ELEVATED IL-8 PRODUCTION BY TRAUMA PATIENTS MONOCYTES IS ASSOCIATED WITH ELEVATED SECRETION OF TNF-ALPHA

IL-8 is a recently described chemokine that increases polymorphonuclea r neutrophil infiltration and has been implicated in inflammatory path ology. This study assesses monocyte (MO) interleukin-8 (IL-8) levels i n severe trauma patients (injury severity score > 16) who have elevate d levels of MO cell-associated tumor necrosis factor alpha (TNF alpha) , a major marker for systemic inflammatory response syndrome after inj ury. We demonstrate elevated (p = .0007) levels of MO IL-8 only in tho se trauma patients who also have increased (p = .0001) MO-secreted TNF alpha whereas the patients having normal MO-secreted TNF alpha levels have normal or even decreased MO IL-8 production. There is no associa tion between MO IL-8 production and cell-associated TNF alpha levels. MO induction by Fc gamma RI cross-linking, a common induction pathway in trauma patients' MO that increases the production of both cell-asso ciated and secreted TNF alpha, can also increase (p = .0022) MO IL-8 l evels. Therefore, post-trauma elevation of MO IL-8 levels may be assoc iated with increased secreted TNF alpha resulting from, at least in pa rt, Fc gamma RI cross-linking stimulation in vivo.