Efficacy of Islet Re-transplantation After Failure of Beta-cell Replacement

Islet transplantation and pancreas transplantation are established therapeutic options for selected individuals with type 1 diabetes experiencing severe glycemic instability and recurrent hypoglycemia. Although these approaches significantly improve glycemic management and quality of life, long-term graft survival remains limited, with a progressive decline in beta-cell function over time. The clinical benefit-risk profile of islet re-transplantation after graft failure remains poorly defined, and outcomes following repeat islet transplantation after prior islet graft failure have not been specifically evaluated. Repeated exposure to multiple donors may increase the risk of alloimmunization, including the development of donor-specific antibodies , which may adversely affect graft survival and limit access to future transplantation. This multicenter retrospective cohort study aims to evaluate the efficacy and safety of islet re-transplantation in adults with type 1 diabetes after failure of initial beta-cell replacement (islet or pancreas transplantation), with outcomes assessed at 3 months, 1 year, and 5 years.

Inclusion Criteria: * Age ≥ 18 years * Diagnosis of type 1 diabetes * Prior beta-cell replacement therapy : islet transplantation or pancreas transplantation * Islet re-transplantation performed after 2005 * Islet re-transplantation performed after documented beta cell graft failure, defined by undetectable C-peptide and/or recurrence of severe hypoglycemia on insulin therapy * Availability of clinical and biological data required for assessment of study outcomes Exclusion Criteria: * Missing or incomplete data preventing assessment of the primary outcome * Patients who did not meet inclusion criteria