Relationship of gastric Helicobacter pylori infection to Barrett’s esophagus and gastro-esophageal reflux disease in Chinese

Abstract

AIM: To evaluate the relationship of Helicobacter pylori infection to reflux esophagitis (RE), Barrett’s esophagus (BE) and gastric intestinal metaplasia (IM).

METHODS: RE, BE and gastric IM were determined by upper endoscopy. Patients were divided into 2 groups; those with squamocolumnar junction (SCJ) beyond gastroesophageal junction (GEJ) ≥ 3 cm (group A), and those with SCJ beyond GEJ < 3 cm (group B). Biopsy specimens were obtained endoscopically from just below the SCJ, gastric antrum along the greater and lesser curvature. Pathological changes and H pylori infection were determined by HE staining, Alcian blue staining and Giemsa staining.

RESULTS: The prevalence of H pylori infection was 46.93%. There was no difference in the prevalence between males and females. The prevalence of H pylori infection decreased stepwise significantly from RE grade I to III. There was no difference in the prevalence between the two groups, and between long-segment and short-segment BE. In distal stomach, prevalence of H pylori infection was significantly higher in patients with IM than those without IM.

CONCLUSION: There is a protective role of H pylori infection to GERD. There may be no relationship between H pylori infection of stomach and BE. H pylori infection is associated with the development of IM in the distal stomach.

INTRODUCTION

The incidence of adenocarcinoma in the esophagus and gastroesophageal junction (GEJ) is increasing, whereas the incidence of distal gastric cancer is falling for the two decades in North America, Europe, Japan and China. In China, the incidence of adenocarcinoma at the GEJ is increasing even more significantly[1-3].

The adenocarcinomas at the esophagus and GEJ differ from those in the stomach[4]. They share epidemiological characteristics with each other, and often originate from segments of Barrett’s esophagus (BE). It has therefore been proposed that both of them can be called “esophagocardia adenocarcinoma”[5]. BE is a well-defined premalignant condition for esophageal adenocarcinoma and most of adenocarcinomas at GEJ[6,7]. Neoplastic progression of BE has been shown to involve multiple steps with intestinal metaplasia and dysplasia serving as histopathologic markers[5]. It is considered that the absence of specialized intestinal metaplasia in many patients with adenocarcinoma at the GEJ may be due to the complete replacement of the metaplastic epithelium by the tumor, and in these tumors, IM usually is confined to ultrashort segments that may easily be overgrown by the tumor[8].

Gastro-esophageal reflux disease (GERD) can give rise to BE, and reflux symptoms are important indicators that a patient is at risk of having Barrett’s metaplasia. Recently, interest has focused on the relationship between H pylori infection and GERD as well as BE, but controversial findings have been obtained Several retrospective studies have examined the association of Barrett’s adenocarcinoma with gastric H pylori infection, yielding discordant results. It has been known that the prevalence of H pylori infection in China is high. It is necessary to clarify whether H pylori infection is the causally associated with BE or whether it has a protective effect on BE. In addition, further investigations are also required to clarify the relationship between H pylori infection and GERD. Therefore, the aim of this prospective study was to evaluate the relationship between gastric H pylori infection and reflux esophagitis (RE), BE, and gastric IM in China.

MATERIALS AND METHODS

Patients

Consecutive patients undergoing esophagogastroendoscopy at Second Hospital, Xi’an Jiaotong University, Xi’an, China from August 1, 2000 to the end of August 1, 2001 were included in the study. Exclusion criteria included previous gastric or esophagus resection, contraindication to performing biopsies, prior history of H pylori eradication therapy, and/or use of bismuth-containing compounds or antibiotics within the previous 4 weeks.The study was approved by the Ethics Committee of the hospital, and informed consents were obtained from all patients before entry.

Endoscopy and biopsy

Endoscopy was performed in a standardized manner by ex perien ced en doscop ists . The app earance o f the squamoucolumnar junction (SCJ) was carefully studied in the prograde view after insufflation of air and after retroversion in the stomach. According to the length from the GEJ to SCJ, patients were divided into two groups; those with velvety red gastric-like mucosa lining the distal esophagus for 3 cm or over (group A) and those with velvety red gastric-like mucosa lining the distal esophagus for less than 3 cm (group B). Endoscopic esophagitis was graded as I, mucosal erythema; II, non-circumferential mucosal breaks or erosions; III, circumferential erosion or ulcer.

