In May, James Shapiro wrote in our pages about progress using the Edmonton Protocol to transplant islet cells into patients with type 1 diabetes. In this week?s New England Journal of Medicine, he and a number of colleagues around the world report the results of a phase 1-2 trial of the protocol in 36 patients. The findings were consistent which previous studies that Shapiro discussed in his May piece: 16 patients (44%) met the primary endpoint of insulin independence with adequate glycemic control one year after their final transplant, five of whom remained insulin-independent at 2 years. In the entire group, 10 had partial function, 10 had complete graft loss, and 21 were able to attain insulin independence with good glycemic control at any point throughout the trial. Of these 21 subjects, 16 required insulin again at 2 years.

The results ?confirmed that islet transplantation may successfully restore long-term endogenous insulin production and glycemic stability in subjects who have type 1 diabetes mellitus with unstable baseline control,? the authors conclude. ?However, normal endocrine reserve is rarely achieved, and insulin independence is gradually lost in most cases over time.?

?Therefore, islet transplantation may best be considered as an evolving therapy for use in highly selected patients with severe hypoglycemia or labile type 1 diabetes mellitus, provided all other attempts to stabilize glycemic control have been exhausted,? they write.

A guardedly optimistic editorial accompanying the study sounds similar notes: ?It is clear that poor long-term results, high costs, and the relatively high incidence of major and minor serious adverse events make it difficult to argue for expansion of islet transplantation to the general population,? Jonathan S. Bromberg and Derek LeRoith write. ?Nonetheless, the dramatic discoveries and successful dissemination of information in a relatively short period encourage us to believe these advances will continue apace."