In diffuse atrophic gastritis, routine histology underestimates Helicobacter pylori infection

The histologic detection of Helicobacter pylori in seropositive subjects is affected by pathology and secretory ability of the stomach

BACKGROUND

Helicobacter pylori is unevenly distributed in hypochlorhydric environments. The study aim was to elucidate the risk factors for a negative Giemsa staining finding in seropositive subjects by measuring the secretory ability of the stomach.

METHODS

Subjects aged over 18 years were included consecutively after endoscopic biopsy at gastric lesions with color or structural changes. Blood was sampled for the serum pepsinogen (PG) assay and H. pylori serology test. After excluding the subjects with past H. pylori eradication, the risk factors for a negative Giemsa staining finding in seropositive subjects were analyzed.

RESULTS

Among 872 included subjects, a discrepancy between the serum anti-H. pylori IgG and Giemsa staining findings was found in 158 (18.1%) subjects, including 145 Giemsa-negative, seropositive subjects. Gastric adenocarcinoma/adenoma (OR = 11.090, 95% CI = 3.490-35.236) and low serum PG II level (OR = 0.931, 95% CI = 0.899-0.963) were the independent risk factors for a negative Giemsa staining finding in seropositive subjects. The cutoff value of serum PG II level was 7.45 ng/mL (area under curve [AUC] = 0.904, 95% CI = 0.881-0.927). Follow-up studies of Giemsa staining at different sites of the stomach revealed that 75% of the Giemsa-negative seropositive subjects with adenocarcinoma are positive, whereas none of those with low serum PG II level of <7.45 ng/mL revealed positive findings.

CONCLUSIONS

The risk of a negative Giemsa staining finding in seropositive subjects is increased in gastric adenocarcinoma/adenoma specimens and in subjects with a diminished gastric secretory ability with low serum PG II level of <7.45 ng/mL. A false-negative Giemsa staining finding is common in subjects with adenocarcinoma, and therefore, additional biopsies at different sites should be performed in these subjects.

Link between Serum Pepsinogen Concentrations and Upper Gastrointestinal Endoscopic Findings

The serum pepsinogen (PG) assay findings are correlated with the status of Helicobacter pylori infection, but there are controversies on the link with upper gastrointestinal (UGI) endoscopic findings. The aim of this study was to determine the significance of a serum PG assay for correlating with endoscopic findings in H. pylori-seroprevalent adult population. Korean adults who visited for a health check-up were included consecutively. Subjects after gastrectomy or H. pylori eradication were excluded. After completing the serum PG assay and anti-H. pylori immunoglobulin G (IgG) titer on the same day of UGI endoscopy, subjects with equivocal serology test finding or gastric neoplasm were excluded. Of the 4,830 included subjects, 3,116 (64.5%) were seropositive for H. pylori. Seropositive finding was related to high serum PG I (P < 0.001) and PG II (P < 0.001) concentrations, low PG I/II ratio (P < 0.001), old age (P < 0.001), and male gender (P = 0.006). After adjusting age and gender, the serum PG I and II concentrations were positively correlated with the presence of nodular gastritis (NG) (all P = 0.003). The serum PG I was positively correlated with gastric ulcer (P = 0.003), and it was correlated with duodenal ulcer in seropositive subjects (P = 0.008). The PG I/II ratio was positively correlated with erosive esophagitis, while it was inversely related to chronic atrophic gastritis and metaplastic gastritis (all P < 0.001). Our findings suggest that the serum PG assay finding correlates well with the UGI endoscopic finding. A higher serum PG concentration in subjects with NG and peptic ulcer disease suggests that endoscopic findings reflect gastric secreting ability.

Investigation of mucosal pattern of gastric antrum using magnifying narrow-band imaging in patients with chronic atrophic fundic gastritis

BACKGROUND

Magnifying narrow-band imaging (M-NBI) can reportedly help predict the presence and distribution of atrophy and intestinal metaplasia in the gastric corpus. However, the micro-mucosal pattern of the antrum shown by M-NBI differs from that of the corpus. We studied the distribution and histology of the micro-mucosal pattern in the antrum based on magnifying endoscopy.

METHODS

Endoscopic images of the greater curvature of the antrum were evaluated in 50 patients with chronic atrophic fundic gastritis (CAFG). The extent of CAFG was evaluated by autofluorescence imaging. The micro-mucosal pattern was evaluated by M-NBI and classified into groove and white villiform types. The localization of white villiform type mucosa was classified into three types in relation to the areae gastricae: null, central, and segmental types. Biopsies were taken from regions showing different micro-mucosal patterns. Associations among the extent of CAFG, micro-mucosal pattern, and histology were examined.

