Cancer arising after pancreas and/or kidney transplantation in a series of 99 diabetic patients

Post-Transplant Malignancies following Pancreas Transplantation: Incidence and Implications on Long-Term Outcome from a Single-Center Perspective

Chronic immunosuppression is associated with an increased risk of malignancy. The main objective of this study is to evaluate the incidence and effect of post-transplant malignancies (PTMs) following pancreas transplantation. The 348 first pancreas transplants performed between 1985 and 2015 were retrospectively analyzed in this study. Incidences of PTMs, as well as patient and graft survival, were evaluated. Out of 348 patients, 71 (20.4%) developed a PTM. Median time to diagnosis was 130 months. Thirty-six patients (50.7%) developed skin cancers (four patients with melanoma, 32 with NMSCs). Solid organ malignancy occurred in 25 (35.2%), hematologic malignancy in ten patients (14.1%). Affected patients were transplanted earlier [2000 (IQR 1993−2004) vs. 2003 (IQR 1999−2008); p < 0.001]. No differences in induction therapy were seen, both groups demonstrated comparable patient and graft survival. Pancreas transplant recipients with solid organ and hematologic malignancies had a three- and six-fold increased hazard of death compared to those with skin cancers [aHR 3.04 (IQR 1.17–7.91); p = 0.023; aHR 6.07 (IQR 1.87–19.71); p = 0.003]. PTMs affect every fifth patient following pancreas transplantation. Skin cancers are the most common malignancies accounting for 50% of all PTMs. These results underscore the importance of close dermatologic follow-up.

Pancreas transplant with enteric drainage at a single institute in Asia

BACKGROUND/OBJECTIVE

This study is to assess immunological and graft survival outcomes after pancreas transplant at a single institute in Asia.

METHODS

Patients undergoing pancreas transplant with enteric drainage were included. Clinical data and outcomes were evaluated and compared between each subgroup.

RESULTS

There were 165 cases of pancreas transplant, including 38 (23 %) simultaneous pancreas-kidney transplant (SPK), 24 (15 %) pancreas after kidney transplant (PAK), 75 (46 %) pancreas transplant alone (PTA), and 28 (17 %) pancreas before kidney transplant (PBK). The overall surgical complication rate was 46.1 %, with highest (62.5 %) in PAK and lowest (32.0 %) in PTA, P = 0.008. The late complications included 32.7 % infection and 3.6 % malignancy. Overall rejection of pancreas graft was 24.8 % including 18.2 % acute and 9.7 % chronic rejection. Rejection was highest in PTA group (36.0 %) and lowest in PBK (3.6 %). There were 56 cases (33.9 %) with graft loss in total, with highest graft loss rate in PTA (38.7 %). The 1-year, 5-year and 10-year pancreas graft survivals for total patients were 98.0 %, 87.7 % and 70.9 % respectively.

CONCLUSIONS

Enteric drainage in pancreas transplant could be applied safely not only in SPK but also in other subgroups. Enteric drainage itself would not compromise the immunological and graft survival outcomes.

Cervical dysplasia after renal transplantation: A retrospective cohort study

Objective:

Since the first days of organ transplantation, it has been accepted that solid transplant recipients have a high risk of developing cancer. Chronic immunosuppression and environmental factors play a role in cancer development in recipients. In the present study, we tried to evaluate the cumulative incidence of cervical dysplasia after renal transplantation, risk factors for disease development, and the time until high-grade dysplasia occurred.

Materials and Methods:

A total of 50 patients with renal transplantation who presented for gynecologic follow-up was included in the study. The medical records of the patients were reviewed until the last clinical visit, their demographic characteristics, transplant history, gynecologic history, and gynecologic examination results (cervical cytology and histology reports) were reviewed.

Results:

Of the 50 women in the study population, 29 (58%; 95% confidence interval: 8.8-15.9) developed cervical dysplasia after the first transplant at a median follow-up of 7.8 (range: 4.6-12.9) years. Twenty-one women with benign cervical cytology before transplantation had evidence of low-grade intraepithelial lesions + after transplant (47% of these were within 2 years after transplant). During the follow-up, 8 women (18.2%) were diagnosed as having high-grade intraepithelial lesions + (within 5 years after transplantation).

