Characteristics of Helicobacter pylori-seropositive subjects according to the stool antigen test findings: a prospective study

Diagnostic value of IgG antibody and stool antigen tests for chronic Helicobacter pylori infections in Ibb Governorate, Yemen

The stool antigen test (SAT) and the serum Helicobacter pylori (H. pylori) IgG antibody assays exhibit significant utility in the clinical diagnosis of H. pylori infection and in distinguishing between acute and chronic infections. The main objective of the current study was to identify the diagnostic value of serum H. pylori IgG antibody and SAT in the detection of H. pylori infections among chronic H. pylori-infected patients residing in Ibb Governorate, Yemen. 200 patients with H. pylori infection, confirmed through positive results in the serum immunochromatographic antibody test, were selected for H. pylori infection confirmation using serum H. pylori IgG antibodies and SAT across diverse hospitals, gastroenterology, and Hepatology clinics in Ibb Governorate. After the selection of patients, blood and stool specimens were obtained from all participants and underwent analysis via the Statistical Package for the Social Sciences (SPSS). The prevalence of H. pylori infection demonstrated variability based on the confirmatory tests, with rates of 54% for SAT and 78.5% for serum H. pylori IgG antibody, contrasting with a 100% prevalence observed in the screening serum immunochromatographic antibody test. Clinically, the study categorized H. pylori infections into four stages, whereby a significant proportion of patients (40.5%) exhibited positivity for both serum H. pylori IgG antibody and SAT, indicative of active chronic infections. The majority of positive cases only manifested serum H. pylori IgG antibody presence (chronic infections) at 38%, whereas 13.5% exclusively tested positive for SAT, corresponding to acute infections. Moreover, 88% of patients did not have either serum H. pylori IgG antibody or SAT (absence of infections) during confirmatory tests. Noteworthy is the study's approach employing multiple tests for H. pylori infection detection, focusing predominantly on chronic infections-prevailing types caused by H. pylori. The results revealed a significant association between serum levels of H. pylori IgG antibody and SAT results with the presence of diverse gastrointestinal symptoms among patients, which increased with long H. pylori infection durations.

The clinical significance of some serum tumor markers among chronic patients with Helicobacter pylori infections in Ibb Governorate, Yemen

BACKGROUND

Helicobacter pylori (H. pylori) is a carcinogenic bacterium, it is the greatest risk factor for gastric cancer (GC), according to these evidences, there may be a certain association between chronic H. pylori infections and serum levels of tumor markers. This study was conducted to determine serum levels of some tumor markers, namely carcinoembryonic antigen (CEA), cancer antigen 19-9 (CA19-9) and cancer antigen 72-4 (CA72-4) in patients with chronic H. pylori infections and evaluate the association between serum tumor marker levels and chronic patients with H. pylori infections in Ibb Governorate, Yemen.

SUBJECTS AND METHODS

This study involved 200 patients who had been diagnosed with H. pylori infections using a serum immunochromatography antibody test. Stool and blood samples were collected from all patients to confirm the presence of H. pylori through detection of serum H. pylori IgG antibody and stool antigen test (SAT). Additionally, serum samples were analyzed to measurement the level of certain tumor markers CEA, CA19-9 and CA72-4. These tests were conducted at various Hospitals, Gastroenterology and Hepatology clinics in Ibb governorate, Yemen from October 2019 to November 2020.

RESULTS

The findings of current study showed that the prevalence of H. pylori infections by rapid anti H. pylori test were 200 (100%), 157 (78.5%) by serum H. pylori IgG antibody and 108 (54%) by SAT. In addition, the results showed that 42 (21%) of the patients had abnormal level of CEA, 30 (15%) had abnormal level of CA19-9 and 31 (15.5%) had abnormal level of CA72-4. Most importantly, the results indicated that the serum tumor marker levels CEA, CA19-9 and CA72-4 were correlated with the levels of serum H. pylori IgG antibody as well as positive results from the SAT (P < 0.05). Furthermore, the results indicated that serum tumor marker levels were associated with different infection status. Finally, the results indicated that the serum levels of tumor markers were associated with older ages, symptomatic patients and long duration of H. pylori infections (P < 0.05).

CONCLUSION

The findings of this study indicated that there is a significant association between chronic H. pylori infections and the serum levels of tumor markers (CEA, CA19-9 and CA72-4). This suggests that the patients with active chronic H. pylori infection may have an increased risk of developing GC. Therefore, monitoring and early detection of H. pylori infection and tumor markers levels in these patients may be crucial for identifying individuals at higher risk and implementing appropriate interventions.

Clinical Evaluation of a Novel Stool Antigen Test Using Bioluminescent Enzyme Immunoassay for Detecting Helicobacter pylori

BACKGROUND

BLEIA ™ "EIKEN" Helicobacter pylori antigen (B[EIA]) is based on the bioluminescent enzyme immunoassay (BLEIA) method that was newly developed with high sensitivity in detecting Helicobacter pylori (H. pylori) antigen in feces.

METHODS

In the project for H. pylori screening and treatment in Saga Prefecture in 2019, 141 students received the stool H. pylori antigen test as a secondary test. For 141 students, a comparative test was conducted between B (EIA) and extracorporeal diagnostic agents that were marketed in Japan as of 2019. The detection performance of H. pylori ATCC43504 standard strain and H. pylori antigen in commercial human fecal specimens were conducted.

