Type 1 diabetics insulin-independent after islet transplantation

Dr James Shapiro and his team in Alberta, Canada, have successfully treated type 1 diabetes mellitus by combining islet transplantation with glucocortoid-free immunosuppression.

In a study, published in the July 27 issue of The New England Journal of Medicine, all seven patients treated by Dr Shapiro's team remained insulin independent for a median follow-up of 11.9 months.

7 patients have successful islet cell transplant.

Each patient received an average of 11547 islets/kg body weight, in two infusions from different donors. One patient needed a third infusion from another donor.

The islets were delivered by percutaneous transhepatic portal embolization.

An immunosuppressive regimen consisting of sirolimus, tacrolimus and daclizumab was initiated immediately before islet transplantation.

"Islet transplantation results in insulin independence with excellent metabolic control." Dr James Shapiro

All seven patients became insulin-independent shortly after transplantation, with fluctuations in blood glucose concentrations becoming far less pronounced.

The mean amplitude of glycemic excursions, used as a measure of blood glucose fluctuations, fell from 11.1 mmol/L before transplantation to 2.8 mmol/L once insulin independence had been reached.

The success of the therapy is unprecedented. Data for previous islet transplantations reveal that only 8% of patients remain free of insulin therapy for one year.

Dr Paul Robertson, writing in an editorial in the same issue of the journal, puts the success of the study down to the "very high quality islets" used for transplantation and the modification of the immunosuppressive regimen.