title: Comparison of human islet isolation outcomes using a new mammalian tissue-free enzyme versus collagenase NB-1.
abstract: BACKGROUND
  After the discontinuation of the manufacturing Liberase HI because of a small potential for prion disease transmission, Roche Diagnostics (Indianapolis, IN) developed a new enzyme product (Liberase MTF [mammalian tissue free]), which is similar to Liberase HI with the exception that no mammalian tissue is used in the manufacture of the collagenase component. We report our experience using the MTF enzyme in clinical islet isolations compared with Serva NB-1 with modified enzyme delivery method.
  
  
  METHODS
  Islets were isolated from 41 pancreata using MTF enzyme (n=17) or NB-1 enzyme (n=24). NB-1 enzymes were delivered using a modified (nonsimultaneous) enzyme delivery method whereas isolations using MTF used the standard method of simultaneous collagenase and thermolysin perfusion. Islets were purified on a COBE 2991 Cell Blood Processor and subsequently cultured.
  
  
  RESULTS
  The average islet mass after purification was 392+/-36 x 10 islet equivalent (IE) for MTF versus 371+/-40 x 10 IE for Serva NB-1 (P=0.63). Post-IE/cm of tissue was 110+/-9 x 10 IE/cm and 91+/-11 x 10 IE/cm for MTF and NB-1, respectively (P=0.07). The isolation success rate (>400,000 IE) for MTF was 53% compared with 33% for Serva (P=0.33).
  
  
  CONCLUSIONS
  We conclude that MTF may be successfully used for high-yield human islet isolation and clinical transplantation and provides similar quality islets to those derived using NB-1.
authors.affiliation: 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: Sharleen
authors.initials: S
authors.lastname: Imes
authors.forename: Rena
authors.initials: R
authors.lastname: Pawlick
authors.forename: Peter
authors.initials: P
authors.lastname: Senior
authors.forename: A M James
authors.initials: AM
authors.lastname: Shapiro
mesh_terms: D001786:Blood Glucose / Q000378:metabolism; D002096:C-Peptide / Q000097:blood; D047009:Hathewaya histolytica / Q000201:enzymology*; D017364:Collagenases / Q000302:isolation & purification / Q000378:metabolism*; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage; D007328:Insulin / Q000008:administration & dosage; D007515:Islets of Langerhans / Q000187:drug effects / Q000378:metabolism; D016381:Islets of Langerhans Transplantation; D003012:Microbial Collagenase / Q000302:isolation & purification / Q000378:metabolism*; D008875:Middle Aged; D013820:Thermolysin / Q000302:isolation & purification / Q000378:metabolism*; D013997:Time Factors; D046509:Tissue Culture Techniques; D014022:Tissue Survival; D020858:Tissue and Organ Harvesting / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D001786:Blood Glucose; D002096:C-Peptide; D007004:Hypoglycemic Agents; D007328:Insulin; D017364:Collagenases; C106635:Liberase; D013820:Thermolysin; D003012:Microbial Collagenase