Prospective evaluation of a new stool antigen test for the detection of Helicobacter pylori, in comparison with histology, rapid urease test, (13)C-urea breath test, and serology

Comparison of the STANDARD F and SD BIOLINE stool antigen tests for diagnosis of Helicobacter pylori infection

We compared the performance of the STANDARD F and SD BIOLINE stool antigen tests in 335 patients. The performance of STANDARD F (sensitivity: 95.6%; specificity: 94%) was highly comparable to that of SD BIOLINE (sensitivity: 92.6%; specificity: 93.5%), suggesting that STANDARD F is useful for the detection of Helicobacter pylori infection.

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.

Focusing on Helicobacter pylori infection in the elderly

As a confirmed carcinogen, Helicobacter pylori (H. pylori) is the main cause of inflammatory diseases of the upper digestive tract and even gastric cancer. There is a high prevalence of H. pylori infection among the elderly population, which may cause adverse clinical outcomes. Particularly noteworthy is that guidelines or expert consensus presently available on H. pylori infection overlook the management of the elderly population as a special group. A brief overview of H. pylori in the elderly is as follows. The detection of H. pylori infection can be divided into invasive and non-invasive techniques, and each technique has its advantages and shortcomings. There may be more side effects associated with eradication treatment in elderly individuals, especially for the frail population. Physical conditions and risk-benefit assessments of the elderly should be considered when selecting therapeutic strategies for H. pylori eradication. Unless there are competing factors, elderly patients should receive H. pylori eradication regimens to finally reduce the formation of gastric cancer. In this review, we summarize the latest understanding of H. pylori in the elderly population to provide effective managements and treatment measures.

Helicobacter pylori Infection, Its Laboratory Diagnosis, and Antimicrobial Resistance: a Perspective of Clinical Relevance

Despite the recent decrease in overall prevalence of Helicobacter pylori infection, morbidity and mortality rates associated with gastric cancer remain high. The antimicrobial resistance developments and treatment failure are fueling the global burden of H. pylori-associated gastric complications. Accurate diagnosis remains the opening move for treatment and eradication of infections caused by microorganisms. Although several reports have been published on diagnostic approaches for H. pylori infection, most lack the data regarding diagnosis from a clinical perspective. Therefore, we provide an intensive, comprehensive, and updated description of the currently available diagnostic methods that can help clinicians, infection diagnosis professionals, and H. pylori researchers working on infection epidemiology to broaden their understanding and to select appropriate diagnostic methods. We also emphasize appropriate diagnostic approaches based on clinical settings (either clinical diagnosis or mass screening), patient factors (either age or other predisposing factors), and clinical factors (either upper gastrointestinal bleeding or partial gastrectomy) and appropriate methods to be considered for evaluating eradication efficacy. Furthermore, to cope with the increasing trend of antimicrobial resistance, a better understanding of its emergence and current diagnostic approaches for resistance detection remain inevitable.

Helicobacter pylori infection and iron deficiency in non-elderly adults participating in a health check-up program

BACKGROUND/AIMS

Helicobacter pylori infection is presumably associated with iron deficiency and iron deficiency anemia (IDA). This study aimed to evaluate the relationship between H. pylori infection and the decline in iron stores in non-elderly adults during their health check-ups.

METHODS

We identified a total of 1,069 subjects who were tested for iron, ferritin, and total iron-binding capacity during their health check-ups, from January 2016 to May 2017. Of these, subjects who underwent endoscopy via rapid urease test and those aged 65 years or below were finally enrolled.

RESULTS

Overall, 281 subjects were enrolled, and 187 patients (66.5%) tested positive for H. pylori. The mean age was 36.1 years (range, 22 to 65), and 176 subjects (62.6%) were male. The mean levels of hemoglobin (14.1 ± 1.7 g/dL vs. 14.6 ± 1.4 g/dL, p = 0.019) and ferritin (121.7 ± 106.9 ng/mL vs. 151.8 ± 107.8 ng/mL, p = 0.027) in the H. pylori-positive group were significantly lower than those in the H. pylori-negative group. Iron deficiency (ferritin < 30 ng/mL) was more common in patients with H. pylori infection (p = 0.002). There was no significant difference in anemia (hemoglobin < 13 g/dL in men, < 12 g/dL in women) or IDA (anemia, ferritin < 10 ng/mL, and transferrin saturation < 16%) with H. pylori. Logistic regression analysis demonstrated that female sex (odds ratio, 197.559; 95% confidence interval, 26.461 to 1,475.015) and H. pylori infection (odds ratio, 3.033; 95% confidence interval, 1.216 to 7.567) were factors associated with iron deficiency.

CONCLUSION

H. pylori infection is associated with iron deficiency, suggesting a decline in iron stores among infected non-elderly adults.

Sex differences between Helicobacter pylori infection and cholesterol levels in an adult health checkup program

BACKGROUND

Helicobacter pylori (H pylori) infection is suggested to be a risk factor of metabolic syndrome (MS) and lipid abnormalities. The aim of this study was to investigate the influence of H pylori infection on MS and lipid abnormalities according to sex differences.

MATERIALS AND METHODS

We analyzed a total of 4551 adults who received health checkups from January 2016 to May 2017. We enrolled participants who did not have a history of hypertension, diabetes, hyperlipidemia, or cancer among those who underwent endoscopy with a rapid urease test.

