Investigation of Helicobacter pylori antigen in stool samples of patients with upper gastrointestinal complaints

Stool Antigen Test for Helicobacter Pylori Infection in Adults : A Meta-analysis of Diagnostic Test Accuracy

OBJECTIVE

The stool antigen test (SAT) is a convenient noninvasive option for the diagnosis of Helicobacter pylori ( H. pylori ) infection. However, despite having been previously evaluated, there is currently a lack of evidence regarding the comparative accuracy of conventional and rapid SATs utilizing monoclonal or polyclonal antibodies in adults. Here, we perform a thorough statistical synthesis to determine and compare the diagnostic accuracy of conventional and rapid SATs for the diagnosis of H. pylori infection in adults.

MATERIALS AND METHODS

We conducted independent searches through July 25, 2023, for studies evaluating the accuracy of SAT against a reference standard. We assessed methodological quality using Quality Assessment of Diagnostic Accuracy Studies-2 and calculated overall accuracy measures using the bivariate random-effect model. We also conducted subgroup analyses based on model and assessment technique, and Spearman correlation analysis to investigate a possible threshold effect. We generated summary receiver operating characteristic curves to assess heterogeneity and evaluated publication bias.

RESULTS

Conventional SAT demonstrated superior sensitivity (92.19% vs 85.79%), specificity (92.93% vs 91.18%), likelihood ratios (LR+ 9.68 vs 8.16; LR- 0.10 vs 0.15), and area under the curve (0.958 vs 0.940) compared with rapid SAT. Notably, the diagnostic odds ratio for conventional SAT (114.70) significantly outperformed rapid SAT (diagnostic odds ratio: 57.72). Correlation analysis revealed no threshold effect and summary receiver operating characteristic curves showed consistent accuracy for both tests.

CONCLUSION

Our study establishes evidence of the superior diagnostic accuracy of conventional SATs over rapid SATs for detecting H. pylori infection in adults. Also, we provide valuable insights into the impact of using monoclonal or polyclonal antibodies and different assessment techniques on diagnostic accuracy measures.

Sero-salivary detection of H. pylori immunoglobulins and parasitic infection among healthcare individuals suffering from gastrointestinal disorders with correlation to personal hygiene

BACKGROUND

Gastrointestinal microbial infections among healthcare individuals (HCIs) are common due to several risk factors, including poor personal hygiene and socio-economic lifestyle.

OBJECTIVES

This is the first cross-sectional study that stratifies HCIs to correlate personal hygiene and socio-economic lifestyle with gastrointestinal microbial infections. Additionally, it compares serum and saliva levels of H. pylori-IgG and IgA to assess the potential of saliva as a non-invasive alternative to serum.

METHODS

Based on Fisher's formula, 200 HCIs suffering from gastritis-including hospital workers, employees, nursing students, nurses, and doctors-were enrolled. Blood, saliva, and stool samples were collected for microbial infection investigations. Personal hygiene and socio-economic factors were scored based on WHO guidelines. Parasitic infections were identified microscopically, while H. pylori antigen and antibodies were detected via ELISA, with diagnostic significance determined by ROC curve analysis.

RESULTS

A high prevalence of intestinal microbial infections was observed among HCIs. Blastocystis spp. was the most common pathogen (72%), followed by Cryptosporidium spp. (59.5%). Cases of single, double, and multiple infections were detected. H. pylori antigen was present in 36 (18%) cases, often as a co-infection with intestinal parasites. Infection rates were highest among workers and nurses (100%), followed by employees (97.4%) and nursing students (81.7%), with doctors having the lowest rate (50%). Poor personal hygiene and socio-economic lifestyle were directly linked to increased infection risk. Additionally, H. pylori-IgG was positive in 14 cases and negative in 186 cases, while H. pylori-IgA was positive in 2 cases and negative in 198 cases in both serum and saliva. These findings indicate consistency between serum and saliva levels of H. pylori immunoglobulins.

CONCLUSIONS

Poor personal hygiene and socio-economic lifestyle significantly increase the risk of gastrointestinal microbial infections among HCIs. Salivary immunoglobulins show consistency with serum levels, suggesting saliva as a viable non-invasive alternative for detecting H. pylori infection.

