Prospective cohort study of procalcitonin levels in children with cancer presenting with febrile neutropenia

BACKGROUND: Febrile neutropenia (FNP) causes significant morbidity and mortality in children undergoing treatment for cancer. The development of clinical decision rules to help stratify risks in paediatric FNP patients and the use of inflammatory biomarkers to identify high risk patients is an area of recent research. This study aimed to assess if procalcitonin (PCT) levels could be used to help diagnose or exclude severe infection in children with cancer who present with febrile neutropenia, both as a single measurement and in addition to previously developed clinical decision rules. METHODS: This prospective cohort study of a diagnostic test included patients between birth and 18 years old admitted with febrile neutropenia to the Paediatric Oncology and Haematology Ward in Leeds between 1(st) October 2012 and 30(th) September 2013. Each admission with FNP was treated as a separate episode. Blood was taken for a procalcitonin level at admission with routine investigations. 'R' was used for statistical analysis. Likelihood ratios were calculated and multivariable logistic regression. RESULTS: Forty-eight episodes from 27 patients were included. PCT >2 ng/dL was strongly associated with increased risk of severe infection (likelihood ratio of 26 [95% CI 3.5, 190]). The data suggests that the clinical decision rules are largely ineffective at risk stratification, frequently over-stating the risk of individual episodes. High procalcitonin levels on admission are correlated with a greatly increased risk of severe infection. CONCLUSIONS: This study does not show a definitive benefit in using PCT in FNP though it supports further research on its use. The benefit of novel biomarkers has not been proven and before introducing new tests for patients it is important their benefit above existing features is proven, particularly due to the increasing importance of health economics

Can procalcitonin measurement help in differentiating between bacterial infection and other kinds of inflammatory processes?

Objective: To study the levels of procalcitonin (PCT) in various inflammatory states seen in an internal medicine department and to evaluate the possible discriminative role of PCT in differentiating bacterial infection from other inflammatory processes. Methods: PCT, C reactive protein (CRP), and white blood cell count (WBC) were measured in patients admitted to the department for fever or biological inflammatory syndrome, or both. The serum of 173 consecutive patients was analysed according to the aetiological diagnosis. The patients were divided into two groups: group I (n=60) with documented bacterial or fungal infection; group II (n=113) with abacterial inflammatory disease. Results: PCT levels were >0.5 ng/ml in 39/60 (65%) patients in group I. In group II, three patients with a viral infection had slightly increased PCT levels (0.7, 0.8, and 1.1 ng/ml) as did two others, one with crystal arthritis and the other with vasculitis (0.7 ng/ml in both cases). All other patients in group II had PCT levels <0.5 ng/ml. In this study a value of PCT >0.5 ng/ml was taken as the marker of bacterial infection (sensitivity 65%, specificity 96%). PCT values were more discriminative than WBC and CRP in distinguishing a bacterial infection from another inflammatory process. Conclusion: PCT levels only rose significantly during bacterial infections. In this study PCT levels >1.2 ng/ml were always evidence of bacterial infection and the cue for starting antibiotic treatment