Progress in clinical and biological research
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Prog. Clin. Biol. Res. · Jan 1998
ReviewAntibiotic-mediated release of endotoxin and the pathogenesis of gram-negative sepsis.
Since the earliest days of antibiotic chemotherapy to treat infection with Gram-negative microbes, investigators have recognized that such treatments may result in the release of microbial constituents that might, in turn, exacerbate the pathophysiological manifestations of disease. Both in vitro studies and in vivo animal experiments have over the years provided evidence in support of this concept; however, the actual clinical importance of this phenomenon to patients with Gram-negative sepsis is unclear. Recently published reports from a number of laboratories have shown that cell wall-active antibiotics that differ in their fundamental mechanisms of action in disrupting microbial growth (via selective interactions with various penicillin binding proteins) also differ in their relative ability to induce the release of biologically active endotoxin both in vitro and in vivo. ⋯ Of potential significance is the finding that these differences are also reflected in differential production of cytokines from endotoxin-stimulated mononuclear phagocytes and other host target cells, including 11-6 and TNF. Since these immunologic hormones have been strongly implicated as contributing factors to the pathogenesis of Gram-negative sepsis, interest in the potential use of this chemotherapeutic approach as a means of controlling the host immunopathologic response has increased. Carefully controlled clinical trials in which different antibiotic treatments are correlated with production of cytokines will be of significant potential value in evaluating the actual significance of this phenomenon in the Gram-negative septic patient.
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Prog. Clin. Biol. Res. · Jan 1991
ReviewAnti-lipopolysaccharide and anti-tumor necrosis factor/cachectin antibodies for the treatment of gram-negative bacteremia and septic shock.
Endotoxin is composed of lipid A, the toxic moiety, of the core region, a conserved structure among Gram-negative bacteria, and of the O-side chains, a highly variable part responsible for the antigenic specificity. The concept of cross-protection afforded by antiserum raised against the core region of endotoxin is supported by the following data: experimentally antiserum protected against infections caused by a wide range of Gram-negative bacteria or endotoxins; in patients with Gram-negative bacteremia, survival was associated with high levels of anti-core antibodies, and mortality was reduced by the prophylactic or therapeutic use of immune serum or plasma. However, the proof that protection is afforded by cross-protective anti-core antibodies is still lacking. ⋯ In children with meningococemia and in adults with Gram-negative septic shock, TNF was associated with the patient's outcome. Anti-TNF monoclonal antibodies are presently undergoing clinical investigation in patients with septic shock. However, one should keep in mind that TNF serves both beneficial and detrimental functions depending upon its concentration in body fluids.