title: Rescue purification maximizes the use of human islet preparations for transplantation.
abstract: The relative inefficiency of the islet purification process may hamper obtaining enough islets for transplantation even with adequate pre-purification counts. In this study, we determined the effect of an additional purification step on total islet yields and pancreas utilization at our center. Twenty-five pancreata were processed using the automated method followed by continuous gradient purification (CGP), and the less pure islet fractions were subjected to additional rescue gradient purification (RGP). CGP and RGP islets were combined and transplanted into patients with type 1 diabetes. CGP and RGP islets showed no significant differences in cell viability, insulin secretion in vitro and function when transplanted into chemically diabetic mice. Mean RGP contribution to the final preparation was 27.9 +/- 19.9%. In 12 of 25 preparations, CGP yielded <5000 IEQ/kg of recipient body weight, and inclusion of RGP islets to the final preparation allowed to obtain the minimal islet number required for transplantation. Transplanted islets resulted in sustained C-peptide production, HbA1(C) normalization and insulin-independence or reduced insulin requirements. Taken together, our data suggest that RGP islets are comparable in terms of viability and potency to CGP islets. RGP may be of assistance in maximizing the number of islet preparations successfully used in transplant protocols.
authors.affiliation: Diabetes Research Institute, University of Miami School of Medicine, Miami, Florida, USA.
authors.forename: Hirohito
authors.initials: H
authors.lastname: Ichii
authors.forename: Antonello
authors.initials: A
authors.lastname: Pileggi
authors.forename: R Damaris
authors.initials: RD
authors.lastname: Molano
authors.forename: David A
authors.initials: DA
authors.lastname: Baidal
authors.forename: Aisha
authors.initials: A
authors.lastname: Khan
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Kuroda
authors.forename: Luca
authors.initials: L
authors.lastname: Inverardi
authors.forename: John A
authors.initials: JA
authors.lastname: Goss
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Alejandro
authors.forename: Camillo
authors.initials: C
authors.lastname: Ricordi
mesh_terms: D000818:Animals; D002096:C-Peptide / Q000378:metabolism; D002469:Cell Separation / Q000379:methods*; D002470:Cell Survival; D002499:Centrifugation, Density Gradient; D003921:Diabetes Mellitus, Experimental; D003922:Diabetes Mellitus, Type 1 / Q000628:therapy; D005452:Fluoresceins / Q000494:pharmacology; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000096:biosynthesis; D006085:Graft Survival; D006801:Humans; D007515:Islets of Langerhans / Q000166:cytology*; D016381:Islets of Langerhans Transplantation / Q000379:methods*; D008297:Male; D051379:Mice; D008819:Mice, Nude; D010179:Pancreas / Q000166:cytology*; D010477:Perfusion; D011419:Propidium / Q000494:pharmacology; D013997:Time Factors; D014019:Tissue Donors; D014021:Tissue Preservation; D009927:Tissue and Organ Procurement
chemical_list: D002096:C-Peptide; D005452:Fluoresceins; D006442:Glycated Hemoglobin; D011419:Propidium; C018506:diacetylfluorescein