Conclusion:

Renal transplant patients were found to have higher abnormal cervical cytology and histology rates than the normal population.

Preneoplastic Lesion in a Pancreas Allograft: Dilemma for the Pancreas Transplant Surgeon

Although the relationship between immunosuppression and cancer risk is well-documented, the association between immunosuppression and the development of preneoplastic lesions (PNL) is less clear. PNLs pose a unique clinical conundrum in the transplanted pancreas because their prevalence in the general population is not infrequent. We present the case of a 58-year-old man with a history of diabetes mellitus type 1 who underwent successful pancreas transplantation with bladder drainage. His kidney function failed 13 years after his transplant and he developed recurrent painful hematuria with symptomatic anemia 2 years after initiating hemodialysis. Upon work-up, he was found to have a 4 cm intraductal papillary mucinous neoplasm in his pancreas allograft. At his enteric conversion, the intraductal papillary mucinous neoplasm was removed through a distal pancreatectomy due to concern for its malignant potential. He recovered well from surgery and continues to be insulin-free. With the rising incidence of PNLs from improved detection and the improved survival of pancreas allografts, the implications of PNLs may be more pronounced in the future. This case raises several important considerations for the pancreas transplant surgeon regarding adequate allograft surveillance protocols, treatment, and follow-up.

Hyperglycemic clamp and oral glucose tolerance test for 3-year prediction of clinical onset in persistently autoantibody-positive offspring and siblings of type 1 diabetic patients

CONTEXT AND OBJECTIVE

In preparation of future prevention trials, we aimed to identify predictors of 3-year diabetes onset among oral glucose tolerance test (OGTT)- and hyperglycemic clamp-derived metabolic markers in persistently islet autoantibody positive (autoAb(+)) offspring and siblings of patients with type 1 diabetes (T1D).

DESIGN

The design is a registry-based study.

SETTING

Functional tests were performed in a hospital setting.

PARTICIPANTS

Persistently autoAb(+) first-degree relatives of patients with T1D (n = 81; age 5-39 years).

MAIN OUTCOME MEASURES

We assessed 3-year predictive ability of OGTT- and clamp-derived markers using receiver operating characteristics (ROC) and Cox regression analysis. Area under the curve of clamp-derived first-phase C-peptide release (AUC(5-10 min); min 5-10) was determined in all relatives and second-phase release (AUC(120-150 min); min 120-150) in those aged 12-39 years (n = 62).

RESULTS

Overall, the predictive ability of AUC(5-10 min) was better than that of peak C-peptide, the best predictor among OGTT-derived parameters (ROC-AUC [95%CI]: 0.89 [0.80-0.98] vs 0.81 [0.70-0.93]). Fasting blood glucose (FBG) and AUC(5-10 min) provided the best combination of markers for prediction of diabetes within 3 years; (ROC-AUC [95%CI]: 0.92 [0.84-1.00]). In multivariate Cox regression analysis, AUC(5-10 min)) (P = .001) was the strongest independent predictor and interacted significantly with all tested OGTT-derived parameters. AUC(5-10 min) below percentile 10 of controls was associated with 50-70% progression to T1D regardless of age. Similar results were obtained for AUC(120-150 min).

CONCLUSIONS

Clamp-derived first-phase C-peptide release can be used as an efficient and simple screening strategy in persistently autoAb(+) offspring and siblings of T1D patients to predict impending diabetes.

