Decreased levels of perforin-positive lymphocytes are associated with posttraumatic complications in patients with major trauma

Abstract Objective Posttraumatic immune disorder can cause complications including systemic inflammatory response syndrome (SIRS) and multiple-organ dysfunction syndrome (MODS). Cytotoxic granules containing perforin and granzyme-B (GrB) are released by cytotoxic CD8 + T lymphocytes, NK and γδT cells after major trauma. This prospective clinical study was designed to analyze the association between these immune components and complications after major trauma. Methods We retrospectively studied 48 patients aged between 16 and 65 years admitted within 90 min of major trauma (Injury Severity Score > 16) and surviving beyond 7 days, and 20 healthy controls. Blood samples were drawn on admission and after 1, 3 and 7 days. CD8 + T, NK and γδT cell counts in peripheral blood and the levels of perforin and GrB in these cells were analyzed by flow cytometry. Clinical aspects of MODS and SIRS were recorded daily. Results CD8 + T cell counts were not significantly different in patients with SIRS or uncomplicated group, but were depressed in the MODS group after trauma. However, NK cell counts in patients with MODS were significantly depressed only at day 7 after injury, and γδT cell counts were significantly depressed after trauma. Perforin levels in CD8 + T, NK and γδT cells in patients with MODS were depressed after trauma. GrB levels in NK, CD8 + T and γδT cells in patients with MODS were significantly depressed at 3 and 7 days post trauma. Conclusion Posttraumatic MODS is associated with early, sustained, and severe depression of lymphocytes.