RESULTS

We included a total of 1065 participants, and 663 patients (62.3%) were H pylori-positive. The H pylori infection rate was 59.3% (426/719) in males and 68.5% (237/346) in females. The mean level of total cholesterol (P = .003), low-density lipoprotein (LDL) cholesterol (P = .046), and triglycerides (P = .029) were statistically higher in H pylori-infected males. The mean level of high-density lipoprotein (HDL) cholesterol was statistically lower in H pylori-infected females (P = .032). Multivariate analysis showed that total cholesterol in males (odds ratio [OR], 1.007; 95% confidence interval [CI], 1.002-1.011) and HDL cholesterol in females (OR, 0.983; 95% CI, 0.968-0.998) were associated with active H pylori infection. The prevalence of MS was higher in both male and female H pylori-infected groups; however, there was no statistical significance.

CONCLUSIONS

H pylori infection is significantly related to increased total cholesterol in males and to decreased HDL cholesterol in females, which suggests that H pylori could affect lipid profiles and may be different by sex.

Serology Is More Sensitive Than Urea Breath Test or Stool Antigen for the Initial Diagnosis of Helicobacter pylori Gastritis When Compared With Histopathology

OBJECTIVES

To assess the concordance and performance characteristics of Helicobacter pylori laboratory tests compared with histopathology and to propose algorithms for the diagnosis of H pylori that minimize diagnostic error.

METHODS

H pylori diagnostics were reviewed from a 12-year period within a health system (2,560 cases). Analyses were performed to adjust diagnostic performance based on treatment and consensus histopathologic diagnoses among pathologists. Markers of access to care, including test cancellation frequency and turnaround time, were assessed. Costs and performance of candidate noninvasive testing algorithms were modeled as a function of disease prevalence.

RESULTS

Serum H pylori IgG demonstrated a higher sensitivity (0.94) than urea breath and stool antigen tests (0.64 and 0.61, respectively). Evidence of an advantage in access to care for serology included a lower cancellation rate. Interobserver variability was higher (κ = 0.34) among pathologists for cases with a discordant laboratory test than concordant cases (κ = 0.56). A model testing algorithm utilizing serology for first-time diagnoses minimizes diagnostic error.

CONCLUSIONS

Although H pylori serology has modestly lower specificity than other noninvasive tests, the superior sensitivity and negative predictive value in our population support its use as a noninvasive test to rule out H pylori infection. Reflexive testing with positive serology followed by either stool antigen or urea breath test may optimize diagnostic accuracy in low-prevalence populations.

Helicobacter pylori infection in children: an overview of diagnostic methods

Children differ from adults regarding Helicobacter pylori (H. pylori) infection in many terms. H. pylori infection represents a key factor in the pathogenesis of duodenal ulcer and chronic gastritis in children. H. pylori infection causes some extraintestinal diseases as well as gastrointestinal diseases. Although, among these illnesses in children, symptoms like recurrent abdominal pain are not specific. Moreover, the role of the pathogen in the growth faltering, iron deficiency anemia, and asthma still remains controversial. A reliable method to detect H. pylori infection is a crucial issue, sand is still a matter of active debate. The tests applied for H. pylori diagnosis are grouped as either invasive or non-invasive methods. Invasive methods consist of endoscopic evaluation, the rapid urease test (RUT), histology, and bacterial culture. Non-invasive tests include the urea breath test (UBT), stool antigen test (SAT), serology, and molecular diagnostic approaches. Use of endoscopy is a pre-requisite for all invasive methods and poses difficulties in children as it is a difficult procedure and requires patient's cooperation. For this reason, the non-invasive tests have been commonly used in children, although their accuracy is not very reliable in some cases. Invasive tests may be opted to confirm the diagnosis as and when needed. This review presents the diagnostic tests used to detect H. pylori infection in children.

Non-invasive tests for the diagnosis of helicobacter pylori: state of the art

Usually, non-invasive tests are the first methods for diagnosing Helicobacter pylori (HP) infection. Among these, serological test, stool antigen research and urea breath test are the most used. Antibodies anti-HP are not recommended in low prevalence population, moreover they cannot reveal an ongoing infection, but they only prove a contact with the bacterium. Also, they can persist for a long time after the eradication of the infection, therefore, they should not be used to verify the success of eradication therapy. Stool antigen research and Urea Breath Test (UBT) are useful both in diagnosis and during follow-up after eradication treatment. The stool antigen test is cheaper than Urea breath test with similar sensitivity and specificity. Non-invasive tests are not able to diagnose the associated complications to HP infection. (www.actabiomedica.it)

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

BACKGROUND/AIMS

In countries with a higher risk of gastric atrophic gastritis, noninvasive tests are helpful for a more reliable diagnosis of Helicobacter pylori infection. The aim of this study was to evaluate the characteristics of seropositive subjects according to their stool H. pylori antigen test, serum pepsinogen (PG) assay, and endoscopic findings.

METHODS

Consecutive subjects who visited Konkuk University Medical Center for upper gastrointestinal endoscopy for a regular check-up were included in a prospective setting if the serum anti-H. pylori immunoglobulin G assay was positive. A H. pylori antigen stool test was measured using a stool H. pylori antigen enzyme-linked immunosorbent assay kit on the same day as a serum PG assay and endoscopy.

