Safety and tolerability of the T-cell depletion protocol coupled with anakinra and etanercept for clinical islet cell transplantation

Background: Islet cell transplantation (ICT) is a promising approach to cure patients with type 1 diabetes. We have implemented a new immunosuppression protocol with antithymoglobulin plus anti-inflammatory agents of anakinra and eternacept for induction and tacrolimus plus mycophenolate mofetil for maintenance [T-cell depletion with anti-inflammatory (TCD-AI) protocol], resulting in successful single-donor ICT. Methods: Eight islet recipients with type 1 diabetes reported adverse events (AEs) monthly. AEs were compared between three groups: first infusion with the TCD-AI protocol (TCD-AI-1st) and first and second infusion with the Edmonton-type protocol (Edmonton-1st and Edmonton-2nd). Results: The incidence of symptomatic AEs within the initial three months in the TCD-AI-1st group was less than in the Edmonton-1st and Edmonton-2nd groups, with a marginally significant difference (mean ± SE: 5.5 ± 0.3, 7.5 ± 0.5, and 8.3 ± 1.3, respectively; p = 0.07). A significant reduction in liver enzyme elevation after ICT was found in the TCD-AI-1st group compared with the Edmonton-1st and Edmonton-2nd groups (p < 0.05). Because of AEs, all patients in the Edmonton protocol eventually converted to the TCD-AI protocol, whereas all patients tolerated the TCD-AI protocol. Conclusions: TCD-AI protocol can be tolerated for successful ICT, although this study includes small cohort, and large population trial should be taken.