51
|
Narang AS, Mahato RI. Biological and Biomaterial Approaches for Improved Islet Transplantation. Pharmacol Rev 2006; 58:194-243. [PMID: 16714486 DOI: 10.1124/pr.58.2.6] [Citation(s) in RCA: 137] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Islet transplantation may be used to treat type I diabetes. Despite tremendous progress in islet isolation, culture, and preservation, the clinical use of this modality of treatment is limited due to post-transplantation challenges to the islets such as the failure to revascularize and immune destruction of the islet graft. In addition, the need for lifelong strong immunosuppressing agents restricts the use of this option to a limited subset of patients, which is further restricted by the unmet need for large numbers of islets. Inadequate islet supply issues are being addressed by regeneration therapy and xenotransplantation. Various strategies are being tried to prevent beta-cell death, including immunoisolation using semipermeable biocompatible polymeric capsules and induction of immune tolerance. Genetic modification of islets promises to complement all these strategies toward the success of islet transplantation. Furthermore, synergistic application of more than one strategy is required for improving the success of islet transplantation. This review will critically address various insights developed in each individual strategy and for multipronged approaches, which will be helpful in achieving better outcomes.
Collapse
Affiliation(s)
- Ajit S Narang
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, 26 S. Dunlap St., Feurt Building, Room 413, Memphis, TN 38163, USA
| | | |
Collapse
|
52
|
Balamurugan AN, Bottino R, Giannoukakis N, Smetanka C. Prospective and challenges of islet transplantation for the therapy of autoimmune diabetes. Pancreas 2006; 32:231-43. [PMID: 16628077 DOI: 10.1097/01.mpa.0000203961.16630.2f] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Pancreatic islet cell transplantation is an attractive treatment of type 1 diabetes (T1D). The success enhanced by the Edmonton protocol has fostered phenomenal progress in the field of clinical islet transplantation in the past 5 years, with 1-year rates of insulin independence after transplantation near 80%. Long-term function of the transplanted islets, however, even under the Edmonton protocol, seems difficult to accomplish, with only 10% of patients maintaining insulin independence 5 years after transplantation. These results differ from the higher metabolic performance achieved by whole pancreas allotransplantation, and autologous islet cell transplantation, and form the basis for a limited applicability of islet allografts to selected adult patients. Candidate problems in islet allotransplantation deal with alloimmunity, autoimmunity, and the need for larger islet cell masses. Employment of animal islets and stem cells, as alternative sources of insulin production, will be considered to face the problem of human tissue shortage. Emerging evidence of the ability to reestablish endogenous insulin production in the pancreas even after the diabetic damage occurs envisions the exogenous supplementation of islets to patients also as a temporary therapeutic aid, useful to buy time toward a possible self-healing process of the pancreatic islets. All together, islet cell transplantation is moving forward.
Collapse
Affiliation(s)
- A N Balamurugan
- Thomas E. Starzl Transplantation Institute, Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | | | | | | |
Collapse
|
53
|
Lacík I. Polymer Chemistry in Diabetes Treatment by Encapsulated Islets of Langerhans: Review to 2006. Aust J Chem 2006. [DOI: 10.1071/ch06197] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Polymeric materials have been successfully used in numerous medical applications because of their diverse properties. For example, development of a bioartificial pancreas remains a challenge for polymer chemistry. Polymers, as a form of various encapsulation device, have been proposed for designing the semipermeable membrane capable of long-term immunoprotection of transplanted islets of Langerhans, which regulate the blood glucose level in a diabetic patient. This review describes the current situation in the field, discussing aspects of material selection, encapsulation devices, and encapsulation protocols. Problems and unanswered questions are emphasized to illustrate why clinical therapies with encapsulated islets have not been realized, despite intense activity over the past 15 years. The review was prepared with the goal to address professionals in the field as well as the broad polymer community to help in overcoming final barriers to the clinical phase for transplantation of islets of Langerhans encapsulated in a polymeric membrane.
