The predictive value of interleukin-8 (IL-8) in hospitalised patients with fever and chemotherapy-induced neutropenia.

Aim: To demonstrate whether serum Interleukin-8 (IL-8) is a relevant parameter to select hospitalised patients with chemotherapy-induced neutropenic fever with low or high probability of infection.

Results: 90 assessable febrile episodes in 73 patients were evaluated; 46% of the febrile episodes were microbiologically documented infection (MDI), 8% clinical documented infection (CDI), and 47% fever of unknown origin (FUO). Median IL-8 level was lower in the FUO group compared to CDI and MDI (p<0.0005). In 45 of 48 episodes (94%) with CDI/MDI, IL-8 level at the start was > or =60 ng/l while in 18 of 21 episodes (86%) with IL-8 level <60 ng/l, no infectious cause was demonstrated. FUO and CDI/MDI patients with IL-8 > or =60 ng/l and responsive on antibiotic treatment showed a decline of IL-8 levels within days in contrast to non-responding patients.

Conclusions: Serum IL-8 level can be a useful marker to identify hospitalised FUO patients with low probability of infection.