Procalcitonin as a diagnostic marker in differentiating parapneumonic effusion from tuberculous pleurisy or malignant effusion

An Integrated Clinical and Computerized Tomography-Based Radiomic Feature Model to Separate Benign from Malignant Pleural Effusion

INTRODUCTION

Distinguishing between malignant pleural effusion (MPE) and benign pleural effusion (BPE) poses a challenge in clinical practice. We aimed to construct and validate a combined model integrating radiomic features and clinical factors using computerized tomography (CT) images to differentiate between MPE and BPE.

METHODS

A retrospective inclusion of 315 patients with pleural effusion (PE) was conducted in this study (training cohort: n = 220; test cohort: n = 95). Radiomic features were extracted from CT images, and the dimensionality reduction and selection processes were carried out to obtain the optimal radiomic features. Logistic regression (LR), support vector machine (SVM), and random forest were employed to construct radiomic models. LR analyses were utilized to identify independent clinical risk factors to develop a clinical model. The combined model was created by integrating the optimal radiomic features with the independent clinical predictive factors. The discriminative ability of each model was assessed by receiver operating characteristic curves, calibration curves, and decision curve analysis (DCA).

RESULTS

Out of the total 1,834 radiomic features extracted, 15 optimal radiomic features explicitly related to MPE were picked to develop the radiomic model. Among the radiomic models, the SVM model demonstrated the highest predictive performance [area under the curve (AUC), training cohort: 0.876, test cohort: 0.774]. Six clinically independent predictive factors, including age, effusion laterality, procalcitonin, carcinoembryonic antigen, carbohydrate antigen 125 (CA125), and neuron-specific enolase (NSE), were selected for constructing the clinical model. The combined model (AUC: 0.932, 0.870) exhibited superior discriminative performance in the training and test cohorts compared to the clinical model (AUC: 0.850, 0.820) and the radiomic model (AUC: 0.876, 0.774). The calibration curves and DCA further confirmed the practicality of the combined model.

CONCLUSION

This study presented the development and validation of a combined model for distinguishing MPE and BPE. The combined model was a powerful tool for assisting in the clinical diagnosis of PE patients.

Diagnostic value of soluble biomarkers for parapneumonic pleural effusion

Parapneumonic pleural effusion (PPE) is a common complication in patients with pneumonia. Timely and accurate diagnosis of PPE is of great value for its management. Measurement of biomarkers in circulating and pleural fluid have the advantages of easy accessibility, short turn-around time, objectiveness and low cost and thus have utility for PPE diagnosis and stratification. To date, many biomarkers have been reported to be of value for the management of PPE. Here, we review the values of pleural fluid and circulating biomarkers for the diagnosis and stratification PPE. The biomarkers discussed are C-reactive protein, procalcitonin, presepsin, soluble triggering receptor expressed on myeloid cells 1, lipopolysaccharide-binding protein, inflammatory markers, serum amyloid A, soluble urokinase plasminogen activator receptor, matrix metalloproteinases, pentraxin-3 and cell-free DNA. We found that none of the available biomarkers has adequate performance for diagnosing and stratifying PPE. Therefore, further work is needed to identify and validate novel biomarkers, and their combinations, for the management of PPE.

Pleural fluid biochemical analysis: the past, present and future

Identifying the cause of pleural effusion is challenging for pulmonologists. Imaging, biopsy, microbiology and biochemical analyses are routinely used for diagnosing pleural effusion. Among these diagnostic tools, biochemical analyses are promising because they have the advantages of low cost, minimal invasiveness, observer independence and short turn-around time. Here, we reviewed the past, present and future of pleural fluid biochemical analysis. We reviewed the history of Light’s criteria and its modifications and the current status of biomarkers for heart failure, malignant pleural effusion, tuberculosis pleural effusion and parapneumonic pleural effusion. In addition, we anticipate the future of pleural fluid biochemical analysis, including the utility of machine learning, molecular diagnosis and high-throughput technologies. Clinical Chemistry and Laboratory Medicine (CCLM) should address the topic of pleural fluid biochemical analysis in the future to promote specific knowledge in the laboratory professional community.

