Does the antibody production ability affect the serum anti-Helicobacter pylori IgG titer?

Table 1 Baseline characteristics of the included subjects n (%)

Variables	Subjects (n = 111)
Age (years old, mean ± SD)	55.3 ± 9.7
Gender (male:female)	66:45
Serum anti-H. pylori IgG titer (AU/mL, mean ± SD)	3.26 ± 0.97
Serum PG I level (ng/mL, mean ± SD)	72.0 ± 28.8
Serum PG II level (ng/mL, mean ± SD)	22.0 ± 9.2
Serum PG ratio (mean ± SD)	3.5 ± 1.2
Presence of corpus gastric atrophy as reflected by serum PG assay	23 (20.7)
Degree of H. pylori infiltration on biopsy
Mild	14 (12.6)
Moderate	23 (20.7)
Marked	74 (66.7)
Scores based on Updated Sydney system
Activity (mean ± SD)	1.92 ± 0.69
Chronic inflammation (mean ± SD)	2.04 ± 0.38
Atrophy (median with ranges)	0.97 (0-3)
Intestinal metaplasia (median with ranges)	0.64 (0-3)
Biopsied site
Antrum	69 (62.2)
Body or angle	36 (32.4)
Fundus or cardia	6 (5.4)
Serum HBsAb titer (mIU/mL, median with ranges)	102.19 (1-1000)
Positive HBsAb assay	78 (70.3)
Platelet (× 103/μL, mean ± SD)	235.3 ± 48.2
White blood cell count (× 103/μL, mean ± SD)	5853.8 ± 1595.9
Neutrophil (%)	56.0 ± 9.3
Lymphocyte (%)	36.4 ± 8.7
Monocyte (%)	4.7 ± 1.6
Eosinophil (%)	1.84 (0-13)
Basophil (%)	0.41 (0-5)

HBsAb: Hepatitis B surface antibody; PG: Pepsinogen; H. pylori: Helicobacter pylori.

Table 2 Characteristics of the subjects according to the degree of H. pylori infiltration on gastric biopsy n (%)

Variables	Mild H. pylori infiltration (n = 14)	Moderate H. pylori infiltration (n = 23)	Marked H. pylori infiltration (n = 74)	P value
Age (yr, mean ± SD)	54.7 ± 8.4	57.7 ± 12.0	54.7 ± 9.0	0.428
Gender (male)	6 (42.9)	16 (69.6)	44 (59.5)	0.276
Serum anti-H. pylori IgG titer (AU/mL)1	2.39 (0.36-4.00)	3.37 (1.86-4.00)	3.95 (0.82-4.00)	< 0.001
Serum PG I level (ng/mL, mean ± SD)	58.0 ± 19.3	75.5 ± 32.6	73.6 ± 28.7	0.146
Serum PG II level (ng/mL, mean ± SD)	15.6 ± 6.3	22.9 ± 9.5	22.9 ± 9.2	0.021
Serum PG I/II ratio (mean ± SD)	4.1 ± 1.7	3.4 ± 1.0	3.4 ± 1.1	0.118
Presence of corpus gastric atrophy as reflected by PG assay	3 (21.4)	5 (21.7)	15 (20.3)	0.986
Biopsied site (antrum:body or angle:fundus or cardia)	1:3:0	15:7:1	43:26:5	0.625
Scores based on Updated Sydney system
Activity (mean ± SD)	1.5 ± 0.7	1.9 ± 0.5	2.0 ± 0.7	0.034
Inflammation (mean ± SD)	1.9 ± 0.5	2.0 ± 0.2	2.1 ± 0.4	0.052
Atrophy (median with ranges)	0.8 (0-3)	1.3 (0-3)	0.9 (0-3)	0.589
Intestinal metaplasia (median with ranges)	0.6 (0-3)	0.9 (0-3)	0.6 (0-3)	0.771
Positive HBsAb finding	9 (64.3)	17 (73.9)	52 (70.3)	0.824
HBsAb titer (mIU/mL)1	174.9 (1-1000)	120.7 (1-1000)	86.8 (1-1000)	0.601
Platelet (× 103/μL, mean ± SD)	252.2 ± 41.9	231.9 ± 51.9	233.2 ± 48.1	0.375
White blood cell count (× 103/μL, mean ± SD)	5688.6 ± 1552.3	5780.0 ± 1390.9	5908.0 ± 1678.0	0.869
Neutrophil (%)	55.1 ± 9.3	54.9 ± 10.3	45.5 ± 9.1	0.702
Lymphocyte (%)	36.8 ± 8.7	37.0 ± 9.8	36.2 ± 8.4	0.919
Monocyte (%)	4.9 ± 1.6	4.9 ± 2.1	4.6 ± 1.5	0.732
Eosinophil (%)	2.4 (0-6)	2.0 (0-1)	1.8 (0-1)	0.819
Basophil (%)	0.4 (0-1)	0.5 (0-1)	0.4 (0-5)	0.771

¹Values are shown as median with ranges due to asymmetrical distribution. HBsAb: Hepatitis B surface antibody; PG: Pepsinogen; H. pylori: Helicobacter pylori.

