Low levels of interleukin-8 and interferon-inducible protein-10 in serum are associated with fatal infections in acute Lassa fever

To investigate the role of inflammatory mediators in the pathogenesis of La ssa fever, the levels of a number of pro- and anti-inflammatory cytokines a nd chemokines in serum samples collected from hospitalized patients with fa tal and nonfatal acute Lassa fever were compared with those from 2 control groups: patients with other febrile illnesses and uninfected individuals. S erum interleukin (IL)-8 and interferon (IFN)-inducible protein (IP)-10 leve ls were significantly higher in patients with acute nonfatal Lassa fever th an in control subjects. In striking contrast, levels of these chemokines we re low or undetectable in patients with fatal Lassa fever. IFN-gamma, IL-12 , IL-6, and RANTES levels were elevated in all the febrile study groups. Tu mor necrosis factor-alpha levels were not elevated in patients with fatal o r nonfatal Lassa fever. These data indicate that acute nonfatal Lassa fever is associated with high levels of circulating IL-8 and IP-10 and that low levels or absence of these mediators correlates with a poor outcome.