Link between Serum Pepsinogen Concentrations and Upper Gastrointestinal Endoscopic Findings

Serum pepsinogen level as a biomarker for atrophy, reflux esophagitis, and gastric cancer screening in Indonesia

Background

Chronic dyspepsia's symptoms are frequently seen in primary to tertiary healthcare in Indonesia. This study aimed to describe the potential usability of pepsinogen (PG) values in determining gastric mucosal conditions, including superficial gastritis and atrophic gastritis.

Materials and Methods

We recruited 646 adult dyspeptic patients and then analyzed PG values (including PGI, PGII, and PGI/II ratio) with endoscopic findings, gastric mucosal damages, and Helicobacter pylori infection. The gastric mucosal damage and H. pylori infection were evaluated using histological examination based on the updated Sydney system.

Results

Among 646 enrolled patients, 308 (47.2%), 212 (32.8%), 91 (14.1%), 34 (5.2%), and 1 (0.2%) patient were diagnosed with normal mucosa, gastritis, reflux esophagitis, peptic ulcer disease, and gastric cancer, respectively. Significant differences in PGI, PGII, and PGI/II ratio values were observed among ethnic groups (all P < 0.01). The PGI and PGII levels were significantly higher and PGI/II was significantly lower in H. pylori-infected patients than in uninfected ones (all P < 0.001). The optimal cutoff value for PGII and PGI/II was 12.45 ng/mL with an area under the curve (AUC) value of 0.755 (0.702-0.811), sensitivity 59.3%, and specificity 77.1%; and 4.75 with AUC value of 0.821 (0.763-0.855), sensitivity 81.5%, and specificity 78.7%, respectively, to determine moderate-severe atrophy.

Conclusion

Serum PG levels, a useful biomarker, represent the endoscopic findings, especially for reflux esophagitis. In addition, the benefits of PG values detecting atrophic gastritis were limited to moderate-severe atrophic gastritis. This usefulness requires careful attention for several ethnic groups in Indonesia.

Serum Assay Findings after Successful Helicobacter pylori Eradication

Serum pepsinogen (PG), anti-Helicobacter pylori (H. pylori) immunoglobulin G (IgG), and gastrin-17 (G-17) are plasma biomarkers for gastritis. H. pylori serology titers and PG levels increase during active H. pylori infection; moreover, elevated PG II levels indicate a high risk for diffuse-type gastric cancer in East Asian populations. Serum PG I/II ratios and PG I levels decrease with the progression of gastric corpus atrophy; thus, a combination of serum PG I levels ≤70 ng/mL and a PG I/II ratio ≤3 (serologic atrophy) indicates a high risk of intestinal-type gastric cancer. Serum G-17 is often not used as an indicator in H. pylori-seroprevalent populations because it is usually elevated in subjects with H. pylori infections. When H. pylori is eradicated, most patients show a rapid decrease in serum PG II levels and anti-H. pylori IgG titers within a few months. Seroreversion is required for several months to years after regression of H. pylori. Moreover, seroreversion may not always be achieved in all eradicated cases. The serum PG I/II ratio starts to increase after eradication; therefore, serologic atrophy improves accordingly, unless severe atrophy is present. Thus, some eradicated patients may show normal serum assay findings but have a higher risk for developing gastric cancer than H. pylori-naive subjects. Furthermore, serum PG levels decrease after gastrectomy and increase with the intake of certain drugs (e.g., aspirin or acid suppressants) or in renal failure patients. Due to such wide variations, serum assays are inadequate for the confirmation of H. pylori eradication. It is useful when interpreted with gastroscopy and other H. pylori test findings.

What Is New in Helicobacter pylori Diagnosis. An Overview

Helicobacter pylori infection remains one of the most prevalent infections worldwide, especially in low-resource countries, and the major risk factor for peptic ulcer and gastric cancer. The “test-and-treat” strategy is recommended by several guidelines and consensus. The choice of testing method is based on patient age, presence of alarm signs and/or symptoms, use of non-steroidal anti-inflammatory drugs, as well as local availability, test reliability, and cost. Culture is the gold standard to detect H. pylori and, possibly, to perform susceptibility testing, however, it requires upper endoscopy and dedicated labs. Recent advances in molecular biology have provided new strategies in detecting infection and antimicrobial resistance without invasive tests. In this review we attempt to offer a comprehensive panorama on the new diagnostic tools and their potential use in clinical settings, in order to accomplish specific recommendations.

