Islet transplantation with alemtuzumab induction and calcineurin-free maintenance immunosuppression results in improved short- and long-term outcomes.
BACKGROUND
Only a minority of islet transplant recipients maintain insulin independence at 5 years under the Edmonton protocol of immunosuppression. New immunosuppressive strategies are required to improve long-term outcomes.


METHODS
Three subjects with unstable type 1 diabetes mellitus underwent islet transplantation with alemtuzumab induction and sirolimus-tacrolimus maintenance for 3 months and then sirolimus-mycophenolic acid maintenance thereafter. Follow-up was more than 2 years. Comparison was with 16 historical subjects transplanted under the Miami version of the Edmonton protocol.


RESULTS
Insulin independence was achieved in 2 of 3 alemtuzumab and 14 of 16 historical subjects. Those who did not achieve insulin independence only received a single islet infusion. Insulin-independence rates remained unchanged in the alemtuzumab group, but decreased from 14 of 16 (88%) to 6 of 16 (38%) in the historical group over 2 years. Insulin requirements increased in the historical group while remaining stable in the alemtuzumab group. Comparison of functional measures at 3 months suggested better engraftment with alemtuzumab (P=NS). Further comparison of alemtuzumab versus historical groups, up to 24 months, demonstrated significantly better: Mixed meal stimulation index (24 months, 1.0+/-0.08 [n=3] vs. 0.5+/-0.06 pmol/mL [n=6], P<0.01), mixed meal peak C-peptide (24 months, 5.0+/-0.5 [n=3] vs. 3.1+/-0.3 nmol/mL [n=6], P<0.05), HbA1c (24 months, 5.4+/-0.15 [n=3] vs. 6.3+/-0.12 pmol/mL [n=10], P<0.01). Administration of alemtuzumab was well tolerated. There was no increased incidence of infections in alemtuzumab subjects despite profound, prolonged lymphocyte depletion.


CONCLUSIONS
Islet transplantation with alemtuzumab induction was well tolerated and resulted in improved short- and long-term outcomes. Further investigation is underway for validation.
Froud
Tatiana
T
Clinical Islet Transplant Program, Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL, USA.
Baidal
David A
DA
Faradji
Raquel
R
Cure
Pablo
P
Mineo
Davide
D
Selvaggi
Gennaro
G
Kenyon
Norma S
NS
Ricordi
Camillo
C
Alejandro
Rodolfo
R
D000328:Adult; D000074323:Alemtuzumab; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D000912:Antibodies, Neoplasm / Q000627:therapeutic use*; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism; D015992:Body Mass Index; D002096:C-Peptide / Q000097:blood; D019703:Calcineurin; D003922:Diabetes Mellitus, Type 1 / Q000601:surgery*; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D005500:Follow-Up Studies; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007328:Insulin / Q000627:therapeutic use; D016381:Islets of Langerhans Transplantation / Q000276:immunology*; D020123:Sirolimus / Q000627:therapeutic use; D016559:Tacrolimus / Q000627:therapeutic use; D016896:Treatment Outcome
D000074323:Alemtuzumab; D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000912:Antibodies, Neoplasm; D000970:Antineoplastic Agents; D001786:Blood Glucose; D002096:C-Peptide; D019703:Calcineurin; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D007166:Immunosuppressive Agents; D007328:Insulin; D020123:Sirolimus; D016559:Tacrolimus