Prediction of gram-negative bacteremia in patients with cancer and febrile neutropenia by means of interleukin-8 levels in serum: targeting empirical monotherapy versus combination therapy.

In a prospective observational study of 133 neutropenic episodes, interleukin (IL)-8 serum levels > 2000 pg/mL at the onset of fever had a sensitivity of 53% and a specificity of 97% as a predictor of gram-negative bacteremia (GNB; positive predictive value, 73%; negative predictive value, 94%). The rates of early death differed significantly between patients with high and those with low IL-8 levels (3/11 vs. 1/122; P< .01). Serum IL-8 levels at the onset of fever define a low-risk subgroup of patients who can safely be treated with monotherapy.