Collapse
|
54
|
Brandhorst D, Huettler S, Alt A, Raemsch-Guenther N, Kurfuerst M, Bretzel RG, Brandhorst H. Adjustment of the Ratio Between Collagenase Class II and I Improves Islet Isolation Outcome. Transplant Proc 2005; 37:3450-1. [PMID: 16298625 DOI: 10.1016/j.transproceed.2005.09.079] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND Previous studies have clarified the distinct roles of collagenase class I (ccI) and class II (ccII) in enzymatic release of islets from pancreatic tissue. The present study sought to enhance the limited knowledge about the optimal ratio between collagenase classes. METHODS Rat islets were isolated utilizing 0.4 DMC-U of neutral protease and 20 PZ-U of fractionated NB-1 collagenase recombined to obtain a ccII/I ratio of 0.5, 1.0, and 1.5. Quality control included assessment of yield (islet equivalents), trypan-blue exclusion, insulin release during static glucose incubation, and transplant function in diabetic nude mice. Data are expressed as mean values +/- SEM. RESULTS Digestion time was only minimally influenced by different ccII/I ratios. The highest islet yield (P < .05) was obtained using a ccII/I ratio of 1.0. Purity and glucose stimulation index were only marginally affected by different ccII/I ratios. A significant loss of islet viability after 24-hour culture (P < .05) was observed only in islets isolated by means of a ccII/I ratio of 0.5 and 1.5 but not 1.0. Transplantation into diabetic nude mice revealed sustained islet graft function in all experimental groups. CONCLUSIONS The present study indicates that the ratio between ccII and ccI is of significant relevance for optimizing islet yield and viability.
Collapse
Affiliation(s)
- D Brandhorst
- Third Medical Department, University Hospital, Rodthohl 6, 35385 Giessen, Germany.
| | | | | | | | | | | | | |
Collapse
|
55
|
Papas KK, Hering BJ, Guenther L, Gunther L, Rappel MJ, Colton CK, Avgoustiniatos ES. Pancreas Oxygenation Is Limited During Preservation With the Two-Layer Method. Transplant Proc 2005; 37:3501-4. [PMID: 16298642 DOI: 10.1016/j.transproceed.2005.09.085] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
BACKGROUND The two-layer method (TLM) for pancreas preservation reportedly improves islet yield and transplantation outcome relative to previous methods. Increased ATP concentrations support the hypothesis that these improvements are related to better oxygenation from the perfluorocarbon solution. However, there are limited direct measurements of oxygen partial pressure, (pO(2)) in pancreata preserved with the TLM. Theory predicts that only a small fraction of a human pancreas can be oxygenated externally. In this report we examine pancreas oxygenation with the TLM using theory and direct pO(2) measurements. METHODS pO(2) profiles in cylindrical pancreata were calculated at various temperatures with a diffusion-reaction model. The pO(2) was measured using fiber optic sensors in the core of porcine pancreatic tissue preserved with the TLM in media saturated with 100% oxygen. RESULTS The model predicts that at 8 degrees C, even in the absence of an external pO(2) gradient, oxygen penetration depth is about 1 mm and insensitive to pancreas diameter, while the oxygenated volume fraction is about 15% for a 2.5-cm-diameter pancreas. Experimental measurements verified that pO(2) is virtually zero in the core of a 1-cm-thick pancreatic piece preserved with the TLM. Penetration of solution around the sensor may be responsible for the observed lag and for the previously reported nonzero pO(2) measurements. Reoxygenation of heat-treated tissue took several hours. CONCLUSIONS The TLM can oxygenate only a small volume fraction of a human pancreas. Pancreas oxygenation through the native vasculature should be explored to further improve yield of viable islets.
Collapse
Affiliation(s)
- K K Papas
- Department of Surgery, University of Minnesota, 420 Delaware Street SE, Minneapolis, MN 55455, USA
| | | | | | | | | | | | | |
Collapse
|
56
|
Bucher P, Mathe Z, Buhler LH, Andres A, Bosco D, Berney T, Morel P. [Diabetes Type I therapy through transplantation]. ACTA ACUST UNITED AC 2005; 130:374-83. [PMID: 15992762 DOI: 10.1016/j.anchir.2005.06.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2004] [Accepted: 06/01/2005] [Indexed: 11/25/2022]
Abstract
Diabetes is one of the most common chronic diseases in our society. While insulin treatment for diabetes type I could delay and reduce the incidence of diabetic complications, it is associated with an increased risk of severe hypoglycemia. To restore physiologic insulin metabolism, transplantation of insulin producing cells (pancreatic Beta cells) represent the sole available therapy. It could be done either through pancreas or islet of Langerhans transplantation. In this paper, we review actual knowledge regarding these two types of transplantations.
