Reduction in peripheral nerve allograft antigenicity with warm and cold temperature preservation

Area of Science:

• Immunology
• Transplantation Biology
• Nerve Regeneration

Background:

• Peripheral nerve allografts are crucial for nerve repair.
• Understanding immune responses to allografts is key to improving outcomes.
• Graft preservation methods can influence immunogenicity.

Purpose of the Study:

• To investigate how preservation time, temperature, and harvest technique affect immune cell infiltration into peripheral nerve allografts.
• To compare lymphocyte migration into fresh versus preserved allografts and autografts.

Main Methods:

• Peroneal nerve allografts were harvested from live or cadaveric donors.
• Grafts were preserved at 5°C or 37°C for 1, 3, 5, or 7 days.
• Sheep received autografts, fresh allografts, and preserved allografts; lymphocyte migration was quantified using radiolabeled cells.

Main Results:

• Lymphocyte migration into fresh allografts was significantly higher than into autografts (p < 0.05).
• Short-term preservation (24 hours) at both 5°C and 37°C enhanced lymphocyte migration compared to fresh allografts.
• Long-term preservation (7 days) at both temperatures reduced lymphocyte migration to levels similar to autografts.
• No significant difference in migration was observed between live and cadaveric donor grafts after 5 days of cold preservation.

Conclusions:

• Graft preservation duration and temperature critically modulate the immune response to peripheral nerve allografts.
• Long-term preservation effectively reduces allograft immunogenicity, making them more comparable to autografts.
• Preservation protocols can be optimized to manage immune cell infiltration in nerve allografts for transplantation.