P-181

Validation of a new bag for islet culture and transplantation.

M. Ståhle¹, A. Friberg¹, O. Korsgren¹, M. Goto^2
1 Uppsala University, Immunology, Genetics and Pathology, Uppsala, Sweden; ² Division of Advanced Surgical Science and Technology, Tohoku University, Sendai, Japan

Objective: The aim of this study was toevaluate a newly developed culture bag consisting of highly gas-permeable andtransparent plastic.

Methods: Porcine islets were cultured at37 ° C in5% CO2 for 24 hours under 3 different conditions: 1. Culture flasks (CF), 2. FenvalTransfer pack for platelet concentrates (Ftp) and 3. the new Tohoku bag (Tb).Porcine islets were evaluated by: recovery rate, respiratory activity,transplantation to diabetic athymic mice, and intraperitoneal glucose tolerancetest (IPGTT). Oxygen permeability of each device during 4 hours was alsoexamined. Human islets were cultured at 37 ° C in 5% CO2 for 2-4 days eitherin Ftp or in Tb. The islets were then subjected to the following assays:ADP/ATP-ratio, intracellular insulin content, dynamic glucose stimulated insulinrelease and expression of IL-6, IL-8, tissue factor and MCP-1.

Results: Porcine islets: There was a significantdifference in recovery rate (Tb=87.5 vs. CF=78.8%, p=0.003, Tb=87.5 vs. Ftp=83.1%, p=0.009: Wilcoxon matched-pairs t-test) but not in respiratory activity, curativerate of diabetic mice ((CF (9/15), Ftp (9/14), Tb (12/15)), oxygen permeabilityor IPGTT (AUC: CF=4177, Ftp =3739, Tb=4228 min*mg/dl). There was significantdifference in oxygen permeability (CF=415 ± 32, Ftp =543 ± 79, Tb=631 ± 77 mmHg,p<0.0001: One-Way ANOVA Friedman test). For the human islets there was nosignificant difference in any of the tests.

Conclusions: The newly developed Tohoku bag show equal or even enhanced capacityfor islet culture. Another benefit of the Tohoku bag is that it allows visualinspection prior to islet transplantation and good recovery of the islets dueto the non-adherent surface.

P-182

Impact of purification on clinical autologous islet transplantation

S. Matsumoto¹, M. Takita¹, M. Shimoda², K. Sugimoto¹, T. Itoh¹, D. Chujo³, J. SoRelle⁴, Y. Tamura⁵, A. Rahman⁵, N. Onaca¹, B. Naziruddin⁵, M. Levy^5
1 Baylor Research Institute, Islet Cell Laboratory, Fort Worth, USA; ² Baylor University Medical Center, Dallas, USA; ³ Baylor Institute for Immunology Research, Dallas, USA; ⁴ Baylor University, Waco, USA; ⁵ Baylor Regional Transplant Institute, Dallas, USA

Background: Total pancreatectomy followed by autologous islet transplantation is anexcellent treatment for patients with severe chronic pancreatitis. Traditionally, chronically damaged pancreata weredigested for islet isolation without purification steps. Purification couldprevent portal thrombosis; however, the impact of islet purification onautologous islet transplantation is unknown. The purpose of this study is to assess the impact of islet purificationon clinical autologous islet transplantation.

Methods: We have performed 27 autologous islet transplantations following totalpancreatectomy since 2006. Islets wereisolated using the modified Ricordi method. When tissue volume exceeded 15-20 ml, islets were purified. The pancreas weight, islet yield, portalpressure, clinical outcomes were compared.

Results: Islets were purified in 13 cases (purification group). The average pancreas weight (95.8±6.7 g vs.73.2±6.8 g, P<0.03) and pre-purification tissue volumes (32.8±3.9 g vs.8.1±1.6 ml, P<0.0001) were significantly higher in the purificationgroup. There was no significantdifference in the final tissue volumes between the purification (11.7±1.2mL)and non-purified (8.1±1.6 ml) groups. Bothpre-purification (611,648±64,6084IE, P<0.01) and final (519,109±63,742IE, P<0.04) islet yields were significantly higher in the purification groupcompared to the non-purified group (315,436±66,570 IE). The peak-, final- and delta- portal pressureswere 17.8±1.9,14.3±1.7and 11.3±1.4mmHgrespectively in purification group and 16.8±1.5, 15.2±1.3 and 7.3±1.9in non-purification group and there were no significant differences between thetwo groups in each category. Seven out ofthirteen purified transplants (54%) and 5 out of 14 non-purified transplants (36%)achieved insulin independence. Portalthrombosis occurred once (8%) in the purification group and twice (14%) in the non-purifiedgroup.

Conclusion: Purification successfully reduced tissue volume and improved insulin the independencerate with high islet yield. Purification is beneficial when tissue volume islarge for autologous islet transplantation.