The Effect of 131I Therapy on the Eradication of Helicobacter pylori in Patients with Thyroid Disorders: A Preliminary Study

The leading cause of gastritis and its complications is Helicobacter pylori Radioactive iodine (131I) accumulates significantly in the stomach after consumption. On this basis, we decided to determine whether different doses of 131I in the stomach would be effective in eradicating the infection. Methods: All patients with hyperthyroidism or differentiated thyroid carcinoma who were referred for 131I treatment were invited to the study. A stool antigen test was conducted before consumption of 131I (0.15-5.5 GBq) and was repeated 2 mo later to detect H. pylori infection. Results: H. pylori positivity was found in 51.8% (14/27) of the patients. At 2 mo after treatment, 13 of the 14 patients with differentiated thyroid carcinoma or hyperthyroidism who had been identified as positive for H. pylori stool antigen before 131I administration were still positive, representing a nonsignificant eradication rate of 7.1%. Conclusion: Administration of 131I to patients with H. pylori did not show potential to eliminate the infection.

Accuracy of Stool Antigen Test in the Diagnosis of Helicobacter pylori Infection in the Dominican Republic

Introduction: Helicobacter pylori is a well-studied infectious agent due to its pathogenic potential for peptic ulcers and gastric cancer. It has a high prevalence worldwide and has several diagnostic methods, both invasive and non-invasive. It is important to address the diagnostic efficacy of these tests, as the data vary by location and the specific population in which they are used. Therefore, an effective testing method should be obtained, evaluating the possibility of substantially reducing invasive procedures and, therefore, associated costs.

OBJECTIVE

This study proposes to define the diagnostic accuracy of the stool antigen test for H. pylori infection in the Dominican Republic.

METHODS

An observational, retrospective, and cross-sectional study was conducted. The results of the stool antigen test for H. pylori infection were compared with the results of the gastric biopsy, as a gold standard test. Patients over 18 years of age with an indication for endoscopy due to suspicion of H. pylori infection, who attended the gastroenterology clinic in 2021, were included in the study.

RESULTS

It was shown that the stool antigen test for H. pylori infection has a 61.54% sensitivity and 59.65% specificity. According to the study population, the positive predictive value (PPV) was 67.60% and the negative predictive value (NPV) was 53.13%.

CONCLUSION

Low numbers of both sensitivity and specificity were determined, which is why it is pertinent to study alternative non-invasive methods. However, it is important to assess the antibiotic exposure of the study population, since the diagnostic accuracy of the stool test can be influenced by this factor.

Frequency of significant virulence genes in gastric biopsies of Helicobacter pylori-positive patients with gastritis

Helicobacter pylori is one of the most common bacteria affecting human societies worldwide, and is mainly associated with gastrointestinal complications due to different virulence factors. This study aimed to investigate some virulence genes of H. pylori in gastric biopsies of patients with gastritis in Sari city, North of Iran. Informed consent forms were obtained from the studied patients, and those who needed endoscopy were included in the study. To evaluate the prevalence of cagA, iceA1, iceA2, vacA, dupA, and oipA genes, gastric biopsies with positive or negative rapid urease test were collected from 50 patients (25 in each group) with gastro-duodenal diseases. The bacterial DNAs were extracted by a specific kit, and the presence of the genes was analyzed by PCR using specific primers. Eighteen (72%) biopsies from 25 H. pylori-positive samples were cagA-positive, while 17 (68%) biopsies contained the vacA gene, and 11 (44%) samples had both vacA and cagA genes. However, 16 (64%), 12 (48%), 13 (52%), and 14 (56%) biopsies contained dupA, iceA1, iceA2, and oipA genes, respectively. Due to the significant role of the studied virulence factors in the pathogenicity of H. pylori, the high prevalence of these factors in biopsies of patients with gastritis is a concern needing to the management in this region.

Helicobacter Pylori Infection among Patients Attending the Gastroenterology Department in Tertiary Care Hospital, Kathmandu, Nepal

Helicobacter pylori is one of the most pathogenic organisms that cause gastritis, peptic ulcer, gastric adenocarcinoma, and mucosa-associated lymphoid tissue (MALT) lymphoma in humans. The main aim of this study was to determine the H. pylori infection among patients undergoing upper GI endoscopy and to compare the efficacy of the diagnostic method of H. pylori infection including invasive tests (biopsy-based tests like the rapid urease test (RUT), direct smear, and culture) and the noninvasive test (HpSA). A total of 100 stool samples and 200 gastric biopsy specimens were collected (2 samples from each patient) from June to November 2019. Stool samples were processed for the detection of an H. pylori stool antigen (HpSA) by a kit method. One biopsy specimen was processed for the RUT, and another was transported to the laboratory in an Eppendorf tube containing normal saline for preparation of the smear and culture. Out of 100 participants, 26% were found to be H. pylori positive by the RUT, 11% by the direct smear, 6% by the culture, and 17% by the stool antigen test. The prevalence of H. pylori infection was found to be 14%, considering at least two of the three biopsy-based tests that gave positive results. H. pylori infection was found to be higher in the age group of 46-55 years. The overall prevalence of H. pylori infection was higher in gastric ulcer cases, followed by erosive pangastritis and gastroduodenitis. Tea drinking habits and the frequency of meal consumption more than twice a day were found to be significantly associated with H. pylori infection (P < 0.05). Hence, the RUT was found to be more efficient than the direct smear and the culture method for finding H. pylori in the biopsy sample. However, none of these methods can be considered to be the gold standard alone. Thus, the RUT combined with other tests is preferable for the detection of H. pylori.