RESULTS

Of 318 seropositive subjects, 256 (80.5%) showed positive stool test findings. Subjects with a negative stool test result showed lower serum PG I (p < 0.001) and PG II (p < 0.001) levels and higher PG I/II ratio (p < 0.001) than those with a positive stool test. Chronic atrophic gastritis was more common in the positive stool test group than the negative stool test group on endoscopic finding (p = 0.009). A higher serum PG I level (p = 0.001) and a lower serum PG I/II ratio (p = 0.001) were independent risk factors for the presence of H. pylori antigen in stool.

CONCLUSION

A high serum PG level denotes an ongoing current H. pylori infection with positive stool H. pylori antigen test findings. Seropositive subjects with increased gastric secreting ability tend to have H. pylori in their fecal material as reflected by a positive stool H. pylori antigen test finding.

Association between gastrointestinal tract infections and glycated hemoglobin in school children of poor neighborhoods in Port Elizabeth, South Africa

Background

Low- and middle-income countries are facing a dual disease burden with infectious diseases (e.g., gastrointestinal tract infections) and non-communicable diseases (e.g., diabetes) being common. For instance, chronic parasite infections lead to altered immune regulatory networks, anemia, malnutrition, and diarrhea with an associated shift in the gut microbiome. These can all be pathways of potential relevance for insulin resistance and diabetes. The aim of this study was to investigate the association between common gastrointestinal tract infections and glycemia in children from non-fee paying schools in South Africa.

Methodology

We conducted a cross-sectional survey among 9- to 14-year-old school children in Port Elizabeth. Stool and urine samples were collected to assess infection status with parasitic worms (e.g., Ascaris lumbricoides, Enterobius vermicularis, and Trichuris trichiura), intestinal protozoa (e.g., Cryptosporidium parvum and Giardia intestinalis), and the bacterium Helicobacter pylori. Glycated hemoglobin (HbA1c) was measured in finger prick derived capillary blood. All children at schools with a high prevalence of helminth infections and only infected children at the schools with low infection rates were treated with albendazole. The association of anthelmintic treatment with changes in HbA1c 6 months after the drug intervention was also investigated.

Findings

A high prevalence of 71.8% of prediabetes was measured in this group of children, with only 27.8% having HbA1c in the normal range. H. pylori was the predominant infectious agent and showed an independent positive association with HbA1c in a multivariable regression analysis (β = 0.040, 95% confidence interval (CI) 0.006–0.073, p<0.05). No association of HbA1c with either any other infectious agent or albendazole administration was found.

Conclusion

The role of H. pylori in diabetes needs confirmation in the context of longitudinal treatment interventions. The specific effect of other gastrointestinal tract infections on glycemia remains unclear. Future studies should integrate the measurement of biomarkers, including immunological parameters, to shed light on the potential mediating mechanisms between parasite infections and diabetes.

Parasitic worms (e.g., pinworm, roundworm, and whipworm), intestinal protozoa (e.g., Cryptosporidium parvum and Giardia intestinalis), and the bacterium Helicobacter pylori persist at high rates in the gastrointestinal tract of people from low- and middle-income countries. These infectious agents are increasingly paralleled by high rates of non-communicable diseases, such as diabetes. We studied the association of glycemia, measured as HbA1c with common gastrointestinal tract infections among school children aged 9–14 years from disadvantaged neighborhoods in Port Elizabeth, South Africa. Our goal was to deepen the understanding of whether specific gastrointestinal tract infections might be early life determinants of elevated HbA1c levels that might lead to diabetes. We found that the bacterium H. pylori was very common among our group of children with a positive association with hyperglycemia. None of the other infectious agents showed such an association. Additional, longitudinal studies are needed to determine whether there is causality for the observed association between H. pylori and hyperglycemia. The integration of biomarkers will allow studying mediating mechanisms.

Non-invasive diagnostic tests for Helicobacter pylori infection

BACKGROUND

Helicobacter pylori (H pylori) infection has been implicated in a number of malignancies and non-malignant conditions including peptic ulcers, non-ulcer dyspepsia, recurrent peptic ulcer bleeding, unexplained iron deficiency anaemia, idiopathic thrombocytopaenia purpura, and colorectal adenomas. The confirmatory diagnosis of H pylori is by endoscopic biopsy, followed by histopathological examination using haemotoxylin and eosin (H & E) stain or special stains such as Giemsa stain and Warthin-Starry stain. Special stains are more accurate than H & E stain. There is significant uncertainty about the diagnostic accuracy of non-invasive tests for diagnosis of H pylori.

OBJECTIVES

To compare the diagnostic accuracy of urea breath test, serology, and stool antigen test, used alone or in combination, for diagnosis of H pylori infection in symptomatic and asymptomatic people, so that eradication therapy for H pylori can be started.

SEARCH METHODS

We searched MEDLINE, Embase, the Science Citation Index and the National Institute for Health Research Health Technology Assessment Database on 4 March 2016. We screened references in the included studies to identify additional studies. We also conducted citation searches of relevant studies, most recently on 4 December 2016. We did not restrict studies by language or publication status, or whether data were collected prospectively or retrospectively.