Collapse
Affiliation(s)
- P Bucher
- Département de chirurgie, service de chirurgie viscérale et de transplantation, hôpitaux universitaires de Genève, 24 rue Micheli-Du-Crest, 1211 Geneva 14, Switzerland.
| | | | | | | | | | | | | |
Collapse
|
57
|
Eckhard M, Brendel MD, Brandhorst D, Brandhorst H, Bretzel RG. Can the density of native pancreatic tissue slices predict human islet isolation and purification outcome? Transplant Proc 2005; 36:2845-8. [PMID: 15621165 DOI: 10.1016/j.transproceed.2004.09.077] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
INTRODUCTION With currently available technology, the outcomes of human islet isolation and purification are still inconsistent, in part due to a lack of control of the pancreas donor and the procurement conditions. Using a single donor pancreas, the critical islet mass for establishing insulin independence of approximately 5000 engrafted islet equivalents (IEQ)/kg of recipient weight can only be retrieved from about one third of isolations. The purpose of this study was to analyze whether successful islet isolation and purification outcomes might be predicted from the density of native pancreatic tissue. METHODS Tissue slices (TS) were obtained from the neck of 9 nondistended human donor pancreata. The density of the TS was determined using gravity sedimentation in continuous density gradients under either iso-osmolar or hyperosmolar conditions. Correlation coefficients were calculated with regard to the density of isolated exocrine and endocrine tissue, donor age, body mass index (BMI), cold ischemia time (CIT), IEQ prepurification and postpurification, IEQ recovery, and purity. RESULTS (1) There was no change in density over time for TS in 300 mOsm/kg (mean, 1.079 +/- 0.0019 g/cm(3)) (2) In 500 mOsm/kg, there was a significant increase in density from 1.086 +/- 0.0021 g/cm(3) to 1.092 +/- 0.0021 g/cm(3) over time. (3) Density of isolated exocrine and endocrine became more distinct with lower density of TS (r = -0.776; P < .05). (4) Donor age, BMI, recovery of IEQ from gradients, and number of IEQ after purification did not correlate significantly with TS density. (5) In contrast, a significant inverse correlation existed betwen TS and CIT (r = -0.829; P < .05), and between TS versus IEQ number prior to purification (r = -0.867; P < .05). CONCLUSION No homogeneous distribution of pancreas tissue density was seen among 9 consecutive human organs. Taken together, the density of native pancreas TS is not a suitable sole predictor for successful islet isolation and purification.
Collapse
Affiliation(s)
- M Eckhard
- 3rd Medical Clinic and Policlinic, University Hospital, 35392 Giessen, Germany.
| | | | | | | | | |
Collapse
|
58
|
Eckhard M, Brandhorst D, Brandhorst H, Brendel MD, Bretzel RG. Optimization in osmolality and range of density of a continuous ficoll-sodium-diatrizoate gradient for isopycnic purification of isolated human islets. Transplant Proc 2005; 36:2849-54. [PMID: 15621166 DOI: 10.1016/j.transproceed.2004.09.078] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
INTRODUCTION According to previous estimates from large animals and man, a minimum of approximately 5000 to 6000 engrafted islet equivalents (IEQ)/kg recipient weight is critical to establish insulin independence. Utilizing a single donor, this threshold yield of purified islets can be retrieved from approximately one third of all isolations. The aim of this study was to improve human islet purification by optimization of the osmolality and the density range of the continuous Ficoll-sodium-diatrizoate (FSD) gradient to facilitate consistent purities >80% of human islet preparations without considerable loss of islet yield. METHODS Aliquots of human pancreatic digests were placed on continuous density gradients. After centrifugation, sequential aliquots were extracted for amylase and insulin to determine the relative and cumulative density distribution of endocrine and exocrine tissue. We addressed the impact of two factors: (1) osmolalities (300 to 600 mosm/kg) in the gradient of FSD covering a density range of 1.070 to 1.100 g/cm(3); and (2) density (FSD 500/1.070 to 1.100) versus density-osmolarity gradient (DO-FSD 400-530/1.080 to 1.113). RESULTS The density of exocrine and endocrine tissue increased with rising osmolality. Differences in density of both tissues were highest at 450 and lowest at 300 and 600 mOsmol/kg. Purity and recovery were highest at 450 versus 400 or 500 mOsm/kg (NS). Exocrine but not endocrine tissue was more dense in DO-FSD than in FSD gradient (P < .05). The differences in density were 0.004 versus 0.013 g/cm(3) (P < .01), resulting in an increased islet purity and recovery. CONCLUSION The best osmolality for the FSD 1.070 to 1.100 g/cm(3) is at 450 mOsm/kg. Using the DO-FSD may improve human islet purification allowing successful clinical islet transplantation.