Four-quadrant biopsies were taken from the area immediately distal to the SCJ. Additional targeted biopsies were also taken from erosions, nodules or ulcers. For assessment of H pylori status biopsies were taken from antral greater curvature (two), and lesser curvature (two).

Biopsy specimens were fixed in 40 g/L buffered formaldehyde, embedded in paraffin, serially sectioned, and then stained with hematoxylin and eosin. BE was defined as the presence of distended, barrel-shaped goblet cells, indicative of intestinal metaplasia[6,31,32], which was further confirmed by staining with Alcian blue pH2.5.

In addition, BE was divided into long-segment Barrett’s esophagus (LSBE, the segments of IM more than or equal to 3 cm in length) and short-segment Barrett’s esophagus (SSBE, the segment of IM less than 3 cm in length).

The presence of gastric H pylori infection was defined when one or more of Giemsa-stained gastric biopsy specimens demonstrated typical H pylori-like organisms.

The gastric IM was defined by the presence of barrel-shaped goblet cells.

Statistical analysis

Statistical analyses were performed using the Χ² test.

RESULTS

Altogether, 391 patients were recruited. Of these patients, 253 had esophageal disorders; 103 with RE (39 grade I, 35 grade II and 29 grade III), 120 with BE (26 LSBE and 94 SSBE), 12 with dysplasia (seven low–grade and five high-grade), 17 with adenocarcinoma at the GEJ and one with adenocarcinoma at lower esophagus (Table 1). Males were more likely to have esophageal disorders than females. The average age ranged from 52.41 to 62.64 years old, with and increased progressively from RE→BE→LGD→HGD→adenocarcinoma.

Table 1.

Clinic features of study population

	No.	Mean age (yr)	Male: Female
No. Of patients	391	52.41	211:180
RE I	39	52.12	26:13
II	35	53.67	26:9
III	29	55.56	24:5
BE SSBE	94	54.71	62:32
LSBE	26	58.66	20:6
Low-grade dysplasia	7	59.57	5:2
High-grade dysplasia	5	62.00	3:2
Adenocarcinoma at GEJ	17	62.64	14:3

Status of H pylori infection was available for 375 patients. The prevalence of H pylori infection was 46.93% (176/375). There was no significant difference in the prevalence between males and females (males, 48.71% and females, 45.00%) (P > 0.05) (Table 2). The prevalence of H pylori infection in Group A was 41.84% (41/98), which was slightly lower than that 48.73% (135/277) in group B (P > 0.05), The prevalence of H pylori infection decreased stepwise significantly from RE Grade I (51.72%), grade II (28.57%) to grade III (20.68%) (P < 0.05) (Table 2).

Table 2.

Comparisons of H pylori status among patients with sex, length of SCJ, grade of RE

	No.	Hp+ (%)	Hp- (%)	P
No. Of patients	375	(46.93)	(53.06)
Male: Female	195:180	95: 81	100:99	0.534
Group A	98	41 (41.84)	57 (58.16)	0.239
Group B	277	135 (48.73)	142 (51.26)
RE I	29	15 (51.72)	14 (48.28)	0.032
II	35	10 (28.57)	25 (41.43)
III	29	6 (20.68)	23 (79.31)

The prevalence of IM in group A (LSBE) (26.53%) was slightly lower than that in group B (SSBE) (33.94%) (P > 0.05). In groups A and B the prevalence of H pylori infection (46.15% and 51.06%, respectively) in patients with IM was slightly higher than that (40.27% and 47.54%, respectively) in those without IM (both P > 0.05) (Table 3). The prevalence of H pylori infection of LSBE (46.15%) is slightly lower than that of SSBE(51.06%) (P > 0.05). However, in the distal stomach, the prevalence of H pylori infection in patients with IM (56.29%) was significantly higher than that in those without IM (37.89%) (P < 0.05) (Table 3).

Table 3.