SELECTION CRITERIA

We included diagnostic accuracy studies that evaluated at least one of the index tests (urea breath test using isotopes such as 13C or 14C, serology and stool antigen test) against the reference standard (histopathological examination using H & E stain, special stains or immunohistochemical stain) in people suspected of having H pylori infection.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the references to identify relevant studies and independently extracted data. We assessed the methodological quality of studies using the QUADAS-2 tool. We performed meta-analysis by using the hierarchical summary receiver operating characteristic (HSROC) model to estimate and compare SROC curves. Where appropriate, we used bivariate or univariate logistic regression models to estimate summary sensitivities and specificities.

MAIN RESULTS

We included 101 studies involving 11,003 participants, of which 5839 participants (53.1%) had H pylori infection. The prevalence of H pylori infection in the studies ranged from 15.2% to 94.7%, with a median prevalence of 53.7% (interquartile range 42.0% to 66.5%). Most of the studies (57%) included participants with dyspepsia and 53 studies excluded participants who recently had proton pump inhibitors or antibiotics.There was at least an unclear risk of bias or unclear applicability concern for each study.Of the 101 studies, 15 compared the accuracy of two index tests and two studies compared the accuracy of three index tests. Thirty-four studies (4242 participants) evaluated serology; 29 studies (2988 participants) evaluated stool antigen test; 34 studies (3139 participants) evaluated urea breath test-13C; 21 studies (1810 participants) evaluated urea breath test-14C; and two studies (127 participants) evaluated urea breath test but did not report the isotope used. The thresholds used to define test positivity and the staining techniques used for histopathological examination (reference standard) varied between studies. Due to sparse data for each threshold reported, it was not possible to identify the best threshold for each test.Using data from 99 studies in an indirect test comparison, there was statistical evidence of a difference in diagnostic accuracy between urea breath test-13C, urea breath test-14C, serology and stool antigen test (P = 0.024). The diagnostic odds ratios for urea breath test-13C, urea breath test-14C, serology, and stool antigen test were 153 (95% confidence interval (CI) 73.7 to 316), 105 (95% CI 74.0 to 150), 47.4 (95% CI 25.5 to 88.1) and 45.1 (95% CI 24.2 to 84.1). The sensitivity (95% CI) estimated at a fixed specificity of 0.90 (median from studies across the four tests), was 0.94 (95% CI 0.89 to 0.97) for urea breath test-13C, 0.92 (95% CI 0.89 to 0.94) for urea breath test-14C, 0.84 (95% CI 0.74 to 0.91) for serology, and 0.83 (95% CI 0.73 to 0.90) for stool antigen test. This implies that on average, given a specificity of 0.90 and prevalence of 53.7% (median specificity and prevalence in the studies), out of 1000 people tested for H pylori infection, there will be 46 false positives (people without H pylori infection who will be diagnosed as having H pylori infection). In this hypothetical cohort, urea breath test-13C, urea breath test-14C, serology, and stool antigen test will give 30 (95% CI 15 to 58), 42 (95% CI 30 to 58), 86 (95% CI 50 to 140), and 89 (95% CI 52 to 146) false negatives respectively (people with H pylori infection for whom the diagnosis of H pylori will be missed).Direct comparisons were based on few head-to-head studies. The ratios of diagnostic odds ratios (DORs) were 0.68 (95% CI 0.12 to 3.70; P = 0.56) for urea breath test-13C versus serology (seven studies), and 0.88 (95% CI 0.14 to 5.56; P = 0.84) for urea breath test-13C versus stool antigen test (seven studies). The 95% CIs of these estimates overlap with those of the ratios of DORs from the indirect comparison. Data were limited or unavailable for meta-analysis of other direct comparisons.

AUTHORS' CONCLUSIONS

In people without a history of gastrectomy and those who have not recently had antibiotics or proton ,pump inhibitors, urea breath tests had high diagnostic accuracy while serology and stool antigen tests were less accurate for diagnosis of Helicobacter pylori infection.This is based on an indirect test comparison (with potential for bias due to confounding), as evidence from direct comparisons was limited or unavailable. The thresholds used for these tests were highly variable and we were unable to identify specific thresholds that might be useful in clinical practice.We need further comparative studies of high methodological quality to obtain more reliable evidence of relative accuracy between the tests. Such studies should be conducted prospectively in a representative spectrum of participants and clearly reported to ensure low risk of bias. Most importantly, studies should prespecify and clearly report thresholds used, and should avoid inappropriate exclusions.

Epidemiology, Diagnosis, and Risk Factors of Helicobacter pylori Infection in Children

H. pylori infection is a global public health problem associated with some gastrointestinal diseases in children, especially in developing countries, since prevalence of H. pylori is low in the developed world. Both noninvasive (stool antigen test, urea breath test, and blood test) and invasive (histology, rapid urease test, and microbiological culture) tests have been utilized to detect H. pylori infection. However, a single test is not reliable enough and does not provide accurate enough data to determine H. pylori infection among children. Risk factors of H. pylori infection in children were related to ethnicities, household properties, geographic location, living conditions, water sources, type of housing, presence/absence of sewage systems, and garbage collection within the living environment. These risk factors were usually associated with the socioeconomic status of the family. This review article aims to determine the gaps in the knowledge of the epidemiology, risk factors, and diagnostic tests of H. pylori infection among children.

How to cite this article: Ozbey G, Hanafiah A. Epidemiology, Diagnosis, and Risk Factors of Helicobacter pylori Infection in Children. Euroasian J Hepato-Gastroenterol 2017;7(1):34-39.