Diagnosis of parapneumonic pleural effusion with serum and pleural fluid Activin A

OBJECTIVE

The aim is to evaluate the diagnostic value of Activin A levels in serum and pleural fluid on Parapneumonic Pleural Effusion (PPE).

METHODS

The authors collected serum and pleural fluid from 86 PPE and 37 Non-PPE (NPPE) patients. Including Activin A, levels of biomarkers such as Lactate Dehydrogenase (LDH), Procalcitonin (PCT), and C-Reactive Protein (CRP) were measured. All factors were calculated for association with days after admission. The diagnostic potential of biomarkers on PPE was considered by Receiver Operating Characteristic (ROC) curve analysis.

RESULTS

Levels of Activin A in serum and pleural fluid of PPE patients were significantly higher than those of the NPPE patients. Moreover, concentrations of Activin A in pleural fluid showed a more obvious relevant days after admission. ROC curve analysis found that Activin A in pleural fluid had AUCs of 0.899 with 93% sensitivity and 84% specificity for PPE diagnosis.

CONCLUSION

Activin A in pleural fluid correlated with disease severity could act to diagnose PPE.

Efficacy of procalcitonin and pentraxin-3 as early biomarkers for differential diagnosis of pleural effusions

Objectives

Pleural effusion, defined as an abnormal accumulation of fluid in pleural space, can be of two types: transudative and exudative. The primary aim of the study was to assess the predictive accuracy of procalcitonin (PCT) and pentraxin-3 (PTX-3) in comparison to other biochemical markers such as C-reactive protein (CRP), and adenosine deaminase (ADA) in the differential diagnosis of pleural effusions.

Methods

A cross-sectional analytical study was conducted on patients with pleural effusion. Multiple comparisons and receiver-operating characteristics (ROC) analyses were made to evaluate the diagnostic significance of biochemical markers.

Results

Sixty-six patients with exudative pleural effusion classified as malignant, tuberculous, and parapneumonic effusions (malignant pleural effusion [MPE], tuberculous [TPE], and parapneumonic [PPE]) were included. Significant differences in pleural fluid levels in both PCT (p-value: 0.001) and PTX-3(p-value: 0.001), as well as serum levels of PCT (p-value: 0.001), were observed between the three groups. ROC analysis showed both PTX-3 and PCT having favorable discrimination ability with high sensitivity (≥90%) and specificity to predict PPE from TPE and MPE.

Conclusions

Evaluation of serum and pleural fluid PCT and levels of PTX-3 in the pleural fluid may be used as an early biomarker to differentiate the etiology of pleural effusion.

Associations of procalcitonin, C-reaction protein and neutrophil-to-lymphocyte ratio with mortality in hospitalized COVID-19 patients in China

Coronavirus disease 2019 (COVID-19) is an important and urgent threat to global health. Inflammation factors are important for COVID-19 mortality, and we aim to explore whether the baseline levels of procalcitonin (PCT), C-reaction protein (CRP) and neutrophil-to-lymphocyte ratio (NLR) are associated with an increased risk of mortality in patients with COVID-19. A retrospective study was conducted and a total of 76 patients with confirmed COVID-19 were included between January 17, 2020 to March 2, 2020, of these cases, 17 patients were dead. After adjusting covariates, PCT (≥ 0.10 ng/mL) and CRP (≥ 52.14 mg/L) exhibited independent increasing risks of mortality were used hazard ratio (HR) of 52.68 (95% confidence interval [CI]: 1.77–1571.66) and 5.47 (95% CI: 1.04–28.72), respectively. However, NRL (≥ 3.59) was not found to be an independent risk factor for death in our study. Furthermore, the elevated PCT levels were still associated with increasing risk of mortality in the old age group (age ≥ 60 y), and in the critically severe and severe patients after adjustment for complications. Thu Baseline levels of PCT and CRP have been addressed as independent predictors of mortality in patients with COVID-19.

Procalcitonin Measurement in Pleural Fluid to Predict Infectious Complications of the Chest Post Lung Resection

AIM

Procalcitonin (PCT) is variably used in clinical practice to identify infectious processes. This study investigated whether PCT level in pleural fluids could predict the infectious complications in the chests of patients undergoing lobectomy.