Incidence of Infection among Subjects with Helicobacter pylori Seroconversion

Background/Aims

Helicobacter pylori (H. pylori) seroconversion may occur during screening for gastric cancer. Our study aimed to assess the number of seroconverted subjects with H. pylori and their results in follow-up tests.

Methods

Data were consecutively collected on subjects who were H. pylori-seronegative and presented for gastric cancer screening. Subjects who were followed up using the same serology test and pepsinogen (PG) assays on the day of endoscopy were included in the study.

Results

During the follow-up of 57.7 ± 21.4 months, 61 (15.0%) of 407 seronegative subjects showed seroconversion. H. pylori infection was detected in six (9.8%) of 61 seroconverted subjects. A diffuse red fundal appearance, with a significant increase in the Kyoto classification scores for gastritis, was observed in the infected subjects (p<0.001). Compared to the false-seropositive subjects, infected subjects showed higher serology titers (p<0.001) and PG II levels (p<0.001), and lower PG I/II ratios (p=0.002), in the follow-up tests.

Conclusions

Seroconversion occurred in 3.3% of seronegative subjects per year; however, only 9.8% had H. pylori infection. The majority (90.2%) of the seroconverted subjects showed false seropositivity without significant changes in the follow-up test results. The diffuse red fundal appearance could be an indicator of H. pylori infection.

Chronic atrophic gastritis: an update on diagnosis

Background and aim

Atrophic gastritis is a precancerous gastric lesion, therefore its early detection is a priority in preventing gastric cancer. The aim of the present paper is to develop a narrative synthesis of the present knowledge on diagnostic methods of chronic atrophic gastritis.

Methods

A literature search was carried out on main databases: PubMed, Hinari, SpringerLink and Scopus (Elsevier) for the period 2000–2020. The searched keywords were: chronic atrophic gastritis, intestinal metaplasia and dysplasia + diagnosis. Inclusion criteria were focused on the articles about the invasive and non-invasive diagnosis of chronic atrophic gastritis and of precancerous gastric lesions, intestinal metaplasia and dysplasia; exclusion criteria were articles published before 2000 and those that did not include the proposed theme.

Results

The search returned 575 papers addressing the topic of precancerous lesions. From these, 60 articles were qualified representative for the materials published on the topic of this synthesis article, being those that met the inclusion criteria. The data emphasize the need to use upper digestive endoscopy with biopsies for the diagnosis of chronic atrophic gastritis. However serological diagnosis is available as alternative mainly recommended in follow up.

Conclusions

There are two main methodological approaches for the evaluation of chronic atrophic gastritis as a precancerous gastric lesions: invasive examination, which requires histological analysis of biopsy samples taken during upper digestive endoscopy, being the “gold standard” for diagnosis, and non-invasive serological examination using markers of gastric function.

Preliminary Study on Reference Interval of Serum Pepsinogen in Healthy Subjects

OBJECTIVE

This study determined the reference interval of pepsinogen (PG) of healthy people in the local region to provide a basis for early screening of gastric cancer.

METHODS

Among the healthy people who underwent a physical examination in our hospital from January 2020 to December 2020, 2568 subjects were selected based on the relevant screening criteria. Their serum PG I and II levels and PG I:PG II ratio were determined by chemiluminescent microparticle immunoassay (CIMA), and the results were statistically analyzed. Finally, according to document CLSI-C28-A3, the PG reference interval of the local region was determined.

RESULTS

The PG I and II levels of the males in all age groups were higher than those of the females in the corresponding age groups, and the differences were statistically significant (P < 0.05). However, the differences in the PG I:PG II ratio between the genders in the different age groups were not statistically significant (P > 0.05). The PG I and II levels increased with age in both men and women, while the PG I:PG II ratio was not correlated with age in either gender.

CONCLUSION

The PG reference interval of the local region was initially determined as providing a reliable reference basis for clinical treatment.

Comparison of Serum Trefoil Factor-3 to Endoscopy in Diagnosing Helicobacter Pylori Associated Gastric Ulcer

Background and aim of the work:

Helicobacter pylori-associated gastric ulcer (H.pylori-GU) is a serious condition, not only because H.pylori is identified as a grade 1 carcinogen but also because GU is a precancerous condition. Identification and treatment of H.pylori-GU may prevent the sequential progression of dysplasia to carcinoma. Trefoil factor 3 (Tf3) has been implicated in gastric mucosal repair. We compared serum Tf3 to gastric endoscopy in diagnosing H.pylori-GU.