Collapse
Affiliation(s)
- M Eckhard
- Third Medical Department and Policlinic, University of Giessen, 35932 Giessen, Germany.
| | | | | | | | | |
Collapse
|
59
|
Dufrane D, Goebbels RM, Guiot Y, Squifflet JP, Henquin JC, Gianello P. A simple method using a polymethylpenten chamber for isolation of human pancreatic islets. Pancreas 2005; 30:e51-9. [PMID: 15782089 DOI: 10.1097/01.mpa.0000157584.22880.f6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
OBJECTIVES Isolation of large numbers of intact and functional human islets remains difficult and expensive. We describe a novel method using a polymethylpenten chamber (PMPC) and compare its efficacy to the classic method using a stainless steel chamber (SSC). METHODS Five pancreases obtained from cadaveric donors were processed with the SSC method, and the islets were purified with a Cobe cell separator. The next 15 pancreases (similar donor characteristics) were distended with Liberase HI, minced, and digested in a PMPC whose thermic properties did not require continuous heating to maintain temperature of the prewarmed medium at 37 degrees C. The digestion was done in 2 phases to avoid damaging the first freed islets. Digested tissue was filtered on a column of 6-mm glass beads and 500-microm mesh screen, so that tissue volume was small enough to permit purification on discontinuous Ficoll gradients in tubes. RESULTS With the PMPC method, the extent of digestion (+/-70%), yield (approximately 5000 IEQ/g), and final purity (73%) and viability (84%) of the islets was similar to those with the SSC, but the proportion of large islets (>150 microm in diameter) was higher. Cell composition (beta vs. non-beta cells) of isolated islets was not different from that of islets in situ in the same pancreas. Islet function, assessed by perifusion, showed an excellent average stimulation index of approximately 13-fold (15 vs. 1 mmol/L glucose, without cAMP-raising agent). CONCLUSIONS This new method for isolation of human islets uses simple, low-cost, and potentially disposable material and requires a team of only 2 persons. The technique is as efficient as the classic SSC method and provides islets with excellent integrity and insulin-secreting capacity.
Collapse
Affiliation(s)
- Denis Dufrane
- Laboratory of Experimental Surgery, Université Catholique de Louvain, Faculty of Medicine, Brussels, Belgium.
| | | | | | | | | | | |
Collapse
|
60
|
Brandhorst H, Alt A, Huettler S, Raemsch-Guenther N, Kurfuerst M, Bretzel RG, Brandhorst D. The ratio between class II and class I collagenase determines the amount of neutral protease activity required for efficient islet release from the rat pancreas. Transplant Proc 2005; 37:215-6. [PMID: 15808598 DOI: 10.1016/j.transproceed.2004.12.256] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
UNLABELLED Previous investigations clearly showed that the successful release of islets from the pancreas is mediated by both neutral protease (NP) and collagenase, consisting of subclasses I and II showing different capacities to cleave islets from the pancreas. Since no informations about the optimal ratio between class II and class I collagenase (II/I-ratio) are available yet, the present study sought to evaluate the efficient range for the II/I-ratio. METHODS Following intraductal pancreas collagenase distension, rat islets were isolated utilizing 20 PZ-U Serva collagenase NB 1 and 1.0 or 0.4 DMC-U NP. After purification we determined the islet yield (IEQ), viability (trypan-blue exclusion) and function in diabetic nude mice. RESULTS At 1.0 DMC-U NP, a II/I-ratio of 2.6, 1.5 or 0.7 yielded 2200 +/- 280, 2185 +/- 420, and 2205 +/-90 IEQ, respectively (ns). Viability varied between 70% and 80% (ns). Digestion time was significantly lowest (P < .05) using a II/I-ratio of 0.7. Utilization of 0.4 DMC-U NP resulted in a viability of >98% among all experimental groups (P < .001 vs 1.0 DMC-U). Islet yield decreased at a II/I-ratio of 2.6 (1520 +/- 120 IEQ, P < .05) and 1.5 (1780 +/- 130 IEQ, ns), but not at 0.7 (2310 +/- 160 IEQ, ns). Again, digestion time was lowest (P < .001) using a II/I- ratio of 0.7. Transplantation into diabetic nude mice demonstrated islet function in all experimental groups. CONCLUSIONS NP significantly affects islet viability. This study indicates that the minimal amount of NP required for efficient islet cleavage depends on the II/I-ratio.
