Esmay Hammink1, Jason Doppenberg2, Françoise Carlotti1, Marten Engelse1, Eelco De Koning1
1 Department of Internal Medicine, Leiden University Medical Center, Leiden, Netherlands. 2 Transplant Center, Leiden University Medical Center, Leiden, Netherlands.
Background
Traditionally, islets from older organ donors were not considered for clinical islet transplantation as they were thought to cause inferior islet transplantation outcomes. However, robust data related to islet transplantation outcomes using islets from older donors are lacking. The scarcity of suitable donors for islet transplantation emphasizes the need to utilize the available donor pool as efficiently as possible, of which older donors constitute a growing proportion. Therefore, we investigated whether islet grafts from older donors (≥ 55 years) show similar function and clinical outcomes post-transplantation when compared to those from younger donors (<55 years).
Methods
We retrospectively analyzed islet isolation procedures from 2008-2024 that led to transplantation, resulting in 80 islet preparations from younger donors and 43 islet preparations from older donors. Islet functionality was studied in vitro. Then, patients receiving grafts from younger donors (n=42) were compared to patients receiving only older donor grafts (n=11). Mixed meal tests were performed three months post-transplantation to assess graft function, and C-peptide levels were measured at 3 months and 1 year post-transplantation. Clinical outcomes were evaluated using the IGLS 2.0 score.
Results
In vitro insulin secretion following glucose stimulation revealed no significant difference in the AUC stimulation index between islets from younger and older donors (p=0.97). Three months post-transplantation, the mixed meal test demonstrated similar insulin secretory capacity between the two groups (p=0.61). The increase in C-peptide levels from pre-transplantation to 3 months and 1 year post-transplantation did not significantly differ between the donor groups, as confirmed by two-way repeated measures ANOVA (p=0.31). Similarly, the IGLS 2.0 score at 1 year post-transplantation did not show significant differences between the two groups (p=0.73).
Conclusion
Islet grafts from older donors (≥55 years) have a similar functional capacity as islet grafts from younger donors and can be used for clinical islet transplantation.