Use of inflammatory markers for early detection of bacteraemia in patients with febrile neutropenia

The aim of the study was to evaluate the ability of procalcitonin, C-reactive protein, serum amyloid A, interleukin-6 and interleukin-8 to predict bacteraemia during the 2 first d of fever in neutropenic patients. A total of 94 febrile neutropenic episodes in 60 patients were studied. Plasma samples were analysed at 10-h intervals from the onset of fever. Clinical events were categorized into 4 groups: 1) bacteraemia caused by other agents than coagulase-negative staphylococci (non-CNS bacteraemia) (n = 21), 2) coagulase-negative staphylococci bacteraemia (n = 15), 3) microbiologically or clinically documented infection without bacteraemia (n = 26) and 4) fever of unknown origin (n = 32). In non-CNS bacteraemia all markers, except for serum amyloid A, showed significantly higher levels compared to patients with fever of unknown origin (p < 0.05). For non-CNS bacteraemia the highest negative predictive value was found for procalcitonin (94%), followed by interleukin-6 (89%), C-reactive protein (88%) and interleukin-8 (87%). Procalcitonin, with a cut-off level of 1.4 ng/ml during 10-20 h after fever onset, showed the highest positive predictive value (67%) for a non-CNS bacteraemia. In conclusion, the value of the analysed markers to predict a non-CNS bacteraemia in neutropenic patients was limited due to low sensitivity and positive predictive value. However, procalcitonin, interleukin-6, C-reactive protein, and interleukin-8 could give useful information for the clinician in excluding a non-CNS bacteraemia.