Islets after Kidney Transplantation in the GRAGIL network: impact of the number of infusions

S. Borot¹, N. Niclauss¹, A. Wojtusciszyn², C. Brault³, Y. Müller¹, L. Giovannoni¹, G. Parnaud¹, R. Meier¹, L. Badet⁴, F. Bayle⁵, L. Kessler⁶, E. Morelon⁷, A. Penfornis⁸, C. Thivolet⁹, C. Toso¹, P. Morel¹, D. Bosco¹, C. Colin³, P.Y. Benhamou¹⁰, T. Berney^1
1 Geneva University Hospitals, Islet Isolation and Transplantation Center, GENEVA 14, Switzerland; ² Diabetology, Montpellier University Hospitals, Montpellier, France; ³ Pôle Information Médicale Evaluation Recherche, Hospices Civils de Lyon, Lyon, France; ⁴ Urology and Transplantation surgery, Hospices Civils de Lyon, Lyon, France; ⁵ Nephrology, Grenoble University Hospital, Grenoble, France
⁶ Diabetology, Strasbourg University Hospitals, Strasbourg, France; ⁷ Nephrology, Hospices Civils de Lyon, Lyon, France; ⁸ Diabetology, Besançon University Hospital, Besançon, France; ⁹ Diabetology, Hospices Civils de Lyon, Lyon, France; ¹⁰ Diabetology, Grenoble University Hospitals, Grenoble, France

Background: Insulin independence after islet transplantation is generally achieved after multiple islet infusions. However, single infusions would allow increasing the number of islet transplant recipients. The aim of this study was to evaluate the results of IAK transplantation in type 1 diabetic patients according to the number of islet infusions.

Methods: Islets were isolated at the University of Geneva and shipped and transplanted between 2004 and 2010 into French patients from the Swiss-French GRAGIL network, on the “Edmonton” immunosuppression protocol.

Results: Nineteen patients were transplanted with 33 preparations isolated from 36 donors. Fifteen patients reached 24 months follow-up after the first islet infusion: 8 subjects were single graft recipients (Group 1) and 7 were double graft recipients (Group 2). Single graft recipients received 5,312 IEQ/kg (5,186-6,388) vs 10,564 (10,054-11,375) for double graft recipients. Insulin-independence was achieved in 5/8 Group 1 subjects vs 5/7 in Group 2 subjects. Insulin-independence duration was 4.7 months (3.1-15.2) in Group 1 vs 19 months (9.6-20.8) in Group 2. At 24 months post-transplant, insulin doses were reduced by 58% in Group 1 (31-80) vs 97% (60-100) in Group 2, HbA1c was 6.5% (5.9-6.8) in Group 1 vs 6.2% (5.9-6.3) in Group 2, and basal C-peptide was 0.9 ng/mL (0.4-1.4) in Group 1 vs 1.8 (1.2;2.4) in Group 2.

Conclusions: One infusion achieves good glycemic control and sometimes insulin-independence. However, patients with 2 infusions remain insulin-free longer, and have lower HbA1c and better graft function 24 months after the first transplant.