title: Clinical islet isolation outcomes with a highly purified neutral protease for pancreas dissociation.
abstract: BACKGROUND
  Pancreas dissociation is a critical initial component of the islet isolation procedure and introduces high variability based on factors including the enzyme type, specificity and potency. Product refinement and alterations to the application strategies have improved isolation outcomes over time; however, islet utilization from donor organs remains low. In this study we evaluate a low endotoxin-high activity grade neutral protease in clinical islet isolation.
  
  
  METHODS
  The use of a non-collagenolytic enzyme, either thermolysin or high active neutral protease, was randomized in clinical islet isolations to evaluate efficacy. Additionally a retrospective comparison to neutral protease NB was conducted.
  
  
  RESULTS
  The thermolysin group had lower trapped islet population and increased purity and post-culture islet mass in comparison to high active grade neutral protease. Comparison of neutral protease NB GMP grade to high active neutral protease displayed no measurable difference in islet mass or viability and transplantation outcomes at 1 mo post-transplant were favorable for both groups.
  
  
  CONCLUSIONS
  High activity neutral protease can generate clinical grade islets and may prove beneficial to islet function and viability based on a reduced endotoxin load but dosing of neutral protease requires ongoing optimization.
authors.affiliation: Clinical Islet Transplant Program; Department of Transplant Services; Alberta Health Services; Edmonton, AB Canada.
authors.forename: Doug
authors.initials: D
authors.lastname: O'Gorman
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Kin
authors.forename: Rena
authors.initials: R
authors.lastname: Pawlick
authors.forename: Sharleen
authors.initials: S
authors.lastname: Imes
authors.forename: Peter A
authors.initials: PA
authors.lastname: Senior
authors.forename: A M James
authors.initials: AM
authors.lastname: Shapiro
mesh_terms: D000328:Adult; D001426:Bacterial Proteins / Q000378:metabolism*; D002448:Cell Adhesion; D047009:Hathewaya histolytica / Q000201:enzymology; D017364:Collagenases / Q000378:metabolism; D003922:Diabetes Mellitus, Type 1 / Q000503:physiopathology / Q000628:therapy*; D010450:Endopeptidases / Q000378:metabolism*; D006085:Graft Survival; D006801:Humans; D007202:Indicators and Reagents / Q000378:metabolism*; D007262:Infusions, Intravenous; D007515:Islets of Langerhans / Q000502:physiology*; D016381:Islets of Langerhans Transplantation / Q000009:adverse effects*; D008875:Middle Aged; D011169:Portal Vein; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013820:Thermolysin / Q000378:metabolism; D046509:Tissue Culture Techniques; D014022:Tissue Survival; D020858:Tissue and Organ Harvesting
chemical_list: D001426:Bacterial Proteins; D007202:Indicators and Reagents; D010450:Endopeptidases; D017364:Collagenases; C106635:Liberase; D013820:Thermolysin; C023139:dispase
keywords: enzyme dissociation; islet isolation; islet transplantation; neutral protease; pancreas; pancreas dissociation; thermolysin