Circulating leukemia inhibitory factor levels correlate with disease severity in meningococcemia.

Circulating concentrations of the proinflammatory cytokine leukemia inhibitory factor (LIF) were prospectively determined by radioreceptor competition assay (sensitivity, 1 ng/mL) in 33 subjects with meningococcemia. LIF was detected in the plasma of 13 subjects and was associated with development of septic shock (P < .01), disseminated intravascular coagulation (P < .05), multiorgan failure (P < .05), and death (P < .01). Plasma LIF concentrations were highest (1-1772 ng/mL) at hospital admission and became undetectable within 36 h, and the peak levels correlated inversely with systolic blood pressure (r, -.70, P < .001), peripheral blood leukocyte count (r, -.58, P < .01), and prodromal interval (r, -.60, P < .001). Plasma LIF concentrations > 400 ng/mL were present only in subjects with fatal fulminant infection. LIF concentrations in plasma collected within 12 h of hospital admission correlated with disease severity in patients with meningococcemia. It is likely that LIF participates in the host response to infection, and it may contribute to the pathogenesis of septic shock.