RESULTS

As the extent of CAFG increased, the proportion of white villiform type mucosa increased, whereas that of groove type mucosa decreased (P=0.022). In patients with extensive CAFG, most of the areae gastricae was composed of the segmental or central type of white villiform type mucosa (P=0.044). The white villiform type mucosa had significantly higher grades of atrophy (P=0.002) and intestinal metaplasia (P<0.001) than did the groove type mucosa.

CONCLUSION

White villiform type mucosa is indicative of atrophy and intestinal metaplasia in the gastric antrum. It extends to the whole or central part of the areae gastricae as CAFG becomes more extensive.

Analysis of Gastric Microbiota by Pyrosequencing: Minor Role of Bacteria Other Than Helicobacter pylori in the Gastric Carcinogenesis

BACKGROUND

Little is known about the role of gastric microbiota except for Helicobacter pylori (HP) in human health and disease. We compared the differences of human gastric microbiota according to gastric cancer or control and HP infection status and assessed the role of bacteria other than HP.

METHODS

Gastric microbiota of 63 antral mucosal and 18 corpus mucosal samples were analyzed by bar-coded 454 pyrosequencing of the 16S rRNA gene. Antral samples were divided into four subgroups based on HP positivity in pyrosequencing and the presence of cancer. The analysis was focused on bacteria other than HP, especially nitrosating or nitrate-reducing bacteria (NB). The changes of NB in antral mucosa of 16 subjects were followed up.

RESULTS

The number of NB other than HP (non-HP-NB) was two times higher in the cancer groups than in the control groups, but it did not reach statistical significance. The number of non-HP-NB tends to increase over time, but this phenomenon was prevented by HP eradication in the HP-positive control group, but not in the HP-positive cancer group.

CONCLUSION

We could not find the significant role of bacteria other than HP in the gastric carcinogenesis.

Endoscopic gastritis, serum pepsinogen assay, and Helicobacter pylori infection

Endoscopic findings of the background gastric mucosa are important in the Helicobacter pylori-seroprevalent population. It is strongly correlated not only with the risk of gastric cancer, but also with the excretion ability of gastric mucosa cells. In noninfected subjects, common endoscopic findings are regular arrangement of collecting venules, chronic superficial gastritis, and erosive gastritis. In cases of active H. pylori infection, nodularity on the antrum, hemorrhagic spots on the fundus, and thickened gastric folds are common endoscopic findings. The secreting ability of the gastric mucosa cells is usually intact in both noninfected and actively infected stomachs, and the intragastric condition becomes hyperacidic upon inflammation. Increased serum pepsinogen II concentration correlates well with active H. pylori infection, and also indicates an increased risk of diffuse-type gastric cancer. In chronic inactive H. pylori infection, metaplastic gastritis and atrophic gastritis extending from the antrum (closed-type chronic atrophic gastritis) toward the corpus (open-type chronic atrophic gastritis) are common endoscopic findings. The intragastric environment is hypoacidic and the risk of intestinal-type gastric cancer is increased in such conditions. Furthermore, there is a decrease in serum pepsinogen I concentration when the secreting ability of the gastric mucosa cells is damaged. Serologic and endoscopic changes that occur upon H. pylori infection are important findings for estimating the secreting ability of the gastric mucosa cells, and could be applied for the secondary prevention of gastric cancer.

Endoscopic tri-modal imaging improves detection of gastric intestinal metaplasia among a high-risk patient population in Singapore

BACKGROUND

Detection of pre-neoplastic gastric mucosal changes and early gastric cancer (EGC) by white-light endoscopy (WLE) is often difficult. In this study we investigated whether combined autofluorescence imaging (AFI) and narrow band imaging (NBI) can improve detection of pre-neoplastic lesions and early gastric cancer in high-risk patients.

PATIENTS AND METHODS

Chinese patients who were 50-years-old or above with dyspepsia were examined by both high-resolution WLE and combined AFI followed by NBI (AFI-NBI), consecutively in a prospective randomized cross-over setting, by two experienced endoscopists. The primary outcome was diagnostic ability of the two methods for patients with pre-neoplastic lesions such as intestinal metaplasia (IM) and mucosal atrophy.

RESULTS

Sixty-five patients were recruited. One patient with large advanced gastric cancer was found and excluded from the analysis. Among the remaining 64 patients, 38 (59%) had IM; of these, 26 (68%) were correctly identified by AFI-NBI (sensitivity 68%, specificity 23%) and only 13 (34%) by WLE (sensitivity 34%, specificity 65%). AFI-NBI detected more patients with IM than did WLE (p=0.011). Thirty-one patients (48%) had mucosal atrophy. Ten patients (32%) were identified by AFI-NBI (sensitivity 32%, specificity 79%) and four patients (13%) by WLE (sensitivity 13%, specificity 88%) (p=0.100). No dysplasia or EGC was found.

