Serum-mediated depression of neutrophil chemiluminescence following blunt trauma

To investigate one possible mechanism responsible for decreased neutrophil bactericidal activity following trauma, the chemiluminescence response of normal neutrophils was measured following incubation in nonseptic and septic serum from 19 blunt trauma patients. Incubation of normal neutrophils in septic patients' sera (61 studies) resulted in a marked decrease in the chemiluminescence response (36 +/- 26% of control), compared to incubation in nonseptic sera (92 studies, 80 +/- 53% of control; p less than 0.005). This difference between nonseptic and septic serum was apparent immediately after injury, prior to the development of sepsis (47 +/- 4% versus 77 +/- 12%; p less than 0.05). The depression of the CL response was due to a suppressive factor present in septic patients' sera. This factor was nondialyzable and was present in high performance liquid chromatography (HPLC) fractions containing protein of molecular weight 50 to 100,000. Removal of albumin using Affigel-blue did not remove the suppressive factor. In contrast to the suppressive effect of septic trauma serum, septic patients' neutrophils had a normal chemiluminescence response after their isolation and washing. We conclude that trauma results in the generation of a serum factor that suppresses neutrophil chemiluminescence and that is present in greater amounts in patients who eventually become septic. This factor may be responsible for the decreased bactericidal activity and depressed host defense following injury.