A machine learning strategy to mitigate the inappropriateness of procalcitonin request in clinical practice.

Aim: The aim of this study was to develop machine learning (ML) models to mitigate the inappropriate request of Procalcitonin (PCT) in clinical wards. Material and methods: We built six different ML models based on both demographical data, i.e., sex and age, and laboratory parameters, i.e., cell blood count (CBC) parameters, inclusive of monocyte distribution width (MDW), and C-reactive protein (CRP). The dataset included 1667 PCT measurements of different patients. Based on a PCT cut-off of 0.50 ng/mL, we found 1090 negative (65.4%) and 577 positive (34.6%) results. We performed a 70:15:15 train:validation:test splitting based on the outcome. Results: Random Forest, Support Vector Machine and eXtreme Gradient Boosting showed optimal performances for predicting PCT positivity, with an area under the curve ranging from 0.88 to 0.89. Conclusions: The ML models developed could represent a useful tool to predict PCT positivity, avoiding unusefulness PCT requests. ML models are based on laboratory tests commonly ordered together with PCT but have the great advantage to be easy to measure and low-cost.

Monocyte Distribution Width (MDW) as a biomarker of sepsis: An evidenced-based laboratory medicine approach.

Monocyte Distribution Width (MDW) is a new generation cell blood count parameter providing a measure of monocyte anisocytosis. In the last decades, it has emerged as a reliable biomarker of sepsis in the acute setting, especially emergency department, and intensive care unit. MDW has several advantages over commonly used sepsis biomarkers, including low-cost, ease and speed of measurement. The clinical usefulness of MDW has been established in several studies and some clinical laboratory medicines have already implemented it in their routine. In this article, we describe the analytical and clinical features of MDW to guide its appropriate use in clinical practice by integrating the research evidence with real-world laboratory experience. The proper use of a biomarker is critical for improving patients' care and outcome as well as ensuring healthcare quality.

The Value of a Complete Blood Count (CBC) for Sepsis Diagnosis and Prognosis.

Sepsis represents an important global health burden due to its high mortality and morbidity. The rapid detection of sepsis is crucial in order to prevent adverse outcomes and reduce mortality. However, the diagnosis of sepsis is still challenging and many efforts have been made to identify reliable biomarkers. Unfortunately, many investigated biomarkers have several limitations that do not support their introduction in clinical practice, such as moderate diagnostic and prognostic accuracy, long turn-around time, and high-costs. Complete blood count represents instead a precious test that provides a wealth of information on individual health status. It can guide clinicians to early-identify patients at high risk of developing sepsis and to predict adverse outcomes. It has several advantages, being cheap, easy-to-perform, and available in all wards, from the emergency department to the intensive care unit. Noteworthy, it represents a first-level test and an alteration of its parameters must always be considered within the clinical context, and the eventual suspect of sepsis must be confirmed by more specific investigations. In this review, we describe the usefulness of basic and new complete blood count parameters as diagnostic and prognostic biomarkers of sepsis.

Independent Validation of Sepsis Index for Sepsis Screening in the Emergency Department.

(1) Background: The early detection of sepsis is still challenging, and there is an urgent need for biomarkers that could identify patients at a high risk of developing it. We recently developed an index, namely the Sepsis Index (SI), based on the combination of two CBC parameters: monocyte distribution width (MDW) and mean monocyte volume (MMV). In this study, we sought to independently validate the performance of SI as a tool for the early detection of patients at a high risk of sepsis in the Emergency Department (ED). (2) Methods: We enrolled all consecutive patients attending the ED with a request of the CBC. MDW and MMV were measured on samples collected in K3-EDTA tubes on the UniCel DxH 900 haematology analyser. SI was calculated based on the MDW and MMV. (3) Results: We enrolled a total of 703 patients stratified into four subgroups according to the Sepsis-2 criteria: control (498), infection (105), SIRS (52) and sepsis (48). The sepsis subgroup displayed the highest MDW (median 27.5, IQR 24.6-32.9) and SI (median 1.15, IQR 1.05-1.29) values. The ROC curve analysis for the prediction of sepsis showed a good and comparable diagnostic accuracy of the MDW and SI. However, the SI displayed an increased specificity, positive predictive value and positive likelihood ratio in comparison to MDW alone. (4) Conclusions: SI improves the diagnostic accuracy of MDW for sepsis screening.

A new tool for sepsis screening in the Emergency Department.

