Original ContributionThe use of pleural fluid procalcitonin and C-reactive protein in the diagnosis of parapneumonic pleural effusions: a systemic review and meta-analysis☆
Introduction
Approximately 20% of patients with pneumonia may develop a parapneumonic pleural effusion, of whom 35% have empyema and 5.3% will ultimately need surgical intervention. Among those with parapneumonic effusion requiring surgical intervention, a mortality rate as high as 20% has been reported [1], [2], [3], [4], [5].
The diagnosis of a parapneumonic pleural effusion is not always straightforward, especially when patients have coexisting heart failure or malignancy [4], [6]. Conventional leukocyte counts, effusion cell and differential counts, and Light criteria did not provide adequate information [1], [2], [3], [4], [7], [8]. Microbiologic studies can provide more definitive results; however, the yield rate is only approximately 60%, and the long turnaround time may result in delayed diagnosis [3], [4], [9]. By contrast, unselective administration of broad-spectrum empirical antibiotics will result in the overuse of antibiotics and possible antibiotic resistance or Clostridium difficile infection.
Biomarkers of infection or inflammation, such as procalcitonin (PCT) and C-reactive protein (CRP), have been recently used to improve the diagnosis of parapneumonic effusion. C-reactive protein is an acute-phase reactant produced primarily by hepatocytes. Its production is induced by systemic inflammation of either infectious or noninfectious origin. The production of PCT, unlike that of CRP, is elevated only in response to bacterial infection but not to noninfectious inflammation or nonbacterial infection [10], [11]. The usefulness of PCT has been widely demonstrated in the diagnosis of sepsis and in the management of antibiotic use among patients with lower respiratory tract infection [12].
Only a few studies have investigated the diagnostic role of pleural fluid PCT or CRP in the etiology of pleural effusion, and these studies had relatively small sample sizes [3], [13], [14], [15], [16], [17]. To summarize current evidence on the use of pleural fluid PCT or CRP in the diagnosis of parapneumonic effusion, we performed a systemic review and meta-analysis.
Section snippets
Search strategy and selection criteria
We searched 3 electronic databases (MEDLINE, EMBASE, and Cochrane database) for studies published through December 2011 with the following Medical Subject Heading terms and free text: “pleural effusion,” “pleural fluid,” “pleurisy,” “biomarker,” and “procalcitonin.” We did not set any time or language restrictions for these searches. We checked the reference lists of relevant review articles. For comparison of diagnostic performance of pleural fluid PCT and CRP, we only include studies that
Identification of studies and their quality
Our initial search yielded 34 citations, of which 18 were excluded after abstract and title screening. We retrieved 16 studies for full-text reading, of which 6 met our inclusion criteria (Fig. 1). The 6 included studies were published from 3 countries between 2009 and 2011, and the studies included 780 patients (median, 74.5 [range, 41-308]) [3], [13], [14], [15], [16], [17]. Parapneumonic effusion was confirmed in 306 patients (overall prevalence, 39.2% [range, 12.0-67.3%]). Six [3], [13],
Discussion
Using pooled data from 6 studies comprising 760 patients, we found an only low-to-moderate diagnostic accuracy of pleural fluid PCT levels (AUROC = 0.71; 95% CI, 0.67-0.75) in predicting parapneumonic effusion among patients with pleural effusion of unknown origin. Pleural fluid CRP, although still having a low-to-moderate diagnostic value, appeared to have better diagnostic accuracy than PCT (AUROC = 0.83; 95% CI, 0.76-0.90), notably regarding its rule-in value (PCT LR+: 3.25 vs CRP LR+: 2.24).
Conclusion
The available evidence examining the diagnostic accuracy of pleural fluid PCT levels as a predictor of parapneumonic effusion is limited and does not allow for a firm conclusion. The pooled accuracy estimates of 6 different studies indicated only a low-to-moderate diagnostic value of pleural fluid PCT. Serum PCT appeared to have comparable diagnostic value with pleural fluid PCT, whereas pleural fluid CRP appeared to have a superior rule-in value to PCT in predicting infectious parapneumonic
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2022, ClinicsCitation Excerpt :In the previous study, PCT concentrations in serum and pleural fluid showed predictive roles in PPE patients.21 However, unexpected sensitivity and specificity of PCT in the diagnosis of PPE were concluded in a meta-analysis study.22 The present data found levels of PCT in serum levels in serum and in pleural fluid predicted PPE with AUC values (0.821 and 0782).
The Combined Use of Pleural Fluid Parameters Improves Diagnostic Accuracy in Complicated Pleural Infection/Empyema
2019, Archivos de BronconeumologiaManagement of Parapneumonic Pleural Effusion in Adults
2015, Archivos de BronconeumologiaCitation Excerpt :Moreover, if a CRP > 100 mg/l is accompanied by a pH < 7.20 or glucose < 60 mg/dl, the specificity for the diagnosis of CPPE is 97%.38 Although procalcitonin (PCT) values are high in bacterial infections, the advantage of determining this peptide in PF and its capacity to differentiate CPPEs from UPPEs remains unclear.39–42 Nevertheless, a recent study confirmed that PCT is a specific biomarker for infection, and that PCT levels are not affected by non-infectious inflammation.43
Procalcitonin: Potential role in diagnosis and management of sepsis
2015, Advances in Clinical ChemistryCitation Excerpt :It is likely to be more useful, therefore, when used within validated management algorithms. The limitations of the literature, including the heterogeneity of studies [17] and the variability of the gold standard [15,18], are other important considerations. In pediatric settings, existing studies of PCT used for identifying children with severe infection are limited by their quality, heterogeneity, and are heavily weighted to the emergency department setting.
Usefulness of pericardial and pleural fluids for the postmortem diagnosis of sepsis
2014, Journal of Forensic and Legal MedicineCitation Excerpt :In the clinical field, numerous studies have focused on pleural fluid PCT and CRP values in order to assess the diagnostic performance of these biomarkers in differentiating parapneumonic effusion in patients with pleural effusions.10–12 The results of a meta-analysis performed by Zou et al. revealed that both pleural fluid and serum PCT had low sensitivity and specificity to differentiate parapneumonic effusion from other etiologies of pleural effusion, whereas CRP had higher specificity, a higher positive likelihood ration and, thus, a higher rule-in value than PCT.10 Studies pertaining to sTREM-1 concentrations in the bronchoalveolar lavage fluid revealed increased concentrations in patients with pneumonia compared to control subjects.
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Conflict of interest: None declared.