Value of human epididymis secretory protein 4 in differentiating malignant from benign pleural effusion: an analysis of two cohorts.

BACKGROUND: Lung cancer is the most common cause of malignant pleural effusion (MPE). Serum human epididymis secretory protein 4 (HE4) is a useful diagnostic marker for lung cancer. OBJECTIVE: This study aimed to evaluate the diagnostic accuracy of pleural fluid HE4 for MPE. DESIGN: A prospective, double-blind diagnostic test accuracy study. METHODS: Patients with undiagnosed pleural effusion were enrolled in two cohorts (Hohhot and Changshu). Electrochemiluminescence immunoassay was used to detect pleural fluid HE4. The diagnostic accuracy of HE4 was evaluated by a receiver operating characteristic (ROC) curve, and the net benefit of HE4 was assessed by a decision curve analysis (DCA). RESULTS: A total of 66 MPEs and 86 benign pleural effusions (BPEs) were enrolled in the Hohhot cohort. In the Changshu cohort, 26 MPEs and 32 BPEs were enrolled. In both cohorts, MPEs had significantly higher pleural fluid HE4 than BPEs. The area under the ROC curve (AUC) of HE4 was 0.73 (95% CI: 0.64-0.81) in the Hohhot cohort and 0.79 (95% CI: 0.67-0.91) in the Changshu cohort. At a threshold of 1300 pmol/L, HE4 had sensitivities of 0.44 (95% CI: 0.33-0.56) in the Hohhot cohort and 0.54 (95% CI: 0.35-0.73) in the Changshu cohort. The corresponding specificities were 0.90 (95% CI: 0.83-0.95) in the Hohhot cohort and 0.94 (95% CI: 0.84-1.00) in the Changshu cohort. In subgroup analyses, HE4 had an AUC (95% CI) of 0.78 (0.71-0.85) in exudates and an AUC of 0.69 (0.57-0.81) in patients with negative effusion cytology. The DCA revealed that HE4 determination had a net benefit in both cohorts. CONCLUSION: Pleural fluid HE4 has moderate diagnostic accuracy for MPE and has net benefit in pleural effusion patients with unknown etiology.

Diagnostic value of nucleic acid amplification tests for tuberculous pleural effusion.

Diagnosing tuberculous pleural effusion (TPE) is challenging for pulmonologists and laboratory scientists. The gold standards for TPE diagnosis are pleural fluid Ziehl-Neelsen staining, Mycobacterium tuberculosis (Mtb) culture and pleural biopsy. These tools have limitations, including low sensitivity, long turnaround time and invasiveness. The nucleic acid amplification test (NAAT) is a rapid and minimally invasive tool for diagnosing TPE. This review summarizes the diagnostic accuracy of available NAATs for TPE, with a focus on the evidence from systematic reviews and meta-analyses. The NAATs summarized in this review include in-house NAATs, GeneXpert-MTB/RIF, GeneXpert-MTB/RIF Ultra, simultaneous amplification and testing-tuberculosis, FluoroType MTB and loop-mediated isothermal amplification.

Long-term stability of pleural fluid carcinoembryonic antigen and its effect on the diagnostic accuracy for malignant pleural effusion.

BACKGROUND: The in vitro stability assessment is essential for investigating the diagnostic accuracy of pleural biomarkers. This study aimed to investigate the long-term stability of pleural fluid carcinoembryonic antigen (CEA) at -80°C to -70°C. In addition, we analyzed the effects of frozen storage on the diagnostic accuracy of CEA for malignant pleural effusion (MPE). METHODS: Pleural fluid CEA of participants in two prospective cohorts were stored at -80°C to -70°C for 1-3 years. The CEA level in the stored specimen was measured with an immunoassay, and its level in the fresh specimen was extracted from medical records. The Bland-Altman method, Passing-Bablok regression, and Deming regression were used to analyze the agreement of CEA between the fresh and frozen pleural fluid. In addition, we used receiver operating characteristic (ROC) curves to evaluate the diagnostic accuracy of CEA in the fresh and frozen specimens for MPE. RESULTS: A total of 210 participants were enrolled. The median CEA levels in frozen and fresh pleural fluid specimens were similar (frozen, 2.32 ng/mL; fresh, 2.59 ng/mL; p < 0.01). The slopes and intercepts in the Passing-Bablok regression (intercept 0.01, slope 1.04) and Deming regression (intercept 0.65; slope 1.00) were not statistically significant (p > 0.05 for all). No significant difference was observed between the area under the ROC curves of CEA in the fresh and frozen specimens (p > 0.05 for all). CONCLUSION: Pleural fluid CEA is seemingly stable when stored at -80°C to -70°C for 1-3 years. Frozen storage does not significantly affect the diagnostic accuracy of CEA for MPE.

Pleural fluid soluble Fas ligand and tuberculous pleural effusion: a prospective diagnostic test accuracy study.

