Increased activity of lymph node cells in thermal injury.

While trauma-induced suppression of T-cell responses is well documented, only few studies address lymphocyte activation. The aim of this study was to investigate the functional activity of lymph node cells in rats subjected to scald injury, proliferative activity, cytokine production, and responsiveness to exogenously added cytokines was evaluated in cells from lymph nodes draining burned tissue and from distant, nondraining lymph node cells. Results presented clearly show that lymph node cells in scalded rats are activated in vivo although the extent of proliferation and pattern of cytokine production differ: a) proliferative activity was elevated both in draining and distant lymph nodes, but was more pronounced in cells from lymph nodes draining the injured region; b) increased production of IL-2, and particularly IL-1 and IL-6 was found and coincides well with peak of proliferative activity of draining lymph node cells; IL-2 production by distant lymph node cells remained unchanged, IL-1 and IL-6 production was significantly increased coinciding with increased proliferation; c) increased responsiveness to exogenously supplied cytokines was found in draining lymph node cells, while it remained unchanged in nondraining lymph node cells. Early activation of lymphocytes demonstrated in our experiments could be one of the previously unrecognized consequences of trauma-induced immunosuppression.