Successful Long-Term Survival of Pancreatic Islet Al log rafts in Spontaneous or Pancreatectomy-induced Diabetes in Dogs Cyclosporine-induced Immune

Nineteen pancreatectomized beagles and three sponta-neously diabetic dogs were recipients of canine islet allografts from one or more unrelated donors. The is-lets, enriched 30-45-fold for endocrine cells and con-tained in a packed cell volume of <1.5 ml, were en-grafted in the livers of recipient animals. Treatment of diabetic recipients with cyclosporine (CsA) was begun 3-5 days before islet transplantation and the initial dosage was adjusted to attain and maintain CsA serum trough levels between 400 and 600 ng/ml. Five dogs with CsA levels less than this (155 ± 35 SEM ng/ml) at the time of transplantation promptly rejected their grafts, whereas rejection was encountered in only 1 of 17 diabetic animals in which the initial level exceeded 400 ng/ml. CsA was discontinued 30, 60, or 90 day