Adenosine deaminase in exudative pleural effusions.

Sir,

The report on ‘Adenosine Deaminase in Exudative Pleural Effusions’ is very interesting.[1] Mehta et al. have concluded that ‘pleural fluid adenosine deaminase (ADA) is cost-effective and a good screening test for the diagnosis of tuberculosis (TB)’.[1] This conclusion must be carefully considered. First, the reported predictive values of the test, in the present report, are not good.[1] This finding is similar to that of a previous report by Khow-Ean et al.[2] As Islam et al. have noted, the test must be used along with the conventional method to get a diagnosis.[3] Khan et al. have also reported that the use of pleural fluid interferon-gamma can provide a better diagnostic result than ADA.[4] Second, Mehta et al. have not performed any analysis for cost-effectiveness, hence, the conclusion on cost-effectiveness may not be possible. A good report that has considered the cost-effectiveness analysis of using ADA is the previous report by Sharma et al.[5]