Diagnosis of Helicobacter pylori infection: Current options and developments

Accurate diagnosis of Helicobacter pylori (H. pylori) infection is a crucial part in the effective management of many gastroduodenal diseases. Several invasive and non-invasive diagnostic tests are available for the detection of H. pylori and each test has its usefulness and limitations in different clinical situations. Although none can be considered as a single gold standard in clinical practice, several techniques have been developed to give the more reliable results. Invasive tests are performed via endoscopic biopsy specimens and these tests include histology, culture, rapid urease test as well as molecular methods. Developments of endoscopic equipment also contribute to the real-time diagnosis of H. pylori during endoscopy. Urea breathing test and stool antigen test are most widely used non-invasive tests, whereas serology is useful in screening and epidemiological studies. Molecular methods have been used in variable specimens other than gastric mucosa. More than detection of H. pylori infection, several tests are introduced into the evaluation of virulence factors and antibiotic sensitivity of H. pylori, as well as screening precancerous lesions and gastric cancer. The aim of this article is to review the current options and novel developments of diagnostic tests and their applications in different clinical conditions or for specific purposes.

Clinical characteristics of primary gastric lymphoma detected during screening for gastric cancer in Korea

BACKGROUND AND AIM

The role of screening endoscopy in primary gastric lymphoma (PGL) has not been investigated. This study aimed to evaluate the clinical characteristics and outcomes of PGLs detected by screening endoscopy in the high prevalence area of Helicobacter pylori (H. pylori) infection.

METHODS

This retrospective cohort study enrolled consecutive subjects who were diagnosed with PGL by endoscopic screening in Seoul National University Hospital Healthcare System Gangnam Center, Seoul, Korea, between October 2003 and September 2013. The characteristics and outcome of screening-detected patients (screening group) were compared with consecutive subjects diagnosed with PGL in the outpatient clinic (outpatient group).

RESULTS

Of the 105 194 recipients of screening upper endoscopy, 52 (0.049%) were found to have PGL. The median age was 54.2 years (range 23-79), and 65.4% were women. The proportion of PGL to gastric malignancy was 12.1% (52/429) overall, but >30% (25/73) in middle-aged (40-59) women. PGLs in the screening group were more likely to be mucosa-associated lymphoid tissue lymphoma (98.1% vs 60.0%, P < 0.001) and treated with H. pylori eradication alone (90.0% vs 48.1%, P < 0.001) than those in the outpatient group. Moreover, the screening group showed better 5-year overall survival (100.0% vs 89.3%, P = 0.016) and progression-free survival (94.9% vs 83.4%, P = 0.040) than the outpatient group.

CONCLUSIONS

In Korea, a high prevalence area of H. pylori infection, PGL seems more prevalent than in Western countries. Endoscopic screening may help to detect early stage H. pylori-positive mucosa-associated lymphoid tissue lymphoma. A high index of suspicion is needed, especially in middle-aged women.

Systematic review of time trends in the prevalence of Helicobacter pylori infection in China and the USA

It has been suggested that the prevalence of Helicobacter pylori infection has stabilized in the USA and is decreasing in China. We conducted a systematic literature analysis to test this hypothesis. PubMed and Embase searches were conducted up to 19 January 2015. Trends in the prevalence of H. pylori infection over time were assessed by regression analysis using Microsoft Excel. Overall, 25 Chinese studies (contributing 28 datasets) and 11 US studies (contributing 11 datasets) were included. There was a significant decrease over time in the H. pylori infection prevalence for the Chinese studies overall (p = 0.00018) and when studies were limited to those that used serum immunoglobulin G (IgG) assays to detect H. pylori infection (p = 0.014; 20 datasets). The weighted mean prevalence of H. pylori infection was 66 % for rural Chinese populations and 47 % for urban Chinese populations. There was a significant trend towards a decreasing prevalence of H. pylori infection for studies that included only urban populations (p = 0.04; 9 datasets). This trend was no longer statistically significant when these studies were further restricted to those that used serum IgG assays to detect H. pylori infection, although this may have been because of low statistical power due to the small number of datasets available for this analysis (p = 0.28; 6 datasets). There were no significant trends in terms of changes in the prevalence of H. pylori infection over time for studies conducted in the USA. In conclusion, the prevalence of H. pylori infection is most likely decreasing in China, due to a combination of increasing urbanization, which we found to be associated with lower H. pylori infection rates, and possibly also decreasing rates of H. pylori infection within urban populations. This will probably result in a gradual decrease in peptic ulcer and gastric cancer rates in China over time.

Diagnosis of Helicobacter pylori infection: Current options and developments

Accurate diagnosis of Helicobacter pylori (H. pylori) infection is a crucial part in the effective management of many gastroduodenal diseases. Several invasive and non-invasive diagnostic tests are available for the detection of H. pylori and each test has its usefulness and limitations in different clinical situations. Although none can be considered as a single gold standard in clinical practice, several techniques have been developed to give the more reliable results. Invasive tests are performed via endoscopic biopsy specimens and these tests include histology, culture, rapid urease test as well as molecular methods. Developments of endoscopic equipment also contribute to the real-time diagnosis of H. pylori during endoscopy. Urea breathing test and stool antigen test are most widely used non-invasive tests, whereas serology is useful in screening and epidemiological studies. Molecular methods have been used in variable specimens other than gastric mucosa. More than detection of H. pylori infection, several tests are introduced into the evaluation of virulence factors and antibiotic sensitivity of H. pylori, as well as screening precancerous lesions and gastric cancer. The aim of this article is to review the current options and novel developments of diagnostic tests and their applications in different clinical conditions or for specific purposes.

