Evaluation of pleural fluid YKL-40 as a marker of malignant pleural effusion

The glycoprotein YKL-40 is synthesized both by cancer cells and by tumor-associated macrophages and plays a functional role in tumor progression. Consequently, high serum YKL-40 levels have been associated with a poor prognosis in patients with several cancer types.The aim of this study is to assess pleural effusion and serum concentrations of YKL-40 in patients with different types of pleural effusions and to evaluate the diagnostic performance of YKL-40 in detecting malignant pleural effusion.Patients and methodsA prospective cohort study was carried out of 88 consecutive patients presenting with pleural effusions. The patients were divided into four groups: 22 patients with transudative effusions, 24 patients with parapneumonic pleural effusion and 8 patients with tuberculous pleural effusion and 34 patients with malignant pleural effusions. Blood and pleural fluid YKL-40 levels were measured using enzyme-linked immunosorbent assay.ResultsBoth serum HE4 levels and pleural effusion YKL-40 levels were significantly higher in patients with malignant effusions than in patients with transudative or non-malignant exudative effusions. A pleural fluid YKL-40 cut-off value of 256 ng/mL was found to predict malignant pleural effusions with a diagnostic sensitivity of 85.3% and specificity of 90.7%.ConclusionThe current study reports a finding of increased serum and pleural fluid YKL-40 levels in patients with malignant pleural effusions compared to non-malignant effusions.