Demographic, Chemical, and Helicobacter pylori Positivity Assessment in Different Types of Gallstones and the Bile in a Random Sample of Cholecystectomied Iranian Patients with Cholelithiasis

BACKGROUND

The occurrence of stones in the gallbladder or common bile duct and the symptoms and complications they cause is called gallstone disease. The symptoms of gallstone disease range from mild, nonspecific symptoms to a severe right quadrant abdominal pain. Characteristics of gallstone types in an Iranian population have not been well studied before and there are very limited studies on the demographic pattern of stone types in our country, so this study is one of the first studies on its kind on the epidemiology of gallstone types in Iran. As information on chemical components of the stone will help in the management and prevention of gallstones, in this study, we aimed to do chemical component analysis of gallstones including cholesterol, bilirubin, and calcium. Given the conflicting reports about the relationship between H. pylori infections and gallstone formation, this study aimed to investigate the relationship between H. pylori positivity in the bile specimen of Iranian patients with cholelithiasis and formation and type of stone.

METHODS

This prospective study reviewed a total of 196 patients who underwent cholecystectomy for symptomatic cholelithiasis at Shahid Beheshti Training and Research Hospital affiliated to the Yasuj University of Medical Sciences between September 2015 and May 2018. Chemical analysis of gallstone components performed using the colorimetry method. Microbiological analysis for H. pylori was done using the OnSite H. pylori Ag Rapid Test on the bile sample. For the validation test of bile, the H. pylori Rapid Stool Ag Test on stool was used, and Cohen's Kappa statistical analysis was done next.

RESULTS

There were significant associations between the stone types and age, chemical composition of the stones such as calcium, cholesterol, and bilirubin levels, and also H. pylori positivity and cholesterol and bilirubin levels; however, no significant association was found between the stone types and sex, H. pylori positivity and age, sex, stone types, and calcium level. The main bile and validity tests were matched to the substantial agreement according to Cohen's Kappa analysis. The most common drugs used were proton pump inhibitors, nonsteroidal anti-inflammatory drugs, antihypertensive drugs, and oral contraceptives.

CONCLUSIONS

This study suggested that the chemical composition of the stones could predict the presence of bacteria, there is no correlation between H. pylori and gallstone formation, and some of the drugs could be predisposing factors for gallstones. This work provides an objective basis for further research into gallbladder stone formation; meanwhile, it has great significance in the treatment and prevention of gallbladder stones. Trial registration. The project was found to be in accordance to the ethical principles and the national norms and standards for conducting research in Iran with the approval ID IR.YUMS.REC.1399.147 and date 2020.09.23, and this project is the result of a residency dissertation to obtain the specialty in general surgery, which has been registered with the research project number 960159 in the Vice Chancellor for Research and Technology Development of the Yasuj University of Medical Sciences, Yasuj, Iran, URL: https://ethics.research.ac.ir/EthicsProposalViewEn.php?id=160634.

Hyperemesis Gravidarum in First-Trimester Pregnant Saudi Women: Is Helicobacter pylori a Risk Factor?

Introduction

Hyperemesis gravidarum (HG) is a serious complication of pregnancy involving nausea and vomiting which affects all facets of the lives of many women. Helicobacter pylori infection has been linked to HG in some regions of the world. However, the prevalence of H. pylori in Saudi Arabian pregnant women and its link to HG has not been the subject of previous research. Detecting and treating H. pylori infection in women early in their pregnancies may lower the likelihood of adverse maternal outcomes. This study aims to assess the connection between the pathogenesis of HG and H. pylori infection in this population.

Methods

Forty-five pregnant women with HG were recruited from the outpatient clinic for antenatal care in the Gynecology and Obstetrics Department at King Abdulaziz University Hospital. Forty-five pregnant women without HG were matched as controls. Both groups underwent testing for the H. pylori antigen in stool samples.