Comparisons of H pylori status between patients with IM in LSBE, SSBE and distal stomach

IM	Group A		Group B		Distal stomach
	+ (%)	_ (%)	+ (%)	_ (%)	+ (%)	_ (%)
HP+	12 (46.15)	29 (40.27)	48 (51.06)	87 (47.54)	76 (56.29)	97 (37.89)
HP-	14 (53.84)	43 (59.72)	46 (48.93)	96 (52.45)	59 (43.70)	159 (62.11)
Total	26	72	94	183	135	256

Comparision of H pylori status between LSBE (IM+ in group A) and SSBE (IM+ in group B), P = 0.658, (Χ² = 0.196); Comparision of H pylori status between IM “+” and IM “–” in group A, P = 0.603, (Χ² = 0.271); Comparision of H pylori status between IM “+” and IM “–” in group B, P = 0.579, (Χ² = 0.308); Comparision of H pylori status between IM “+” and IM“–” in distal stomach, P = 0.000, (Χ² = 12.14).

Comparision of H pylori status between LSBE (IM+ in group A) and SSBE (IM+ in group B), P = 0.658, (Χ² = 0.196); Comparision of H pylori status between IM “+” and IM “–” in group A, P = 0.603, (Χ² = 0.271); Comparision of H pylori status between IM “+” and IM “–” in group B, P = 0.579, (Χ² = 0.308); Comparision of H pylori status between IM “+” and IM“–” in distal stomach, P = 0.000, (Χ² = 12.14).

DISCUSSION

Since the isolation of H pylori from gastric mucosa by Warren and Marshall in 1983, there has been renewed interest in a possible bacterial cause of upper gastrointestinal diseases[9]. H pylori is now widely accepted as a major cause of antral gastritis and peptic ulcer disease[10,11]. Epidemiological evidence for an association with gastric carcinoma has also been reported[12,13]. In addition, gastric mucosa-associated lymphoid tissue (MALT) lymphoma has been linked to H pylori infection[14,15]. The relationship of H pylori to GERD and BE is less clear. Some groups have reported a lower prevalence of H pylori infection in individuals with GERD, and have postulated that infection may reduce the risk of reflux esophagitis[16-18]. However, other epidemiological studies have found little or no association between H pylori infection and GERD[19-21]. With regard to Barrett’s esophagus the majority of studies have found no association with H pylori infection[22,23]. However, there is also evidence to the contrary[18]. Our prospective study tried to evaluate the relation between gastric H pylori infection and RE, BE, and gastric IM in Chinese.

H pylori infection can be diagnosed by a variety of noninvasive or invasive tests. Histological examination with special staining of gastric biopsy specimens is accepted as the gold standard for H pylori diagnosis[24,25]. Gastric antrum is the most common place for H pylori colonization[26,27]. Modified Giemsa staining, which has been shown to have a high specificity and sensitivity[25,28], was used to detect H pylori status in this study.

In early studies, BE was defined as the presence of specialized IM in a columnar-lined mucosa encompassing more than 3 cm proximal to GEJ or a LSBE[29]. Any columnar-lined mucosa less than 3 cm above the GEJ was thought to be a normal variant. However studies over the past years have indicated that there is a spectrum of involvement that includes the distal 3 cm of esophagus or a SSBE[30,31]. What is important is the presence of IM relating to adenocarcinoma. It has been shown that a patient with LSBE has a higher risk to develop dysplasia or cancer[32]. It also has been shown that the development of LSBE is more closely related to gastresophageal reflux[33]. Therefore, in our study, patients were divided into two groups; those with a velvety red gastric-like mucosa lining the distal esophagus for 3 cm or over and those with a velvety red gastric-like mucosa lining the distal esophagus for less than 3 cm. Because esophageal hiatal hernia is often complicated by GERD and BE, many researchers think that to define an esophageal hiatal hernia, the presence of a velvety red gastric-like mucosa lining the distal esophagus for 2 cm should be considered as normal. In our study, therefore, we referred to this definition; the length from the GEJ to SCJ for esophageal hiatal hernia reduced 2 cm[34,35].

