Author's reply.

We would like to thank Wiwanitkit et al., for their interest in our study and their valuable observations.

In response to the authors’ comments about the reported lower predictive value of the adenosine deaminase (ADA) test in our article,[1] we want to clarify that as per our study, ADA is a valuable test to differentiate malignancy from TB. Our study showed that only three (8%) out of 36 cases of malignant pleural effusion had ADA ≥40 U/l.

We agree with the authors’ comments that ADA must be used along with the conventional method to get a diagnosis, as suggested by Islam et al.[2]

Khan et al.[3] has showed that use of the pleural fluid interferon-gamma can provide a better diagnostic result than ADA, but at a higher cost.[3] We would also like to quote from the meta-analysis by Greco et al., which showed that the joint sensitivity and specificity of ADA (93%) was similar to IFN-γ (96%) and no significant difference was present in the performance of both the tests in the diagnosis of TB pleurisy.[4]

We accept that we have not conducted a cost-effectiveness analysis for our study,[1] and it is improper to state in conclusion that the ADA test is cost-effective. Despite what has just been stated, it has been seen that the ADA test is less expensive than other invasive tests like the thoracoscopy-guided or blind pleural biopsy.