Role of fibulin-3 in the diagnosis of malignant mesothelioma

Background: Early detection of malignant pleural mesothelioma (MPM)is critical to survival, the use of pleural or blood fibuin-3 might allow this early detection. Aim: studying the validity of measuring serum and pleural fibulin-3 in the diagnosis of MPM. Subjects & Methods: Fibulin-3 levels were measured in serum & pleural fluid by enzyme-linked immunosorbant assay (ELISA) in 45 patients with exudative pleural effusion. Patients with non-conclusive cytology or microbiological examination had undergone medical thoracosope for histopathological examination. Results: 25 were diagnosed as MPM, 11 cases as pleural metastasis of carcinoma (Mets) and 9 cases with benign pleural effusions. Patients with MPM had significantly higher pleural effusion and serum fibulin-3 levels than those with metastatic effusion of carcinoma or benign pleural effusion( p- value <0.001). Using a cut-off point of pleural fluid fibulin-3 (150 ng/ml) with AUC of 0.878 (sensitivity 72.3%, specificity 80) and at a cut-off point of serum fibulin-3 (66.5 ng/ml), with AUC of 0.776 (sensitivity 88%, specificity 81.8%), discrimination between MPM and Mets occured. Also, using a cut-off point of pleural fluid fibulin-3 (127.5 ng/ml) with AUC of 0.909 (sensitivity 88%, specificity 77.8%), and at a cut-off point of serum fibulin-3 (18 ng/ml), with AUC of 0.931 (sensitivity 100%, specificity 77.8%), discrimination between MPM and benign pleural effusion could occur. Conclusions: Fibulin-3 in the serum and pleural fluid is a good biomarker in the diagnosis of MPM and in differentiation between MPM from malignant pleural metastasis other than mesothelioma and also from benign pleural effusions.