Modified two-layer preservation method (M-Kyoto/PFC) improves islet yields in islet isolation.

Area of Science:

• Transplantation immunology
• Organ preservation
• Diabetes research

Background:

• Islet allotransplantation is a key treatment for type I diabetes, aiming for insulin independence.
• The two-layer method (TLM) using oxygenated perfluorochemical (PFC) and UW solution improves pancreas preservation compared to simple cold storage.
• UW solution, while effective, inhibits crucial enzymes like Liberase, potentially impacting islet isolation efficiency.

Purpose of the Study:

• To evaluate a novel preservation solution, M-Kyoto solution, for pancreas preservation in islet transplantation.
• To compare the efficacy of M-Kyoto solution against UW solution, particularly concerning enzyme activity and islet yield.
• To assess the components of M-Kyoto solution, trehalose and ulinastatin, for their cytoprotective and enzyme-inhibiting properties.

Main Methods:

• Porcine islet isolation was performed using M-Kyoto solution/PFC and UW solution/PFC.
• Pancreas ATP content was measured to assess energy source differences.
• Trypsin and collagenase activity were measured in both M-Kyoto and UW solutions during the digestion step.

Main Results:

• The M-Kyoto/PFC group showed a significantly higher islet yield compared to the UW/PFC group.
• No significant difference in pancreas ATP content was observed between the groups.
• M-Kyoto solution demonstrated significant trypsin inhibition and less inhibition of collagenase digestion compared to UW solution.

Conclusions:

• M-Kyoto solution offers advantages in islet transplantation due to its trypsin inhibition and minimal collagenase inhibition.
• The enhanced islet yield observed with M-Kyoto solution is not attributable to differences in energy sources.
• M-Kyoto solution is now utilized for clinical islet transplantation from non-heart-beating donors, improving outcomes for type I diabetes patients.