PATIENTS AND METHODS

Thirty-four patients undergoing lobectomy for lung cancer were enrolled. PCT levels were measured in serum (S-PCT) and pleural effusion (PF-PCT) on consecutive postoperative days (PODs). The patients were grouped according to the development of chest infectious complications (atelectasis/pneumonia, postoperative infected pleural effusion/empyema/infected space, prolonged air leak >5 days with evidence of infection, lung torsion, and lung infarction). Multivariate analysis was performed to identify if S-PCT or PF-PCT and on which PODs were predictive of chest infectious complications. Receiver operating characteristic (ROC) analysis was further performed to identify cutoff values.

RESULTS

Eleven patients experienced infectious complications within a median of 4 days (range 3-5 days) postoperatively. S-PCT and PF-PCT in non-complicated patients did not significantly increase postoperatively and followed a decreasing course. Only PF-PCT was significantly increased in complicated patients from POD1; the level peaked on POD4, as did that of S-PCT. PF-PCT on POD2 and 3 and S-PCT on POD3 independently predicted chest infectious complications. ROC analysis showed that PF-PCT > 0.88 ng/dL on POD2 was the most sensitive predictor of such complications (area under the ROC curve [AUC]: 0.979, sensitivity 85%/specificity 91%, p < .001) compared to S-PCT POD3 and PF-PCT POD3.

CONCLUSION

Compared to PCT concentrations in serum, those in pleural fluids were more sensitive and predicted chest infectious complications earlier in patients undergoing lobectomy.

Diagnostic performance of C-reactive protein for parapneumonic pleural effusion: a meta-analysis

Background

Parapneumonic pleural effusion (PPE) refers to effusion secondary to lung infection, the accurate diagnosis of which remains a clinical challenge. Many studies have suggested that the C-reactive protein (CRP) may be useful for diagnosing PPE, but the results have varied. This study aimed to summarize the overall diagnostic ability of serum/pleural CRP for PPE through a meta-analysis.

Methods

Eligible studies were searched for within PubMed, EMBASE, and other databases up to March 1, 2018. The main diagnostic indexes, sensitivity, specificity, positive likelihood ratio/negative likelihood ratio (PLR/NLR), and diagnostic odds ratio (DOR), were then pooled from the individual studies. The summary receiver operating characteristic curves and area under the curve (AUC) were used to summarize the overall test performance.

Results

Eighteen publications were included in this meta-analysis. Summary estimates of the diagnostic performance of pleural CRP for PPE were as follows: sensitivity, 0.80; specificity, 0.82; PLR, 4.51; NLR, 0.25; DOR, 18.26; and AUC, 0.88. The AUC of serum CRP in diagnosing PPE was 0.79. The diagnostic indexes for pleural CRP in differentiating complicated PPE (CPPE) from uncomplicated PPE were as follows: sensitivity, 0.65; specificity, 0.85; PLR, 4.26; NLR, 0.41; DOR, 10.38; and AUC, 0.83. There was no evidence of publication bias.

Conclusions

Both serum and pleural CRP help to diagnose PPE but with moderate diagnostic ability. Pleural CRP measurements also can aid in differentiating CPPE from uncomplicated PPE. However, the results of the CRP assay should be interpreted with additional biomarker tests.

Comparison of serum PCT and CRP levels in patients infected by different pathogenic microorganisms: a systematic review and meta-analysis

To avoid the abuse and misuse of antibiotics, procalcitonin (PCT) and C-reactive protein (CRP) have been used as new approaches to identify different types of infection. Multiple databases were adopted to search relevant studies, and the articles that satisfied the inclusion criteria were included. Meta-analyses were conducted with Review Manager 5.0, and to estimate the quality of each article, risk of bias was assessed. Eight articles satisfied the inclusion criteria. The concentrations of both PCT and CRP in patients with bacterial infection were higher than those with non-bacterial infection. Both PCT and CRP levels in patients with G− bacterial infection were higher than in those with G+ bacterial infection and fungus infection. In the G+ bacterial infection group, a higher concentration of CRP was observed compared with fungus infection group, while the difference of PCT between G+ bacterial infection and fungus infection was not significant. Our study suggested that both PCT and CRP are helpful to a certain extent in detecting pneumonia caused by different types of infection.

