EARLY, COMPLETE BURN WOUND EXCISION PARTIALLY RESTORES CYTOTOXIC T-LYMPHOCYTE FUNCTION

Background. Cytotoxic lymphocytes (CTLs) are an important component of immune function, involved in antigen recognition and resistance to vi ral infection. Burn injury suppresses cell-mediated immunity, induces allograft tolerance, and increases the risk of viral infection, but th e mechanisms are not well understood. This study analyzes the effect o f burn size and burn wound excision on CTL activity. Methods, Anesthet ized CBA mice (n = 12) received a 0%, 20%, or 40% body surface area co ntact bum. Additional mice (n = 16) received a 40% burn that was total ly, partially, or not excised 72 hours after burn. Excised areas were covered with normal, syngeneic skin. Two weeks later harvested splenoc ytes were cocultured with allogeneic stimulators. CTL activity was det ermined by a Cr-51 release assay, in which CTL effecters were tested o n allogeneic, radiolabeled targets. Dilution curves of CTL activity we re compared by ANOVA. Results. Both 20% and 40% burns significantly in hibited CTL activity (p < 0.05). Total but not partial excision of a 4 0% burn restored CTL activity (p < 0.01). Both total and partial wound excision also improved survival (p < 0. 05). Conclusions. Burn injury inhibits CTL activity in a size-dependent manner, and total wound exc ision significantly improves both CTL function and survival after inju ry. This study suggests a mechanism for the immunosuppressive effects of bunt injury and provides an immunologic rationale for early, comple te burn wound excision.