CONCLUSION

AFI-NBI identified significantly more patients with IM than did WLE. Our result warrants further studies to define the role of combined AFI-NBI endoscopy for detection of precancerous conditions.

Screening and treating intermediate lesions to prevent gastric cancer

Early gastric cancer is defined as adenocarcinoma confined to the mucosa or submucosa irrespective of lymph node involvement. In Japan, mucosal high-grade neoplasia is diagnosed as intramucosal early gastric cancer. Some early gastric cancers progress to advanced gastric cancer after several years of follow-up. Image-enhanced endoscopy (chromoendoscopy), narrow-band imaging, and magnifying endoscopy increase the diagnostic yield in characterizing early gastric cancer. Endoscopic resection of intramucosal early gastric cancer with endoscopic mucosal resection or endoscopic submucosal dissection is currently performed in East Asian countries to prevent the development of advanced gastric cancer and preserve patients' quality of life after treatment.

Optimal biopsy site for Helicobacter pylori detection during endoscopic mucosectomy in patients with extensive gastric atrophy

BACKGROUND

Helicobacter pylori eradication is essential for metachronous gastric cancer prevention in patients undergoing endoscopic mucosectomy (EMR). This study was aimed to determine the optimal biopsy site for H. pylori detection in the atrophic remnant mucosa of EMR patients.

MATERIAL AND METHODS

Data were analyzed from 91 EMR patients. Three paired biopsies for histology were taken at antrum, corpus lesser (CLC), and greater curve (CGC). Additional specimens were obtained at antrum and CGC for rapid urease test (RUT). H. pylori infection was defined as at least two positive specimens on histology and/or RUT. Serologic atrophy was determined by pepsinogen levels.

RESULTS

Overall H. pylori infection rate was 72.5%. The proportions of moderate-to-marked atrophy/intestinal metaplasia at CGC (5.6/6.6%) were significantly lower than those at antrum (58.6/75.8%) and CLC (60.7/70.0%). Sensitivity of histology in detecting H. pylori was significantly higher at CGC than at antrum and CLC (84.8 vs 30.3 and 47.0%, respectively; p < .001). On RUT, detection at CGC also showed higher sensitivity than at antrum (77.3 vs 33.3%, p < .001). Specificities of all three biopsy sites were more than 90%. Regardless of serologic atrophy, CGC showed consistently higher sensitivities on histology and RUT. In patients with serologic atrophy, antral sensitivities were much lower than those of nonatrophic patients, 9.5 versus 40.0% on histology (p = .012) and 14.3 versus 42.2% on RUT (p = .025).

CONCLUSIONS

CGC is the optimal biopsy site for H. pylori diagnosis in EMR patients with extensive atrophy. Antral biopsy should be avoided, especially in serologically atrophic patients.

Comprehensive investigation of areae gastricae pattern in gastric corpus using magnifying narrow band imaging endoscopy in patients with chronic atrophic fundic gastritis

BACKGROUND

Barium radiographic studies have suggested the importance of evaluating areae gastricae pattern for the diagnosis of gastritis. Significance of endoscopic appearance of areae gastricae in the diagnosis of chronic atrophic fundic gastritis (CAFG) was investigated by image-enhanced endoscopy.

MATERIALS AND METHODS

 Endoscopic images of the corpus lesser curvature were studied in 50 patients with CAFG. Extent of CAFG was evaluated with autofluorescence imaging endoscopy. The areae gastricae pattern was evaluated with 0.2% indigo carmine chromoendoscopy. Micro-mucosal structure was examined with magnifying chromoendoscopy and narrow band imaging.

RESULTS

 In patients with small extent of CAFG, polygonal areae gastricae separated by a narrow intervening part of areae gastricae was observed, whereas in patients with wide extent of CAFG, the size of the areae gastricae decreased and the width of the intervening part of areae gastricae increased (p < 0.001). Most areae gastricae showed a foveola-type micro-mucosal structure (82.7%), while intervening part of areae gastricae had a groove-type structure (98.0%, p < 0.001). Groove-type mucosa had a higher grade of atrophy (p < 0.001) and intestinal metaplasia (p < 0.001) compared with foveola type.

CONCLUSIONS

 As extent of CAFG widened, multifocal groove-type mucosa that had high-grade atrophy and intestinal metaplasia developed among areae gastricae and increased along the intervening part of areae gastricae. Our observations facilitate our understanding of the development and progression of CAFG.

The COX-2-1195AA Genotype Is Associated with Diffuse-Type Gastric Cancer in Korea

BACKGROUND/AIMS

The potential role of the cyclooxygenase (COX)-2 polymorphism has been reported in relation to the risk of gastrointestinal tract malignancies. Therefore, we investigated whether COX-2 polymorphisms are associated with the risk of gastric cancer (GC) in Korea, one of the areas with a high prevalence of this condition.