Confronting the challenge: individualized immune monitoring after organ transplantation using the cellular immune function assay

The survival of a transplanted organ is dependent on avoidance of rejection, achieved through continuous immuno-suppression. Management of the transplant recipient confronts the clinician with a key challenge of post-transplant immune monitoring. Early detection of an activated allo-immune response is a harbinger of incipient rejection. Thus, timely intervention may prevent acute and chronic injury to the transplanted organ. Similarly, over immune-suppression can lead to infections or malignancies, hence the importance of early detection of the precarious suppression. The need for non-invasive systemic immune monitoring of the transplant recipient is therefore imperative. This review describes the cellular immune function assay--a non-invasive diagnostic method for evaluation of the net state of the recipient's cellular immune function. We describe the background that brought about the need for a reliable diagnostic tool for serial immune monitoring, and we overview the main mile-stones in the assimilation of the assay and its implementation in the clinic. The arising conclusion presents a novel non-invasive diagnostic bio-marker for post-transplant immune monitoring which enables the clinician to intervene prior to manifestation of clinical complications. The usefulness of the assay in detecting a state of over-suppression has been consensually described in multiple publications while its contribution in detection and management of under-suppression conditions remains to be determined by means of prospective interventional studies. The cellular immune function assay can be useful and beneficial for patient care only if used for longitudinal monitoring through serial testing.

Pancreatic transplantation: surgical technique, normal radiological appearances and complications

Pancreas transplantation is a surgical treatment for diabetes mellitus. More than 23,000 pancreas transplants have now been reported to the International Transplant Registry (IPTR). Early diagnosis and therapy for graft-related complications are essential for graft survival. Radiologists must therefore understand the surgical procedure and the potential complications. During the course of this review, we will illustrate the normal post-operative anatomy and the imaging appearances of common potential complications.

Posttransplant lymphoproliferative disorder following pancreas transplantation

The incidence, risk factors and impact on patient and graft survival were evaluated for posttransplant lymphoproliferative disorder (PTLD) among 212 pancreas transplant recipients. Thirteen (6.1%) developed PTLD during 71 +/- 27 months follow-up. Cumulative incidences of PTLD at 1, 3, 5 and 10 years posttransplant were 4.2%, 5.3%, 6.0% and 7.0%, respectively. Incidence of PTLD was lower for recipients of simultaneous pancreas kidney compared to pancreas after kidney transplant or pancreas transplant alone, though not significantly so. Recipient Epstein-Barr virus (EBV) seronegativity and number of doses of depleting antibody therapy administered at transplant were associated with increased risk of PTLD, while recipient age, gender, transplant type, cytomegalovirus mismatch maintenance immunosuppression type and treated acute rejection were not. All 13 cases underwent immunosuppression reduction, and 10 received anti-CD20 monoclonal antibody. During follow-up, 10/13 (77%) responded to treatment with complete remission, while 3 (23%) died as a result of PTLD. Patient and graft survivals did not differ for recipients with and without PTLD. The strong association of PTLD with EBV-seronegativity requires considering this risk factor when evaluating and monitoring pancreas transplant recipients. With reduction of immunosuppression and anti-CD20 therapy, survival for pancreas transplant recipients with PTLD was substantially better than previously reported.

Human papilloma virus infection and cervical intraepithelial neoplasia in transplanted patients

Progress in diagnosis and treatment has led to an increased number of transplantation patients who consequently have immunological depression and emergence of tumors. The incidence of cervical neoplasia, according to previous studies, is 11%; this tumor is the only one that can be investigated by screening before and after a graft. Our purpose was to evaluate whether transplanted patients showed an increased incidence of genital human papilloma virus (HPV) infection and whether this infection produced greater progression of disease in cases of low-risk HPV infections. Our study involved 151 transplant patients who underwent Papanicolaou (Pap) and HPV tests. Patients listed for grafts underwent Pap and HPV tests 6 months before and 6 months after transplantation. All patients had negative Pap tests before their grafts. After their grafts 16 patients (10.59%) had negative Pap tests, but positive viral typing. Eleven patients (7.28%) showed positive Pap tests, 6 of whom had low-grade squamous intraepithelial lesion (SIL) and 5 patients high-grade SIL. The final HPV infection incidence (15.23%) was consistent with the literature. The incidence of lower female genital tract intraepithelial lesions (7.28%) was higher than the healthy population or analogous studies (4.5%-8.5%). We showed a constant association between high-risk HPV infection and gynecologic intraepithelial neoplasia, whereas there was no association between low-risk broods HPV infection and neoplasia. In conclusion, screening should start at almost 6 months before grafting to avoid an irreversible situation that is difficult to treat.

