Table 4. Comparison of performance of the ALS assay between smear positive (C-1) and smear negative (C-2) TB cases.

TB Antigens		Sensitivity (95% CI)	Specificity (95% CI)	LR−	LR+
BCG	AFB+	91% (83%–95%)	88% (81%–93%)	0.10	7.58
	AFB−	88% (80%–93%)	88% (80%–93%)	0.14	7.33
LAM	AFB+	92% (84%–96%)	87% (80%–93%)	0.09	7.08
	AFB−	86% (78%–92%)	87% (79%–92%)	0.16	6.62
TB15.3	AFB+	87% (79%–92%)	86% (78%–92%)	0.15	6.21
	AFB−	71% (67%–82%)	86% (74%–90%)	0.34	5.07
TB51A	AFB+	88% (80%–93%)	86% (78%–92%)	0.14	6.29
	AFB−	79% (71%–86%)	86% (77%–91%)	0.24	5.64
CW	AFB+	89% (81%–93%)	84% (77%–90%)	0.13	5.56
	AFB−	79% (71%–87%)	84% (75%–89%)	0.25	4.94
CFP	AFB+	88% (80%–93%)	83% (75%–90%)	0.14	5.18
	AFB−	76% (69%–84%)	83% (74%–89%)	0.29	4.47
BCG and LAM	AFB+	93% (86%–96%)	89% (82%–94%)	0.08	8.45
	AFB−	87% (79%–92%)	89% (81%–94%)	0.15	7.91
All Ag	AFB+	92% (84%–96%)	88% (81%–93%)	0.09	7.67
	AFB−	88% (80%–93%)	88% (80%–93%)	0.14	7.33

BCG vaccine- glutamate-BCG vaccine for intradermal use, lot 1861, Japan BCG Laboratories, Japan; CFP10-ESAT6-A- fusion protein of Culture filtrate protein-10 and Early secretory antigenic target-6; TB51A, TB15.3 antigens from RD1 region; CFP− culture filtrate proteins and CW− cell wall fraction from M. tuberculosis H37Rv and clinical isolate CSU93; LAM− lipoarabinomannan of M. tuberculosis H37Rv. AFB+, sputum AFB smear positive; AFB−, sputum AFB smear negative. ALS titers are given from 48 hrs culture. The cut-off values for all antigens were very close (0.408 to 0.423) except for CFP10-ESAT6-A (0.397).