DIFFERENTIAL ALTERATIONS IN PLASMA COLONY-STIMULATING FACTOR CONCENTRATIONS IN MENINGOCOCCEMIA

To determine whether circulating levels of any of the colony-stimulati ng factors (CSF) might contribute to the host response in severe sepsi s, plasma concentrations of granulocyte CSF (G-CSF), granulocyte-macro phage CSF (GM-CSF), and macrophage CSF (M-CSF) were measured by immuno assays in 20 subjects with meningococcaemia, a bloodstream infection c aused by Neisseria meningitidis, that has proven to be a valuable mode l to study the responses of other inflammatory mediators during sepsis and septic shock in humans. Plasma G-CSF concentrations were transien tly elevated in most subjects during the early phase of meningococcaem ia, and were higher in subjects with septic shock (mean +/- s.d. = 165 +/- 142 ng/ml, n = 9) compared with those who remained normotensive ( mean +/- s.d. = 7 +/- 2 ng/ml, n = 10) (P < 0.05). Peak plasma G-CSF c oncentrations > 10 ng/ml were associated with the development of septi c shock (P < 0.01), disseminated intravascular coagulation (P < 0.01), fulminant infection (P < 0.05), and a fatal outcome (P < 0.01). Plasm a GM-CSF concentrations > 1 ng/ml were briefly present in subjects wit h life-threatening septic shock (1-15 ng/ml, n = 5), and were strongly associated with fulminant meningococcaemia (P < 0.01). Plasma M-CSF c oncentrations were marginally elevated in all subjects, but were not a ssociated with complications related to or arising from sepsis-induced organ injury. This study demonstrates that plasma levels of G-CSF, GM -CSF and M-CSF show very different responses during meningococcaemia, changes which presumably reflect the different roles played by these m ediators in sepsis and, potentially, in septic shock.