Helicobacter pylori stool antigen test

Objective :Helicobacter pylori (H.pylori) infection is usually acquired in early childhood. Invasive techniques used for diagnosis ofH.pylori infection require endoscopic examination which is expensive and inconvenient and may cause complications. the aim of this study was to evaluate the performance of a new noninvasive diagnostic method, stool antigen test forH.pylori in untreated children with recurrent abdominal pain.Methods: Eighty children (35 female, 45 male) who have undergone upper gastrointestinal endoscopy due to recurrent abdominal pain were included in the study. theH.pylori stool antigen test (HpSA) is based on a sandwich enzyme immunoassay with antigen detection. HpSA sensitivity, specificity, and positive and negative predictive values were determined with reference to the results of both histology and rapid urease test as a gold standard (H. pylori status).Results: While 49 of the 80 children (61%) tested were positive forH.pylori according to the results of both histology and rapid urease test, 28 children had negativeH.pylori status. Among those 49 children, 48 were found to be positive by HpSA. Of 28 patients with negativeH.pylori status, 28 were H.py/ori-negative also in the stool test. the sensitivity, specificity, and positive and negative predictive values of HpSA were found to be 98%, 100%, 100%, and 96.5%, respectively.Conclusion: these findings have demonstrated that HpSA as a relatively simple, inexpensive and time saving noninvasive test is a reliable method for detection ofH.pylori infections in children.     

Primary Antibiotic Resistance to Helicobacter pylori Strains Isolated From Children in Northern Iran: A Single Center Study

Background:

Initial resistance to antibiotics is the main reason for the failure of Helicobacter pylori (H. pylori) eradication in children.

Objectives:

As we commonly face high antibiotic resistance rates in children, we aimed to determine the susceptibility of H. pylori to common antibiotics.

Patients and Methods:

In this cross-sectional in vitro study, 169 children younger than 14 years with clinical diagnosis of peptic ulcer underwent upper gastrointestinal endoscopy. Biopsy specimens from stomach and duodenum were cultured. In isolated colonies, tests of catalase, urease, and oxidase as well as gram staining were performed. After confirming the colonies as H. pylori, the antibiogram was obtained using disk diffusion method.

Results:

Culture for H. pylori was positive in 12.3% of the specimens, urease test in 21.3%, serological test in 18.9% and stool antigen test was positive in 21.9%. We could show high specificity but moderate sensitivity of both histological and H. pylori stool antigen tests to detect H. pylori. The overall susceptibility to metronidazole was 42.9%, amoxicillin 95.2%, clarithromycin 85.7%, furazolidone 61.9%, azithromycin 81.0%, and tetracycline 76.2% with the highest resistance to metronidazole and the lowest to clarithromycin.

Conclusions:

In our region, there is high resistance of H. pylori to some antibiotics including metronidazole and furazolidone among affected children. To reduce the prevalence of this antibiotic resistance, more controlled use of antibiotics should be considered in children.     

Comparison of non-invasive tests to detect Helicobacter pylori infection in children and adolescents: results of a multicenter European study

OBJECTIVE: To compare the current non-invasive tests for Helicobacter pylori infection in children and adolescents. STUDY DESIGN: This multicenter, multinational study investigated the sensitivity, specificity, and positive and negative predictive values of four non-invasive tests: urea breath test (UBT), stool antigen test, and antibody detection in serum and urine, in comparison with biopsy-based tests. RESULTS: Of 503 patients included pre-treatment, 473 fulfilled the definition of H pylori status and among those 316 had results available for the four non-invasive tests (including 133 H pylori -positive patients). The specificity was excellent for all tests. The UBT had the best sensitivity in all age groups, followed by serology, stool test, and antibody detection in urine. A trend for better sensitivity with an increase in age was observed except for the stool test. The receiver operating characteristics (ROC) curves showed that sensitivity of serology, stool test, and urinelisa could be improved by changing the cutoff value. An inadequate storage of the specimens may explain the poor results of the stool test. CONCLUSION: The UBT appears to be an excellent test for diagnosis of H pylori infection for children and adolescents.     

