Survival of nerve allografts in sensitized rats treated with cyclosporin A.

This study examined the effect of immunosuppressive treatment with cyclosporin A (Cy-A) on the survival of nerve allografts in sensitized rats. Nerve- or skin-sensitized untreated rats rejected a second nerve allograft of the same genotype as the first in an accelerated manner. In this situation, only a few host axons grew into the proximal 1 cm of a 4 cm-long nerve allograft. However, if sensitized rats were given Cy-A (10 mg/kg daily), the second nerve allograft survived, and numerous host axons regenerated through the 4-cm length of the allograft. These results indicated that Cy-A was an effective immunosuppressive agent in sensitized rats. We conclude that, in rats, donor-specific sensitization is not a contraindication to the use of nerve allografts to aid in the repair of injured nerve when Cy-A is used for immunosuppression.