A novel biomarker for pleural effusion diagnosis: Interleukin‐36γ in pleural fluid

Abstract

Background Numerous studies have described the critical importance of interleukin (IL) ‐36γ in host defense against lung infections, but it is unknown whether it plays a role in infectious pleural effusion (IPE). This study aimed to examine the levels of IL‐36γ in pleural effusions of different etiologies and evaluate the diagnostic accuracy of IL‐36γ in the differential diagnosis of IPE. Methods A total of 112 individuals was enrolled in this research. IL‐36γ levels in pleural fluids of all 112 patients were measured by enzyme‐linked immunosorbent assay (ELISA). We also characterized these markers' diagnostic values across various groups. Results Patients with tuberculous pleural effusion (TPE) and parapneumonic effusion (PPE) had exhibited markedly higher IL‐36γ levels in their pleural fluid than the malignant pleural effusion (MPE) and transudative effusion patients. Furthermore, the IL‐36γ concentrations in TPE patients were evidently higher than in uncomplicated parapneumonic effusion (UPPE) patients but significantly lower than in complicated parapneumonic effusion (CPPE)/empyema patients. Pleural fluid IL‐36γ is a useful marker to differentiate TPE from UPPE, at a cut‐off value for 657.5 pg/ml (area under the curve = 0.904, p < 0.0001) with 70.0% sensitivity and 95.7% specificity. Conclusions The elevated IL‐36γ in pleural effusion may be used as a novel biomarker for infectious pleural effusion diagnosis, particularly in patients with CPPE/empyema, and is a potentially promising biomarker to differentiate between TPE and UPPE.

Thoracic empyema: aetiology, diagnosis, treatment, and prevention

“…Molecular methods such as PCR are increasingly used for culture negative empyema or suspected tuberculosis (TB) empyema, but novel markers are being discovered, which may help differentiate between different stages of infected pleural effusion. IL-36γ appears to be present in significantly higher quantities in TB pleural effusions and parapneumonic effusions compared to malignant pleural effusions and transudative effusions [10 ▪ ]. This novel biomarker is potentially promising in helping to differentiate TB-infected pleural effusions from other complicated pleural effusions, and perhaps may provide an early signal of a transudative or uncomplicated effusion progressing to being infected.…”

Infective Pleural Effusions—A Comprehensive Narrative Review Article

“…For instance, pleural fluid CRP has been thought of as a sensitive marker to discriminate between complicated and uncomplicated parapneumonic effusions; however, its use has not been universally implemented [ 39 ]. Factors such as Nicotinamide phosphoribosyltransferase (NAMPT), L-36γ, and pleural cytokines have been shown to improve diagnostic accuracy; however, their availability is limited to specialized centers [ 40 , 41 , 42 , 43 ]. Regardless, this diagnostic field is rapidly progressing and multiple other markers such as the carcinoembryonic antigen, vascular endothelial growth factor A, programmed death-ligand 1, neutrophil gelatinase-associated lipocalin, the triggering receptor expressed in myeloid cells type-1, gamma-interferon, and calprotectin were evaluated but did not demonstrate advantages over the classic parameters [ 44 ].…”