The analytical and clinical aspects pleural fluid analysis

Abstract

Etiological diagnosis of pleural effusion (PE) remains a challenge for clinicians. Although thoracoscopy has high diagnostic accuracy in patients with undiagnosed PE, it has some limitations, such as invasiveness and the requirement for special training. Pleural fluid analysis shows a high diagnostic accuracy in undiagnosed PE. Compared with thoracoscopy, pleural fluid analysis has the advantages of noninvasiveness, low cost, no requirement for special training, and objectivity. PE can be categorized into transudate and exudate according to the underlying etiology. Transudates are caused by systemic disorders, such as cardiac failure and liver cirrhosis, and exudates are associated with local inflammation of the pleura. The first step in the etiological diagnosis of pleural effusion is separating transudates from exudates. The landmark work in separating exudates and transudate is the Light’s criteria (1). The most common causes of exudate are malignancy, pneumonia, and tuberculous pleurisy. Additional biomarkers beyond the Light’s criteria are needed to verify the underlying causes of exudate. In this special issue of pleural fluid analysis, some issues in the pleural fluid analysis were discussed. The diagnostic accuracy of tumor markers for malignant pleural effusion (MPE) is controversial, and the results from the available studies are always inconsistent. Consequently, systematic reviews and meta-analyses are needed to ascertain the diagnostic accuracy of a given marker. In this special issue, the diagnostic accuracy of pleural endostatin for MPE was investigated by a meta-analysis. The results indicate that the endostatin’s diagnostic accuracy for MPE is low (doi: 10.21037/ jlpm-20-91). Machine learning (ML) represents a novel and promising strategy for investigating the diagnostic accuracy of multiple biomarkers (2). A previous study showed that ML improved the diagnostic accuracy of conventional biomarkers for tuberculosis pleural effusion (TPE) (3). In this special the of for (MPM) was evaluated. to findings in indicated accuracy of tumor markers for MPM (doi: 10.21037/jlpm-20-90).