水平及其与胰岛素抵抗、胰岛β细胞功能的相关性。方法研究对象为403例T2DM住院患者,记录患者性别、年龄、身高、体重、病史等一般信息。测定其骨钙素(osteocalcin,OC)、钙(calcium,Ca)、镁(magnesium,Mg)、磷(phosphorus,P)、甲状旁腺素(parathyroid hormone,PTH)、25羟维生素D(25-hydroxyvitamin D,25(OH)D)、空腹血糖(fasting blood glucose,FBG)、空腹胰岛素(fasting insulin,FINS)、糖化血红蛋白(glycosylated hemoglobin,Hb A1c),行葡萄糖耐量实验后测定其2小时血糖(2-hours blood glucose,2h BG)、2小时胰岛素(2-hours Insulin,2h INS),计算体重指数(body mass index,BMI)、稳态模型胰岛素抵抗指数(homeostasis model assessment of insulin resistance,HOMA-IR)、稳态模型胰岛素分泌指数(homeostasis model assessment ofβcell,HOMA-β)。将研究对象分别按年龄、性别、BMI、骨钙素水平分组比较其代谢水平,根据研究对象骨钙素中位数水平分为低骨钙素组(OL组,n=201)和高骨钙素组(OH组,n=202),分析骨钙素水平与胰岛素抵抗及胰岛β细胞功能相关性。结果青年组的Ca水平高于老年组(P0.05)。女性组患者的OC(Z=4.596,P0.001)、PTH(Z=3.150,P=0.002)、P(t=5.258,P0.001)水平高于男性组患者(P0.05)。男性组患者的25(OH)D水平高于女性组患者(Z=3.196,P=0.001)。肥胖组患者的25(OH)D水平低于超重组和正常体重组(P0.05)。超重组的OC水平低于正常体重组(P0.05)。OL组患者的Hb A1c(t=4.479,P0.001)、FBG(Z=3.579,P0.001)、2h BG(Z=4.413,P0.001)水平高于OH组患者(P0.05);OL组患者的2h INS(Z=3.482,P0.001)、HOMA-β(Z=2.397,P=0.017)低于OH组(P0.05)。OC水平与2h INS(r=0.152)和HOMA-β(r=0.121)呈正相关(P0.05),与Hb A1c(r=-0.244)、FBG(r=-0.176)、2h BG(r=-0.241)呈负相关(P0.001)。结论 2型糖尿病患者骨代谢等相关指标存在差异性,血清OC与糖代谢之间存在显著的相关性,血清OC可能通过改善胰岛β细胞功能、促进胰岛素分泌等途径参与血糖代谢调节。     

Long-term graft function after allogeneic islet transplantation

Islet transplants are emerging as a viable option for the treatment of type 1 diabetes mellitus. From 1989 to 1995 we conducted a series of simultaneous islet-kidney transplants in six uremic type 1 diabetic patients. We report two of these patients who have shown persistent islet graft function over many years. Two female patients with duration of diabetes of 27 and 37 years underwent simultaneous islet-kidney transplant under steroid- and cyclosporine-based immunosuppression. Freshly isolated islets were supplemented with cryopreserved islets from our low-temperature bank of frozen islets. A total islet mass of 9,866 and 15,061 islet equivalents/kg body weight, respectively, was transplanted into the liver through portal vein. Reasonable blood glucose control has been achieved for up to 6 years posttransplant in one patient, but there was minimum clinical benefit from the islet graft at 10 years. In contrast, sustained insulin secretion with nearly normal HbA1c at 13 years follow-up was observed in another patient, providing hope for improving long-term graft outcomes for islet transplant recipient.     