Background: The diagnosis of tuberculous pleural effusion (TPE) is challenging for pulmonologists. Adenosine deaminase (ADA), interferon-gamma (IFN-γ), and interleukin-27 (IL-27) have some limitations for diagnosing TPE. Soluble Fas ligand (sFasL) had a high diagnostic value for TPE. However, it remains unknown: (I) whether sFasL has an additional diagnostic value to the traditional markers (e.g., ADA); (II) whether sFasL provides a net benefit in patients with undiagnosed pleural effusion; (III) factors affecting the diagnostic accuracy of sFasL for TPE. This study aimed to evaluate the additional diagnostic value and benefit of pleural fluid sFasL for TPE. Methods: We prospectively enrolled 211 patients with undiagnosed pleural effusion. The concentration of sFasL in pleural fluid was measured by an enzyme-linked immunosorbent assay (ELISA). The diagnostic accuracy and net benefit of sFasL and ADA for TPE were analyzed by a receiver operating characteristic (ROC) curve, decision curve analysis (DCA), net reclassification improvement (NRI), and integrated discriminant improvement (IDI). Results: The area under the ROC curves (AUCs) of sFasL and ADA were 0.74 (95% CI: 0.65-0.83) and 0.80 (95% CI: 0.71-0.90), respectively. The decision curve of sFasL revealed net benefit. The continuous NRI and IDI of sFasL were 0.36 (0.00-0.72, P=0.05) and 0.02 (-0.01-0.06, P=0.18), respectively. Conclusions: Pleural fluid sFasL has moderate diagnostic accuracy for TPE.

Diagnostic utility of pleural cell-free nucleic acids in undiagnosed pleural effusions.

Pleural effusion (PE) is a common sign caused by various disorders. Microbiology, histology and cytology are reference standards for these disorders. However, these diagnostic tools have limitations, including invasiveness, high cost, long turnaround time, and observer-dependent. Soluble biomarkers in pleural fluid (PF) are promising diagnostic tools because they are mininvasive, economical, and objective. Recent studies have revealed that some cell-free nucleic acids (e.g., DNA, mRNA, microRNA, and lncRNA) in PF are potential diagnostic markers for many disorders. Here, we review the performance of PF cell-free nucleic acids for differentiating and stratification of PE.

Pleural homocysteine for malignant pleural effusion: A prospective and double-blind diagnostic test accuracy study.

OBJECTIVE: To assess the accuracy of pleural fluid homocysteine for discriminating malignant pleural effusion (MPE) and benign pleural effusion (BPE). METHODS: A total of 194 patients from two cohorts (Hohhot and Changshu) with undiagnosed pleural effusion were prospectively enrolled. Their pleural homocysteine was measured, and its diagnostic accuracy and net benefit for MPE were analyzed by receiver operating characteristic (ROC) curve analysis and decision curve analysis, respectively. RESULTS: In the Hohhot cohort (n = 136) and the Changshu cohort (n = 58), MPE patients had significantly higher homocysteine levels than BPE patients. The areas under the ROC curves of homocysteine for the diagnosis of MPE were 0.61 (p = 0.027) and 0.59 (p = 0.247), respectively. The decision curves of homocysteine were close to the reference line in both the Hohhot cohort and the Changshu cohort. CONCLUSION: The diagnostic accuracy of pleural fluid homocysteine for MPE was low.

Tumor cell-derived exosomal microRNA-146a promotes non-small cell lung cancer cell invasion and proliferation by inhibiting M1 macrophage polarization.

Background: Tumor-associated macrophages (TAMs) affects the outcomes of non-small cell lung cancer (NSCLC). NSCLC cells released exosomes to suppress the antitumor activity of TAMs. MiR-146a is a critical regulator in TAM polarization. We hypothesized that NSCLC cells released exosomal miR-146a to regulate TAM polarization and thus affected its antitumor activity. Methods: We used H1299 cells-derived exosomes to stimulate THP-1 cells that was pretreated with phorbol 12-myristate 13-acetate (M0 macrophage). Flow cytometry and reverse transcription-quantitative polymerase chain reaction (PCR) were used to determine the polarization of macrophages. The conditioned medium of exosome-treated M0 cells was used to culture H1299 cells, and the Cell Counting Kit-8, Ki67, transwell and scratch wound assays were used to determine the biological behavior of H1299 cells. To investigate whether exosomal miR-146a regulates TAM macrophages through targeting tumor necrosis factor receptor-associated factor 6 (TRAF-6) and interleukin-1 receptor-associated kinase 1 (IRAK-1), we used small interfering RNA to knockdown the expressions of them. Results: Upregulation of miR-146a inhibited M1 polarization and thus impaired the antitumor activity of TAMs. Exosomes released by H1299 cells can be taken by M0 macrophage, and they upregulated the expression of miR-146a in M0 macrophage. The exosome suppresses M1 polarization by exosomal miR-146a. TRAF-6 and IRAK-1 mediated the inhibitive effects of exosomal miR-146a on M1 polarization. Conclusions: NSCLC cells released exosomal miR-146a to inhibit the expressions of TRAF-6 and IRAK-1 in TAMs, resulting in the impaired antitumor activity of TAMs. NSCLC cell-derived exosomal miR-146a represents a novel therapeutic target for NSCLC treatment.