Comparison between the diagnostic validities of Xpert MTB/RIF and interferon-γ release assays for tuberculous pericarditis using pericardial tissue

Abstract

BackgroundThis study aimed to assess the diagnostic performance of Xpert MTB/RIF for tuberculous pericarditis (TBP) using pericardial tissues.MethodsThe study involved 30 patients admitted with suspected TBP from January–December 2016; three patients were later excluded. The interferon-γ release assay (T-SPOT.TB) and the Xpert MTB/RIF test were performed using peripheral blood and pericardial tissues, respectively. TBP was confirmed using pericardial histopathology and a composite reference standard (CRS). We analyzed the sensitivity, specificity, predictive value (PV), likelihood ratio (LR), and area under curve (AUC) of both assays.ResultsFourteen patients were confirmed as TBP, 10 as non-TBP, and 3 as probable TBP. The sensitivity, specificity, positive PV (PPV), negative PV (NPV), PLR, NLR, and AUC (95% confidence interval [CI]) of the Xpert MTB/RIF assay were 78.6% (49.2–95.3%) and 70.6% (44.0–89.7%); 92.3% (64.0–99.8%) and 100% (69.2–100%); 91.7% (61.5–99.8%) and 100% (73.5–100%); 80.0% (51.9–95.7%) and 66.7% (38.4–88.2%); 10.21 (1.52–68.49) and the PLR value was undefined with CRS as the reference; 0.23 (0.08–0.64) and 0.29(0.14–0.61); and 0.854 (0.666–0.959) and 0.853 (0.664–0.959), against histopathology and CRS, respectively. The sensitivity, specificity, PPV, NPV, PLR, NLR, and AUC values (95% CI) of T-SPOT.TB were 92.9% (66.1–99.8%) and 94.1% (71.3–99.9%); 15.4% (1.9–45.5%) and 20.0% (2.5–55.6%); 54.2% (32.8–74.5%) and 66.7% (44.7–84.4%); 66.7% (9.4–99.2%) and 66.7% (9.4–99.2%); 1.10 (0.83–1.44) and 1.18 (0.84–1.6); 0.46 (0.05–4.53) and 0.29 (0.03–2.85); and 0.541(0.340–0.733) and 0.571(0.367–0.758), against histopathology and CRS, respectively. The differences in sensitivity, PPV, and AUC of Xpert MTB/RIF and T-SPOT.TB were not statistically significant (P > 0.05), compared to those of histopathology and CRS. However, the differences in specificity and NPV of the two assays were significant (P < 0.05), compared to those of histopathology and CRS.ConclusionsXpert MTB/RIF test is a valid diagnostic technique for TBP with higher sensitivity and specificity than T-SPOT.TB.

Diagnostic values of Xpert MTB/RIF, T-SPOT.TB and adenosine deaminase for HIV-negative tuberculous pericarditis in a high burden setting: a prospective observational study

“…Diagnostic values of t-Spot.tB. In TBP patients, the frequency of SFCs was 229 per million PEMC (IQR, 86-492), which was significantly higher than in non-TB patients (14 [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] , P < 0.001). Evaluation of the efficiency of the T-SPOT.TB assay (cut-off point in current clinical use: 6 or more spots and twice the number of spots than the negative control well) showed that it had sensitivity, specificity, PPV, NPV, PLR, NLR, and DOR values of 92.3%, 87.9%, 81.8%, 95.1%, 7.6, 0.088, and 87.0, respectively (Table 2).…”

“…The reported positive rate of conventional MTB culture on PF was only 53%, and the sensitivity of pericardial biopsy varied from 10 to 64% 5 . In addition, pericardial biopsy was invasive, and the histopathological results were influenced by the location of the biopsy site, the quality of equipment, and the experience of physicians 14 . Thus, the number of false-positive cases might be overestimated when diagnostic tests are evaluated against culture or histopathology, leading to underestimation of specificity.…”

“…First, only 2 patients in our study were diagnosed by histopathology because pericardial biopsy was not routinely performed in most TB endemic settings. Using pericardial tissue might increase the sensitivity of Xpert 14 , but further studies are needed. Second, Xpert Ultra, the next-generation Xpert that has better capabilities for TB detection, was not evaluated in our study but had been shown to produce higher sensitivity than Xpert on pleural fluids 36 .…”

Diagnostic test accuracy of Xpert MTB/RIF for tuberculous pericarditis: a systematic review and meta-analysis

“…Figure 1 showed the flowchart of the research collection, while Table 1 provided a summary of the included studies. Of the nine studies included, three were carried out in Pakistan 10 , 13 , 15 , two were conducted in South Africa 12 , 14 , and the rest were carried out in Turkey 17 , Iran 9 , China 16 , and Spain 11 . All studies used a prospective observational design.…”

“…Regarding the risk of bias in the subject preference area, six studies 9 , 10 , 12 , 14 , 16 , 17 were labeled as low risk, two studies 13 , 15 were labeled as high risk, and one study 11 was labeled as an unclear risk because it did not explain the exclusion criteria clearly. The reason for the high risk of bias in this domain was due to inappropriate exclusion criteria.…”