Antisecretory medication is associated with decreased Helicobacter pylori detection in gastric marginal zone lymphoma

Helicobacter pylori status influences the prognosis and management of gastric extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma), so accurate determination of H pylori status is of clinical importance. The low rate of histologic H pylori positivity among gastric MALT lymphoma cases at our institution prompted investigation for possible causes. A case series of 24 patients as having gastric MALT lymphoma (with no diffuse large B-cell component) in a tertiary care setting between 1997 and 2010 was identified, and clinical records were reviewed. Immunohistochemical staining for H pylori and BCL10 was performed. This study received institutional review board approval (protocol number M13-033). Thirty-nine percent of cases (9/23) were H pylori positive by histology, and 4 additional patients had positive serologic results; overall, 57% of cases (13/23) were positive for H pylori. Treatment with antisecretory medications was associated with a lower likelihood of histologic positivity (13% among treated patients vs 75% among untreated; P = .04). Nuclear localization of BCL10 was seen in 2 cases and was not associated with H pylori status. Antisecretory medications decrease the likelihood of histologic detection of H pylori in gastric MALT lymphoma cases. Incorporation of results of serologic or other testing is needed to ensure correct classification with respect to H pylori status.

Comparison of Serum IgG Antibody Test with Gastric Biopsy for the Detection of Helicobacter Pylori Infection among Egyptian Children

BACKGROUND:

In developing countries, Helicobacter pylori (H. pylori) infection is mainly acquired during childhood and may be a predisposing factor for peptic ulcer or gastric cancer later in life. Noninvasive diagnostic tools are particularly useful in children for screening tests and epidemiological studies. Data on serologic testing of children are lacking. Accurate noninvasive tests for diagnosing Helicobacter pylori infection in children are strongly required.

AIM:

The aim of this study was to evaluate the performance of a serological test (serum IgG antibody for H. pylori) in Egyptian children with recurrent abdominal pain necessitating endoscopy.

SUBJECTS AND METHODS:

One hundred children, referred to the endoscopy unit at Mansoura University. Upper endoscopy was done for each with rapid urease test (RUT) and histological examination as the gold standard test for detection of H. pylori infection. Serum samples were collected for detecting IgG for H. pylori infection.

RESULTS:

The mean age of the subjects included in the study was 7.23 ± 1.94 year. Serological test (IgG to H. pylori) was positive in 60% of all cases. A highly significant association between the standard test and the serological test at a cutoff > 10 U/ml at p = 0.001 were detected for the diagnosis of H. pylori infection. The sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio for the IgG antibody a cutoff > 10 U/ml, were 96.5%, 93%, 13.83, 0.038 respectively.

CONCLUSION:

Serum IgG antibody to H. pylori infection has a high diagnostic value and can be considered as a suitable and reliable noninvasive test for detection of H. pylori infection.

Stability of (13) C-Urea Breath Test Samples Over Time in the Diagnosis of Helicobacter pylori

BACKGROUND

The accuracy and repeatability of breath test in the diagnosis of Helicobacter pylori infection have not been adequately investigated. Although it has been shown that storage for long periods does not affect the analysis results, no data are available on the effect of repetitive testing. In this study, our aim was to evaluate the repeatability of the analyses of breath samples at room temperature.

METHODS

A total of 202 positive breath samples were collected in duplicates, before and after administration of 75 mg (13) C- urea dissolved in 100 ml of orange juice. Breath test results were expressed as delta (13) CO2 . The cut-off value was 3.5 parts per thousand. Each sample was analyzed in a mass spectrometer 7, 14, 21, and 28 days after collection. The accuracy calculation was based on the comparison of the delta (13) CO2 obtained in the three consecutive weeks following the first test run to the delta (13) CO2 obtained in the first test run.

RESULTS

Two hundred (99%), 197 (97.52%), and 196 (97%) of the 202 samples tested positive in the second, third, and fourth test runs, respectively. The accuracy of the delta (13) CO2 was 98.6%, 99.2%, and 96.7% in the three consecutive runs, respectively.

CONCLUSION

Short-term storage of 1 month does not affect sample stability or the results of (13) C-urea breath tests in up to three consecutive repeats.

Helicobacter pylori infection - recent developments in diagnosis

Considering the recommended indications for Helicobacter pylori (H. pylori) eradication therapy and the broad spectrum of available diagnostic methods, a reliable diagnosis is mandatory both before and after eradication therapy. Only highly accurate tests should be used in clinical practice, and the sensitivity and specificity of an adequate test should exceed 90%. The choice of tests should take into account clinical circumstances, the likelihood ratio of positive and negative tests, the cost-effectiveness of the testing strategy and the availability of the tests. This review concerns some of the most recent developments in diagnostic methods of H. pylori infection, namely the contribution of novel endoscopic evaluation methodologies for the diagnosis of H. pylori infection, such as magnifying endoscopy techniques and chromoendoscopy. In addition, the diagnostic contribution of histology and the urea breath test was explored recently in specific clinical settings and patient groups. Recent studies recommend enhancing the number of biopsy fragments for the rapid urease test. Bacterial culture from the gastric biopsy is the gold standard technique, and is recommended for antibiotic susceptibility test. Serology is used for initial screening and the stool antigen test is particularly used when the urea breath test is not available, while molecular methods have gained attention mostly for detecting antibiotic resistance.

