Comparison of Telomerase Activity between Malignant and Tuberculous Pleural Effusions
Kittipong Maneechotesuwan MD, PhD*, Aroon Lertworawiwat MD*, Jamsak Tscheikuna MD*, Valla Wamanuttajinda MSc**
Affiliation : * Division of Respiratory Diseases and Tuberculosis, Faculty of Medicine, Siriraj Hospital, Mahidol University ** Department of Pharmacology, Faculty of Medicine, Siriraj Hospital, Mahidol University
Objective : To determine if telomerase activity can differentiate malignant from tuberculous pleural effusions.
Design : Telomerase activity in malignant and tuberculous pleural effusions was measured in a blinded manner
using a PCR-based telomeric repeat amplification protocol (TRAP) assay.
Materials and Methods : Fifty-two patients with lymphocytic exudative pleural effusions were identified on
thoracocentasis over a period of 18 months
Results : Telomerase activity was detected in 34% of malignant pleural fluid samples and 50% of tuberculous
pleural effusions. The positive rate of telomerase activity was 30.7% for primary lung cancer and 37.5% for
metastatic pleural effusion. The sensitivity and specificity of telomerase activity assay were extremely low
(35.7% and 52.9%, respectively), compared with that of cytological examination (52.6% and 65.4%, respec-
tively). Moreover, the diagnostic accuracy of telomerase activity in combination with cytology was even lower
than cytological examination alone (46.7% vs. 60%, respectively). This finding was in contrast to previous
reports and demonstrated that the detection rate of telomerase activity in tuberculous pleural effusions was
greater than that observed in malignant pleural exudates.
Conclusion : Telomerase activity does not appear to be a useful marker for differentiating malignant from
tuberculous effusions
Keywords : Telomerase activity, Malignancy, Tuberculosis, Pleural effusion