OBJECTIVES: In this study, we developed and evaluated the diagnostic accuracy of the Sepsis Index for early sepsis screening in the Emergency Department (ED). METHODS: Sepsis Index is based on the combination of monocyte distribution width (MDW) and mean monocyte volume (MMV). Sepsis Index≥1 was selected to define sepsis. We tested its diagnostic accuracy in an ED population stratified in four groups: controls, Systemic Inflammatory Response Syndrome (SIRS), infection, and sepsis, according to Sepsis-2 criteria. RESULTS: Patients with sepsis displayed higher median Sepsis Index value than patients without sepsis. At the receiver operating characterictis (ROC) curve analysis for the prediction of sepsis, the area under the curve (AUC) of MDW and Sepsis Index were similar: 0.966 (95%CI 0.947-0.984), and 0.964 (95%CI 0.942-0.985), respectively. Sepsis Index showed increased specificity than MDW (94.7 vs. 90.6%), without any decrease in sensitivity (92.0%). Additionally, LR+ increased from 9.8 (MDW) to 17.4 (Sepsis Index), without any substantial change in LR- (respectively 0.09 vs. 0.08). Finally, PPV increased from 0.286 (MDW) to 0.420 (Sepsis Index). CONCLUSIONS: Sepsis Index improves the diagnostic accuracy of MDW alone for sepsis screening.

Reference interval of monocyte distribution width (MDW) in healthy blood donors.

BACKGROUND: The aim of the study was to accurately establish the reference interval (RI) of monocyte distribution width (MDW) in healthy blood donors by the direct method using different statistical approaches. METHODS: MDW was measured in 486 subjects. RI of MDW was calculated by the non-parametric method, the robust method and, the Harrell-Davis bootstrap method and using different tests to identify potential outliers (Dixon-Reed and Tukey). RESULTS: Lower and upper reference limits of the RI calculated by the non-parametric method were, 16.22 (90%CI 15.78-16.47) - 23.15 (90%CI 22.80-24.10) (without outlier removal), and 16.44 (90%CI 16.21-16.67) - 22.99 (90%CI 22.33-23.22) (after outlier removal). The RIs based on the robust method were, respectively, 16.29-22.98 (without) and 16.50-22.67 (with outlier removal). Finally, the RIs calculated by the Harrell-Davis bootstrap method, without or after outlier removal, were 16.19-23.24 and 16.43-22.93. Thus, the RIs obtained by the three calculation methods were very similar. Additionally, no RI partition was done since no significant gender or age association was found. CONCLUSIONS: Our results support the use of a unique RI of MDW, independently of sex and age.

Monocyte distribution width (MDW) as a screening tool for sepsis in the Emergency Department.

Objectives The diagnosis of sepsis in the Emergency Department (ED) is challenging and a reliable biomarker is needed. The current study aimed to evaluate the diagnostic accuracy of monocyte distribution width (MDW) for the early identification of sepsis in the ED. Methods We performed a large observational study including consecutive adult patients (≥18 years of age) presenting to the ED between September and November 2019, with an order for complete blood count (CBC) evaluation. A total of 2,215 patients were enrolled and classified based on Sepsis-2 criteria as the control group (1,855), infection group (172), Systemic Inflammatory Response Syndrome (SIRS) group (100), and sepsis group (88). Results MDW levels were higher in patients with sepsis than in all other groups (p<0.001). ROC curve analysis showed an optimal diagnostic accuracy of MDW for sepsis prediction at a cut-off point of 23.5, with an AUC of 0.964, sensitivity and specificity of 0.920 and 0.929, respectively. Conclusions Our findings encourage further investigation to validate the use of MDW as a screening tool for the early identification of patients at risk of sepsis in the ED.

Presepsin and Midregional Proadrenomedullin in Pediatric Oncologic Patients with Febrile Neutropenia.

OBJECTIVE: In this study, we investigated the roles of presepsin (PSP) and midregional proadrenomedullin (mr-proADM) in children with febrile neutropenia (FN) due to chemotherapy. METHODS: We assessed 36 FN episodes in 26 children. Patients were classified into bacteremia (B) and fever of unknown origin (FUO) groups. We evaluated PSP and mr-proADM at admission (T0), after 24/48 h (T1), and after 5 days (T2). RESULTS: PSP and mr-proADM levels were elevated at T0 and significantly decreased at T2. mr-proADM levels did not significantly differ between the B and FUO groups. PSP levels significantly differed between the B and FUO groups only at T1. Both PSP and mr-proADM levels at T0 were a predictor of length of hospital stay but not of the duration of fever. Finally, receiver operating characteristic curve analysis showed that PSP and mr-proADM had low diagnostic accuracy for blood culture positivity. CONCLUSION: PSP and mr-proADM display poor clinical usefulness for FN in oncologic children.