Collapse
Affiliation(s)
- H Brandhorst
- Third Medical Department, University Hospital, Giessen, Germany.
| | | | | | | | | | | | | |
Collapse
|
61
|
Brandhorst H, Brendel MD, Eckhard M, Bretzel RG, Brandhorst D. Influence of neutral protease activity on human islet isolation outcome. Transplant Proc 2005; 37:241-2. [PMID: 15808607 DOI: 10.1016/j.transproceed.2004.12.254] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
UNLABELLED Observations in rat pancreata have revealed that enzymatic islet release is mediated by both collagenase and neutral protease (NP), a critical effector of islet integrity. Since no information is available about the effect of NP activity on islet release from the human pancreas, the present study evaluated the effect of various NP concentrations on the outcome of human islet isolation. METHODS Following intraductal collagenase distension, pancreata obtained from adult multiorgan donors were digested using 2000 PZ-U of purified Serva collagenase NB 1 supplemented with 2.6 (n = 10) or 4.5% (DMC-U/PZ-U) (n = 10) of NP. RESULTS Increasing NP from 2.6% to 4.5% reduced the amount of undigested tissue from 22 +/- 2 to 17 +/- 2 g (P < .05) while simultaneously increasing the volume of digested tissue (26 +/- 2 vs 40 +/- 3 mL, P < .01). Increased NP concentrations increased the islet yield prepurification (459,800 +/- 22,900 vs 587,600 +/- 69,000 IEQ, P < .05), but simultaneously affected islet purification, resulting in equal islet yields (345,700 +/- 31,200 vs 391,500 +/- 35,400 IEQ, NS) and less purity (70 +/- 6 vs 49% +/- 5%, P < .01). A NP concentration of 4.5% reduced the stimulation index (4.7 +/- 1.2 vs 2.0 +/- 0.5, P < .01) and viability (100 +/- 1 vs 95% +/- 3%, P < .05). CONCLUSIONS Although increased NP activity seems to improve islet release from adult human pancreata, it significantly affects islet viability and function. The reduction in purity reflected damage to acinar tissue by increased NP activity presumably affecting islet integrity.
Collapse
Affiliation(s)
- H Brandhorst
- Third Medical Department, University Hospital, Giessen, Germany.
| | | | | | | | | |
Collapse
|
62
|
Matsumoto S, Tanaka K, Strong DM, Reems JA. Efficacy of human islet isolation from the tail section of the pancreas for the possibility of living donor islet transplantation. Transplantation 2004; 78:839-43. [PMID: 15385802 DOI: 10.1097/01.tp.0000130177.03326.d5] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND Islet transplantation is on the rise for the treatment of type 1 diabetes. Apparent donor shortages could be alleviated through use of living donor pancreata. A critical issue for using a section of pancreas from living donors is whether islet yields would be sufficient for transplantation. METHODS After obtaining human pancreata, islets were isolated from the head section (n=20, head group), tail section (n=23, tail group) or whole pancreas (n=24, whole group). Islets were isolated by enzymatic digestion followed by purification, then assessed for yields, purity, morphology, functionality, and insulin content. RESULTS Fifteen of twenty cases (75%) in the head group, all cases (100%) in the tail group, and 23 of 24 cases (96%) in the whole group were successfully completed for islet isolation. Islet yield per gram pancreas was significantly higher in the tail group compared with both the head and whole groups (head, 1,472+/-326 IE/g; tail, 4,256+/-574 IE/g; whole, 2,424+/-506 IE/g). Total islet yield from the head group was significantly lower compared with both tail and whole groups (head, 75,016+/-18,933 IE; tail, 197,469+/-28,236 IE; whole, 208,207+/-43,414 IE), and the tail group showed similar islet yield to the whole group. The whole group showed significantly lower purities and the head group showed significantly lower morphologic scores. There were no significant differences in viability, function, and insulin content among the three groups. CONCLUSIONS The tail section of the human pancreas is suitable for islet isolation. The living donor islet transplantation may be feasible using only this section of the pancreas for the first transplantation to reduce hypoglycemic unawareness for small recipients, which might be followed by the second islet transplantation from cadaveric donor.
Collapse
Affiliation(s)
- Shinichi Matsumoto
- Kyoto University Hospital Transplantation, Unit 54, Shogoin, Kawara-cho, Sakyo-ku, Kyoto, Japan.
| | | | | | | |
Collapse
|
63
|
Abstract
The transplant recipient has traded a life-threatening illness for a chronically immunosuppressed state. Subsequent anesthetic management for non-transplant surgical procedures may be challenging. The anesthesia provider must be aware of the degree of post-transplant organ dysfunction and alter anesthesia techniques accordingly. This article reviews the anesthetic concerns for patients who have undergone a variety of organ transplants.
