Kidney Alone Versus Islet-After-Kidney in Type 1 Diabetic Kidney Transplant Recipient.

Islet transplantation is associated with a benefit on glycaemic control compared to optimized insulin therapy in recent clinical trials. However, there is a lack of evidence concerning the long-term impact of islet transplantation on type 1 diabetic kidney transplant recipients' prognosis. The objective of the study is to assess the impact of islet transplantation in patients with type 1 diabetes and a kidney transplantation on the risk of graft failure. Every type 1 diabetic recipient transplanted with a kidney in France between 2000 and 2017 is included. Patients transplanted with pancreatic islets are compared to controls treated with insulin alone according to a matching method based on time-dependent propensity scores which allow to ensure patients comparability at the time of islet transplantation. Time-dependent propensity scores are built according to variables associated with both the probabilities of being transplanted with islets and the outcome of interest. These variables are assessed by a direct acyclic graph. The primary outcome consists in death-uncensored graft survival, defined by death or return to dialysis. Secondary outcomes include the risk of death, or the risk of death-censored graft survival.