Results

A statistically significant difference (P < 0.05) was observed between the cases and controls in terms of the occurrence of H. pylori. Thirty-eight women in the HG group (84.4%) tested positive for H. pylori, while the same was true of only 20 of the controls (44.4%). The mean level of blood hemoglobin in positive cases was significantly lower than that in negative cases (9.56 ± 1.29 vs. 11.90 ± 1.18 g/dl, P = 0.012).

Conclusion

H. pylori may play a contributing role in the presence of HG in the study population. It may be included with other investigations of HG, especially with cases that do not respond to conventional management and continue into the second trimester. Women with H. pylori were also more likely to suffer from anemia compared to those without the infection. For this reason, those working with pregnant women should pay close attention to those infected with H. pylori. Additional large case–control studies are necessary to better understand the part H. pylori plays and the pathogenesis of HG.

STOOL ANTIGEN (HPSA) TEST IN DETECTION OF HELICOBACTER PYLORI INFECTION AMONG ADULT DYSPEPTIC PATIENTS IN TRIPOLI, LIBYA

Background. Helicobacter pylori is the most common infection in the world. Relationship between H. pylori and dyspepsia was confirmed by many studies, it has been strongly associated with peptic ulcer disease and gastric cancer. In that respect, several invasive and noninvasive methods for the diagnosis of H. pylori infection were utilized. Objective. The aim of the study was to evaluate the association between dyspepsia and the positivity of H. pylori stool antigen test, to compare this test with serological IgG test. Methods. 125 adult patients were randomly selected from gastroenterology units of Mediterranean and Tajurah clinics in Tripoli. Stool samples were taken for detection of H. pylori antigen by enzyme immunoassay. Blood samples for detection of anti-H. pylori IgG antibodies were taken. Data were statistically analyzed using SPSS. Results. 125 dyspeptic patients: 47 male and 78 female, aged 18-83 years old were examined. 80 patients were infected by H. pylori that was proved by a positive stool test, 88 had a positive IgG test. The prevalence was higher in the patients aged 28-47 years old. There was substantial relation to age, marital status and economic risk factors; there was no association between H. pylori and gender, sources of drinking water, living standards, smoking, family history of peptic ulcer, drug consumption, and blood groups. Conclusions. Relatively high rates of detection by HpSA prove that stool testing might be a reliable, simple, inexpensive, and non-invasive alternative test ащк detectшщт of H. pylori, diagnosing active infection and confirming cure. However IgG test has a low sensitivity, specificity, and accuracy compare to the HpSA test. Thus it can be used for screening purposes.

Possible Metabolic Alterations among Autistic Male Children: Clinical and Biochemical Approaches

The present cross-sectional, hospital-based study was carried out on 146 Egyptian male children, 73 males with autism who were comparable with another 73 healthy age- and sex-matched children, recruited from the outpatients' psychiatric clinics of the Neuropsychiatric and Pediatric Departments of South Valley and Assiut University Hospitals, Egypt. Neuropsychological assessments of autistic males were done using CARS, short sensory profile and intelligent quotients. Serum markers of mitochondrial dysfunction (lactate, pyruvate, and lactate to pyruvate ratio, creatine kinase (CK), L-carnitine, ammonia, lactate dehydrogenase, pyruvate kinase, alanine transaminase and aspartate transaminase), oxidative stress and blood levels of heavy metals (mercury, lead and aluminium) were measured. Serum cholesterol, cortisol, free testosterone, estradiol, dehydroepiandrostenedione, adenosine deaminase and Helicobacter pylori antigen in stool were also performed. There was evidence of mitochondrial dysfunction among autistic children. Additionally, there were significantly lower serum total cholesterol, cortisol and estradiol as well as significantly higher dehydroepiandrostenedione (DHEA) and free testosterone (p < 0.05 for all markers). Twenty-eight (38%) cases were positive for H. pylori antigen in their stool with significant higher serum ammonia and lower adenosine deaminase than in H. pylori-negative autistic children. Mitochondrial dysfunction, H. pylori infection and low cholesterol were prevalent among autistic male children, which should be targeted during autism management.

Highly clarithromycin-resistant Helicobacter pylori infection in asymptomatic children from a rural community of Cajamarca-Peru

Objective

The objective of this study was to determine the prevalence of clarithromycin-resistant Helicobacter pylori in asymptomatic children in a rural community of Cajamarca (northern Peru).

Results

Helicobacter pylori was detected in 17.2% (49/285) of the samples. Unboiled water consumption the most frequent associated factor in patients with positive PCR for H. pylori infection (93.9%). Clarithromycin resistant mutations were found in 79.6% (39/49) of the positive samples for H. pylori. The most frequent mutation was A2142G (46.9%), followed by the double-mutation A2142G–A2143G (28.6%).

