Monoclonal antibodies against ICAM‐1 and LFA‐1 prolong nerve allograft survival

In a rat nerve allograft model, specific immunosuppression was approached with monoclonal antibodies (MAbs) against cell‐surface molecules. After engraftment, recipients were treated with antiintercellular adhesion molecule‐1 (ICAM‐1) and antilymphocyte function‐associated antigen‐1 (LFA‐1) MAbs for 14 days. Functional recovery was evaluated biweekly. Electrophysiological and histological assessments were performed at 6 and 16 weeks. Immunologic responsiveness in the recipients was assessed with a cytotoxic T lymphocyte (CTL) assay at 16 weeks and skin grafts at 18 weeks. The untreated allograft group demonstrated complete disruption of fascicular architecture with poor nerve regeneration. The MAb‐treated allografts maintained well‐organized nerve architecture with a dense population of well‐myelinated fibers. These animals showed functional and electrophysiological recovery. Suppression of CTL activity was nerve donor specific and the survival time of nerve donor skin grafts was prolonged, suggesting induction of alloantigen‐specific tolerance. MAb therapy directed against ICAM‐1/LFA‐1 presents a new approach for the management of the peripheral nerve allograft response.© 1995 John Wiley &Sons, Inc.