P-181

Validation of a new bag for islet culture and transplantation.

M. Ståhle¹, A. Friberg¹, O. Korsgren¹, M. Goto^2
1 Uppsala University, Immunology, Genetics and Pathology, Uppsala, Sweden; ² Division of Advanced Surgical Science and Technology, Tohoku University, Sendai, Japan

Objective: The aim of this study was toevaluate a newly developed culture bag consisting of highly gas-permeable andtransparent plastic.

Methods: Porcine islets were cultured at37 ° C in5% CO2 for 24 hours under 3 different conditions: 1. Culture flasks (CF), 2. FenvalTransfer pack for platelet concentrates (Ftp) and 3. the new Tohoku bag (Tb).Porcine islets were evaluated by: recovery rate, respiratory activity,transplantation to diabetic athymic mice, and intraperitoneal glucose tolerancetest (IPGTT). Oxygen permeability of each device during 4 hours was alsoexamined. Human islets were cultured at 37 ° C in 5% CO2 for 2-4 days eitherin Ftp or in Tb. The islets were then subjected to the following assays:ADP/ATP-ratio, intracellular insulin content, dynamic glucose stimulated insulinrelease and expression of IL-6, IL-8, tissue factor and MCP-1.

Results: Porcine islets: There was a significantdifference in recovery rate (Tb=87.5 vs. CF=78.8%, p=0.003, Tb=87.5 vs. Ftp=83.1%, p=0.009: Wilcoxon matched-pairs t-test) but not in respiratory activity, curativerate of diabetic mice ((CF (9/15), Ftp (9/14), Tb (12/15)), oxygen permeabilityor IPGTT (AUC: CF=4177, Ftp =3739, Tb=4228 min*mg/dl). There was significantdifference in oxygen permeability (CF=415 ± 32, Ftp =543 ± 79, Tb=631 ± 77 mmHg,p<0.0001: One-Way ANOVA Friedman test). For the human islets there was nosignificant difference in any of the tests.

Conclusions: The newly developed Tohoku bag show equal or even enhanced capacityfor islet culture. Another benefit of the Tohoku bag is that it allows visualinspection prior to islet transplantation and good recovery of the islets dueto the non-adherent surface.

P-182

Impact of purification on clinical autologous islet transplantation

S. Matsumoto¹, M. Takita¹, M. Shimoda², K. Sugimoto¹, T. Itoh¹, D. Chujo³, J. SoRelle⁴, Y. Tamura⁵, A. Rahman⁵, N. Onaca¹, B. Naziruddin⁵, M. Levy^5
1 Baylor Research Institute, Islet Cell Laboratory, Fort Worth, USA; ² Baylor University Medical Center, Dallas, USA; ³ Baylor Institute for Immunology Research, Dallas, USA; ⁴ Baylor University, Waco, USA; ⁵ Baylor Regional Transplant Institute, Dallas, USA

Background: Total pancreatectomy followed by autologous islet transplantation is anexcellent treatment for patients with severe chronic pancreatitis. Traditionally, chronically damaged pancreata weredigested for islet isolation without purification steps. Purification couldprevent portal thrombosis; however, the impact of islet purification onautologous islet transplantation is unknown. The purpose of this study is to assess the impact of islet purificationon clinical autologous islet transplantation.

Methods: We have performed 27 autologous islet transplantations following totalpancreatectomy since 2006. Islets wereisolated using the modified Ricordi method. When tissue volume exceeded 15-20 ml, islets were purified. The pancreas weight, islet yield, portalpressure, clinical outcomes were compared.

Results: Islets were purified in 13 cases (purification group). The average pancreas weight (95.8±6.7 g vs.73.2±6.8 g, P<0.03) and pre-purification tissue volumes (32.8±3.9 g vs.8.1±1.6 ml, P<0.0001) were significantly higher in the purificationgroup. There was no significantdifference in the final tissue volumes between the purification (11.7±1.2mL)and non-purified (8.1±1.6 ml) groups. Bothpre-purification (611,648±64,6084IE, P<0.01) and final (519,109±63,742IE, P<0.04) islet yields were significantly higher in the purification groupcompared to the non-purified group (315,436±66,570 IE). The peak-, final- and delta- portal pressureswere 17.8±1.9,14.3±1.7and 11.3±1.4mmHgrespectively in purification group and 16.8±1.5, 15.2±1.3 and 7.3±1.9in non-purification group and there were no significant differences between thetwo groups in each category. Seven out ofthirteen purified transplants (54%) and 5 out of 14 non-purified transplants (36%)achieved insulin independence. Portalthrombosis occurred once (8%) in the purification group and twice (14%) in the non-purifiedgroup.

Conclusion: Purification successfully reduced tissue volume and improved insulin the independencerate with high islet yield. Purification is beneficial when tissue volume islarge for autologous islet transplantation.