Clinical Practice: Helicobacter pylori infection in childhood

Helicobacter pylori infection is recognised as a cause of gastritis and peptic ulcer disease (PUD) and usually acquired during the first years of life. While there is a decline in the prevalence of H. pylori infection in northern and western European countries, the infection is still common in southern and eastern parts of Europe and Asia. Symptoms of H. pylori-related PUD are nonspecific in children and may include epigastric pain, nausea and/or vomiting, anorexia, iron deficiency anaemia and hematemesis. Besides, only a small proportion of children develop symptoms and clinically relevant gastrointestinal disease. H. pylori infection can be diagnosed either by invasive tests requiring endoscopy and biopsy or non-invasive tests including the ¹³C-urea breath test, detection of H. pylori antigen in stool and detection of antibodies in serum, urine and saliva. The aim of treatment is at least 90 % eradication rate of the bacteria, and a combination of two antibiotics plus a proton pump inhibitor has been recommended as first-line treatment. However, frequent use of antibiotics during childhood is associated with a decline in eradication rates and the search for new treatment strategies as well. This is an overview of the latest knowledge and evidence-based guidelines regarding clinical presentation, diagnosis and treatment of H. pylori infection in childhood.     

Diagnostic de l’infection à Helicobacter pylori chez l’enfant : quoi de neuf en 2003 ?Helicobacter pylori (H. pylori) infection in childhood: what is new in 2003?

A high prevalence and early colonization of Helicobacter pylori (H. pylori) infection in childhood characterizes the developing countries in contrast to developed ones. Upper gastrointestinal endoscopy including gastric biopsies is the diagnostic gold standard method. Non invasive tests can be used in children, including serology, ¹³C-urea breath test and immunoassay enzyme stool antigen test (HpSA). They present good performance in adults, but less in children under 6 years of age. They can be used for screening, epidemiological studies. Only the ¹³C-urea breath test and the immunoassay enzyme stool antigen test (HpSA) are recommended for the control of eradication. The infection remains often asymptomatic in children and the role of this bacterium in clinical manifestations is the subject of conflicting reports. The treatment of H. pylori infection is influenced by the resistance to the antibiotics used. We suggest that eradication of H. pylori infection should take place only after susceptibility testing since the resistance rate for the metronidazole is of 43% and for the clarithromycine 21% in France. The association of proton pump inhibitor and two antibiotics for 1–2 weeks seems to give the best eradication rates. The crucial question is whether asymptomatic children should be treated to prevent cancer in the future.     

Consideration of Helicobacter pylori infection in childhood: Immune response,endoscopic and morphological findings

Seventy-five children (aged 9–14 years) infected with Helicobacter pylori were studied endoscopically and morphologically for the signs of infection and immune response by ELISA technique (total IgE and specific IgG against H. pylori); a control group of 36 children (not infected with H. pylori) were studied simultaneously. Helicobacter pylori positive children examined endoscopically revealed a number of mucous membrane changes including erythema, erosions, lymphoid nodular hyperplasia and ulcers. Gastritis was confirmed by histology in 58 children; 6% were termed ‘active’, others were ‘non-active’. When studying the concentrations of anti-H. pylori IgG in children from the control group they were considered to be seronegative but in children infected with H. pylori a considerable increase was noted. An evaluation of the interaction between anti-H. pylori IgG titers and age, endoscopic signs and histology was carried out. Suppositions were made about the presence of links between these characteristics. Children with H. pylori infection showed a considerable increase of total IgE titers in comparison with the control group. The role of IgG and IgE in the development of chronic gastroduodenal diseases associated with H. pylori is discussed.     

Helicobacter pylori stool antigen test: A method to confirm eradication in children

We evaluated an antigen-based stool assay as an indicator of Helicobacter pylori (Hp) status during treatment aimed at eradicating Hp in 22 Hp-positive patients and 63 negative control patients. The sensitivity and specificity of the assay was 100% and 70%, respectively, when the manufacturer's cutoff was used. When we used the cutoff calculated from a receiver operating characteristic curve, the specificity of this test increased. Under these conditions, the test could be used in monitoring treatment and verifying eradication of Hp infection. Further studies must be carried out to standardize the cutoff in children. (J Pediatr 2002;140:775-7)     

Utility of diagnostic tests for detection of Helicobacter pylori in children in northeastern Mexico

