Islet cell transplantation.
OBJECTIVE
The transplantation of human islets has come a long way since the first diabetic person became insulin independent in 1989. The advent of a steroid-free immunosuppressive protocol in 2000 resulted in most recipients becoming insulin independent and remaining so for a year. However, beta-cell function declines thereafter. Strategies to enhance the islet mass transplanted and preserve beta-cell function are necessary.


RESULTS
This review covers recent advances in determining the selection of appropriate enzymes for islet isolation, use of pancreases from heart-dead donors and techniques for predicting the functional capacity of isolated islets prior to transplantation. Changing the transplantation site away from the liver, where many islets are destroyed by an inflammatory process, is reviewed, and the possibility of seeding islets onto three-dimensional biodegradable scaffolds discussed. A method of preventing apoptosis of the beta cells prior to transplantation is detailed, as is the beneficial effect of using exenatide, after transplantation. Novel techniques to image islets are discussed, and this requires the labelling of the islets prior to implantation. Enhancing the vascularization of islets is shown to enhance functional outcomes. Encapsulation of the islets should obviate the need for using antirejection drugs, and it may be possible to expand beta cells in vitro.


CONCLUSIONS
The above strategies are likely to enhance the outcomes of clinical islet transplants.
Vaithilingam
Vijayaganapathy
V
Diabetes Transplant Unit, Prince of Wales Hospital and University of New South Wales, Sydney, Australia.
Sundaram
Gayathri
G
Tuch
Bernard E
BE
D000818:Animals; D017209:Apoptosis; D049109:Cell Proliferation; D002478:Cells, Cultured; D017364:Collagenases / Q000737:chemistry; D003922:Diabetes Mellitus, Type 1 / Q000473:pathology / Q000601:surgery*; D000077270:Exenatide; D006084:Graft Rejection / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D006085:Graft Survival / Q000187:drug effects*; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D050417:Insulin-Secreting Cells / Q000187:drug effects / Q000637:transplantation; D007515:Islets of Langerhans / Q000098:blood supply / Q000187:drug effects* / Q000473:pathology; D016381:Islets of Langerhans Transplantation / Q000379:methods; D018919:Neovascularization, Physiologic; D010455:Peptides / Q000627:therapeutic use; D013194:Staining and Labeling / Q000379:methods; D013820:Thermolysin / Q000737:chemistry; D014019:Tissue Donors; D054457:Tissue Scaffolds; D014688:Venoms / Q000627:therapeutic use
D007166:Immunosuppressive Agents; D010455:Peptides; D014688:Venoms; D000077270:Exenatide; D017364:Collagenases; C106635:Liberase; D013820:Thermolysin