[Guidelines for the diagnosis and treatment of Helicobacter pylori infection in Korea, 2013 revised edition]

Since the Korean College of Helicobacter and Upper Gastrointestinal Research has first developed the guideline for the diagnosis and treatment of Helicobacter pylori infection in 1998, the revised guideline was proposed in 2009 by the same group. Although the revised guideline was made by comprehensive review of previous articles and consensus of authoritative expert opinions, the evidence-based developmental process was not applied in the revision of the guideline. This new guideline has been revised especially in terms of changes in the indication and treatment of H. pylori infection in Korea, and developed by the adaptation process as evidence-based method; 6 guidelines were retrieved by systematic review and the Appraisal of Guidelines for Research and Evaluation (AGREE) II process, 21 statements were made with grading system and revised by modified Delphi method. After revision, 11 statements for the indication of test and treatment, 4 statements for the diagnosis and 4 statements for the treatment have been developed, respectively. The revised guideline has been reviewed by external experts before the official endorsement, and will be disseminated for usual clinical practice in Korea. Also, the scheduled update and revision of the guideline will be made periodically.

Guidelines for the diagnosis and treatment of Helicobacter pylori infection in Korea, 2013 revised edition

The Korean College of Helicobacter and Upper Gastrointestinal Research first developed guidelines for the diagnosis and treatment of Helicobacter pylori (H. pylori) infection in 1998, and revised guidelines were proposed in 2009 by the same group. Although the revised guidelines were based on a comprehensive review of published articles and the consensus of expert opinions, the revised guidelines were not developed using an evidence-based process. The new guidelines presented in this study include specific changes regarding indication and treatment of H. pylori infection in Korea, and were developed through the adaptation process using an evidence-based approach. After systematic review of the literature, six guidelines were selected using the Appraisal of Guidelines for Research and Evaluation (AGREE) II process. A total of 21 statements were proposed with the grading system and revised using the modified Delphi method. After the guideline revisions, 11 statements about indication of test and treatment, four statements about diagnosis, and four statements about treatment of H. pylori infection were developed. The revised guidelines were reviewed by external experts before receiving official endorsement from the Korean College of Helicobacter and Upper Gastrointestinal Research, and disseminated to physicians and other medical professionals for use in clinical practice in Korea. The guidelines will continue to be updated and revised periodically.

A review of Helicobacter pylori diagnosis, treatment, and methods to detect eradication

Helicobacter pylori (H. pylori) affects nearly half of the world’s population and, thus, is one of the most frequent and persistent bacterial infections worldwide. H. pylori is associated with peptic ulcer disease, gastric ulcers, mucosa-associated lymphoid tissue lymphoma, and gastric cancer. Various diagnostic methods exist to detect infection, and the choice of one method or another depends on several factors, such as accessibility, advantages and disadvantages of each method, cost, and the age of patients. Once H. pylori infection is diagnosed, the clinician decides whether treatment is necessity, according to the patient’s clinical condition. Typically, eradication of H. pylori is recommended for treatment and prevention of the infection. Cure rates with the standard triple therapy are acceptable, and effective quadruple therapies, sequential therapies, and concomitant therapies have been introduced as key alternatives to treat H. pylori infection. In this work, we review the main diagnostic methods used to identify H. pylori infection and to confirm eradication of infection. In addition, key factors related to treatment are reviewed.

Evaluation of a new fluorescence quantitative PCR test for diagnosing Helicobacter pylori infection in children

Background

Numerous diagnostic tests are available to detect Helicobactor pylori (H. pylori). There has been no single test available to detect H. pylori infection reliably. We evaluated the accuracy of a new fluorescence quantitative PCR (fqPCR) for H. pylori detection in children.

Methods

Gastric biopsy specimens from 138 children with gastritis were sent for routine histology exam, rapid urease test (RUT) and fqPCR. ¹³C-urea breath test (¹³C-UBT) was carried out prior to endoscopic procedure. Gastric fluids and dental plaques were also collected for fqPCR analysis.

Results

38 children (27.5%) were considered positive for H. pylori infection by gold standard (concordant positive results on 2 or more tests). The remaining 100 children (72.5%) were considered negative for H. pylori. Gastric mucosa fqPCR not only detected all 38 H. pylori positive patients but also detected 8 (8%) of the 100 gold standard-negative children or 11 (10.7%) of the 103 routine histology-negative samples. Therefore, gastric mucosa fqPCR identified 46 children (33.3%) with H. pylori infection, significantly higher than gold standard or routine histology (P<0.01). Both gastric fluid and dental plaque fqPCR only detected 32 (23.2%) and 30 (21.7%) children with H. pylori infection respectively and was significantly less sensitive than mucosa fqPCR (P<0.05) but was as sensitive as non-invasive UBT.

Conclusions

Gastric mucosa fqPCR was more sensitive than routine histology, RUT, ¹³C-UBT alone or in combination to detect H. pylori infection in children with chronic gastritis. Either gastric fluid or dental plaque PCR is as reliable as ¹³C-UBT for H. pylori detection.

