title: A simplified approach to human islet quality assessment.
abstract: BACKGROUND
  The successful treatment of patients with type 1 diabetes by islet transplantation is affected by a multitude of factors of which infusion of the highest quality tissue is essential. The current standard pretransplant quality assessments lack sensitivity, accuracy, and objectivity in the determination of islet viability and potency. We hypothesized that a multiparametric approach focused on islet cell metabolic state, mitochondrial integrity, and in vitro glucose-stimulated insulin secretion (GSIS) could provide data predictive of in vivo function. The objective of this study was to validate a novel set of islet quality assays and develop a simplified islet quality scoring system for both basic research and clinical applications.
  
  
  METHODS
  A series of 42 human islet preparations were screened using standard and novel methods, which included determination of yield, viability by fluorescent microscopy, GSIS, percentage of islet loss in culture, quantification of adenine nucleotides, flow cytometric measurement of viability, apoptosis, and mitochondrial membrane potential (MMP). In vivo functional potency was tested by minimal model transplant in streptozotocin-induced diabetic NOD.scid mice.
  
  
  RESULTS
  Functionally potent islet preparations showed significantly greater numbers of cells with polarized MMP, higher ATP-to-ADP ratios, and increased glucose-induced insulin secretion. The MMP, ATP-to-ADP ratio, and GSIS data were combined into a single islet scoring formula that showed more than 86% accuracy in predicting in vivo functional potency.
  
  
  CONCLUSIONS
  Our study demonstrates that a multiparametric approach using objective assessments focused on islet cell mitochondrial integrity and in vitro function can provide data predictive of in vivo function.
authors.affiliation: Department of Surgery, University of Wisconsin-Madison, WI, USA.
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Hanson
authors.forename: Elisa E
authors.initials: EE
authors.lastname: Park
authors.forename: Mallory L
authors.initials: ML
authors.lastname: Sears
authors.forename: Krista K
authors.initials: KK
authors.lastname: Greenwood
authors.forename: Juan Sebastian
authors.initials: JS
authors.lastname: Danobeitia
authors.forename: Debra A
authors.initials: DA
authors.lastname: Hullett
authors.forename: Luis A
authors.initials: LA
authors.lastname: Fernandez
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000032:analysis; D018929:Cell Culture Techniques; D002470:Cell Survival; D003921:Diabetes Mellitus, Experimental / Q000601:surgery; D003922:Diabetes Mellitus, Type 1 / Q000601:surgery; D004579:Electron Transport; D005434:Flow Cytometry / Q000379:methods; D005947:Glucose / Q000494:pharmacology; D006085:Graft Survival / Q000502:physiology*; D006801:Humans; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D016381:Islets of Langerhans Transplantation / Q000473:pathology / Q000502:physiology; D051379:Mice; D016688:Mice, Inbred NOD; D008928:Mitochondria / Q000502:physiology*; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D007328:Insulin; D005947:Glucose