TELOMERASE ACTIVITY IN PLEURAL EFFUSIONS - DIAGNOSTIC-SIGNIFICANCE

Purpose: To determine the diagnostic value of pleural fluid telomerase activity in distinguishing a malignant from a nonmalignant pleural ef fusion in a cohort of patients undergoing thoracentesis. Patients and Methods: Using ct polymerase chain reaction (PCR)-based assay, telomer ase activity was examined in the pleural fluid cells obtained from 144 consecutive, unselected patients. According to the final diagnosis ac hieved, these patients were classified into three groups: group I cons isted of 70 malignant pleural effusions diagnosed by either fluid cyto logy or pleural biopsy, group II consisted of 52 nonmalignant pleural effusions, and another 22 samples were categorized to be suspicious ma lignant pleural effusions (group III) due to inconclusive results in e ffusion cytology and percutaneous pleural biopsy, but were strongly su spicious in clinical settings. Results: The presence of telomerase act ivity was observed in 64 of 70 samples in group I (91.4%), three of 52 samples in group II (5.8%), and 20 of 22 samples in group III. All th ree nonmalignant, telomerase-positive pleural effusion samples in grou p II were obtained from patients with tuberculosis. As a diagnostic cr iterion for malignant pleural effusion in group I and group II patient s, positive telomerase activity had a sensitivity of 91.4%, a specific ity of 94.2%, and a positive and negative predictive value of 0.96 and 0.89, respectively. Conclusion: Our results indicate that the detecti on of telomerase activity may be a useful adjunct to cytopathologic me thods in the diagnosis of malignant pleural effusions. (C) 1998 by Ame rican Society of Clinical Oncology.