The long-term management of pancreas transplantation

Diabetes mellitus (DM) is a major health problem worldwide, which affects 18.2 million individuals (6.3% of the population) in the United States. Currently, the prevalence of Type 1 DM in the United States is estimated to be 1,000,000 individuals, and 30,000 new cases are diagnosed each year. In addition to end-stage renal disease (ESRD), DM is associated with blindness, accelerated atherosclerosis, dyslipidemia, cardio- and cerebrovascular disease, amputation, poor quality of life, and overall lifespan reduction. It accounts for more than 160,000 deaths per year in the United States alone. In 2002, the annual national direct and indirect costs of Types 1 and 2 DM exceeded $130 billion, which included hospital and physician care, laboratory tests, pharmaceutical products, and patient workdays lost because of disability or premature death. Hyperglycemia alone or in concert with hypertension is the primary factor influencing the development of major diabetic complications. From 1990 to 2001, the number of existing ESRD cases to DM increased by more than 300%, while the rate per million populations increased from 167% to 491%. The number is expected to grow 10-fold by 2030 to 1.3 million accounting for 60% of ESRD population. To date, DM is the leading indication for transplantation and is the cause of ESRD in more than 40% of all transplant recipients each year.

Enteric drainage pancreatic transplantation

Enteric drainage is currently the preferred method of pancreatic transplantation. This technique results in long-term good control of diabetes. In this report we discuss the postoperative radiologic anatomy and complications.

Posttransplant Lymphoproliferative Disorder in Pancreas Transplantation: A Single-Center Experience

BACKGROUND

Posttransplant lymphoproliferative disorder (PTLD) is a rare, serious complication of transplantation. The characteristics and associations of this disease in pancreas recipients have not been extensively studied.

METHODS

From January 1988 through December 2002, 787 pancreas and 569 kidney-pancreas transplants were performed at our institution. Eighteen pancreas recipients developed polymorphic PTLD or malignant lymphoma. Data on clinical course, organ involvement, molecular characteristics, and association with immunosuppression and recent cytomegalovirus (CMV) infection were compiled from the institutional transplant database. Patient survival was compared to recipients of liver and kidney transplants at the same center by using Kaplan-Meier analysis.

RESULTS

The 5-year cumulative incidence of PTLD in simultaneous pancreas-kidney, pancreas after kidney, and pancreas transplant alone recipients was 2.5%, 1.2%, and 1.0%, respectively (P = 0.23). A noticeably, but not significantly, higher cumulative incidence was seen in the more recent era since 1995 (2.1% vs. 0.9%, P = 0.15). PTLD in pancreas recipients carried a worse prognosis than in liver or kidney for recipients B-cell, early-onset, and Epstein Barr virus-positive lesions. PTLD was more aggressive in pancreas recipients, with a higher stage at presentation and a trend to more bone marrow involvement. There appeared to be a tendency toward association with recent CMV infection. Since 1995, PTLD recipients have had a lower exposure to antilymphocyte preparations (25 +/- 5 vs. 10 +/- 0.8)(P < 0.05).

CONCLUSIONS

PTLD in pancreas recipients remains a rare but aggressive disease, and carries a worse prognosis in comparison to other transplant recipients. These heavily immunosuppressed patients, who often face multiple transplants, may be at greater risk; CMV infection may play an antecedent role.