Collapse
Affiliation(s)
- Mark T Keegan
- Division of Critical Care, Department of Anesthesiology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
| | | |
Collapse
|
64
|
Contreras JL, Xie D, Mays J, Smyth CA, Eckstein C, Rahemtulla FG, Young CJ, Anthony Thompson J, Bilbao G, Curiel DT, Eckhoff DE. A novel approach to xenotransplantation combining surface engineering and genetic modification of isolated adult porcine islets. Surgery 2004; 136:537-47. [PMID: 15349100 DOI: 10.1016/j.surg.2004.05.031] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
BACKGROUND Effective cytoprotection to xenoislets would circumvent the major tissue limitation for pancreatic islet transplantation (PIT). Cell-surface engineering with poly[ethylene glycol] (PEG) derivatives can successfully prevent antibody binding to the surface antigens. Gene transfer of the antiapoptotic Bcl-2 gene has been shown to decrease cytotoxicity mediated by xenoreactive natural antibodies and complement. In this study, we assessed survival and function of surface-engineered porcine islets genetically modified to overexpress Bcl-2. METHODS Incorporation of PEG derivatives into the islet surface and adenovirus-mediated gene transfer of Bcl-2 (AdBcl-2) was accomplished within 24 hours post-isolation. Cytotoxicity induced by human xenoreactive natural antibodies was evaluated by islet intracellular lactate dehydrogenase release and microscopic analysis using membrane-integrity staining. Islet functionality was assessed by static incubation and after intraportal infusion (5000 IEQ) into diabetic NOD-SCID mice reconstituted with human lymphocytes (5 x 10 8 /intraperitoneally/15 days before PIT). RESULTS No significant change in islet viability, morphology, and functionality was demonstrated after the incorporation of PEG-mono-succimidyl-succinate (MSPEG), or PEG-di-succimidyl-succinate "end"-capped with albumin (DSPEG) with or without gene transfer of Bcl-2. Islets treated with MSPEG presented a significant reduction in lactate dehydrogenase release compared with controls (41.2 +/- 3 vs 72.1 +/- 7, respectively, P <.05). Further protection was accomplished by DSPEG or AdBcl-2. The maximal cytoprotection was achieved by DSPEG +AdBcl-2 (15.5 +/- 4.9%, P <.001). Nonfasting glucose >200 mg/dL was found in 100% of the animals given control islets (n = 6) within 48 hours post-transplant. In contrast, euglycemia was achieved in 100% of the animals given islets modified with DSPEG + AdBcl-2 during the observation time. CONCLUSIONS Surface-engineering with functionalized PEG derivatives in combination with genetic modification with Bcl-2 significantly reduced islet loss after PIT. Application of this novel technology may improve results in xenoislet transplantation.
Collapse
Affiliation(s)
- Juan L Contreras
- Department of Surgery, Division of Human Gene Therapy and Gene Therapy Center, University of Alabama at Birmingham, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
65
|
Abstract
Diabetes is a leading cause of morbidity and mortality worldwide. Complications of diabetes including renal failure, retinopathy, neuropathy, and cardiovascular disease limit both survival and quality of life. Pancreatic transplantation can restore euglycemia thereby stabilizing or even reversing secondary complications of diabetes as well as improving quality of life particularly in patients with labile diabetes. Recent evidence also shows an improved survival in diabetic patients that undergo pancreatic transplantation when combined with a kidney transplant. Pancreatic transplantation should more properly be referred to as beta cell replacement as the field today encompasses both whole organ and islet cell transplantation. We have outlined herein the indications and contraindications to islet or whole organ pancreas transplantation and we have described periprocedure care and short- and long-term prognosis.
Collapse
Affiliation(s)
- David L. Bigam
- University of Alberta Hospital, 8440-112 Street NW, Edmonton, Alberta, T6G 2B7, Canada
| | | |
Collapse
|
66
|
Bottino R, Balamurugan AN, Tse H, Thirunavukkarasu C, Ge X, Profozich J, Milton M, Ziegenfuss A, Trucco M, Piganelli JD. Response of human islets to isolation stress and the effect of antioxidant treatment. Diabetes 2004; 53:2559-68. [PMID: 15448084 DOI: 10.2337/diabetes.53.10.2559] [Citation(s) in RCA: 213] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The process of human islet isolation triggers a cascade of stressful events in the islets of Langerhans involving activation of apoptosis and necrosis and the production of proinflammatory molecules that negatively influence islet yield and function and may produce detrimental effects after islet transplantation. In this study, we showed that activation of nuclear factor-kappaB (NF-kappaB) and poly(ADP-ribose) polymerase (PARP), two of the major pathways responsible for cellular responses to stress, already occurs in pancreatic cells during the isolation procedure. NF-kappaB-dependent reactions, such as production and release of interleukin-6 and -8 and macrophage chemoattractant protein 1, were observed days after the isolation procedure in isolated purified islets. Under culture conditions specially designed to mimic isolation stress, islet proinflammatory responses were even more pronounced and correlated with higher islet cell loss and impaired secretory function. Here we present novel evidence that early interventions aimed at reducing oxidative stress of pancreatic cells and islets through the use of the catalytic antioxidant probe AEOL10150 (manganese [III] 5,10,15,20-tetrakis [1,3,-diethyl-2imidazoyl] manganese-porphyrin pentachloride [TDE-2,5-IP]) effectively reduces NF-kappaB binding to DNA, the release of cytokines and chemokines, and PARP activation in islet cells, resulting in higher survival and better insulin release. These findings support the concept that the isolation process predisposes islets to subsequent damage and functional impairment. Blocking oxidative stress can be beneficial in reducing islet vulnerability and can potentially have a significant impact on transplantation outcome.
