BioMed Research International

Research Article

Interferon-Gamma Release Assay Performance of Cerebrospinal Fluid and Peripheral Blood in Tuberculous Meningitis in China

Table 2

Diagnostic performance of PB T-SPOT.TB and CSF T-SPOT.TB in the study population ().
 Cut pointSensitivitySpecificityPPVNPVLR+LR−AUC
Definite and probable TBM compared with non-TBM         
 PB T-SPOT.TB/106 PBMC≥2490.6 
(79.3–96.9)		75.7 
(58.8–88.2)		84.2
(72.1–92.5)		84.8
(68.1–94.9)		3.72
(2.10–6.60)		0.12
(0.05–0.30)		0.89
(0.81–0.95)
 CSF T-SPOT.TB/106CSFMC≥20#60.8 
(46.1–74.2)		97.2 
(85.5–99.9)		96.9
(83.5–99.9)		63.6
(49.6–76.2)		21.88
(3.10–153.10)		0.40
(0.30–0.60)		0.81
(0.72–0.90)
 CSF/PB SFCs ratio≥0.02#66.7
(52.1–79.2)		86.1
(70.5–95.3)		87.2
(72.6–95.7)		64.6
(49.5–77.8)		4.80
(2.10–11.10)		0.39
(0.30–0.60)		0.77
(0.67–0.86)
 CSF and PB T-SPOT.TB positive—58.8
(44.2–72.4)		97.2
(85.5–99.9)		96.8
(82.9–99.9)		62.5
(48.5–75.1)		21.18
(3.00–148.30)		0.42
(0.30–0.60)		0.78
(0.68–0.86)
 CSF or PB T-SPOT.TB positive—92.5
(81.8–97.9)		75.0
(57.8–87.9)		84.5
(72.6–92.7)		87.1
(69.8–96.5)		3.70
(2.10–6.50)		0.10
(0.04–0.30)		0.84
(0.74–0.91)
Definite TBM () compared with non-TBM ()        
 PB T-SPOT.TB/106 PBMC≥2495.2 
(77.3–99.2)		83.8
(68.0–93.8)		76.9
(55.9–91.2)		96.9
(83.8–99.9)		5.87
(2.80–12.30)		0.06
(0.01–0.40)		0.93
(0.83–0.98)
 CSF T-SPOT.TB/106 CSFMC≥2061.9 
(40.9–79.3)		97.2
(85.5–99.9)		92.9
(66.1–99.8)		81.4
(66.4–91.7)		22.29
(3.10–158.50)		0.39
(0.20–0.70)		0.80
(0.67–0.89)
 CSF/PB SFCs ratio≥0.0261.9
(38.4–81.9)		86.1
(70.5–95.3)		72.2
(46.5–90.3)		79.5
(63.5–90.7)		4.46
(1.80–10.70)		0.44
(0.30–0.80)		0.76
(0.63–0.87)
Probable TBM () compared with non-TBM ()        
 PB T-SPOT.TB/106 PBMC≥2487.5 
(71.9–95.0)		83.8
(68.0–93.8)		82.4
(65.5–93.2)		88.6
(73.3–96.8)		5.40
(2.60–11.40)		0.15
(0.06–0.40)		0.87
(0.76–0.94)
 CSF T-SPOT.TB/106CSFMC≥2060.0 
(42.3–75.4)		97.2
(85.5–99.9)		94.7
(74.0–99.9)		74.5
(59.7–86.1)		21.6
(3.10–152.50)		0.41
(0.30–0.60)		0.82
(0.71–0.91)
 CSF/PB SFCs ratio≥0.0270.0
(50.6–85.3)		86.1
(70.5–95.3)		80.8
(60.6–93.4)		77.5
(61.5–89.2)		5.04
(2.20–11.80)		0.35
(0.20–0.60)		0.78
(0.66–0.87)
PBMC, peripheral blood mononuclear cells; CSF, cerebrospinal fluid; CSFMC, cerebrospinal fluid mononuclear cells; SFCs, spot forming cells; PPV, positive predictive value; NPV, negative predictive value; LR+, positive likelihood ratio; LR−, negative likelihood ratio; AUC, area under ROC curve.
#The cut-off of the parameters was established by a new ROC curve between TBM and non-TBM group.
There were 2 and 1 indeterminate CSF T-SPOT.TB results in TBM group and non-TBM group, respectively.
⁢, comparison of PB T-SPOT.TB and CSF T-SPOT.TB in TBM group; , comparison of PB T-SPOT.TB and CSF T-SPOT.TB in non-TBM group.
⁢, sensitivity comparison of PB T-SPOT.TB between definite TBM and probable TBM group.
⁢, sensitivity comparison of CSF T-SPOT.TB between definite TBM and probable TBM group.