Clinical Impact and Reliability of Carbonic Anhydrase XII in the Differentiation of Malignant and Tuberculous Pleural Effusions

Abstract

Objective: To assess the practical utility of pleural fluid carbonic anhydrase XII (CAXII) quantification for differential diagnosis of effusions. Materials and Methods: Fluid was collected prospectively from fifty patients presenting with lymphocytic pleural effusions for investigation and CAXII was quantified by ELISA. Results: Pleural fluid CAXII concentrations were significantly higher in lung cancer patients (n=30) than in tuberculous controls (n=20). The sensitivity and specificity of this biomarker were 60%and 75%, respectively. CAXII measurement was not inferior to cytological examination in the diagnosis and exclusion of pleural effusions from lung cancer patitents (sensitivity 60% vs. 57%; specificity 75% vs. 100%; positive predictive value 77%; negative predictive value 54%). In patients with negative cytology, it offered a sensitivity of 54%. Conclusions: Pleural fluid CAXII is elevated in pleural effusions from lung cancer patients. Measurement of CAXII may be used in the future as a valuable adjunct to cytology in the diagnostic assessment of patients with pleural effusions related to lung cancer, especially when cytological examination is inconclusive.

Utility of Nuclear Morphometry in Effusion Cytology

“…Hence various ancillary techniques like immunocytochemistry, tumor markers, image morphometry, flow cytometry and others are being evaluated (Murugan et al, 2009;Krishan et al, 2010;Bunjhoo et al, 2012;Cheng et al, 2012;Kundu et al, 2012;Liu et al, 2013;Yildirim et al, 2013;Wang et al, 2013;2014). Computerised image analysis can estimate various parameters of the cells.…”

“…Cytological diagnosis of effusion fluids is an important investigation to determine the appropriate treatment.The distinction of reactive mesothelial cells from carcinoma cells can sometimes prove to be a diagnostic challenge even for the experienced cytopathologist. Hence there is an increasing need to develop cost-effective ancillary methods to enhance the accuracy of cytologic diagnosis (Murugan et al, 2009;Bunjhoo et al, 2012;Cheng et al, 2012;Liu et al, 2013;Yildirim et al, 2013;Wang et al, 2013;2014). Image morphometry is one such ancillary technique and often requires expensive software and hardware for image acquisition and analysis.…”