The Evaluation of Procalcitonin as a Diagnostic and Prognostic Marker of Bacterial Infections in Febrile Neutropenic Patients

Objective: The aim of this study was to evaluate the role of procalcitonin (PCT) in the diagnosis, prognosis and follow-up of bacterial infections in febrile neutropenic patients in comparison to the standard parameter, C-reactive protein (CRP). Methods: 40 febrile neutropenic episodes of 37 patients with cancer undergoing chemotherapy were classified as fever of unknown origin (FUO), microbiologically or clinically documented infection. Four sequential serum samples were obtained at the onset of neutropenia, on the first and third days of fever and on the day of defervescence, or on day 5 or 7 of an unresolved fever. Results: At the onset of neutropenia, the PCT levels were found to be normal whereas CRP levels were found to be elevated in all patients. With the febrile episode, PCT levels were elevated in all types of infections which were significantly higher for documented infections compared to FUO (p< 0.05). Procalcitonin levels differed significantly between patients with and without severe sepsis (p<0.001), and the highest levels were seen on the third day of fever. PCT levels decreased rapidly in afebrile patients treated successfully, whereas they remained significantly higher for patients unresponsive to therapy (p<0.001). Conclusions: In conclusion, PCT could be suggested as a useful marker, and was superior to CRP for early diagnosis of documented infections, assessment of the severity of infection and response to therapy in febrile neutropenic patients.