Subjects and methods:

The study included eighty patients suffering from H.pylori induced gastritis, forty of which presented with GU. Gastric endoscopy with slide urease test was used to diagnose H.pylori-GU. Serum Tf3 level was determined using an enzyme immunoassay in all patients as well as thirty healthy volunteers.

Results:

Serum Tf3 showed a significant stepwise decrease among the studied groups. It was significantly lower in patients compared to the control group (p<0.001). Furthermore, it was lower in those with GU compared to those without GU (p=0.023). Based on a receiver operating characteristic curve generated cut off value of 2.4 ng/mL, the diagnostic performance of serum Tf3 as a biomarker of H.pylori-GU revealed a diagnostic specificity of 42.5%, sensitivity of 67.5%, positive and negative predictive values of 54% and 56.67% respectively.

Conclusion:

Although serum Tf3 showed significant variation in H.pylori-GU, further studies are warranted to confirm its role in the pathogenesis of gastric ulcers.

ABC Classification Is Less Useful for Older Koreans Born before 1960

Background/Aims

In the ABC classification system, group A consists of seronegative subjects without gastric corpus atrophy. This study aimed to determine the prevalence and characteristics of pseudo group A subjects.

Methods

Group A subjects were identified among consecutive Korean adults who underwent a serum anti-Helicobacter pylori immunoglobulin G (IgG) test and pepsinogen (PG) assay on the day of endoscopy. Past infection was defined as the presence of either eradication history or endoscopic findings suggesting past infection (i.e., gastric xanthoma, metaplastic gastritis, or advanced atrophy >closed-type 1).

Results

Among 2,620 group A subjects, 448 (17.1%) had eradication history, and 133 (5.1%) showed endoscopic findings suggesting past infection. Older age (odds ratio [OR], 1.148; 95% confidence interval [CI], 1.067 to 1.236) and earlier year of birth (OR, 1.086; 95% CI, 1.009 to 1.168) were independent risk factors for classification into pseudo group A, with cutoff points at 50.5 years and birth year of 1959.5, respectively. Positive H. pylori test findings were found in 22 subjects (3.1%) among the 715 subjects who underwent the urea breath test or Giemsa staining on the same day. Current infection was positively correlated with PG I and PG II levels (p<0.001) but not with age, anti-H. pylori IgG titer, or classification into pseudo group A.

Conclusions

Among the group A subjects, 22.2% had past infection. The risk was higher in subjects older than 50 years, especially those born before 1960. Furthermore, current infection was found in 3.1% of the subjects and was correlated with increased gastric secretory ability.

[Nodular Gastritis as a Precursor Lesion of Atrophic and Metaplastic Gastritis]

Background/Aims

Chronic atrophic gastritis (CAG) and metaplastic gastritis (MG) are precancerous conditions of Helicobacter pylori (H. pylori)-related gastric cancer. This study aimed to identify the characteristics of nodular gastritis (NG) showing CAG or MG after nodule regression.

Methods

H. pylori-infected patients with NG were included after upper gastrointestinal endoscopy. Patients were excluded if their latest endoscopy had been performed ≤36 months after the initial diagnosis of NG. Small-granular-type NG was defined as the condition with 1-2 mm regular subepithelial nodules. Large-nodular-type NG was defined as those with 3-4 mm, irregular subepithelial nodules. The endoscopic findings after nodule regression were recorded.

Results

Among the 97 H. pylori-infected patients with NG, 61 showed nodule regression after a mean follow-up of 73.0±22.0 months. After nodule regression, 16 patients showed a salt-and-pepper appearance and/or transparent submucosal vessels, indicating CAG. Twenty-nine patients showed diffuse irregular elevations and/or whitish plaques, indicating MG. Sixteen patients with other endoscopic findings (14 normal, one erosive gastritis, and one chronic superficial gastritis) showed a higher proportion of H. pylori eradication (12/16, 75.0%) than those in the CAG group (5/16, 31.3%) and MG group (6/29, 20.7%; p=0.001). Patients with small-granular-type NG tended to progress toward CAG (14/27, 51.9%), whereas those with large-nodular-type NG tended to progress toward MG (25/34, 73.5%; p<0.001).