Procalcitonin as Biomarker of Infection: Implications for Evaluation and Treatment

Procalcitonin (PCT) is a quickly measurable marker, assumed to have high sensitivity and specificity for sepsis and infection. A literature search was conducted to evaluate PCT ability as a diagnostic and prognostic tool in infectious processes and its ability to monitor the antibiotic therapy. PCT level is increased in bacterial and fungal infections, but not in viral infections, with a significantly higher level in patients with bacteremia compared with uninfected patients (2.5 vs. 0.3 ng/mL; P < 0.0001). A PCT value of ≤0.1 ng/mL discards bacteremia and microbiological tests (negative predictive value of 96.3%), >0.1 ng/mL needs microbiological tests, and >1.0 ng/mL is indicative of bacteremia. Antibiotic treatment algorithms guided by PCT decreased the need for antibiotic treatment in approximately 50%. PCT is a promising test in clinical practice to decide the introduction of antibiotic therapy in addition to the existing tools, without neglecting the clinical assessment, with a significant decrease in costs.

Higher cut-off serum procalcitonin level for sepsis diagnosis in metastatic solid tumor patients

OBJECTIVE

The current study aimed to know procalcitonin levels in patients with metastatic tumor, and to discover the cut-off point for sepsis in this population. A cross-sectional study was conducted with patients with solid tumor. Sepsis and systemic inflammation response syndrome (SIRS) were identified using clinical, laboratory, and microbiological criteria. The cut-off point was determined using receiver operating characteristic (ROC) curve.

RESULTS

A total of 112 subjects enrolled in this study, 51% male, mean age 47.9 ± 12.47 years. Among 71 (63.4%) patients who had metastasis, 36 (32.1%) had sepsis and 6 (5.3%) experienced SIRS. In the absence of sepsis, the procalcitonin levels were significantly higher in patients with metastatic tumor compared to those without [0.25 ng/mL (0.07-1.76) vs. 0.09 ng/mL (0.03-0.54); p < 0.001]. The ROC curve showed that levels of procalcitonin for sepsis in metastatic solid tumors were in the area under curve (AUC) [0.956; CI 0.916-0.996]. Cut-off point of procalcitonin for sepsis was 1.14 ng/mL, Sn 86%, and Sp 88%. Thus, the results show that metastatic tumor affects the patients' procalcitonin level, even in the absence of sepsis. The cut-off point of procalcitonin level for diagnosing sepsis in the meta-static solid tumor was higher compared to the standard value.

Performance of procalcitonin in diagnosing parapneumonic pleural effusions: A clinical study and meta-analysis

BACKGROUND

Parapneumonic pleural effusion (PPE) is a common complication of pneumonia. The accurate diagnosis of PPE remains a challenge. Recent studies suggest that procalcitonin (PCT) emerges as a potential biomarker for PPE. Our study aimed to determine the diagnostic value of PCT for PPE by a clinical study and summarize the overall diagnostic performance of PCT through a meta-analysis.

METHODS

Demographic and clinical data of the patients with PPE and controls were collected in our clinical study. The diagnostic performances of serum PCT (s-PCT) were analyzed via receiver operating characteristic (ROC) curve analysis, using area under the curve (AUC) as a measure of accuracy. Literature databases were systematically searched for the studies examining the accuracy of PCT for diagnosing PPE. Data on sensitivity, specificity, positive/negative likelihood ratio (PLR/NLR), and diagnostic odds ratio (DOR) were pooled. Summary ROC curves and AUC were used to evaluate overall test performance.

