Analyzing the capability of PSP, PCT and sCD25 to support the diagnosis of infection in cancer patients with febrile neutropenia.

Background Early diagnosis of infection is essential for the initial management of cancer patients with chemotherapy-associated febrile neutropenia (FN). In this study, we have evaluated two emerging infection biomarkers, pancreatic stone protein (PSP) and soluble receptor of interleukin 2, known as soluble cluster of differentiation 25 (sCD25), for the detection of an infectious cause in FN, in comparison with other commonly used infection biomarkers, such as procalcitonin (PCT). Methods A total of 105 cancer patients presenting to the emergency department were prospectively enrolled. We observed 114 episodes of chemotherapy-associated FN. At presentation, a blood sample was collected for the measurement of PCT, PSP and sCD25. In order to evaluate the discriminatory ability of these markers for the diagnosis of infection, the area under the curve (AUC) of the receiver operating characteristic curves was calculated. Results Infection was documented in 59 FN episodes. PCT, PSP and sCD25 levels were significantly higher in infected patients. PCT was the biomarker with the highest diagnostic accuracy for infection (AUC: 0.901), whereas PSP and sCD25 showed a similar performance, with AUCs of 0.751 and 0.730, respectively. In a multivariable analysis, PCT and sCD25 were shown to be independently associated with infection. Conclusions Two novel biomarkers, PSP and sCD25, correlated with infection in cancer patients with chemotherapy-associated FN, but neither PSP nor sCD25 improved the performance of PCT. Based on the results obtained, the introduction of these novel biomarkers as a tool for the diagnosis of infection in this patient group is not recommended.