Release of proinflammatory cytokines by mitogen-stimulated peripheral blood mononuclear cells from critically III multiple-trauma victims☆☆☆

Abstract This study investigated the alterations in circulating proinflammatory cytokines and cytokine production by peripheral blood mononuclear cells (PBMCs) in response to lipopolysaccharide (LPS) or phytohemagglutinin (PHA) after severe trauma. Plasma and PBMCs were collected from 17 severely injured trauma patients and 10 healthy subjects. Plasma was stored at—80°C and analyzed for cytokines. Isolated PBMCs from each subject were stimulated with LPS or PHA and incubated at 5% CO 2 for 24 hours. Supernatants were collected and analyzed for cytokines. There was no significant change in the plasma concentration of free TNF-α and IL-1β between healthy subjects and trauma patients. Plasma IL-6, total TNF-α, and total IL-1β were significantly increased in severely traumatized patients compared with healthy control subjects. PBMCs from trauma patients produced higher levels of TNF-α in response to LPS but it showed no significant change in IL-1β and IL-6 production in response to PHA or LPS in comparison to PBMCs from control subjects. We conclude that severe trauma results in a significant increase in plasma proinflammatory cytokine IL-6. Free TNF-α and IL-1β in plasma remain at levels comparable to those in uninjured controls, while plasma free IL-6 levels in trauma patients remain high. Serious injury is associated with an enhanced production of TNF-α by PBMCs stimulated with LPS.