DEPRESSED NATURAL-KILLER CELL-FUNCTION IN THERMALLY INJURED ADULTS - SUCCESSFUL INVIVO AND INVITRO IMMUNOMODULATION AND THE ROLE OF ENDOTOXIN

  • 1 January 1988
    • journal article
    • research article
    • Vol. 71  (1) , 120-125
Abstract
Natural killer (NK) cells mediate host defense against infections and are regulated by interleukin 2 (IL-2) and other factors. We studied NK cell function in burn patients using a 51Cr release assay with K562 target cells. We found that peripheral blood lymphocytes from burn patients had depressed NK activity (target cell lysis = 22.0 .+-. 3.1% vs 39.8 .+-. 3.2% in healthy volunteers, P < 0.001) and also a lower response to IL-2(28.9 .+-. 3.8% vs 53.2 .+-. 4.3%, P < 0.001). Thirteen burn patients were randomly assigned to receive either standard therapy or 5 days of intravenous polymyxin B in addition to standard therapy. After 2 weeks, the patients not receiving polymyxin B had a significant decline in peripheral blood NK activity (P < 0.01) and response to IL-2 (P < 0.05), while no decline in NK cell activity was seen in patients who received polymyxin B. Sera from burn patients was found to suppress the NK activity of lymphocytes from healthy adults by 5-75%. After using affinity chromatography to remove endotoxin, the sera from burn patients no longer suppressed NK cell activity. Circulating endotoxin appears to be involved in the suppression of NK activity in burn patients.