Collapse
Affiliation(s)
- Rita Bottino
- Department of Pediatrics, University of Pittsburgh, School of Medicine, Pennsylvania, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
67
|
de Groot M, Schuurs TA, van Schilfgaarde R. Causes of limited survival of microencapsulated pancreatic islet grafts. J Surg Res 2004; 121:141-50. [PMID: 15313388 DOI: 10.1016/j.jss.2004.02.018] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2003] [Indexed: 01/02/2023]
Abstract
Successful transplantation of pancreatic tissue has been demonstrated to be an efficacious method of restoring glycemic control in type 1 diabetic patients. To establish graft acceptance patients require lifelong immunosuppression, which in turn is associated with severe deleterious side effects. Microencapsulation is a technique that enables the transplantation of pancreatic islets in the absence of immunosuppression by protecting the islet tissue through a mechanical barrier. This protection may even allow for the transplantation of animal tissue, which opens the perspective of using animal donors as a means to solve the problem of organ shortage. Microencapsulation is not yet applied in clinical practice, mainly because encapsulated islet graft survival is limited. In the present review we discuss the principal causes of microencapsulated islet graft failure, which are related to a lack of biocompatibility, limited immunoprotective properties, and hypoxia. Next to the causes of encapsulated islet graft failure we discuss possible improvements in the encapsulation technique and additional methods that could prolong encapsulated islet graft survival. Strategies that may well support encapsulated islet grafts include co-encapsulation of islets with Sertoli cells, the genetic modification of islet cells, the creation of an artificial implantation site, and the use of alternative donor sources. We conclude that encapsulation in combination with one or more of these additional strategies may well lead to a simple and safe transplantation therapy as a cure for diabetes.
Collapse
Affiliation(s)
- Martijn de Groot
- Surgical Research Laboratory, Department of Surgery, University Hospital Groningen, Hanzeplein 1 (CMC V, Y2144), 9713 GZ Groningen, Netherlands.
| | | | | |
Collapse
|
68
|
Darwish AA, Sokal E, Stephenne X, Najimi M, de Goyet JDV, Reding R. Permanent access to the portal system for cellular transplantation using an implantable port device. Liver Transpl 2004; 10:1213-5. [PMID: 15350017 DOI: 10.1002/lt.20228] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A novel application of the implantable Port-a-Cath (PAC) system is described in the context of cellular transplantation. A silicone catheter was inserted in a collateral branch of the portal vein and connected to a port device positioned subcutaneously on the left thoracic cage. This permanent vascular access allowed iterative intraportal infusions of allogenic hepatocytes without the need of repeated transhepatic catheterization of the portal vein. Using this technique, repeated infusions of cryopreserved and / or fresh hepatocytes were successfully carried out in 3 children with inborn errors of liver metabolism, with the aim of progressively providing a sufficient mass of transplanted liver cells to stabilize the metabolic condition of the patients. We suggest that this technique might also be valuable in pancreatic islet cell transplantation.
