Association of endotoxemia and production of antibodies against endotoxinsafter multiple injuries

Background: Endotoxemia after injury has been a controversial issue, Endoto xins stimulate the innate and adaptive immune system. Objective: To investigate endotoxemia and its effects on the production of antiendotoxin antibodies of cultured mononuclear cells of patients with mul tiple injuries. Methods: Blood samples of 20 patients with multiple injuries were collected up to 12 days after trauma. The endotoxin concentration was measured in th e plasma, and mononuclear cells were isolated and cultured. Specific antibo dies against two lipopolysaccharides, one Lipid A preparation, and alpha-he molysin of Staphylococcus aureus were measured in the cell culture supernat ant by an enzyme-linked immunosorbent assay. Results: Endotoxemia peaked at admission of the patients, decreasing therea fter to almost normal values within 5 days, Isolated mononuclear cells synt hesized antibodies against all tested antigens with a peak at or between da y 5 and day 7. The increase was significant for immunoglobulin (Ig)A and Ig M specific to all endotoxins tested and for IgA specific to alpha-hemolysin , However, there were no significant changes of the concentrations of total IgM, IgA, and IgG, All specific IgG remained unaffected. Conclusion: Patients with multiple injuries initially have temporary endoto xemia, Endotoxin may be suggested as a stimulator of the synthesis of antie ndotoxin antibodies, in particular of the IgA and IgM class in patients wit h multiple injuries.