Diagnostic Accuracy of Ascitic Fluid IFN-γ and Adenosine Deaminase Assays in the Diagnosis of Tuberculous Ascites

Abstract

In this study, we evaluated the diagnostic accuracy and cost-effectiveness of ascitic fluid interferon-gamma (IFN-gamma) and adenosine deaminase (ADA) assays in the diagnosis of tuberculous ascites. Ascitic fluid from patients with proven tuberculosis (TB) (n = 31) and non-TB ascites (n = 88) was analyzed for IFN-gamma and ADA levels. Areas under the receiver operative characteristic (ROC) curves (AUCs) for the two biologic markers were compared. Levels of ascitic fluid IFN-gamma, median (range): 560 (104-1600) pg/mL vs. 4.85 (0-320) pg/mL (p < 0.001), and ADA, median (range): 58 (16-331) IU/L vs. 10 (0-59) IU/L (p = 0.001), were significantly different between TB and non-TB groups. IFN-gamma and ADA assays showed equal sensitivity (0.97) and differed marginally in specificity (0.97 vs. 0.94). Difference in AUCs was not significant (0.99 vs. 0.98, p < 0.62). For differentiating TB from non-TB ascites, optimal cutoff points were 112 pg/mL for IFN-gamma and 37 IU/L for ADA. The accuracy of the ADA assay was similar to that of the IFN-gamma assay in differentiating of TB from non-TB ascites. Because both material and human costs of the ADA assay are far less than those of the IFN-gamma assay, the former is probably the most appropriate diagnostic test for analysis of peritoneal fluid in resource- limited settings.

T-cell-based assays on cerebrospinal fluid and PBMCs for rapid diagnosis of TB meningitis in non-HIV patients

“…However, further prospective studies are needed to validate the practical use of this diagnostic scheme and more accurate diagnostic tests or strategies able to classify the remaining half of patients with suspected TBM need to be developed. In addition, some studies have reported that interferon (IFN)-c concentration measured in unstimulated body fluid supernatant, such as pleural fluid, pericardial fluid and ascitic fluid, was useful for diagnosing active tuberculosis [8][9][10]. Therefore, the comparison between unstimulated IFN-c concentration in CSF and IFN-c release assays using CSF-MC in patients with suspected TBM will be valuable.…”

On the use of Multivariate Receiver Operating Characteristic curve analysis with a special reference to Diagnostic Medicine

“…which play a predominant role in predicting the true status. The following are some of the research papers which address this scenario, Tosteson and Begg [26], Thompson and Zucchini [27], Toledano and Gatsonis [28], Pepe [29][30][31], Alonzo and Pepe [32], Faraggi [33], Dodd and Pepe [34], Cai and Pepe [35], Zhang and Pepe [36]. Further, another stream of work was initiated by assigning weights to each marker.…”

Modern Tools for Diagnosis in Tuberculous Ascites

“…The advantage of blood IGRA tests over tuberculin skin tests is the fact that IGRAs do not cross-react with the Bacillus of Calmete and Guérin (BCG) vaccine antigens, but suboptimal results can be possible in diagnosing EPTB because they aren't able to distinguish latent infection from active disease [27]. According to some researches, M. tuberculosis antigen-speciic T cells may accumulate at infection sites; therefore, investigating body luid IGRAs may increase the accuracy of EPTB diagnosis [28,29].…”