Utility of a novel lipoarabinomannan assay for the diagnosis of tuberculous meningitis in a resource-poor high-HIV prevalence setting

Table 3 Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) values for PCR test and lipoarabinomannan (LAM) ELISA assay in patients with definite and probable tuberculous meningitis (TBM).

		Definite TBM (culture +ve), n = 14		Probable TBM, n = 23
		percentage	95% CI		95% CI
PCR	Sens	93	64 - 95	48	27 - 69
	Spec	77	46 - 94	77	46 - 94
	PPV	81	54 - 95	79	49 - 94
	NPV	91	57 - 100	46	25 - 67
LAM ELISA using 0.1 cut-off point^#	Sens	64	36 - 86	26	11 - 49
	Spec	62	32 - 85	62	32 - 85
	PPV	64	33 - 85	55	16 - 54
	NPV	62	36 - 86	32	25 - 82
LAM ELISA using AUC-derived 0.22 cut-off point^$	Sens	64	36 - 86	22	08 - 44
	Spec	69	39 - 90	69	39 - 90
	PPV	69	39 - 90	56	23 - 85
	NPV	64	36 - 86	33	17 - 54
	AUC	0.60	n/a	0.70	n/a

# the manufacturer-recommended cut-off point for testing of urine samples, 0.1; $ the area under the receiver operating curve-derived cut-point, 0.22.

ISSN: 2045-8118