Collapse
Affiliation(s)
- Ahmed A Darwish
- Pediatric Liver Transplant Program, Université catholique de Louvain, Saint-Luc University Clinics, Brussels, Belgium
| | | | | | | | | | | |
Collapse
|
69
|
Eckhoff DE, Eckstein C, Smyth CA, Vilatoba M, Bilbao G, Rahemtulla FG, Young CJ, Anthony Thompson J, Chaudry IH, Contreras JL. Enhanced isolated pancreatic islet recovery and functionality in rats by 17beta-estradiol treatment of brain death donors. Surgery 2004; 136:336-45. [PMID: 15300200 DOI: 10.1016/j.surg.2004.05.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND Current isolation techniques recover only 20% to 50% of the pancreatic islets. Brain death (BD) is characterized by activation of proinflammatory cytokines (PICs) with reduced islet yields and functionality. We previously reported that 17beta-estradiol (E2) induces cytoprotection to human islets exposed to PICs. Furthermore, inhibition of PIC release has been demonstrated after E2 treatment. In the present study, we evaluated if E2 treatment to BD donors would improve pancreatic islet recovery and functionality. METHODS BD was induced in male, 250- to 350-g Lewis rats by inflation of a Fogarty catheter placed intracranially. Rats were mechanically ventilated for 6 hours. Only rats with mean arterial blood pressure > 75 mm Hg were used. Animals (n = 6) received E2 (1 mg/kg/iv immediately after BD induction), vehicle (V), or the combination of 17beta-estradiol and a selective estrogen receptor antagonist ICI 182,780 (ICI, 3 mg/kg/ip/1 hour before BD induction). Islet viability was determined by ethidium bromide-acridine orange. PICs were assessed by ELISA. Islet functionality was determined by static incubation and glucose disposal rate (Kg) after intraportal transplantation (3000 islet equivalent[IEQ]/syngeneic streptozotocin-induced diabetic rat). RESULTS A 2- to 3-fold reduction in TNF-alpha, IL-1beta, and IL-6 was demonstrated in BD donors given E2; this effect reversed by ICI 182,780. Pancreatic sections from control BD donors presented 26.5% +/- 4% TUNEL-positive beta-cells compared with 15.1% +/- 3% in 17beta-estradio-treated animals. Islet recovery was enhanced in E2-treated donors (1233.4 +/- 123 IEQ/pancreas) compared with controls (725 +/- 224 IEQ, P < .05). Islet viability was significantly enhanced by E2. Higher islet functionality was demonstrated in vitro and in vivo after transplantation in islets recovered from E2-treated BD donors. CONCLUSIONS Islet recovery and functionality in vitro and in vivo were significantly improved by 17beta-estradiol treatment to BD donors. These observations may lead to strategies to reduce the effects of BD on isolated islets and improve the results in clinical islet transplantation.
Collapse
Affiliation(s)
- Devin E Eckhoff
- Division of Transplantation and Transplant Center, Department of Surgery; Prosthodontics and Biomaterials, University of Alabama School of Dentistry, Birmingham, AL, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
70
|
Yoshikawa T, Suzuki Y, Kanashiro M, Li S, Goto T, Tanaka T, Kakinoki K, Sakai T, Tanioka Y, Fujino Y, Kuroda Y. Objective and rapid assessment of pancreas graft viability using 31P-nuclear magnetic resonance spectroscopy combined with two- layer cold storage method. Transplantation 2004; 78:78-82. [PMID: 15257042 DOI: 10.1097/01.tp.0000133516.55002.52] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND With the current shortage of donors, there is a critical need to optimally use "less-than-ideal" donors for pancreas transplantation. Objective and rapid means for assessing graft viability and suitability for transplantation are mandatory. This study examined the possibility of graft viability assessment and posttransplant outcome prediction using (31)P-nuclear magnetic resonance (NMR) spectroscopy combined with the two-layer cold-storage method (TLM). METHODS Canine pancreas grafts were preserved with TLM for 24 hours after 0, 60, or 120 minutes of warm ischemia (groups 1, 2, or 3, respectively). After preservation, we determined intragraft phosphate metabolites noninvasively using (31)P-NMR spectroscopy. Time required for this assessment was 5 minutes. Because our previous studies demonstrated that all grafts in groups 1 and 2 were successfully transplanted (the viable group), whereas all in group 3 failed to survive (the nonviable group), the possibility of posttransplant outcome prediction was examined on the basis of the comparison between these two groups. RESULTS The ratios of inorganic phosphate/gamma-adenosine triphosphate (Pi/gamma-ATP) and Pi/beta-ATP reflected the extent of graft damage, and the differences were statistically significant among groups 1, 2, and 3. On the basis of analyses of receiver operator characteristic curves, the optimum cutoff levels between the viable and nonviable groups were 1.6 and 2.2 for Pi/gammaATP and Pi/betaATP, respectively. The accuracy rates of these ratios were both 83%. CONCLUSION (31)P-NMR spectroscopy combined with TLM preservation could provide an objective, rapid, and possibly noninvasive means to assess pancreas graft viability and to determine suitability of damaged pancreata for organ transplantation.
Collapse
Affiliation(s)
- Takuro Yoshikawa
- Division of Gastroenterological Surgery, Department of Clinical Molecular Medicine, Graduate School of Medical Sciences, Kobe University, Kobe, Japan
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|