METHODS

We evaluated the genotypic frequencies of COX-2-765 and -1195 in 100 peptic ulcer patients, 100 GC patients, and 100 healthy controls. The polymorphisms of the COX-2-765 and -1195 genes were analyzed by polymerase chain reaction and restriction fragment length polymorphisms.

RESULTS

The frequencies of the COX-2-1195 GG, GA, and AA genotype were 20%, 60%, and 20% in intestinal-type GC and 8%, 48%, and 44% in diffuse-type GC, respectively (p=0.021). There were no significant differences in the frequency of COX-2-765 genotypes between intestinal-type GC and diffuse-type GC (p=0.603). Age- and sex-adjusted logistic regression analysis showed that the COX-2-1195 AA genotype was the independent risk factor of diffuse-type GC compared with the COX-2-1195 GG genotype (p=0.041; odds ratio, 6.22; 95% confidence interval, 1.077 to 35.870).

CONCLUSIONS

The COX-2-1195 AA genotype may render subjects more susceptible to diffuse-type GC.

Helicobacter pylori-negative gastric cancer in South Korea: incidence and clinicopathologic characteristics

BACKGROUND AND AIM

It is difficult to determine the exact incidence rate of Helicobacter pylori (H. pylori) infection-negative gastric cancer (HPIN-GC) because H. pylori detection rates decrease with the progression of gastric atrophy and intestinal metaplasia. The aim of this study was to evaluate the incidence and clinicopathologic characteristics of HPIN-GC in South Korea.

METHODS

Helicobacter pylori infection status was evaluated by histology, a rapid urease test (CLO test), culturing, serology, and history of H. pylori eradication for 627 patients with gastric cancer. Current H. pylori infection was defined as positive results from histology, the CLO test, and culturing. Previous H. pylori infection was defined as negative in all three biopsy-based tests and positive serology or history of H. pylori eradication. Patients were considered to be negative for H. pylori infection if all results from five methods were negative. However, patients who were found to have severe gastric atrophy by the serum pepsinogen test or metaplastic gastric atrophy by histology were assumed to have had a previous H. pylori infection even if results from other tests for H. pylori infection were all negative.

RESULTS

The number of patients with gastric cancer with current or previous H. pylori infection was 439 (70.0%) and 154 (24.6%), respectively. The rate of HPIN-GC occurrence was 5.4% (n = 34). Sex, age, Lauren type, location of the tumor, and treatment modalities were not different according to H. pylori infection status. However, HPIN-GC had a more advanced pT classification (T3/T4; 51.9 vs 31.1%, p = .025) and a more advanced stage (more than stage I; 63 vs 41.3%, p = .027) than H. pylori-positive gastric cancer.

CONCLUSION

At least 5.4% cases of gastric cancer were H. pylori negative among South Korean patients. HPIN-GC looks like to have a poorer prognosis than H. pylori-positive cases.

The role of serum pepsinogen and gastrin test for the detection of gastric cancer in Korea

BACKGROUND AND AIM

This study was performed to determine whether serum pepsinogen (PG) and gastrin testing can be used to detect gastric cancer in Korea.

METHODS

Serum levels of PG I (sPGI) and sPGII, PG I/II ratios, and gastrin levels were measured in 1006 patients with gastroduodenal diseases including cancer. Follow-up tests were performed 1 year after Helicobacter pylori eradication.

RESULTS

sPGI and sPGII levels increased and PG I/II ratios decreased in line with the severity of activity, chronic inflammation, and the presence of H. pylori (p < .01). In contrast, sPGI levels and PG I/II ratios decreased in proportion with the severity of atrophic gastritis (AG)/intestinal metaplasia (p < .01). Gastrin levels were found to be correlated with chronic inflammation negatively in the antrum but positively in the corpus. H. pylori eradication reduced sPGI, sPGII, and gastrin levels, and increased PG I/II ratios to the levels of H. pylori-negative patients, and was found to be correlated with reductions in activity and chronic inflammation of gastritis. The sensitivity and specificity of a PG I/II ratio of < or = 3.0 for the detection of dysplasia or cancer were 55.8-62.3% and 61%, respectively. In addition, sPGI and sPGII levels of intestinal-type cancer were significantly lower than those of the diffuse type, respectively (p = .008 and p = .05, respectively). Gastric cancer risk was highest in the H. pylori-positive, low PGI/II ratio (< or = 3.0) group with an odds ratio of 5.52 (confidence interval: 2.83-10.77).

CONCLUSION

PG I/II ratio (< or = 3.0) was found to be a reliable marker for the detection of dysplasia or gastric cancer, especially of the intestinal type. This detection power of PG I/II ratio (< or = 3.0) significantly increased in the presence of H. pylori, and thus, provides a means of selecting those at high risk of developing gastric cancer in Korea.