Table 3 Correlation analysis for the serum anti-H. pylori IgG titer and serum HBsAb titer

Variables	Correlation coefficient	P value
Serum anti-H. pylori IgG titer
Old age	-0.009	0.924
Increased density of H. pylori infiltration	0.389	< 0.001
Increased serum PG I level	0.116	0.224
Increased serum PG II level	0.194	0.042
Increased serum PG I/II ratio	-0.18	0.059
Higher degree of activity	0.272	0.004
Higher degree of inflammation	0.125	0.192
Higher degree of atrophy	0.021	0.826
Higher degree of intestinal metaplasia	-0.047	0.624
Presence of gastric corpus atrophy as reflected by PG assay	-0.015	0.876
Increased HBsAb titer	-0.056	0.557
Increased platelet count	-0.061	0.522
Increased white blood cell count	-0.078	0.417
Serum HBsAb titer
Old age	-0.088	0.358
Increased density of H. pylori infiltration	-0.07	0.466
Increased serum PG I level	0.046	0.634
Increased serum PG II level	-0.054	0.572
Increased serum PG I/II ratio	0.136	0.154
Higher degree of activity	0.077	0.42
Higher degree of inflammation	-0.112	0.24
Higher degree of atrophy	0.036	0.706
Higher degree of intestinal metaplasia	0.054	0.573
Presence of gastric corpus atrophy as reflected by PG assay	-0.164	0.086
Increased platelet count	0.008	0.935
Increased white blood cell count	-0.069	0.473

HBsAb: Hepatitis B surface antibody; PG: Pepsinogen; H. pylori: Helicobacter pylori.

Table 4 Findings of the followed-up subjects n (%)

	Successful H. pylori eradication (n = 25)	Persistent H. pylori infection (n = 16)	P value	Before eradication	After eradication	P value (Z1)	Initial	Follow-up	P value
Initial test findings
Age (yr, mean ± SD)	52.3 ± 7.9	55.3 ± 12.7	0.351
Gender (male:female)	15:10	9:07	1
Degree of H. pylori infiltration on biopsy (mild:moderate: marked)	4:05:16	2:04:10	0.907
Anti-H. pylori IgG titer (AU/ mL, mean ± SD)	3.00 ± 1.17	3.17 ± 0.92	0.632
PG I level (ng/mL, mean ± SD)	79.3 ± 31.7	64.9 ± 23.4	0.126
PG II level (ng/mL, mean ± SD)	23.4 ± 8.5	18.9 ± 9.1	0.117
PG ratio (mean ± SD)	3.5 ± 1.1	3.9 ± 1.5	0.419
Presence of corpus gastric atrophy as reflected by serum PG assay	4 (16.0)	2 (12.5)	0.566
HBsAb titer (mIU/mL, median with ranges)	72.2 (3.1-1000)	170.3 (3.1-1000)	0.632
Positive HBsAb assay	16 (64)	12 (75)	0.513
Duration of the follow-up period (months, median with ranges)	18.1 (2-61)	20.2 (6-41)	0.887
Subjects with successful H. pylori eradication (n = 25)
Follow-up test findings
Degree of H. pylori infiltration on biopsy (none:mild:moderate: marked)				0:4:5:16	25:0:0:0	< 0.001 (-4.520)
Anti-H. pylori IgG assay (negative:lowest:middle:highest quartiles)2				3:2:14:6	20:4:1:0	< 0.001 (-4.171)
PG I level (ng/mL, mean ± SD)				79.3 ± 31.7	54.2 ± 14.5	0.028 (-2.201)
PG II level (ng/mL, mean ± SD)				23.4 ± 8.5	7.0 ± 1.7	0.028 (-2.201)
PG ratio (mean ± SD)				3.5 ± 1.1	7.8 ± 1.6	0.028 (-2.200)
HBsAb titer (mIU/mL, median with ranges)				72.5 (3.1-1000)	18.4 (3.1-1000)	0.308
Subjects with persistent H. pylori infection (n = 16)
Follow-up test findings
Degree of H. pylori infiltration on biopsy (none:mild:moderate: marked)							0:2:4:10	1:3:2:10	0.335
Anti-H. pylori IgG assay (negative:lowest:middle:highest quartiles)2							1:0:8:7	0:2:7:7	1.18
PG I level (ng/mL, mean ± SD)							64.9 ± 23.4	71.8 ± 35.2	1
PG II level (ng/mL, mean ± SD)							18.9 ± 9.1	21.4 ± 10.3	0.779
PG ratio (mean ± SD)							3.9 ± 1.5	3.6 ± 0.8	0.395
HBsAb titer (mIU/mL, median with ranges)							170.3 (3.1-1000)	202.1 (3.1-1000)	0.314

¹Z values are shown for the significant variables using Wilcoxon signed rank test;

²The serum anti-H. pylori IgG titer was compared using the quartiles because it was measured using the Vidas H. pylori IgG assay until 2012, and using the Chorus H. pylori IgG assay thereafter. SD: Standard deviation; HBsAb: Hepatitis B surface antibody; PG: Pepsinogen; H. pylori: Helicobacter pylori.