A comparison study of IFN-γ, ADA, and CA125 as the diagnostic parameters in tuberculous pleuritis

Adenosine deaminase in pleural fluid (pADA), CA125 in serum (sCA125), and IFN-γ in pleural fluid (pIFN-γ) were measured in patients with pleurisy of various causes to evaluate their diagnostic utility in tuberculous pleuritis (TBP). We studied 39 pleural fluid samples, including 11 TBP and 28 non-TBP. With both pADA and sCA125, although the median values were much higher in TBP than in non-TBP groups, there was considerable overlap between the two groups. The sensitivity, specificity, and diagnostic efficiency were 81·8%, 89·3%, and 87·2%, respectively, when pADA values of more than 45 U ml^-1 were considered, and they were 100%, 75·0%, and 84·2%, respectively, when sCA125 values of more than 35 U ml^-1 were considered. In contrast, pIFN-γ values were significantly higher in TBP patients (5·8 ± 3·0 IU ml^-1; mean ± s.d.) than those in non-TBP patients (<0·3 IU ml^-1), leading to both a sensitivity and a specificity of 100%.