Type-II diabetes and pancreatic cancer: a meta-analysis of 36 studies

Pancreatic cancer is the eighth major form of cancer-related death worldwide, causing 227 000 deaths annually. Type-II diabetes is widely considered to be associated with pancreatic cancer, but whether this represents a causal or consequential association is unclear. We conducted a meta-analysis to examine this association. A computer-based literature search from 1966 to 2005 yielded 17 case–control and 19 cohort or nested case–control studies with information on 9220 individuals with pancreatic cancer. The age and sex-adjusted odds ratio (OR) for pancreatic cancer associated with type-II diabetes was obtained from each study. The combined summary odds ratio was 1.82 (95% confidence interval (95% CI) 1.66–1.89), with evidence of heterogeneity across the studies (P=0.002 for case–control and P=0.05 for cohort studies) that was explained, in part, by higher risks being reported by smaller studies and studies that reported before 2000. Individuals in whom diabetes had only recently been diagnosed (<4 years) had a 50% greater risk of the malignancy compared with individuals who had diabetes for ⩾5 years (OR 2.1 vs 1.5; P=0.005). These results support a modest causal association between type-II diabetes and pancreatic cancer.

Multiple Neoplastic Lesions of the Lower Genital Tract in a Human Papilloma Virus-Infected Kidney-Pancreas Allograft Recipient: A Case Report

States of immunodeficiency are associated with an increased rate of certain cancers. Immunosuppressed allograft recipients are at high risk of Human Papilloma Virus (HPV)-related de novo malignancies. A female pancreas plus kidney transplant patient developed multiple genital malignancies within 6 years. The genome of human papilloma virus type 16 was detected in malignant lesions obtained from surgical procedures. All detected lesions were removed at an early state of development.

Pancreas transplantation: indications and consequences

Pancreas transplantation continues to evolve as a strategy in the management of diabetes mellitus. The first combined pancreas-kidney transplant was reported in 1967, but pancreas transplant now represents a number of procedures, each with different indications, risks, benefits, and outcomes. This review will summarize these procedures, including their risks and outcomes in comparison to kidney transplantation alone, and how or if they affect the consequences of diabetes: hyperglycemia, hypoglycemia, and microvascular and macrovascular complications. In addition, the new risks introduced by immunosuppression will be reviewed, including infections, cancer, osteoporosis, reproductive function, and the impact of immunosuppression medications on blood pressure, lipids, and glucose tolerance. It is imperative that an endocrinologist remain involved in the care of the pancreas transplant recipient, even when glucose is normal, because of the myriad of issues encountered post transplant, including ongoing management of diabetic complications, prevention of bone loss, and screening for failure of the pancreas graft with reinstitution of treatment when indicated. Although long-term patient and graft survival have improved greatly after pancreas transplant, a multidisciplinary team is needed to maximize long-term quality, as well as quantity, of life for the pancreas transplant recipient.

Human insulin production and amelioration of diabetes in mice by electrotransfer-enhanced plasmid DNA gene transfer to the skeletal muscle

A first-line gene therapy for type 1 diabetes should be based on a safe procedure to engineer an accessible tissue for insulin release. We evaluated the ability of the skeletal muscle to release human insulin after electrotransfer (ET)-enhanced plasmid DNA injection in mice. A furin-cleavable proinsulin cDNA under the CMV or the MFG promoter was electrotransferred to immune-incompetent mice with STZ-induced severe diabetes. At 1 week, mature human insulin was detected in the serum of 17/20 mice. After an initial peak of 68.5 +/- 34.9 microU/ml, insulin was consistently detected at significant levels up to 6 weeks after gene transfer. Importantly, untreated diabetic animals died within 3 weeks after STZ, whereas treated mice survived up to 10 weeks. Fed blood glucose (BG) was reduced in correspondence with the insulin peak. Fasting BG was near-normalized when insulin levels were 12.9 +/- 5.3 (CMV group, 2 weeks) and 7.7 +/- 2.6 microU/ml (MFG group, 4 weeks), without frank hypoglycemia. These data indicate that ET-enhanced DNA injection in muscle leads to the release of biologically active insulin, with restoration of basal insulin levels, and lowering of fasting BG with increased survival in severe diabetes. Therefore the skeletal muscle can be considered as a platform for basal insulin secretion.

Cardiovascular outcomes after kidney-pancreas and kidney-alone transplantation

BACKGROUND

This study retrospectively assessed, with an intention-to-treat analysis, the effect of kidney-pancreas transplantation (KP) on survival and cardiovascular outcome in type 1 diabetic uremic patients.