Comparison between serology and histology in the diagnosis of advanced gastric body atrophy: a study in a Dutch primary community

GOALS

To assess serologically diagnosed gastric body atrophy (GBA) by histology in a sample of the general population.

BACKGROUND

GBA is a precursor lesion in gastric cancer. Data on GBA in a primary health care community in the Netherlands have not been reported.

STUDY

Thirty-four subjects of 997 consecutive adults from a Dutch family practice had serologic GBA, according to hypergastrinemia (>100 ng/L), hypopepsinogenemia A (<17 microg/L), and a low pepsinogen A/C ratio (<1.6). Two years later, 25 subjects of this group, agreed in serologic retesting and gastroscopy with biopsies for histologic assessment according to the Sydney system.

RESULTS

At serologic retesting, 20 of 25 subjects again fulfilled the serologic criteria of GBA. Histologic examination of the corpus biopsies showed advanced GBA in 18 subjects (75%) of 24 (1 subject had no corpus biopsies) and 17 of 19 (89%) subjects with repeated positive serology. After disclosure of serology results, reexamination of the biopsies revealed GBA also in the 2 patients with initially insufficient evidence of GBA, giving a concordance of 100% (19/19). One subject with normal serum gastrin at retesting had both antral and body atrophy giving a concordance between serologic and histologic GBA of 95% (19/20). No adenomatous polyps, tumors, or dysplastic alterations were found.

CONCLUSIONS

Identification by serology of asymptomatic patients with advanced GBA in primary care is adequately possible and useful in selecting for endoscopy.

Clinical usefulness of gastric-juice analysis in 2007: the stone that the builders rejected has become the cornerstone

BACKGROUND

Gastric juice is usually discarded during upper-GI endoscopy.

OBJECTIVE

By using a novel device, the Mt 21-42, we evaluated the potential of this important organic fluid in clinical practice, exploring its contribution to the diagnosis of Helicobacter pylori infection and atrophic gastritis of the oxyntic mucosa (AGOM).

DESIGN AND PATIENTS

A multicenter study (17,907 patients; 10 endoscopy units) estimated the frequency of diagnosis of AGOM and H pylori infection in routine endoscopic practice. A prospective study (216 patients) at 1 of these units aimed to determine the real prevalence of these conditions and the possible benefits of gastric juice analysis. We considered gastric juice pH and ammonium concentration, endoscopic and histologic features, serologic parameters for atrophy and H pylori, gastric acid secretion, and costs.

RESULTS

We found that H pylori infection and, even more markedly, AGOM were greatly underdiagnosed in routine endoscopic practice (20.1% and 0.8% vs 49.1% and 12.5% in the prospective study, respectively), because of the intrinsic limitations of the conventional tests and lack/inappropriateness of biopsy planning. Gastric-juice analysis proved to be a cheap, simple, and effective way to prevent such underdiagnosis and allowed detection of atrophic gastritis and H pylori in 96% and 98% of cases, and saved costs (cost-effectiveness ratio 209 vs 274-5047).

CONCLUSIONS

Gastric juice provided a valuable source of clinicopathologic information that, properly analyzed, allowed detection of the main risk factors for gastric cancer (H pylori and atrophic gastritis), overcoming the diagnostic limitations associated with these conditions and also producing time and cost savings.

Detection rate of Helicobacter pylori against a background of atrophic gastritis and/or intestinal metaplasia

BACKGROUND

To evaluate the detection rate of the CLOtest, Giemsa stain, and culture for the diagnosis of Helicobacter pylori organisms in patients with or without atrophic gastritis (AG) and/or intestinal metaplasia (IM).

METHODS

We used either the CLOtest, Giemsa staining, or culture to determine the presence of H. pylori in 430 participants who were documented to be infected with H. pylori from September 2003 to June 2006. The detection rates of the methods were evaluated according to the presence of AG and IM in antrum and body, which were classified using the updated Sydney system classification.

RESULTS

Positivity by the CLOtest markedly reduced depending on the degree of AG and IM in both antrum and body (P<0.05), and the positivity of Giemsa staining was markedly reduced as the degree of IM increased (P<0.01), but was not affected by the degree of AG (P=0.08) in antrum or body. When the results of these tests were evaluated in terms of combinations of AG and IM, the positivity of CLOtest was found to be lower in AG with IM than in AG without IM, (50.0% vs. 80.0% in antrum, 47.5% vs. 78.0% in body, respectively, P<0.01). In addition, the positivity of Giemsa stain was less frequent in AG with IM than in AG without IM in antrum (65.1% vs. 100%, respectively, P<0.01). However, the positivity of Giemsa stain in the body showed no statistical difference between AG without IM and AG with IM (97.6% vs. 91.7%, respectively).

