Clinical use of donation after circulatory death pancreas for islet transplantation

British Transplantation Society guidelines on abdominal organ transplantation from deceased donors after circulatory death

The British Transplantation Society (BTS) 'Guideline on transplantation from deceased donors after circulatory death' has recently been updated and this manuscript summarises the relevant recommendations in abdominal organ transplantation from Donation after Circulatory Death (DCD) donors, encompassing the chapters on liver, kidney, pancreas and islet cell transplantation.

European Society for Organ Transplantation (ESOT) Consensus Statement on the Role of Pancreas Machine Perfusion to Increase the Donor Pool for Beta Cell Replacement Therapy

The advent of Machine Perfusion (MP) as a superior form of preservation and assessment for cold storage of both high-risk kidney's and the liver presents opportunities in the field of beta-cell replacement. It is yet unknown whether such techniques, when applied to the pancreas, can increase the pool of suitable donor organs as well as ameliorating the effects of ischemia incurred during the retrieval process. Recent experimental models of pancreatic MP appear promising. Applications of MP to the pancreas, needs refinement regarding perfusion protocols and organ viability assessment criteria. To address the "Role of pancreas machine perfusion to increase the donor pool for beta cell replacement," the European Society for Organ Transplantation (ESOT) assembled a dedicated working group comprising of experts to review literature pertaining to the role of MP as a method of improving donor pancreas quality as well as quantity available for transplant, and to develop guidelines founded on evidence-based reviews in experimental and clinical settings. These were subsequently refined during the Consensus Conference when this took place in Prague.

PRISM: A Novel Human Islet Isolation Technique

BACKGROUND

Successful pancreatic islet isolations are a key requirement for islet transplantation in selected patients with type 1 diabetes. However, islet isolation is a technically complex, time-consuming, and manual process. Optimization and simplification of the islet isolation procedure could increase islet yield and quality, require fewer operators, and thus reduce cost.

METHODS

We developed a new, closed system of tissue collection, washing, buffer change, and islet purification termed PancReatic Islet Separation Method (PRISM). In the developmental phase, pump and centrifuge speed was tested using microspheres with a similar size, shape, and density as digested pancreatic tissue. After optimization, PRISM was used to isolate islets from 10 human pancreases.

RESULTS

Islet equivalents viability (fluorescein diacetate/propidium iodide), morphology, and dynamic glucose-stimulated insulin secretion were evaluated. PRISM could be performed by 1 operator in 1 flow cabinet. A similar islet yield was obtained using PRISM compared to the traditional islet isolation method (431 234 ± 292 833 versus 285 276 ± 197 392 islet equivalents, P = 0.105). PRISM islets had similar morphology and functionality.

CONCLUSIONS

PRISM is a novel islet isolation technique that can significantly improve islet isolation efficiency using fewer operators.

Utility of Islet Cell Preparations From Donor Pancreases After Euthanasia

Patients fulfilling criteria for euthanasia can choose to donate their organs after circulatory death [donors after euthanasia (DCD V)]. This study assesses the outcome of islet cell isolation from DCD V pancreases. A procedure for DCD V procurement provided 13 pancreases preserved in Institut Georges Lopez-1 preservation solution and following acirculatory warm ischemia time under 10 minutes. Islet cell isolation outcomes are compared with those from reference donors after brain death (DBD, n = 234) and a cohort of donors after controlled circulatory death (DCD III, n = 29) procured under the same conditions. Islet cell isolation from DCD V organs resulted in better in vitro outcome than for selected DCD III or reference DBD organs. A 50% higher average beta cell number before and after culture and a higher average beta cell purity (35% vs 24% and 25%) was observed, which led to more frequent selection for our clinical protocol (77% of isolates vs 50%). The functional capacity of a DCD V islet cell preparation was illustrated by its in vivo effect following intraportal transplantation in a type 1 diabetes patient: injection of 2 million beta cells/kg body weight (1,900 IEQ/kg body weight) at 39% insulin purity resulted in an implant with functional beta cell mass that represented 30% of that in non-diabetic controls. In conclusion, this study describes procurement and preservation conditions for donor organs after euthanasia, which allow preparation of cultured islet cells, that more frequently meet criteria for clinical use than those from DBD or DCD III organs.

Hypothermic oxygenated machine perfusion of the human pancreas for clinical islet isolation: a prospective feasibility study

Due to an increasing scarcity of pancreases with optimal donor characteristics, islet isolation centers utilize pancreases from extended criteria donors, such as from donation after circulatory death (DCD) donors, which are particularly susceptible to prolonged cold ischemia time (CIT). We hypothesized that hypothermic machine perfusion (HMP) can safely increase CIT. Five human DCD pancreases were subjected to 6 h of oxygenated HMP. Perfusion parameters, apoptosis, and edema were measured prior to islet isolation. Five human DBD pancreases were evaluated after static cold storage (SCS). Islet viability, and in vitro and in vivo functionality in diabetic mice were analyzed. Islets were isolated from HMP pancreases after 13.4 h [12.9–14.5] CIT and after 9.2 h [6.5–12.5] CIT from SCS pancreases. Histological analysis of the pancreatic tissue showed that HMP did not induce edema nor apoptosis. Islets maintained >90% viable during culture, and an appropriate in vitro and in vivo function in mice was demonstrated after HMP. The current study design does not permit to demonstrate that oxygenated HMP allows for cold ischemia extension; however, the successful isolation of functional islets from discarded human DCD pancreases after performing 6 h of oxygenated HMP indicates that oxygenated HMP may be a useful technology for better preservation of pancreases.

Lower beta cell yield from donor pancreases after controlled circulatory death prevented by shortening acirculatory warm ischemia time and by using IGL-1 cold preservation solution

Organs from donors after controlled circulatory death (DCD III) exhibit a higher risk for graft dysfunction due to an initial period of warm ischemia. This procurement condition can also affect the yield of beta cells in islet isolates from donor pancreases, and hence their use for transplantation. The present study uses data collected and generated by our Beta Cell Bank to compare the number of beta cells in isolates from DCD III (n = 141) with that from donors after brain death (DBD, n = 609), before and after culture, and examines the influence of donor and procurement variables. Beta cell number per DCD III-organ was significantly lower (58 x 106 versus 84 x 106 beta cells per DBD-organ; p < 0.001) but their purity (24% insulin positive cells) and insulin content (17 μg / 106 beta cells in DCD III-organs versus 19 μg / 106 beta cells in DBD-organs) were similar. Beta cell number correlated negatively with duration of acirculatory warm ischemia time above 10 min; for shorter acirculatory warm ischemia time, DCD III-organs did not exhibit a lower beta cell yield (74 x 106 beta cells). Use of Institut Georges Lopez-1 cold preservation solution instead of University of Wisconsin solution or histidine-tryptophan-ketoglutarate also protected against the loss in beta cell yield from DCD III-organs (86 x 106 for IGL-1 versus 54 x 106 and 65 x 106 beta cells respectively, p = 0.042). Multivariate analysis indicates that both limitation of acirculatory warm ischemia time and use of IGL-1 prevent the reduced beta cell yield in islet cell isolates from DCD III-organs.