METHODS

A total of 351 uremic type 1 diabetic patients were enrolled on a waiting list for KP: 130 underwent KP transplantation, 25 underwent kidney transplantation alone (KA), whereas 196 patients remained on dialysis (WL). The three populations had similar cardiovascular conditions. Actuarial survival rates and causes of death were recorded over a period of seven years. Finally, 23 KP and 13 KA patients underwent left radionuclide ventriculography, during a follow-up of four years.

RESULTS

In the entire group of 351 patients the seven-year survival rate was 77.4% for KP, 56.0% for KA and 39.6% for WL (KP vs. WL, P = 0.01). Cardiovascular death rate was 7.6% in KP, 20.0% in KA and 16.1% in WL (KP versus WL, P = 0.03; KP vs. KA, P = 0.16). In the subsample studied with radionuclide ventriculography, left ventricular ejection fraction improved in KP, but did not in KA, with significant differences between groups at two and four years. At four years only the KP patients presented normal values of diastolic parameters, including the peak filling rate, time-to-peak filling rate, and peak filling rate/peak ejection rate ratio. Glycated hemoglobin was negatively associated with the ejection fraction, peak filling rate and peak filling rate/peak ejection rate ratio, and positively associated with the time-to-peak filling rate.

CONCLUSIONS

Normalization of blood glucose metabolism and improvement of blood pressure control obtained with KP transplant is associated with positive effects on survival, cardiovascular death rate, and left ventricular function.

Lessons learned from more than 1,000 pancreas transplants at a single institution

OBJECTIVE

To determine outcome in diabetic pancreas transplant recipients according to risk factors and the surgical techniques and immunosuppressive protocols that evolved during a 33-year period at a single institution.

SUMMARY BACKGROUND DATA

Insulin-dependent diabetes mellitus is associated with a high incidence of management problems and secondary complications. Clinical pancreas transplantation began at the University of Minnesota in 1966, initially with a high failure rate, but outcome improved in parallel with other organ transplants. The authors retrospectively analyzed the factors associated with the increased success rate of pancreas transplants.

METHODS

From December 16, 1966, to March 31, 2000, the authors performed 1,194 pancreas transplants (111 from living donors; 191 retransplants): 498 simultaneous pancreas-kidney (SPK) and 1 simultaneous pancreas-liver transplant; 404 pancreas after kidney (PAK) transplants; and 291 pancreas transplants alone (PTA). The analyses were divided into five eras: era 0, 1966 to 1973 (n = 14), historical; era 1, 1978 to 1986 (n = 148), transition to cyclosporine for immunosuppression, multiple duct management techniques, and only solitary (PAK and PTA) transplants; era 2, 1986 to 1994 (n = 461), all categories (SPK, PAK, and PTA), predominantly bladder drainage for graft duct management, and primarily triple therapy (cyclosporine, azathioprine, and prednisone) for maintenance immunosuppression; era 3, 1994 to 1998 (n = 286), tacrolimus and mycophenolate mofetil used; and era 4, 1998 to 2000 (n = 275), use of daclizumab for induction immunosuppression, primarily enteric drainage for SPK transplants, pretransplant immunosuppression in candidates awaiting PTA.

RESULTS

Patient and primary cadaver pancreas graft functional (insulin-independence) survival rates at 1 year by category and era were as follows: SPK, era 2 (n = 214) versus eras 3 and 4 combined (n = 212), 85% and 64% versus 92% and 79%, respectively; PAK, era 1 (n = 36) versus 2 (n = 61) versus 3 (n = 84) versus 4 (n = 92), 86% and 17%, 98% and 59%, 98% and 76%, and 98% and 81%, respectively; in PTA, era 1 (n = 36) versus 2 (n = 72) versus 3 (n = 30) versus 4 (n = 40), 77% and 31%, 99% and 50%, 90% and 67%, and 100% and 88%, respectively. In eras 3 and 4 combined for primary cadaver SPK transplants, pancreas graft survival rates were significantly higher with bladder drainage (n = 136) than enteric drainage (n = 70), 82% versus 74% at 1 year (P =.03). Increasing recipient age had an adverse effect on outcome only in SPK recipients. Vascular disease was common (in eras 3 and 4, 27% of SPK recipients had a pretransplant myocardial infarction and 40% had a coronary artery bypass); those with no vascular disease had significantly higher patient and graft survival rates in the SPK and PAK categories. Living donor segmental pancreas transplants were associated with higher technically successful graft survival rates in each era, predominately solitary (PAK and PTA) in eras 1 and 2 and SPK in eras 3 and 4. Diabetic secondary complications were ameliorated in some recipients, and quality of life studies showed significant gains after the transplant in all recipient categories.

