Stool antigen tests in the diagnosis of Helicobacter pylori infection before and after eradication therapy

Table 1 Performance of the three stool antigen tests as compared with UBT and serology in 282 subjects at baseline

UBT, serology	HpSA		HpStAR	ImmunoCard
Positive 185	Positive	1701	178	172
	Negative	131	7	13
	2 gray zone2
Negative 97	Negative	93	93	86
	Positive	43	4	11

¹One subject originally had gray zone result.

²Gray zone result even in re-examination.

³Three subjects originally had gray zone results.

Table 2 Performance of the three stool antigen tests as compared with UBT and serology in 182 subjects after eradication therapy

UBT, serology	HpSA	HpStAR	ImmunoCard
Negative 166	Negative 1611	162	161
	Positive 4	4	5
	1 gray zone2
Positive 16	Positive 13	16	15
	Negative 33	0	1

¹Six subjects originally had gray zone result.

²Gray zone result even in re-examination.

³One subject originally had gray zone result.

Table 3 Performance of the three stool antigen tests at baseline

	Sensitivity	Specificity	PPV	NPV	Accuracy
	(%)	(%)	(%)	(%)	(%)
HpSA	91.9	95.9	97.7	87.7	93.3
HpStAR	96.2	95.9	97.8	93.0	96.1
ImmunoCard	93.0	88.7	94.0	86.9	91.5

PPV, positive predictive value; NPV, negative predictive value.

Table 4 Performance of the three stool antigen tests after eradication therapy

	Sensitivity	Specificity	PPV	NPV	Accuracy
	(%)	(%)	(%)	(%)	(%)
HpSA	81.3	97.0	76.5	98.2	95.6
HpStAR	100	97.6	80.0	100	97.8
ImmunoCard	93.8	97.0	75.0	99.4	96.7

PPV, positive predictive value; NPV, negative predictive value.