title: Toward improving human islet isolation from younger donors: rescue purification is efficient for trapped islets.
abstract: Several reports suggest that islets isolated from younger donor pancreata are of better quality for clinical islet transplantation. The relative inefficiency of the continuous gradient purification process (CGP) is one of the major obstacles to the utilization of these younger donor pancreata. This study demonstrates the benefits of utilizing an additional purification step, rescue gradient purification (RGP), to recover trapped islets and examines the possible superiority of these rescued islets. Seventy-three human islet isolations purified by RGP following CGP were divided into two groups based on age, and the isolation results were retrospectively analyzed (group I: age < or = 40, group II: age > 40). The quality of islets from both CGP and RGP were assessed by beta-cell fractional viability (beta FV) and ADP/ATP ratio. Significant increases in the percent islet recovery from RGP and the percent trapped islets in group I compared to group II were observed. Donor age correlated negatively to the percent islets recovered from RGP (R = 0.440) and to the percent of trapped islets (R = 0.511). RGP islets had higher beta FV and better ADP/ATP ratio compared to CGP islets. In conclusion, RGP improved the efficiency in the purification of trapped islets, which often come from younger donor pancreata. The better quality of beta-cells in RGP islets encourages us to perform RGP, considering the higher quality as well as the quantity of remaining islets.
authors.affiliation: Cell Transplant Center, Diabetes Research Institute, University of Miami Leonard M. Miller School of Medicine, Miami, FL 33136, USA.
authors.forename: A
authors.initials: A
authors.lastname: Miki
authors.forename: C
authors.initials: C
authors.lastname: Ricordi
authors.forename: S
authors.initials: S
authors.lastname: Messinger
authors.forename: T
authors.initials: T
authors.lastname: Yamamoto
authors.forename: A
authors.initials: A
authors.lastname: Mita
authors.forename: S
authors.initials: S
authors.lastname: Barker
authors.forename: R
authors.initials: R
authors.lastname: Haetter
authors.forename: A
authors.initials: A
authors.lastname: Khan
authors.forename: R
authors.initials: R
authors.lastname: Alejandro
authors.forename: H
authors.initials: H
authors.lastname: Ichii
mesh_terms: D000328:Adult; D000367:Age Factors; D002470:Cell Survival; D006085:Graft Survival; D006801:Humans; D007515:Islets of Langerhans / Q000166:cytology*; D016381:Islets of Langerhans Transplantation / Q000379:methods*; D008875:Middle Aged; D015999:Multivariate Analysis; D012189:Retrospective Studies; D014019:Tissue Donors; D014021:Tissue Preservation; D009927:Tissue and Organ Procurement / Q000379:methods*