lipid-a and Multiple-Organ-Failure

Topics: Humans; Intestinal Obstruction; Lipid A; Multiple Organ Failure

Topics: Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Antimicrobial Cationic Peptides; Bacteremia; Blood Proteins; Cell Adhesion Molecules; Child; Cytokines; Endotoxins; Genetic Therapy; Humans; Immunotherapy, Adoptive; Lipid A; Membrane Proteins; Multiple Organ Failure; Neutrophils; Shock, Septic

Monophosphoryl lipid A (MPLA) is a TLR4 agonist that has potent immunomodulatory properties and modulates innate immune function to improve host resistance to infection with common nosocomial pathogens in mice. The goal of this study was to assess the safety and efficacy of MPLA in a sheep model of burn injury and Pseudomonas aeruginosa pneumonia. The sheep provides a favorable model for preclinical testing as their response to TLR4 agonists closely mimics that of humans.. Twelve chronically instrumented adult female Merino sheep received 20% total body surface area, third-degree cutaneous burn under anesthesia and analgesia. At 24 h after burn, sheep were randomly allocated to receive: MPLA (2.5 μg/kg i.v., n = 6), or vehicle (i.v., n = 6). At 24 h after MPLA or vehicle treatment, Pseudomonas aeruginosa pneumonia was induced. Sheep were mechanically ventilated, fluid resuscitated and cardiopulmonary variables were monitored for 24 h after induction of pneumonia. Cytokine production, vascular barrier function, and lung bacterial burden were also measured.. MPLA infusion induced small and transient alterations in core body temperature, heart rate, pulmonary artery pressure, and pulmonary vascular resistance. Pulmonary mechanics were not altered. Vehicle-treated sheep developed severe acute lung injury during Pseudomonas aeruginosa pneumonia, which was attenuated by MPLA as indicated by improved PaO2/FiO2 ratio, oxygenation index, and shunt fraction. Sheep treated with MPLA also exhibited less vascular leak, lower blood lactate levels, and lower modified organ injury score. MPLA treatment attenuated systemic cytokine production and decreased lung bacterial burden.. MPLA was well tolerated in burned sheep and attenuated development of acute lung injury, lactatemia, cytokinemia, vascular leak, and hemodynamic changes caused by Pseudomonas aeruginosa pneumonia.

Topics: Adjuvants, Immunologic; Animals; Burns; Disease Models, Animal; Female; Lipid A; Multiple Organ Failure; Pneumonia, Bacterial; Pseudomonas aeruginosa; Pseudomonas Infections; Sheep

We conducted a prospective study in patients with multiple injuries investigating the time course of trauma-related changes of systemic immunologic defense mechanisms.. Patients with multiple injuries with Injury Severity Scores of more than 20 were included if they survived for more than 4 days after injury. Further inclusion criteria were no local or systemic infection (pneumonia, sepsis, soft-tissue infection, acquired immunodeficiency syndrome, tuberculosis, etc.) at the time of injury and no history of liver disease, bowel disease, or abdominal surgery. Serum endotoxin levels were measured from peripheral venous blood, as were the immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies against lipid A and against the core polysaccharide of endotoxin (lipopolysaccharide [LPS]), during the course of intensive care management. Serial central venous levels of interleukin-6 were determined as a marker of the inflammatory response.. The patients were grouped according to their survival, with the survivors belonging to group S (48 patients) and the nonsurvivors belonging to group N (16 patients). The time of death for the nonsurvivors was between days 10 and 32 after the initial trauma. Thirteen of these patients (81%) died of multiple organ failure between days 12 and 17, two died of head trauma, and one died of sepsis. In patients who died of multiple organ failure, a significantly lower production of the IgM and IgG antibodies (AB) against lipid A and LPS was found before death (lipid A IgM-AB, day 11: group N, 29 +/- 11 U/mL; group S, 106 +/- 16 U/mL; p = 0.008; lipid A IgG-AB, day 11: group N, 18 +/- 9 U/mL; group S, 57 +/- 18 U/mL; p = 0.007; LPS IgM-AB, day 11: group N, 36 +/- 14 U/mL; group S, 122 +/- 23 U/mL; p = 0.009; LPS IgG-AB, day 11: group N, 17 +/- 12 U/mL; group S, 56 +/- 19 U/mL; p = 0.03). Interleukin-6 levels were significantly increased in the nonsurvivors (day 1: group N, 1,095 +/- 112 pg/mL; group S, 393 +/- 67 U/L; p = 0.008).. In patients who died of severe trauma and in whom the cause of death was multiple organ failure, a significantly lower production of antiendotoxin antibodies was measured shortly before death. An insufficient immune defense (dysergy) may be involved in the pathomechanisms leading to the development of organ dysfunction.

Topics: Adult; Antibodies; Female; Humans; Immunoglobulin G; Immunoglobulin M; Injury Severity Score; Interleukin-6; Lipid A; Lipopolysaccharides; Male; Multiple Organ Failure; Multiple Trauma; Prospective Studies; Survival Rate