CONCLUSIONS

Invasive H. pylori tests, especially the CLOtest, had a lower detection rate for H. pylori in the presence of mucosal atrophy and IM, and this became more prominent in the presence of higher levels of IM and AG.

Prevalência da infecção por Helicobacter pylori e das lesões precusoras do câncer gástrico em pacientes dispéticos

RACIONAL: A infecção pelo Helicobacter pylori é fator importante no desenvolvimento da carcinogênese gástrica, mas somente uma fração dos pacientes infectados irá desenvolver câncer gástrico. A infecção pelo H. pylori determina gastrite crônica não-atrófica, que pode evoluir para gastrite atrófica e metaplasia intestinal e, finalmente, para displasia e adenocarcinoma. OBJETIVO: Estudar a prevalência da infecção pelo H. pylori e das lesões precursoras de câncer gástrico e sua associação, em pacientes submetidos a endoscopia digestiva alta em serviço de referência da região central do Estado do Rio Grande do Sul. MÊTODOS: Foram analisadas retrospectivamente biopsias de corpo e antro gástrico obtidas de pacientes submetidos a endoscopia digestiva alta no período entre 1994 e 2003, nas quais foi realizada pesquisa de H. pylori. As lâminas foram coradas pelo método da hematoxilina-eosina e os achados histológicos foram classificados de acordo com o sistema de Sydney em mucosa normal, gastrite crônica não-atrófica, gastrite atrófica e metaplasia intestinal. As alterações histológicas encontradas foram relacionadas com a presença de infecção pelo H. pylori. RESULTADOS: Biopsias de 2.019 pacientes foram incluídas no estudo. A idade média dos pacientes foi de 52 (±15) anos e 59% eram do sexo feminino. A pesquisa de H. pylori foi positiva em 76% dos pacientes. Mucosa normal, gastrite crônica não-atrófica, gastrite atrófica e metaplasia intestinal foram diagnosticadas em 5%, 77%, 3% e 15% das biopsias, respectivamente. A infecção por H. pylori determinou uma razão de chances 10 vezes (IC95% 6.50 - 17%) maior de se encontrar algum grau de alteração histológica na mucosa gástrica. A razão de chances dos pacientes infectados apresentarem gastrite crônica não-atrófica, foi igual a 3 (IC95% 2,2 - 3,4). A razão de chances dos pacientes infectados apresentarem gastrite atrófica e metaplasia intestinal foi menor que 1. CONCLUSÃO: A prevalência da infecção por H. pylori foi alta (76%) e os indivíduos infectados apresentaram probabilidade 10 vezes maior para a ocorrência de lesão da mucosa gástrica. Gastrite crônica não-atrófica apresentou prevalência de 77%, gastrite atrófica 3% e metaplasia intestinal 15%. A infecção pelo H. pylori determinou uma probabilidade 3 vezes maior para o desenvolvimento de gastrite crônica não-atrófica e não determinou risco para a ocorrência de gastrite atrófica e metaplasia intestinal, sugerindo que possivelmente outros fatores de risco, além do H. pylori, estejam envolvidos no processo da carcinogênese gástrica.

Progression of atrophic gastritis and intestinal metaplasia drives Helicobacter pylori out of the gastric mucosa

This study was performed to evaluate the implication of anti-H. pylori IgG positivity when CLOtest, histological test, and culture in the antrum and body are all negative, and to find out the specific disease category that is more affected by the hostile relationship of atrophic gastritis and intestinal metaplasia (IM) with H. pylori. Four hundred thirty-six patients (84 controls, 69 with duodenal ulcer, 96 with benign gastric ulcer, 43 with dysplasia, 144 with gastric cancer), who had not received any eradication therapy, were divided into three groups according to H. pylori test: CLOtest or histological H. pylori-positive group (group A; 294 cases), only anti-H. pylori IgG-positive group (group B; 62 cases), and anti-H. pylori IgG-negative group (group C; 80 cases). The grade of neutrophil and monocyte infiltration, atrophic gastritis, and IM was compared according to the updated Sydney system classification. Neutrophil and monocyte infiltrations were significantly severe in the group A. In contrast, the grade of atrophic gastritis and IM in the antrum was significantly higher in group B than the other two groups, A or C. When patients were divided according to the disease outcome in each group, the grade of IM in the body was statistically higher only in the patients with cancer or dysplasia in group B. These results suggest that anti-H. pylori IgG positivity with all negative invasive H. pylori tests represents past infection with H. pylori rather than a false negative, especially in the case of dysplasia and gastric cancer.