CONCLUSIONS

Patient and graft survival rates have significantly improved over time as surgical techniques and immunosuppressive protocols have evolved. Eventually, islet transplants will replace pancreas transplants for suitable candidates, but currently pancreas transplants can be applied and should be an option at all stages of diabetes. Early transplants are preferable for labile diabetes, but even patients with advanced complications can benefit.

Successful treatment of aggressive post transplant lymphoproliferative disorder using rituximab

A 52 year -old female developed a histologically aggressive, Epstein-Barr virus positive, lymphoproliferative disorder involving the brain and liver 4 months following a combined kidney/pancreas transplant. Following a brief trial of reduced immunosuppression, she was treated with rituximab. Despite subsequent re-intensification of immunosuppression, the lesions showed continued regression with almost complete disappearance by 5 months. Rituximab appears to be a safe, effective treatment for post transplant lymphoproliferative disorder.

Reversal of diabetes in mice by implantation of human fibroblasts genetically engineered to release mature human insulin

Autoimmune destruction of pancreatic beta cells in type I, insulin-dependent diabetes mellitus (IDDM) results in the loss of endogenous insulin secretion, which is incompletely replaced by exogenous insulin administration. The functional restoration provided by allogeneic beta-cell transplantation is limited by adverse effects of immunosuppression. To pursue an insulin replacement therapy based on autologous, engineered human non-beta cells, we generated a retroviral vector encoding a genetically modified human proinsulin, cleavable to insulin in non-beta cells, and a human nonfunctional cell surface marker. Here we report that this vector efficiently transduced primary human cells, inducing the synthesis of a modified proinsulin that was processed and released as mature insulin. This retrovirally derived insulin displayed in vitro biological activity, specifically binding to and phosphorylation of the insulin receptor, comparable to human insulin. In vivo, the transplantation of insulin-producing fibroblasts reverted hyperglycemia in a murine model of diabetes, whereas proinsulin-producing cells were ineffective. These results support the possibility of developing insulin production machinery in human non-beta cells for gene therapy of IDDM.

Vascularized pancreas allotransplantation--clinical indications and outcome

AIMS

This review examines the status of vascularized pancreas transplantation as a treatment for Type 1 diabetes mellitus (DM).

METHODS

The world literature, with a particular emphasis on data from the International Pancreas Transplant Registry (IPTR), is reviewed and interpreted particularly for clinical indications and outcome.

RESULTS

Over 9000 cases of vascularized pancreas transplant (VPT) have been registered, with insulin dependence approaching 82% at 1 year with 94% patient survival. The majority of transplants are simultaneous pancreas and kidney (SPK) transplants, with far fewer pancreas after kidney (PAK) or pancreas transplants alone (PTA). The success rates differ between the procedures but are generally improving as technical advances, improvements in immunosupression and greater experience are gained. The most obvious advantage is an improved quality of life (QoL) but there are risks associated with the procedure and with the immunosuppression. There is some evidence coming to light of a very slow beneficial effect on microvascular complications.

CONCLUSIONS

VPT is an attractive option to offer Type 1 DM patients who need or already have a renal allograft. Patients have to decide between the increased surgical risk and the risks of long-term immunosuppression and the benefits of improved QoL. In the absense of end-stage renal failure (ESRF) there is no justification for PTA, except where the diabetes itself poses a greater risk to life than the transplantation procedure.