Feco-prevalence and risk factors of Helicobacter pylori infection among symptomatic patients at Dessie Referral Hospital, Ethiopia

BACKGROUND

Helicobacter pylori (H. pylori) infection is the most common chronic bacterial infection in the world. It can result in various upper gastroduodenal diseases. The prevalence varies among countries, population groups within the same country and testing methods. The aim of the study was to determine feco-prevalence and risk factors of H.pylori infection among symptomatic patients in Amhara region, Northeast Ethiopia.

METHODS

A cross sectional study was conducted in a total of 342 new consecutive outpatients with upper abdominal complaints at Dessie Referral Hospital from May to July, 2016. A structured questionnaire was used to collect the socio-demographic, lifestyle and environmental data. Stool samples were used to detect H. pylori specific antigen. Blood samples were assessed for anti-H. pylori IgG and ABO blood types. SPSS version 20.0 statistical software package was used for data analysis. Chi-square test and logistic regression were used in the analysis and P-value ≤0.05 was considered as statistically significant.

RESULTS

H. pylori stool antigen and serum anti-H.pylori IgG detection rate was 30.4 and 60.5% respectively with kappa measure of agreement of 0.271. Antigen detection was significantly associated with family size (> 3) [AOR = 1.83, 95% CI: 1.10-3.05, p = 0.02], more persons (> 3) sharing the same bed room in the household [AOR = 2.91, 95% CI: 1.39-6.11, p = 0.005], alcohol consumption (> once a week) [AOR = 2.70, 95% CI: 1.49-4.89, p = 0.001] and individuals' blood type: group O [AOR = 8.93, 95%CI: 1.79-44.48, p = 0.008] and group A [AOR = 5.53, 95%CI: 1.08-28.36, p = 0.040]. Gender, age, marital status, occupation, educational level, residence, smoking as well as coffee, tea, fruits and vegetables consumption were not statistically associated with H. pylori antigen detection (p > 0.05).

CONCLUSION

The overall H. pylori stool antigen and anti-H. pylori IgG detection rate was 30.4 and 60.5%, respectively. The test agreement was not strongly convincing and needs further evaluation. Alcohol consumption, overcrowding and ABO blood group were significantly associated with H. pylori antigen detection.

The Evaluation of Diagnostic and Predictive Values of Helicobacter pylori Stool Antigen Test in Iranian Patients with Dyspepsia

BACKGROUND AND OBJECTIVES

Iran, as a developing country, is experiencing high burdens of Helicobacter pylori (Hp)-associated non-communicable diseases. Hp stool antigen test (HpSA) is widely used as an inexpensive and feasible noninvasive method to diagnose Hp infection, instead of invasive approaches. The current study aimed at evaluating the diagnostic and predictive values of HpSA test for Hp infection in Iranian patients with dyspepsia.

METHODS

The current cross sectional study was performed on 100 patients with dyspepsia. Gastric mucosal specimens were taken, processed, and examined according to the standard protocols. Simultaneously, stool samples were obtained and sent to laboratory for further analyses. Hp stool antigen titers were assessed using enzyme-linked immunosorbent assay (ELISA) technique.

RESULTS

Stool antigen titers were not associated with gender (P-value=0.284), but correlated to age (r=0.213, P-value=0.034). Considering 0.385 as a cutoff point, the HpSA test had 80.4% sensitivity and 85.7% specificity.

CONCLUSION

Based on cost-effectiveness of HpSA test, the current study findings corroborated the use of HpSA test to detect and follow-up patients with Hp infection, as an alternative method to detect Hp rather than invasive procedures.

Clinical value of detection of anti-Helicobacter pylori antibody in urine

Helicobacter pylori (H. pylori) is a kind of gram-negative anaerobic bacterium that was first successfully isolated and cultivated from the specimens of the gastric mucosa by Warren and Marshall in 1983. It is one of the risk factors for gastric cancer and is closely related with chronic gastritis, peptic ulcer, gastric cancer and other diseases of the digestive system. There are a variety of detection technologies and diagnostic methods available for H. pylori infection, including direct detection of the bacterium, urease detection, antigen and antibody detection, polymerase chain reaction and so on. Generally, these methods can be divided into two major categories: invasive and non-invasive. However, no single test can be considered the gold standard for the diagnosis of H. pylori infection. In this paper, we will summarize a kind of completely non-invasive detection method - detection of H. pylori antibody in urine, review its use in the diagnosis of ongoing infection, and discuss its value in clinical applications.