The best method of detecting prior Helicobacter pylori infection

AIM

Prior Helicobacter pylori (H pylori) infection has often been underestimated. These underestimations have misled physicians attempting to determine the significance between H pylori and certain gastrointestinal lesions such as intestinal metaplasia, atrophic gastritis, and gastric cancer. Our study endeavored to detect past H pylori infections accurately, easily, and rapidly with the newly developed immunoblot kit, Helico Blot 2.1.

METHODS

Thirty-three patients, including 25 H pylori infected and 8 uninfected cases, were enrolled in our study. All patients received consecutive gastroendoscopic examinations and (13)C-urea breath test (UBT) tests at 6- or 12-mo intervals for up to 4 years. Serum samples were obtained from each patient at the same time. Intragastric H pylori infection was confirmed in accordance with the gold standard. Twenty-five H pylori-infected patients received triple therapies after initial bacterial confirmation, and were successful in eradicating their infections. Serially obtained sera were tested by means of Helico Blot 2.1.

RESULTS

Current infection marker detected by Helico Blot 2.1 was unreliable for representing ongoing H pylori infection. Only 35 and 37 ku antibodies of H pylori had significant seroconversion rates 1 year after having been cured. The seropositive rates of 116 ku (cytotoxin-associated antigen (CagA)) and Helico Blot 2.1 were nearly 100% during 4-year follow-up period. Both CagA antigen and Helico blot 2.1 could serve as indicators of long-term H pylori infection.

CONCLUSION

Helico Blot 2.1 can detect past H pylori infections for up to 4 years, and is the best method to date for detecting previous long-term H pylori infection.

Comparison of Helicobacter pylori infection and gastric mucosal histological features of gastric ulcer patients with chronic gastritis patients

AIM: To compare Helicobacter pylori infection and gastric mucosal histological features of gastric ulcer patients with chronic gastritis patients in different age groups and from different biopsy sites.

METHODS: The biopsy specimens were taken from the antrum, corpus and upper angulus of gastric ulcer and chronic gastritis patients. Giemsa staining, improved Toluidine-blue staining and H pylori-specific antibody immune staining were performed as appropriate for the histological diagnosis of H pylori infection. Hematoxylin-eosin staining was used for the histological diagnosis of activity of H pylori infection, mucosal inflammation, glandular atrophy and intestinal metaplasia and scored into four grades according to the Updated Sydney System.

RESULTS: Total rate of H pylori infection, mucosal inflammation, activity of H pylori infection, glandular atrophy and intestinal metaplasia in 3839 gastric ulcer patients (78.5%, 97.4%, 82.1%, 61.1% and 64.2%, respectively) were significantly higher than those in 4102 chronic gastritis patients (55.0%, 90.3%, 56.2%, 36.8%, and 37.0%, respectively, P<0.05). The rate of H pylori colonization of chronic gastritis in <30 years, 31-40 years, 41-50 years, 51-60 years, 61-70 years and >70 years age groups in antrum was 33.3%, 41.7%, 53.6%, 57.3%, 50.7%, 43.5%, respectively; in corpus, it was 32.6%, 41.9%, 53.8%, 60.2%, 58.0%, 54.8%, respectively; in angulus, it was 32.4%, 42.1%, 51.6%, 54.5%, 49.7%, 43.5%, respectively. The rate of H pylori colonization of gastric ulcer in <30 years, 31-40 years, 41-50 years, 51-60 years, 61-70 years and >70 years age groups in antrum was 60.5%, 79.9%, 80.9%, 66.8%, 59.6%, 45.6%, respectively; in corpus, it was 59.7%, 79.6%, 83.6%, 80.1%, 70.6%, 59.1%, respectively; in angulus, it was 61.3%, 77.8%, 75.3%, 68.8%, 59.7%, 45.8%, respectively. The rate of H pylori colonization at antrum was similar to corpus and angulus in patients, below 50 years, with chronic gastritis and in patients, below 40 years, with gastric ulcer. In the other age- groups, the rate of H pylori colonization was highest in corpus, lower in antrum and lowest in angulus (all P<0.05). The rates of glandular atrophy and intestinal metaplasia were higher and earlier in H pylori-positive patients than those without H pylori infection (both P<0.01). In comparison of gastric ulcer patients with chronic gastritis patients, the rate of glandular atrophy and intestinal metaplasia was higher in H pylori-positive patients with gastric ulcer than in H pylori-positive patients with chronic gastritis (both P<0.01); the rate of glandular atrophy and intestinal metaplasia were also higher in H pylori-negative patients with gastric ulcer than in H pylori-negative patients with chronic gastritis (both P<0.01). Both glandular atrophy and intestinal metaplasia were much more commonly identified in the angulus than in the antrum, lowest in corpus (all P<0.01).

