Presented at:
American Transplant Congress, Washington, DC,
June 2, 2003
Standardization of human islet isolation for an international multi-center transplant trial
J. R. T. Lakey, C. Ricordi, B. Hering, B. DiMercurio, R. Lindblad, J. O'Neil, B. Olack, J. A. Reems, J. Ansite, T. Kirlew, H. Brandhorst, F. Bertuzzi, P. Bucher, J. Oberholzer, E. Ramos, L. Viviano, A. M. J. Shapiro
Clinical Islet Program, University of Alberta, Edmonton, AB, Canada; Diabetes Research Institute, University of Miami, Miami, FL; University of Minnesota, Minneapolis, MN; National Institute of Health, Bethesda, MD; EMMES Corporation, Bethesda, MD; Massachusetts General Hospital, Boston, MA; Washington University, St Louis, MO; Pacific Northwest Research Institute, Seattle, WA; Justus-Leibig University, Giessen, Germany; Milan, Italy;, University of Geneva Hospital, Geneva, Switzerland; Immune Tolerance Network, San Francisco, CA
Consistency and reproducibility of human islet isolations have limited progress in the field of clinical islet transplantation. The Immune Tolerance Network (ITN) multi-center islet transplantation trial using the Edmonton Protocol, sought to define and validate islet isolation procedures amongst the nine participating groups. This was the first attempt at an international multi center trial for islet transplantation. The steps involved in defining and reproducing islet isolations involve developing a protocol, distribution of standard operating procedures including those used to enumerate islets, on-site inspection of facilities and isolation procedures, and review of qualifying data. A major challenge was the identification of suitable lots of Liberase enzyme for this trial. This involved pre-selection of large lots of enzyme, batch testing in investigational sites and distribution of selected/validated lots to each of the isolation groups. Each lot was required to meet qualifying preparation standards prior to inclusion in this trial. A total of 158 organs have been processed at the nine centers to date. Of the total isolations, 48 (27% of total) met the criteria for inclusion in the multicentre transplant trial. An additional 13 (9%) were transplanted under local protocols. Approximately 42% (97) of the isolations, failed to meet acceptable levels of islet recovery or viability. This includes the 30 preparations (22%) that were used for the qualifying stages of the trial. A total of 49 islet transplants have been performed in 32 patients to date as part of the ITN protocol. The mean mass of human islets isolated from those isolations that were transplanted is 377,256 +/- 82,256 (mean +/- SEM). Standardization of human islet isolation remains a difficult challenge. Each organ has unique donor characteristics and there are inconsistencies in enzyme lots, and variability of isolation techniques at each center. This trial has made great strides in standardizing islet enumeration, development and implementation of standard operating procedures and defining minimal site and staffing requirements to isolate human pancreatic islets for clinical transplantation.