Session Time: 3:15pm-4:45pm
Presentation Time: 4:15pm-4:27pm
*Purpose: Phase 3 studies of islet transplant alone (ITA; n=48) and islet-after-kidney (IAK; n=24) transplantation in type 1 diabetes complicated by severe hypoglycemic events (SHE) have been completed by the Clinical Islet Transplantation (CIT) Consortium using the same procedures for islet manufacturing and induction immunosuppression, but differing in maintenance immunosuppression. The primary objective here is to determine the duration of islet graft survival following ITA or IAK assessed by mixed-meal tolerance test (MMTT) stimulated C-peptide >0.3 ng/mL.
*Methods: Both the ITA and IAK studies met their criteria for safety and efficacy over an initial 2 and 3 year planned follow-up, respectively. 41 of these subjects (33/48 ITA & 8/24 IAK) subsequently enrolled in an observational cohort study for up to 8 years of post-transplant follow-up.
*Results: Islet graft survival was maintained by >80% of ITA recipients and ~50% of IAK recipients (P=0.0023) with a median follow up of 6 years following islet transplantation. This difference was not explained by baseline age, diabetes duration, BMI, HbA1c, insulin requirements, or islet equivalents transplanted. Maintenance of post-transplant HbA1c <7%, an important secondary end-point, was greater among ITA compared with IAK recipients (~65 vs 30%; P=0.0042), whereas freedom from SHE was maintained at >90% in both groups. Initial insulin-independence was achieved by ~75% of recipients in both studies, with more than half of these maintaining insulin-independence during long-term follow-up. Serum triglycerides were higher at baseline in IAK than ITA, and decreased in both groups by ~15 mg/dL. Mean trough levels of tacrolimus over the study were higher in IAK than ITA (7.5 vs. 6.4 ng/mL; P<0.001) with tacrolimus used in combination with mycophenolic acid for IAK while with sirolimus for ITA.
*Conclusions: Long-term glycemic control and islet graft survival thus appeared superior in the CIT ITA when compared to IAK study. The differences between outcomes may be due to differences between ITA and IAK recipients or to differences in the maintenance immunosuppression protocols used in each of the studies.
To cite this abstract in AMA style:Rickels MR, Eggerman TL, Bayman L, Qidwai JC, Alejandro R, Bridges ND, Hering BJ, Markmann JF, Senior PA, Hunsicker LG. Long-Term Outcomes with Islet Alone and Islet-after-Kidney Transplantation for Type 1 Diabetes in the Clinical Islet Transplantation Consortium [abstract]. Am J Transplant. 2020; 20 (suppl 3). https://atcmeetingabstracts.com/abstract/long-term-outcomes-with-islet-alone-and-islet-after-kidney-transplantation-for-type-1-diabetes-in-the-clinical-islet-transplantation-consortium/. Accessed September 29, 2020.
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