CONCLUSION: Rate of H pylori infection, glandular atrophy and intestinal metaplasia in gastric ulcer were higher than in chronic gastritis in all-different age -groups. Distribution of H pylori colonization is pangastric in the younger patients. It is highest in corpus, lower in antrum and lowest in angulus in the older age groups. Progression of glandular atrophy and intestinal metaplasia seem to have a key role in the distribution of H pylori colonization. H pylori appears to be the most important risk factor for the development of glandular atrophy and intestinal metaplasia, but it is not the only risk.

Helicobacter pylori infection, glandular atrophy and intestinal metaplasia in superficial gastritis, gastric erosion, erosive gastritis, gastric ulcer and early gastric cancer

AIM: To evaluate the histological features of gastric mucosa, including Helicobacter pylori infection in patients with early gastric cancer and endoscopically found superficial gastritis, gastric erosion, erosive gastritis, gastric ulcer.

METHODS: The biopsy specimens were taken from the antrum, corpus and upper angulus of all the patients. Giemsa staining, improved toluidine-blue staining, and H pylori-specific antibody immune staining were performed as appropriate for the histological diagnosis of H pylori infection. Hematoxylin-eosin staining was used for the histological diagnosis of gastric mucosa inflammation, gastric glandular atrophy and intestinal metaplasia and scored into four grades according to the Updated Sydney System.

RESULTS: The overall prevalence of H pylori infection in superficial gastritis was 28.7%, in erosive gastritis 57.7%, in gastric erosion 63.3%, in gastric ulcer 80.8%, in early gastric cancer 52.4%. There was significant difference (P<0.05), except for the difference between early gastric cancer and erosive gastritis. H pylori infection rate in antrum, corpus, angulus of patients with superficial gastritis was 25.9%, 26.2%, 25.2%, respectively; in patients with erosive gastritis 46.9%, 53.5%, 49.0%, respectively; in patients with gastric erosion 52.4%, 61.5%, 52.4%, respectively; in patients with gastric ulcer 52.4%, 61.5%, 52.4%, respectively; in patients with early gastric cancer 35.0%, 50.7%, 34.6%, respectively. No significant difference was found among the different site biopsies in superficial gastritis, but in the other diseases the detected rates were higher in corpus biopsy (P<0.05). The grades of mononuclear cell infiltration and polymorphonuclear cell infiltration, in early gastric cancer patients, were significantly higher than that in superficial gastritis patients, lower than that in gastric erosion and gastric ulcer patients (P<0.01); however, there was no significant difference compared with erosive gastritis. The grades of mucosa glandular atrophy and intestinal metaplasia were significantly highest in early gastric cancer, lower in gastric ulcer, the next were erosive gastritis, gastric erosion, the lowest in superficial gastritis (P<0.01). Furthermore, 53.3% and 51.4% showed glandular atrophy and intestinal metaplasia in angular biopsy specimens, respectively; but only 40.3% and 39.9% were identified in antral biopsy, and 14.1% and 13.6% in corpus biopsy; therefore, the angulus was more reliable for the diagnosis of glandular atrophy and intestinal metaplasia compared with antrum and corpus (P<0.01). The positivity rate of glandular atrophy and intestinal metaplasia of superficial gastritis with H pylori-positivity was 50.7%, 34.1%; of erosive gastritis 76.1%, 63.0%; of gastric erosion 84.8%, 87.8%; of gastric ulcer 80.6%, 90.9%; and of early gastric cancer 85.5%, 85.3%, respectively. The positivity rate of glandular atrophy and intestinal metaplasia of superficial gastritis with H pylori-negativity was 9.9%, 6.9%; of erosive gastritis 42.5%, 42.1%; of gastric erosion 51.1%, 61.9%; of gastric ulcer 29.8%, 25.5%; and of early gastric cancer 84.0%, 86.0%, respectively. The positivity rate of glandular atrophy and intestinal metaplasia of superficial gastritis, erosive gastritis, gastric erosion, and gastric ulcer patients with H pylori positivity was significantly higher than those with H pylori negativity (P<0.01); however, there was no significant difference in patients with early gastric cancer with or without H pylori infection.

CONCLUSION: The progression of the gastric pre-cancerous lesions, glandular atrophy and intestinal metaplasia in superficial gastritis, gastric erosion, erosive gastritis and gastric ulcer was strongly related to H pylori infection. In depth studies are needed to evaluate whether eradication of H pylori infection will really diminish the risk of gastric cancer.

Diagnosis of Helicobacter pylori infection

Numerous studies are still published on diagnostic tests for Helicobacter pylori, essentially for noninvasive tests. The urea breath test is applied in different types of patients, and there are attempts to have quicker and simpler protocols. Stool tests using monoclonal antibodies are now evaluated while serology is still a subject of interest. The progress in PCR (multiplex PCR, real-time PCR) has also stimulated the research in this area of invasive tests, in order to get insight into virulence factors, macrolide susceptibility and to detect H. pylori in nonconventional specimens.