Serum Helicobacter pylori KatA and AhpC antibodies as novel biomarkers for gastric cancer

Table 1 Association between gastric cancer and seropositivity of catalase and alkyl hydroperoxide reductase antibodies in study subjects n (%)

Virulence factors serostatus	All subjects				H. pylori positive subjects				H. pylori negative subjects
	Case	Control	OR (95%CI)	P value1	Case	Control	OR (95%CI)	P value1	Case	Control	OR (95%CI)	P value1
KatA
Negative	78 (33.62)	228 (86.36)	1.0 (Reference)	< 0.001	47 (35.61)	104 (88.14)	1.0 (Reference)	< 0.001	26 (29.21)	109 (83.85)	1.0 (Reference)	< 0.001
Positive	154 (66.38)	36 (13.64)	12.84 (7.80-21.15)		85 (64.39)	14 (11.86)	14.59 (6.84-31.13)		63 (70.79)	21 (16.15)	12.15 (5.79-25.51)
AhpC
Negative	56 (24.14)	121 (45.83)	1.0 (Reference)	< 0.001	33 (25.00)	57 (48.31)	1.0 (Reference)	< 0.001	54 (54.00)	103 (70.55)	1.0 (Reference)	< 0.001
Positive	176 (75.86)	143 (54.17)	2.40 (1.55-3.73)		99 (75.00)	61 (51.69)	2.30 (1.25-4.23)		46 (46.00)	43 (29.45)	2.04 (1.10-3.78)
Combination of KatA and AhpC
Negative	78 (33.62)	226 (85.61)	1.0 (Reference)	< 0.001	49 (37.12)	104 (88.14)	1.0 (Reference)	< 0.001	33 (33.00)	127 (86.99)	1.0 (Reference)	< 0.001
Positive	154 (66.38)	38 (14.39)	11.64 (7.12-19.01)		83 (62.88)	14 (11.86)	13.40 (6.29-28.53)		67 (67.00)	19 (13.01)	13.91 (6.74-28.74)

¹The P value was obtained from logistic regression analysis adjusted for age, sex, family history of gastric cancer, smoking, and alcohol consumption. KatA: Catalase; AhpC: Alkyl hydroperoxide reductase.