Diagnostic value of CD206⁺CD14⁺ macrophages in diagnosis of lung cancer originated malignant pleural effusion

Background: Pleural effusions are common complications of various diseases. Patients with malignant pleural effusion (MPE) usually face poor prognosis and short life expectancy. Discriminating between MPE and benign pleural effusion remains to be difficult. The aim of our current study was to evaluate whether CD206⁺CD14⁺ macrophages could be a diagnostic biomarker for MPE.
Methods: The percentages of CD14⁺, CD86⁺CD14⁺ and CD206⁺CD14⁺ macrophages in pleural effusions were determined by flow cytometry in 34 patients with MPE and 26 with benign pleural effusion, and their diagnostic performances were evaluated by receiver operating characteristic (ROC) curves.
Results: The percentages of CD14⁺, CD86⁺CD14+ and CD206⁺CD14⁺ macrophages were remarkably higher in MPE than in benign pleural effusion (all P<0.05). With a cutoff value of 39.8%, a high sensitivity of 88.2% and high specificity of 100.0% were found in CD206⁺CD14⁺ macrophages to diagnose MPE. The area under the curve, positive predictive value and negative predictive value of CD206⁺CD14⁺ macrophages were 0.980 (95% CI, 0.905 to 0.999), 100.0 (88.4 to 100.0) and 86.7 (69.3 to 96.2), respectively. The diagnostic performance of CD206⁺CD14⁺ macrophages was more accurate than those of CD14⁺ and CD86⁺CD14⁺ macrophages.
Conclusions: CD206⁺CD14⁺ macrophages could be used to discriminate MPE from benign pleural effusion.