Procalcitonin concentrations in patients with neutropenic fever

To assess the usefulness of markers of inflammation in distinguishing bacte rial infection from severe systemic nonbacterial inflammation, concentratio ns of procalcitonin, neopterin, endotoxin, tumor necrosis factor, and inter leukin-6 were measured in 28 neutropenic patients at the onset of fever and twice thereafter at 4 h intervals. Infection was found in 11 patients, and 17 patients had fever of undetermined origin. The procalcitonin concentrat ion increased rapidly in patients with infection; the response was detectab le within 8 h of the onset of fever. Procalcitonin is a specific but not a sensitive marker of infection in patients with neutropenic fever. Its poor sensitivity was related to an absent or delayed response in patients with g ram-positive infections. Considerable overlap between infected and noninfec ted patients was found in levels of endotoxin, tumor necrosis factor, and i nterleukin-6.