RESULTS

In our clinical study, 47 patients with PPE and 101 controls were included. The s-PCT levels were significantly increased in the setting of PPE (5.44 ± 9.82 ng/mL) compared with malignant PE (0.15 ± 0.19 ng/mL), tuberculous PE (0.18 ± 0.16 ng/mL), and transudates (0.09 ± 0.03 ng/mL) (P < .001). Using a cutoff value of 0.195 ng/mL, the sensitivity and specificity of s-PCT in diagnosing PPE were 0.83 and 0.80, respectively, and AUC was 0.89. In addition, 11 studies were included in our meta-analysis. Summary performance estimates for s-PCT in diagnosing PPE were as follows: sensitivity, 0.78 (95% CI: 0.71-0.84); specificity, 0.74 (95% CI: 0.69-0.78); PLR, 3.46 (95% CI: 2.09-5.74); NLR, 0.27 (95% CI: 0.14-0.54); DOR, 12.37 (95% CI: 4.34-41.17); and AUC, 0.84. The corresponding estimates for p-PCT were as follows: sensitivity, 0.62 (95% CI: 0.57-0.67); specificity, 0.71 (95% CI: 0.68-0.75); PLR 2.31 (95% CI: 1.81-2.95); NLR, 0.47 (95% CI: 0.35-0.63); DOR, 5.48 (95% CI: 3.07-9.77); and AUC, 0.80.

CONCLUSION

Both s-PCT and p-PCT might have modest performance in diagnosing PPE. However, more studies on a large scale should be performed to confirm our findings.

Vascular endothelial growth factor and protein level in pleural effusion for differentiating malignant from benign pleural effusion

Pleural effusion is associated with multiple benign and malignant conditions. Currently no biomarkers differentiate malignant pleural effusion (MPE) and benign pleural effusion (BPE) sensitively and specifically. The present study identified a novel combination of biomarkers in pleural effusion for differentiating MPE from BPE by enrolling 75 patients, 34 with BPE and 41 with MPE. The levels of lactate dehydrogenase, glucose, protein, and total cell, neutrophil, monocyte and lymphocyte counts in the pleural effusion were measured. The concentrations of interleukin (IL)-1β, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, tumor necrosis factor-α, interferon γ, transforming growth factor-β1, colony stimulating factor 2, monocyte chemoattractant protein-1 and vascular endothelial growth factor (VEGF) were detected using cytometric bead arrays. Protein and VEGF levels differed significantly between patients with BPE and those with MPE. The optimal cutoff value of VEGF and protein was 214 pg/ml and 3.35 g/dl respectively, according to the receiver operating characteristic curve. A combination of VEGF >214 pg/ml and protein >3.35 g/dl in pleural effusion presented a sensitivity of 92.6% and an accuracy of 78.6% for MPE, but was not associated with a decreased survival rate. These results suggested that this novel combination strategy may provide useful biomarkers for predicting MPE and facilitating early diagnosis.

The role of serum procalcitonin in establishing the diagnosis and prognosis of pleural infection

Background

Bacterial pleural infection requires prompt identification to enable appropriate investigation and treatment. In contrast to commonly used biomarkers such as C-reactive protein (CRP) and white cell count (WCC), which can be raised due to non-infective inflammatory processes, procalcitonin (PCT) has been proposed as a specific biomarker of bacterial infection. The utility of PCT in this role is yet to be validated in a large prospective trial. This study aimed to identify whether serum PCT is superior to CRP and WCC in establishing the diagnosis of bacterial pleural infection.

Methods

Consecutive patients presenting to a tertiary pleural service between 2008 and 2013 were recruited to a well-established pleural disease study. Consent was obtained to store pleural fluid and relevant clinical information. Serum CRP, WCC and PCT were measured. A diagnosis was agreed upon by two independent consultants after a minimum of 12 months. The study was performed and reported according to the STARD reporting guidelines.

Results

80/425 patients enrolled in the trial had a unilateral pleural effusion secondary to infection. 10/80 (12.5%) patients had positive pleural fluid microbiology. Investigations for viral causes of effusion were not performed. ROC curve analysis of 425 adult patients with unilateral undiagnosed pleural effusions showed no statistically significant difference in the diagnostic utility of PCT (AUC 0.77), WCC (AUC 0.77) or CRP (AUC 0.85) for the identification of bacterial pleural infection. Serum procalcitonin >0.085 μg/l has a sensitivity, specificity, negative predictive value and positive predictive value of 0.69, 0.80, 0.46 and 0.91 respectively for the identification of pleural infection. The diagnostic utility of procalcitonin was not affected by prior antibiotic use (p = 0.80).

Conclusions

The study presents evidence that serum procalcitonin is not superior to CRP and WCC for the diagnosis of bacterial pleural infection. The study suggests routine procalcitonin testing in all patients with unilateral pleural effusion is not beneficial however further investigation may identify specific patient subsets that may benefit.