Additional corpus biopsy enhances the detection of Helicobacter pylori infection in a background of gastritis with atrophy

Background

The best sites for biopsy-based tests to evaluate H. pylori infection in gastritis with atrophy are not well known. This study aimed to evaluate the site and sensitivity of biopsy-based tests in terms of degree of gastritis with atrophy.

Methods

One hundred and sixty-four (164) uninvestigated dyspepsia patients were enrolled. Biopsy-based tests (i.e., culture, histology Giemsa stain and rapid urease test) and non-invasive tests (anti-H. pylori IgG) were performed. The gold standard of H. pylori infection was defined according to previous criteria. The sensitivity, specificity, positive predictive rate and negative predictive rate of biopsy-based tests at the gastric antrum and body were calculated in terms of degree of gastritis with atrophy.

Results

The prevalence rate of H. pylori infection in the 164 patients was 63.4%. Gastritis with atrophy was significantly higher at the antrum than at the body (76% vs. 31%; p<0.001). The sensitivity of biopsy-based test decreased when the degree of gastritis with atrophy increased regardless of biopsy site (for normal, mild, moderate, and severe gastritis with atrophy, the sensitivity of histology Giemsa stain was 100%, 100%, 88%, and 66%, respectively, and 100%, 97%, 91%, and 66%, respectively, for rapid urease test). In moderate to severe antrum or body gastritis with atrophy, additional corpus biopsy resulted in increased sensitivity to 16.67% compare to single antrum biopsy.

Conclusions

In moderate to severe gastritis with atrophy, biopsy-based test should include the corpus for avoiding false negative results.

Epidemiology and diagnosis of Helicobacter pylori infection

Medline, PubMed and the Cochrane databases were searched on epidemiology and diagnosis of Helicobacter pylori for the period of April 2011-March 2012. Several studies have shown that the prevalence of H. pylori infection is decreasing in adults and children in many countries. Various diagnostic tests are available, and most of them have high sensitivity and specificity. The Maastricht IV/Florence consensus report states that the urea breath test using (13)C urea remains the best test to diagnose H. pylori infection. Among the stool antigen tests, the ELISA monoclonal antibody test is recommended. All these tests were used, either as a single diagnostic test or in combination, to investigate H. pylori infection among different populations throughout the world. Of particular interest, current improvements in high-resolution endoscopic technologies enable increased diagnostic accuracy for the detection of H. pylori infection, but none of these techniques, at present, are specific enough for obtaining a real-time diagnosis of H. pylori infection.

Performance of a one-step fecal sample-based test for diagnosis of Helicobacter pylori infection in primary care and mass screening settings

BACKGROUND/PURPOSE

An alternative screening test is needed to efficiently eradicate Helicobacter pylori from a population with prevalent upper gastrointestinal lesions. We evaluated the performance of a new one-step fecal test for H. pylori for diagnosis of H. pylori infection in Taiwan.

METHODS

We developed a fecal test to detect H. pylori based on the immunochronomatographic assay and a mixture of monoclonal antibodies. We first recruited symptomatic patients from the primary care setting to evaluate fecal test performance using a reference standard consisting of (13)C urea breath test, rapid urease test, and histology. We also compared the performance of the fecal test with that of others. Next, we recruited asymptomatic participants from the mass screening setting to evaluate population attendance for the fecal test and compared its performance with that of (13)C urea breath test.

RESULTS

In the primary care setting, 117 patients were recruited; H. pylori infection was confirmed in 58 (49.6%). Fecal test sensitivity, specificity, positive and negative predictive values, and accuracy were 88.0% [95% confidence interval (CI): 79.6-96.4%], 100%, 100%, 89.4% (95% CI, 82.0-96.8%), and 94% (95% CI, 89.7-98.3%), respectively. Fecal test specificity and positive predictive value were significantly higher than those of the serological test, whereas the sensitivity and negative predictive value were lower than those of the (13)C urea breath test (p < 0.05). In the mass screening setting, 2720 of 3520 invited individuals participated (77.3%; 95% CI, 76-78.7%); 649 (23.9%) showed positive results. Concordance rate and kappa statistic between the fecal test and (13)C urea breath test were 91.7% (563/614; 95% CI, 89.9-94.1%) and 0.78 (95% CI, 0.73-0.84), respectively.

CONCLUSION

Given the acceptable sensitivity, excellent specificity, and high participation rate to screening, the one-step H. pylori stool antigen test is feasible for wide application in the community.

Gastric infection by Helicobacter pylori

Helicobacter pylori infects half of the world's population and plays a causal role in ulcer disease and gastric cancer. This pathogenic neutralophile uniquely colonizes the acidic gastric milieu through the process of acid acclimation. Acid acclimation is the ability of the organism to maintain periplasmic pH near neutrality in an acidic environment to prevent a fall in cytoplasmic pH in order to maintain viability and growth in acid. Recently, due to an increase in antibiotic resistance, the rate of H. pylori eradication has fallen below 80% generating renewed interest in novel eradication regimens and targets. In this article, we review the gastric biology of H. pylori and acid acclimation, various detection procedures, antibiotic resistance and the role that gastric acidity plays in the susceptibility of the organism to antibiotics currently in use and propose several novel drug targets that would promote eradication in the absence of antibiotics.