Transplantation Of Macroencapsulated Human Islets Within The Bioartificial Pancreas Air To Patients With Type 1 Diabetes Mellitus

Macroencapsulation devices provide the dual possibility of immunoprotecting transplanted cells while also being retrievable, the latter bearing importance for safety in future trials with stem cell-derived cells. However, macroencapsulation entails a problem with oxygen supply to the encapsulated cells. The Air device solves this with an incorporated refillable oxygen tank. This phase 1 study evaluated the safety and efficacy of implanting the Air device containing allogeneic human pancreatic islets into patients with type 1 diabetes. Four patients were transplanted with 1-2 Air devices, each containing 155 000-180 000 islet equivalents (ie, 1800-4600 islet equivalents per kg body weight), and monitored for 3-6months, followed by the recovery of devices. Implantation of the Air device was safe and successfully prevented immunization and rejection of the transplanted tissue. However, although beta cells survived in the device, only minute levels of circulating C-peptide were observed with no impact on metabolic control. Fibrotic tissue with immune cells was formed in capsule surroundings. Recovered devices displayed a blunted glucose-stimulated insulin response, and amyloid formation in the endocrine tissue. We conclude that the Air device is safe and can support survival of allogeneic islets for several months, although the function of the transplanted cells was limited (Clinicaltrials.gov: NCT02064309).An investigator-initiated phase 1 study of the safety and efficacy of implanting the macroencapsulation device Air with an incorporated refillable oxygen tank containing allogeneic human pancreatic islets into 4 patients with type 1 diabetes shows that the device is safe and can support survival of allogeneic islets for several months, though the function of the transplanted cells is limited.