Single-donor, marginal-dose islet transplantation in patients with type 1 diabetes.
BACKGROUND
Islet allografts from 2 to 4 donors can reverse type 1 diabetes. However, for islet transplants to become a widespread clinical reality, diabetes reversal must be achieved with a single donor to reduce risks and costs and increase the availability of transplantation.


OBJECTIVE
To assess the safety of a single-donor, marginal-dose islet transplant protocol using potent induction immunotherapy and less diabetogenic maintenance immunosuppression in recipients with type 1 diabetes. A secondary objective was to assess the proportion of islet transplant recipients who achieve insulin independence in the first year after single-donor islet transplantation.


METHODS
Prospective, 1-year follow-up trial conducted July 2001 to August 2003 at a single US center and enrolling 8 women with type 1 diabetes accompanied by recurrent hypoglycemia unawareness or advanced secondary complications.


METHODS
Study participants underwent a primary islet allotransplant with 7271 (SD, 1035) islet equivalents/kg prepared from a single cadaver donor pancreas. Induction immunosuppression was with antithymocyte globulin, daclizumab, and etanercept. Maintenance immunosuppression consisted of mycophenolate mofetil, sirolimus, and no or low-dose tacrolimus.


METHODS
Safety (assessed by monitoring the severity and duration of adverse events) and efficacy (assessed by studying the recipients' insulin requirements, C-peptide levels, oral and intravenous glucose tolerance results, intravenous arginine stimulation responses, glycosylated hemoglobin levels, and hypoglycemic episodes) associated with the study transplant protocol.


RESULTS
There were no serious, unexpected, or procedure- or immunosuppression-related adverse events. All 8 recipients achieved insulin independence and freedom from hypoglycemia. Five remained insulin-independent for longer than 1 year. Graft failure in 3 recipients was preceded by subtherapeutic sirolimus exposure in the absence of measurable tacrolimus trough levels.


CONCLUSIONS
The tested transplant protocol restored insulin independence and protected against hypoglycemia after single-donor, marginal-dose islet transplantation in 8 of 8 recipients. These results may be related to improved islet engraftment secondary to peritransplant administration of antithymocyte globulin and etanercept. These findings may have implications for the ongoing transition of islet transplantation from clinical investigation to routine clinical care.
Hering
Bernhard J
BJ
Diabetes Institute for Immunology and Transplantation and Department of Surgery, University of Minnesota, Minneapolis 55455, USA. bhering@umn.edu
Kandaswamy
Raja
R
Ansite
Jeffrey D
JD
Eckman
Peter M
PM
Nakano
Masahiko
M
Sawada
Toshiya
T
Matsumoto
Ippei
I
Ihm
Sung-Hee
SH
Zhang
Hui-Jian
HJ
Parkey
Jamen
J
Hunter
David W
DW
Sutherland
David E R
DE
D000328:Adult; D003922:Diabetes Mellitus, Type 1 / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007165:Immunosuppression Therapy; D016381:Islets of Langerhans Transplantation / Q000379:methods; D010865:Pilot Projects; D011446:Prospective Studies