REDUCTION IN PERIPHERAL-NERVE ALLOGRAFT ANTIGENICITY WITH WARM AND COLD TEMPERATURE PRESERVATION

Lymphocyte migration into fresh and preserved peripheral nerve allogra fts was assessed to determine the effects of preservation time, preser vation temperature, and graft harvest technique on the immunologic res ponse to the peripheral nerve allograft. Peroneal nerve Tvas harvested from either live or cadaveric (tissue) donors and stored as 1.5-cm se gments at 5 degrees C or 37 degrees C for 1, 3, 5, or 7 days. Each of nine outbred ewes then received multiple segments of peroneal autograf t, fresh allograft, and preserved nerve allograft implants. Lymphocyte migration was studied 7 days after implantation by intravenous inject ion of autologous In-111-labeled lymphocytes and quantified by gamma c ounter. Lymphocyte migration into fresh allografts (7212 +/- 1575) inc reased an average of 4.1 times over fresh autograft tissue (1758 +/- 4 21; p < 0.05). Short-term preservation (24 hours) at both temperatures enhanced lymphocyte migration into pretreated allograft tissue (12684 +/- 2575 at 5 degrees C, 8751 +/- 1577 at 37 degrees C) as compared w ith fresh allograft (7212 +/- 1575). Conversely, 7 days of pretreatmen t at both 5 degrees C (3586 +/- 1421) and 37 degrees C (1570 +/- 414) resulted in migration values not significantly different from autograf t. No statistically significant difference was seen between grafts har vested from live (5710 +/- 1651) versus cadaveric (tissue) donors (401 3 +/- 832) after 5 days of cold preservation.