Conclusions

In patients with a persistent H. pylori infection, NG tended to progress to CAG or MG when the nodules regressed. Small-granular-type NG tended to progress to CAG, whereas large-nodular-type NG tended to progress to MG.

[Identification of Nodular Gastritis among Patients Diagnosed with Lymphofollicular Gastritis on a Gastric Biopsied Specimen]

Background/Aims

Nodular gastritis (NG) is a well-known endoscopic finding observed in patients with a Helicobacter pylori infection, which may lead to invasive gastric cancer. Lymphofollicular gastritis consists of lymphoid follicles or lymphoid cell aggregates, and is common in children. The aim of this study was to identify patients with NG from those in whom gastric biopsied specimens showed lymphoid follicles and lymphoid cell aggregates.

Methods

Subjects, whose gastric biopsy specimens showed lymphoid follicles or lymphoid cell aggregates, were included in this study. The inclusion criterion was that they underwent a serum pepsinogen assay on the day of upper gastrointestinal endoscopy. NG was diagnosed if the endoscopy findings revealed regular-sized, multiple, colorless subepithelial nodules.

Results

Among 108 subjects who showed lymphoid follicles or lymphoid cell aggregates, 13 (12.0%) revealed NG on endoscopy, and all these subjects showed positive Giemsa staining. Patients diagnosed with NG were younger (p=0.012) and showed a female predominance (p=0.001) compared to those without NG. The mean serum pepsinogen levels were higher (p=0.001) and lymphoid follicle-dominant subjects were more common (p<0.001) in the NG subjects than in those without NG. Logistic regression analysis revealed a younger age (p=0.041) and female gender (p=0.002) to be significant independent risk factors for NG.

Conclusions

NG should be distinguished from lymphofollicular gastritis because only 12% of patients showing gastric biopsy findings of lymphoid follicles and lymphoid cell aggregates demonstrated NG on endoscopy. NG is an endoscopic finding that is more common in women and in the younger population, irrespective of the biopsy findings and gastric secretory ability.

Diagnosis of Helicobacter pylori infection

The progress this year in Helicobacter pylori diagnosis concerned essentially endoscopy and molecular techniques. New endoscopy techniques such as blue laser imaging and magnifying narrow band imaging allow the visualization of mucosal aspects representing H. pylori infection, intestinal metaplasia, and even ambiguous early gastric cancer. Several real-time PCRs have also been used either to quantify H. pylori or to detect mutations associated with clarithromycin resistance in gastric biopsies or applied on gastric juice, stool specimens, or the oral cavity. The presence of H. pylori in free-living amebae purified from wastewater and drinking water was also determined by PCR and sequencing, as well as culture from a few wastewater samples. Among the noninvasive methods, the urea breath test was used in different conditions, including with a new test meal, which is claimed to avoid the proton-pump inhibitor washout period before testing. Several articles concerning antibody detection and stool antigen test were also published.

Training Effect on the Inter-observer Agreement in Endoscopic Diagnosis and Grading of Atrophic Gastritis according to Level of Endoscopic Experience

BACKGROUND

Endoscopic diagnosis of atrophic gastritis can contribute to risk stratification and thereby tailored screening for gastric cancer. We aimed to evaluate the effect of training on inter-observer agreement in diagnosis and grading of endoscopic atrophic gastritis (EAG) according to the level of endoscopists' experience.

METHODS

Twelve endoscopists (six less-experienced and six experienced) participated in this prospective study. The training session consisted of 1) four interventions with two-week intervals, and 2) a follow-up period (two follow-up assessments without feedback). EAG was categorized as C1 to O3 according to the Kimura-Takemoto classification. Kappa statistics were used to calculate inter-observer agreement.

RESULTS

At baseline, kappa indexes were 0.18 in the less-experienced group and 0.32 in the experienced group, respectively. After four interventions with feedback, the kappa index improved in both groups and was sustained during the follow-up period. Overall diagnostic yields of EAG were 43.1% ± 10.7% in pre-intervention and 46.8% ± 5.9% in post-intervention. Variability in the rate of diagnosis of EAG significantly decreased in the less-experienced group (r = 0.04, P = 0.003).

CONCLUSION

Irrespective of experience level, inter-observer agreement for diagnosis and grading of EAG improved after training and remained stable after intervention.