RESULTS

The comparison of B (EIA) with Quick Chaser ^TM H. pylori (Q [IC]) revealed positive and negative concordance ratios of B (EIA) to Q (IC) of 100.0% (110/110) and 71.0% (22/31), respectively. A comparative test was conducted between B (EIA) and extracorporeal diagnostic agents that were marketed in Japan as of 2019, and B (EIA) was most sensitive on "detecting H. pylori antigen of ATCC43504 standard strain" and "detecting H. pylori antigen in commercial human fecal specimens," compared with other kits. Nine dissociated specimens that were negative for Q (IC) and positive for B (EIA) were confirmed. The measured value of B (EIA) in the dissociation samples were 1.3-87.4 cutoff index in the range that can be evaluated as negative by other fecal H. pylori antigen test kits, all the dissociation samples were H. pylori antigen-positive cases, and finally the cause of result divergence was presumed as false negative due to insufficient sensitivity of Q (IC).

CONCLUSION

B (EIA) that is based on the BLEIA method, which applies firefly luciferase luminescence, is more sensitive than stool antigen test kits that are currently marketed in Japan and is very useful in diagnosing H. pylori infection, especially in situations where noninvasive tests are preferred, such as in children.

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.

Methods for detection of Helicobacter pylori from stool sample: current options and developments

Accurate detection of Helicobacter pylori infection and determination of antibiotics have significant meaning in clinical practice. The detection methods can be categorized into two types, invasive and non-invasive, but nowadays we use the urease breath test most frequently which is non-invasive. However, many developing countries cannot meet the requirements for having specialized equipment and they lack trained personnel. Also, for the children, it is difficult to make them cooperate for the test. Methods that detect Helicobacter pylori from stool sample can be a promising alternative for detection used in children and mass screening. Stool antigen tests have several advantages such as rapidity, simplicity, and cheapness, though their results may be influenced by the heterogenicity of antigens, the nature of biochemical techniques, and the amount of antigen presented in the stool. PCR-based methods can specifically detect Helicobacter pylori infection and antibiotic resistance by targeting specific gene sequence, but they also are limited by the requirements of facilities and experts, the existence of inhibitory substance, and interference from the dead bacteria. Some novel methods also deserve our attention. Here we summarized the results of researches about methods using stool sample and we hope our work can help clinicians choose the appropriate test in clinical practice.

Relationship of delta over baseline with serum levels of gastrin 17, interleukin-32, and soluble interleukin 2 receptor and gastroscopic pathological changes in patients with chronic atrophic gastritis and Helicobacter pylori infection

BACKGROUND

Helicobacter pylori (H. pylori) is a recognized causative factor of gastric cancer. The diagnosis and treatment of chronic atrophic gastritis (CAG) and H. pylori infection have always been the focus of clinical research.

AIM

To investigate the relationship of the delta over baseline (DOB) and serum gastrin 17 (G-17), interleukin-32 (IL-32), soluble interleukin 2 receptor (sIL-2R) levels and gastroscopic pathological changes in patients with CAG and H. pylori infection.

METHODS

A total of 224 CAG patients at the Physical Examination Center of Wenzhou Central Hospital from January 2017 to December 2019 were selected as the research subjects, including 124 patients with H. pylori infection as an observation group, and 100 patients without H. pylori infection as a control group. The clinical data, DOB, and serum levels of G-17, IL-32, and sIL-2R in the two groups were compared. Logistic regression analysis was used to identify the influencing factors of CAG and H. pylori infection, and the correlation of DOB with serum G-17, IL-32, and sIL-2R was analyzed. The levels of DOB and serum G-17, IL-32, and sIL-2R in patients with different gastroscopic pathological changes were compared, and ROC curves were drawn to evaluate the value of DOB, G-17, IL-32, and sIL-2R in assessing CAG and H. pylori infection.

RESULTS

There were statistically significant differences in the course of disease and gastroscopic pathological changes (chronic inflammation, atrophy, intestinal metaplasia, and intraepithelial neoplasia) between the two groups (P < 0.05). The DOB and serum levels of IL-32 and sIL-2R were significantly higher and serum G-17 level was significantly lower in the observation group than in the control group (P < 0.05). Logistic regression analysis showed that the course of disease, chronic inflammation, atrophy, intestinal metaplasia, intraepithelial neoplasia, DOB, and serum G-17, IL-32, and sIL-2R levels were all influencing factors of CAG and H. pylori infection (P < 0.05). Pearson correlation analysis showed that the DOB of patients with CAG and H. pylori infection was negatively correlated with G-17, and positively correlated with IL-32 and sIL-2R (P < 0.05). Spearman correlation analysis showed that the DOB and serum levels of G-17, IL-32, and sIL-2R in patients with CAG and H. pylori infection were significantly related to chronic inflammation, atrophy, intestinal metaplasia, and intraepithelial neoplasia (P < 0.05). ROC curve analysis showed that the area under the curve of combined DOB, G-17, IL-32, and sIL-2R was the largest (0.975), and the best sensitivity and specificity were 85.48% and 98.00%, respectively.

CONCLUSION

Serum levels of G-17, IL-32, and sIL-2R in patients with CAG and H. pylori infection are related to DOB. H. pylori infection may be involved in the occurrence and progression of gastric mucosal pathological changes in CAG patients by affecting the expression of G-17, IL-32, and sIL-2R. Combined detection of all the above indicators can effectively predict H. pylori infection, which is of great significance for clinical diagnosis and treatment.