Long-Term Metabolic and Immunological Follow-Up of Nonimmunosuppressed Patients With Type 1 Diabetes Treated With Microencapsulated Islet Allografts

Four cases

  1. Riccardo Calafiore, MD1
  1. 1Department of Internal Medicine, Laboratory for the Study and Transplant of Pancreatic Islets, University of Perugia, Perugia, Italy
  2. 2Department of Experimental Medicine and Biochemical Sciences, Section of Histology and Embryology, University of Perugia, Perugia, Italy
  3. 3Department of Oncologic Surgery, University of Perugia, Perugia, Italy
  4. 4Division of Transplantation, University of Illinois at Chicago, Chicago, Illinois
  1. Corresponding author: Riccardo Calafiore, islet{at}


OBJECTIVE To assess long-term metabolic and immunological follow-up of microencapsulated human islet allografts into nonimmunosuppressed patients with type 1 diabetes (T1DM).

RESEARCH DESIGN AND METHODS Four nonimmunosuppressed patients, with longstanding T1DM, received intraperitoneal treatment (TX) of microencapsulated human islets. Anti-major histocompatibility complex (MHC) class I–II and GAD65 antibodies and islet cell antibodies were measured before and long term after TX.

RESULTS All patients turned positive for serum C-peptide response, both in basal and after stimulation, throughout 3 years of posttransplant follow-up. Daily mean blood glucose, as well as HbA1c levels, significantly improved after TX, with daily exogenous insulin consumption declining in all cases and being discontinued, just transiently, only in patient 4. Anti-MHC class I–II and GAD65 antibodies all tested negative at 3 years after TX.

CONCLUSIONS The grafts did not elicit any immune response, even in the cases where more than one preparation was transplanted, as a unique finding, compatible with encapsulation-driven “bioinvisibility” of the grafted islets. This result was never achieved with the recipient’s general immunosuppression.

  • Received April 18, 2011.
  • Accepted August 10, 2011.

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This Article

  1. Diabetes Care
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