Altogether, 391 patients were evaluated over the course of the study (Table 1), The presence of IM was confirmed in 26 cases of the 98 patients suspected of having LSBE, and in 94 cases of the 277 patients suspected of having SSBE. Seven BE cases with dysplasia, 103 RE and 17 adenocarcinoma at GEJ were diagnosed. The average age of patients increased gradually with the sequence of RE, BE, LGD, HGD and adenocarcinoma at GEJ from 52.41 to 62.64 years old. Males were more likely to have the diseases. Cameron et al[36] reported that the age after 40 had a high incidence of BE, and development of adenocarcinoma from BE required about 20 years.

Of the entire study population, 375 subjects received histological examination for H pylori infection, with a prevalence of H pylori infection of 46.93%. There was no significant difference between males and females. These results are similar to the report by Hui et al[37] about H pylori infection in the same area of China.

The first change in BE, is the replacement of the normal stratified epithelium with metaplastic columnar epithelium in the distal esophagus, making the SCJ rising upward above the GEJ. It is accepted that BE is an acquired condition, and is related to gastro-esophageal reflux. An excellent overview and hypothesis detailing the role of H pylori infection in the pathogenesis of duodenal ulcer, gastric cancer, and GERD has been given by Graham and Yamaoka[38,39]. H pylori infection has been shown to decrease acid secretion in patients with body-predominant H pylori colonization[40]. With less acid production, the offensive potency of the refluxate may be reduced. An additional mechanism could be neutralization of acid by ammonia produced by H pylori, with subsequence reduction in intragastric acid load and in the reflux of acid into the esophagus, as proposed by Bercik et al[41]. Ammonia may also promote protective adaptation of the esophageal mucosa[42]. So, if H pylori infection can decrease the offensive potency of the refluxate, we could infer indirectly whether H pylori infection has the protective effect in GERD and BE by comparing the RE grade and the prevalence of H pylori infection in different length from the GEJ to the SCJ (i.e. between group A and group B). In our study there was no significant difference in the prevalence of H pylori infection between group A (41.84%) and group B 48.73%. Furthermore, the prevalence of H pylori infection decreased stepwise significantly from RE Grade I (51.72%), grade II (28.57%) to grade III (20.68%) (P = 0.032). These findings suggest that there is no relationship between gastric H pylori infection and GERD, although gastric H pylori infection had an apparent protective effect against the progression of GERD.

Barrett’s metaplasia is precancerous lesion of esophageal adenocarcinoma and most of adenocarcinoma at the GEJ. Progression from metaplasia, LGD, HGD to invasive cancer occurs in a stepwise process. It is unquestionably BE, especially LSBE, is linked with gastresophageal reflux. Our study shows that H pylori infection has the protective effect in GERD. But how about BE The present study demonstrated that there was no significant difference in IM prevalence between group A and group B. Marian et al[33] reported that the prevalence of LSBE was higher than that of SSBE and the prevalence of IM is directly proportional to the length of column-lined esophagus. This finding, which is different from ours, may explain the reason why the incidence of esophageal adenocarcinoma is on the increase in North America and Europe. However, in our study, the prevalence of SSBE was higher than that of LSBE, which may explain the reason why the incidence of adenocarcinoma at the GEJ is more common than that at the esophagus in China. There was no significant difference in the prevalence of H pylori infection between patients with and without IM in both group A and group B. Similarly, there was no significant difference in the prevalence of H pylori infection between LSBE and SSBE. However, in distal stomach, the prevalence of H pylori infection in patients with IM (56.29%) is much higher than that in those without IM (37.89%) (P < 0.001), which is in agreement with previous observations[22,23,43]. It is suggested that H pylori infection is associated with IM in the distal stomach, but may have no protective effect in BE. The distal gastric IM is thought to be less dangerous to progress to gastric carcinoma, and thus it is not suggested to supervise routinely the patients with distal gastric IM[44]. However, patients with BE has an overrated risk, about 30 to 125 times to progress to adenocarcinoma than patients without BE[45,46].

In conclusion, H pylori infection may have a protective role in GERD. There is no relationship between gastric H pylori infection and BE. H pylori infection is associated with IM in the distal stomach.