Comparison of the Diagnostic Performance of Fibulin-3 and Mesothelin in Patients with Pleural Effusions from Malignant Mesothelioma

Background: In the literature, there exist conflicting data on the value of fibulin-3 (FBLN3) for the diagnosis of pleural effusion (PE) in malignant pleural mesothelioma (MPM). Therefore we compared the diagnostic performance of FBLN3 against that of soluble mesothelinrelated peptide (SMRP) in a cohort of Italian patients. Materials and Methods: FBLN3 and SMRP were detected in PE from 33 patients with MPM, 64 with pleural benign lesions and 23 with non-MPM pleural metastases using a commercial enzyme-linked-immunosorbent(ELISA)-assay kit according to manufacturers ' instructions. Results: Levels of FBLN3 were similar in PE from MPM and PE from other pathologies (geometric mean= 68.1 vs. 66.2 ng/ml; p= 0.872) in contrast to SMRP levels, which were significantly higher in PE from MPM (geometric mean= 14.6 vs. 3.2 nM; p < 0.001). Receiver operating characteristic analysis confirmed that SMRP showed a good performance (area under the curve= 0.79, p < 0.001), whereas FBLN3 was not able to discriminate MPM from other pathologies (area under the curve= 0.44, p= 0.838). Conclusion: FBLN3 detection in PE, in contrast to SMRP detection, is not useful as a biomarker for the diagnosis of PE from MPM.