BACKGROUND: The quality and stability of enzyme blends used in islet cell processing are critical for successful human islet isolation. A wide variability in enzymatic activity among lots of Liberase HI has been reported. This study examines the interlot and intralot variability of Liberase HI and the over-time deterioration of enzyme quality based on the analysis of islet isolation outcomes. METHODS: The data of 169 human isolations processed for clinical islet transplantation, using five different lots of Liberase HI, were retrospectively analyzed. Inter- and intralot variables in the islet isolation were assessed over a 15-month period. RESULTS: The analysis revealed significant interlot differences in the digestion time, prepurification islet counts, percent recovery, viability, and glucose stimulation insulin index. Moreover, a significant decrease in the pre- and postpurification islet yield per pancreas weight (IEQ/g) in isolations processed by two different enzyme lots used over a 15-month period was observed, suggesting a progressive deterioration of enzyme quality. CONCLUSIONS: Our data demonstrate a significant lot-to-lot related variability in islet isolation outcomes. In addition, the over-time decline in isolation outcomes processed using a single enzyme lot was observed even when the enzyme blends were used within the expiration dating specified by the manufacturer.
BACKGROUND: The quality and stability of enzyme blends used in islet cell processing are critical for successful human islet isolation. A wide variability in enzymatic activity among lots of Liberase HI has been reported. This study examines the interlot and intralot variability of Liberase HI and the over-time deterioration of enzyme quality based on the analysis of islet isolation outcomes. METHODS: The data of 169 human isolations processed for clinical islet transplantation, using five different lots of Liberase HI, were retrospectively analyzed. Inter- and intralot variables in the islet isolation were assessed over a 15-month period. RESULTS: The analysis revealed significant interlot differences in the digestion time, prepurification islet counts, percent recovery, viability, and glucose stimulation insulin index. Moreover, a significant decrease in the pre- and postpurification islet yield per pancreas weight (IEQ/g) in isolations processed by two different enzyme lots used over a 15-month period was observed, suggesting a progressive deterioration of enzyme quality. CONCLUSIONS: Our data demonstrate a significant lot-to-lot related variability in islet isolation outcomes. In addition, the over-time decline in isolation outcomes processed using a single enzyme lot was observed even when the enzyme blends were used within the expiration dating specified by the manufacturer.
Authors: R Misawa; C Ricordi; A Miki; S Barker; R D Molano; A Khan; S Miyagawa; L Inverardi; R Alejandro; A Pileggi; H Ichii Journal: Cell Transplant Date: 2011-09-16 Impact factor: 4.064
Authors: A Miki; C Ricordi; S Messinger; T Yamamoto; A Mita; S Barker; R Haetter; A Khan; R Alejandro; H Ichii Journal: Cell Transplant Date: 2009 Impact factor: 4.064
Authors: P Andrades; C K Asiedu; B Gansuvd; S Inusah; K J Goodwin; L A Deckard; U Jargal; J M Thomas Journal: Diabetologia Date: 2008-05-09 Impact factor: 10.122
Authors: Magnus Ståhle; Aksel Foss; Bengt Gustafsson; Marko Lempinen; Torbjörn Lundgren; Ehab Rafael; Gunnar Tufveson; Olle Korsgren; Andrew Friberg Journal: Transplant Direct Date: 2015-06-24