In vivo monitoring of postburn immune response.

Following a severe thermal injury (30% TBSA), 50% of the burned mice died within 48 hours. The immune response of the survivors was evaluated in vivo using the popliteal lymph node assay (PLNA) for host versus graft (HVG) or graft versus host (GVH) response. Suppression of GVH reactivity was observed using isolated splenocytes from burned mice harvested on postburn days 3, 8, and 11. Lymphocyte response evaluated in the burn environment using the HVG assay was profoundly deficient on postburn days 3 and 11. Recovery of immune function as determined by measurements of both responses occurred by postburn days 14-21, and coincided with wound healing. The PLNA proved to be a sensitive measure of immune function, and allowed for the evaluation of isolated cell populations, as well as measurement of lymphocyte function in the burn environment in the presence of circulating suppressor factors.