POLYMICROBIAL SEPSIS FOLLOWING TRAUMA INHIBITS INTERLEUKIN-10 SECRETION AND LYMPHOCYTE-PROLIFERATION

Immune competence declines following major injury, and predisposes the trauma patient to infection. Interleukin-10 (IL-10), although an immu nosuppressive cytokine, is also important in the initiation of immune responses. This study investigated alterations in IL-10 and immune fun ction associated with polymicrobial sepsis following trauma using muri ne femur fracture (FFx) and cecal ligation/puncture (CLP) models. Mice were randomized to Normal, FFx, Alcohol and FPx (EtOH+FFx), CLP, FFxCLP, and EtOH+FFx+CLP. Polymicrobial sepsis was induced by performing CLP 4 days after FFx, and animals were killed 14 days later; immune fu nction was assessed by in vitro splenocyte cultures. Lymphocyte prolif erative responses were significantly suppressed in FFx and CLP animals . Splenocyte IL-10 production was significantly reduced in FFx and CLP animals, with concurrent increases in nitrite and tumor necrosis fact or release. This study documents that trauma induces alterations in th e inflammatory cytokine cascade that affect the immune response to sub sequent septic challenges.