Trial registration

The trial was registered with the UK Clinical Research Network (UKCRN ID 8960). The trial was approved by the South West Regional Ethics Committee (Ethical approval number 08/H0102/11).

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-017-0501-5) contains supplementary material, which is available to authorized users.

Pleural fluid cell-free DNA in parapneumonic pleural effusion

OBJECTIVES

To measure the accuracy of pleural fluid cell-free DNA (cfDNA) concentration for diagnosis of parapneumonic pleural effusions (PPE).

DESIGN AND METHODS

We studied pleural fluids obtained by thoracocentesis in patients with pleural effusion. DNA was automatically extracted from pleural fluid using the MagNa Pure Compact instrument (Roche Diagnostics), and was measured by a real-time quantitative PCR assay for the β-globin gene using a Light-Cycler 480 Real-Time PCR instrument (Roche Diagnostics). Patients were classified into two groups according to the etiology of pleural effusion: PPE and NOT PPE. The diagnostic accuracy was determined using receiver operating characteristic (ROC) techniques by analyzing the area under the ROC curve (AUC).

RESULTS

We studied 78 patients with ages between 1 and 86 years old (median=64). Sixteen patients were PPE and 62 were NOT PPE (24 transudative, 30 malignant and 8 other etiology). Pleural fluid cfDNA concentration was higher in patients with PPE (median=46,240 ng/mL) than in those with NOT PPE (median=224 ng/mL). The AUC value was 0.907 (p<0.0001) and the optimal cut-off value was 6740 ng/mL exhibiting 87.5% sensitivity and 80.6% specificity. Also, there were significant differences between transudative and exudative effusions according to pleural fluid cfDNA concentration (p<0.0001). The AUC value was 0.994 and the optimal cut-off value was 162ng/mL exhibiting 100% sensitivity and 96.3% specificity.

CONCLUSIONS

Pleural fluid cfDNA concentration showed high accuracy for diagnosis of PPE and to discriminate between transudative and exudative effusions.

Discovery and verification of serum differential expression proteins for pulmonary tuberculosis

Pulmonary tuberculosis (PTB) is a chronic disease and has remained a severe threat to public health. Valuable biomarkers for improving the detection rate are crucial for controlling this disease. The purpose of this study was to discover potential biomarkers in sera from PTB patients compared with pneumonia patients and normal healthy controls. A total of 336 human serum specimens were enrolled in this study. Differentially expressed proteins were identified using iTRAQ method combining with MALDI-TOF-MS. Data was analyzed using relative bioinformatics methods. Potential biomarkers were further validated by IHC, ELISA and Western blot. As a result, 489 non-redundant proteins were identified in the sera, and 159 of which could be quantified by calculating their iTRAQ ratios. Compared to the controls, 26 differentially expressed proteins were recognized among PTB patients, including 16 overexpressed proteins and 10 downregulated proteins. Analysis of their functional interactions revealed that 12 proteins appeared in the center of the functional network. One of these key proteins, sex hormone binding globulin (SHBG), was found to be significantly elevated among PTB patients as compared with the controls examined by IHC, ELISA and Western blot. This result was consistent with the iTRAQ result. An independent blinded testing set to examine serum SHBG by ELISA achieved an accuracy of 78.74%, sensitivity of 75.6% and specificity of 91.5% in diagnosing PTB. In summary, iTRAQ in combination with MALDI-TOF-MS technology can efficiently screen differentially expressed proteins in sera from the PTB patients. SHBG is suggested to be a possible and novel serum biomarker for PTB.

Diagnostic tools of pleural effusion

Pleural effusion is not a rare disease in Korea. The diagnosis of pleural effusion is very difficult, even though the patients often complain of typical symptoms indicating of pleural diseases. Pleural effusion is characterized by the pleural cavity filled with transudative or exudative pleural fluids, and it is developed by various etiologies. The presence of pleural effusion can be confirmed by radiological studies including simple chest radiography, ultrasonography, or computed tomography. Identifying the causes of pleural effusions by pleural fluid analysis is essential for proper treatments. This review article provides information on the diagnostic approaches of pleural effusions and further suggested ways to confirm their various etiologies, by using the most recent journals for references.