胰岛素依赖型糖尿病患者胚胎胰腺组织脑内移植的远期疗效观察与免疫学研究

目的观察脑内胰腺组织移植治疗胰岛素依赖型糖尿病（ＩＤＤＭ）的远期疗效,并探讨其免疫学变化。方法应用短期培养的人胎胰腺组织脑内移植,共施行３０例,移植术后随访１～７年。结果移植后１年内有效２６例,无效４例;移植后２～３年随访２１例,有效１７例,失效４例;４～５年随访１８例,有效１５例,失效３例;移植后６～７年随访１５例,有效９例,失效６例。在移植有效的病例中,随访资料较完整者２３例,有效维持时间为（４．９±１．７）年,１１例完全或间断停用胰岛素治疗,停用时间达（３．１±１．９６）年,其中超过３年者６例。移植前胰岛细胞抗体（ＩＣＡ）阳性的６例,４例移植无效;移植无效或后期复发的患者,外周血Ｔ淋巴细胞亚群明显失衡。结论脑内胰腺组织移植治疗ＩＤＤＭ的远期效果显著;ＩＣＡ阳性者不宜行胰腺组织移植     

Genetic effects on age-dependent onset and islet cell autoantibody markers in type 1 diabetes

Age-dependent associations between type 1 diabetes risk genes HLA, INS VNTR, and CTLA-4 and autoantibodies to GAD65 (GADAs), ICA512/IA-2, insulin, and islet cells were determined by logistic regression analysis in 971 incident patients with type 1 diabetes and 702 control subjects aged 0-34 years. GADAs were associated with HLA-DQ2 in young but not in older patients (P = 0.009). Autoantibodies to insulin were negatively associated with age (P < 0.0001) but positively associated with DQ8 (P = 0.03) and with INS VNTR (P = 0.04), supporting possible immune tolerance induction. ICA512/IA-2 were negatively associated with age (P < 0.0001) and with DQ2 (P < 0.0001) but positively associated with DQ8 (P = 0.04). Males were more likely than females to be negative for GADA (P < 0.0001), autoantibodies to islet cells (P = 0.04), and all four autoantibody markers (P = 0.004). The CTLA-4 3' end microsatellite marker was not associated with any of the autoantibodies. We conclude that age and genetic factors such as HLA-DQ and INS VNTR need to be combined with islet autoantibody markers when evaluating the risk for type 1 diabetes development.     

Improved metabolic control and quality of life in seven patients with type 1 diabetes following islet after kidney transplantation

BACKGROUND: The beneficial effects of glycemic control on both survival and function of transplanted kidneys in patients with type 1 diabetes mellitus (T1DM) and end-stage renal disease (ESRD) have been recognized. METHODS: Herein, we present the clinical outcome of a single-center pilot trial of islet after kidney (IAK) transplantation in seven patients with T1DM. The immunosuppression protocol for the kidney graft was converted to sirolimus+tacrolimus regimen 6 months before islet transplantation to exclude negative effects on kidney graft function. Primary endpoint was achievement of insulin independence after transplantation. Clinical outcome, metabolic control, severe hypoglycemia, kidney function, Quality of Life (QOL) psychometric measures, and adverse events were monitored. RESULTS: Seven patients showed graft function with improved metabolic control (A1c, fasting glycemia, and metabolic tests) after IAK (14,779+/-3,800 IEQ/kg). One-year insulin independence was 30% with persistent graft function in 86% (C-peptide-positive). A1c reduction was 1.95+/-0.31% from baseline (P<0.0001). No episodes of severe hypoglycemia were observed, even after resuming insulin. The direct consequence of these benefits was a significant improvement in diabetes QOL. Adverse events included procedure-related pleural effusion (n=2), cholecystitis (n=1), and additional immunosuppression-related, all resolved without sequelae. Kidney function (by estimated glomerular filtration rate) remained stable during follow-up in six of seven patients. CONCLUSIONS: Islet transplantation represents a feasible therapeutic option for patients with T1DM bearing a stable kidney allograft. Insulin independence at 1 year is lower than what reported in islet transplant alone. Nevertheless, clear benefits in terms of optimal metabolic control and absence of severe hypoglycemia are invariably present.