Production of interleukin-10 in human fracture soft-tissue hematomas.

Clinical trauma suppresses immunity and experimental wound fluids have been shown to be immunosuppressive. To ascertain whether human wounds contain immunosuppressive cytokines, we assayed serum from fracture/soft-tissue hematomas (FSTH) of 22 patients for interleukin (IL)-10, transforming growth factor (TGF)-beta 1, and IL-4. Results were correlated to concurrent plasma cytokine concentrations in the same patients and in volunteer plasma. IL-10 was present in high concentration (1376 +/- 539 pg/mL) in all (7/7) FSTH < 24 h old. In FSTH > 24 h old, IL-10 was found intermittently and at lower levels (239 +/- 106 pg/mL, p = .011 vs. FSTH < 24 h old). IL-10 was rarely detectable in fracture patient plasma and never detectable (< 20 pg/mL) in normal plasma. No significant variations of IL-4 or total TGF-beta 1 were found in FSTH or plasma. FSTH are significant potential sources of IL-10 activity in trauma patients, which may be overlooked when only plasma is assayed. The potential for a relationship between cytokines found locally at sites of injury and clinical immune modulation in trauma requires further study.