Novel CagA ELISA exhibits enhanced sensitivity of Helicobacter pylori CagA antibody

Table 1 cagA genotype and clinical outcome of subjects

H. pylori infection status and cagA genotype	Gastritis	Peptic ulcer	GERD	Total
H. pylori-infected	95	12	3	110
Western cagA	34	4	0	38
East Asian cagA	61	8	3	72
H. pylori-uninfected	98	3	6	107
Total	193	15	9	217

GERD: Gastroesophageal reflux disease; H. pylori: Helicobacter pylori.

Table 2 Subject Helicobacter pylori-infection status

H. pylori status and cagA genotype	H. pylori infection status		cagA genotype
	Infected	Uninfected	Western	East Asian
ROC analysis group
n	110	107	38	72
Male	63 (57%)1	46 (43%)1	17 (45%)	46 (64%)
Age (yr)
mean ± SD	40.1 ± 12.9	38.5 ± 12.8	38.6 ± 10.8	41.0 ± 13.8
Range	18-76	19-78	18-69	21-76
Gastritis subjects group
n			34	61
Male			19 (56%)	38 (62%)
Age (yr)
mean ± SD			37.5 ± 8.5	39.3 ± 13.0
Range			22-60	20-70

¹Statistically significant between Helicobacter pylori (H. pylori) infected and uninfected status (P < 0.05).

Table 3 Association between cagA genotype and the accuracy of CagA antibody ELISA

Group name	n	Western-type CagA ELISA				East Asian-type CagA ELISA
cagA genotype		(cut off value: 6.25 U/mL)				(cut off value: 45.0 U/mL)
		Sens.	Sp.	AUC	95%CI	Sens.	Sp.	AUC	95%CI
Western and East Asian	110	62.7	97.2	0.87	0.82-0.92	70.9	93.5	0.91	0.86-0.95
Western	38	84.2	97.2	0.92	0.83-0.99	65.8	93.5	0.91	0.86-0.96
East Asian	72	51.41	97.2	0.85	0.79-0.91	73.61	93.5	0.90	0.85-0.95

¹Statistically significant between Western-type CagA ELISA and East Asian-type CagA ELISA (P < 0.001). n: The number of Helicobacter pylori (H. pylori) infected subjects; 107 H. pylori uninfected subjects were added for ROC analysis. Sens.: Sensitivity; Sp.: Specificity; AUC: Area under the curve.