BACKGROUND: The presence of Helicobacter pylori in pediatric population has been associated with recurrent abdominal pain (RAP), although this association is unclear. One of the major problems in studying the role of H. pylori in RAP is that methods used to detect the bacteria in children have poor sensitivity and specificity. The aims of the present study were to determine the prevalence of H. pylori in pediatric patients with RAP in northeastern Mexico and to assess the diagnostic utility of invasive tests and serology in this population. METHODS: A total of 40 patients (mean age, 7.9 years; range 2-16 years; F: M, 0.81), who underwent an endoscopy procedure for RAP, were studied. The presence of H. pylori was assessed using invasive diagnostic tests (culture, rapid urease test, polymerase chain reaction and histology) and one non-invasive test: determination of IgG antibodies. The prevalence of H. pylori in the present group and the diagnostic utility for each test were evaluated. RESULTS: The prevalence of H. pylori in the present pediatric group with RAP was 12.5-42.5% depending on the criteria of positivity used. The non-invasive methods (serology) had acceptable values in sensitivity and specificity in comparison with invasive tests. CONCLUSIONS: This is the first report on prevalence of H. pylori in pediatric patients with RAP from the northeastern region of Mexico. The prevalence of H. pylori was low compared with the adult population in the same geographic region. Serology had the best diagnostic utility.     

Comparison of invasive and non-invasive tests diagnosis and monitoring of Helicobacter pylori infection in children

BACKGROUND: There are few reports which the tests used for diagnosing Helicobacter pylori infection and monitoring its eradication in children. STUDY AIMS: Prospective evaluation of invasive (gastric histology, rapid urease test [RUT]) and non-invasive (stool antigen [FemtoLab H. pylori], urea breath test [UBT]) tests in the diagnosis of H. pylori infection and post-treatment eradication in children and adolescents. METHODS: Ninety-two patients (50 male, 42 female) referred for upper gastrointestinal endoscopy were prospectively enrolled. UBT was performed and stool specimens collected for monoclonal enzyme immunoassay for H. pylori antigen (FemtoLab) 1 to 4 days before endoscopy. H. pylori in gastric biopsies was evaluated by RUT and staining with hematoxylin-eosin and giemsa. Eradication therapy was given to children with abdominal pain and H. pylori gastritis. FemtoLab H. pylori and UBT were repeated 6 weeks after the end of triple therapy. RESULTS: Histology identified H. pylori in 49 of 92 (53%) subjects. Concordance between histology and RUT was found in 78 of 92 children. FemtoLab H. pylori was positive in 41 of 78 (52.6%) children with sensitivity, specificity, positive and negative predictive values of 97.5%, 94.7%, 95.1% and 97.3%, respectively. For UBT, these values were 100%, 96.9%, 97.5% and 100%, respectively. Twenty-six of 36 patients who received triple therapy returned for eradication evaluation. Tests for H. pylori antigen in stool were positive in 10 of 26 and for UBT in 11 of 26. CONCLUSION: Stool antigen (FemtoLab) and UBT were equally effective in diagnosing and confirming eradication of H. pylori infection in children.     

Diagnosis ofHelicobacter Pylori

In view of its potential risk for the development of gastrointestinal disease or even gastric cancer at a later age, the study ofHelicobacter pylori infection in childhood is gaining increasing importance andH. pylori infection is being considered a major issue of public health.H. pylori infection can be detected by a variety of methods. Because of its easy use, affordability, and overall availability, serology is the preferred diagnostic test, especially for large epidemiological studies. Based on our results, one might consider treating a child with recurrent abdominal pain and positive serology forH. pylori without further work-up, and only perform additional investigations when an anti-W.pylori therapy fails to resolve the complaints. According to this proposition, endoscopy of the upper gastrointestinal tract remains indicated in children if the noninvastive tests forHelicobacter pylori are negative in the absence of a diagnosis, or if symptomatology persists despite treatment.     

Contribution of the 13C-urea breath test to the detection of Helicobacter pylori gastritis in children.

Serology, 13C-urea breath test, histology, Campylobacter-like organism testing, and culture were performed in 95 consecutive children to evaluate the contribution of these tests to the detection of Helicobacter pylori infection. In analyses considering any combination of three positive tests as "gold standard" for diagnosing H pylori infection, 26 children were Helicobacter positive (27%), which is only one patient more than the number of children with only a positive culture. The accuracy of culture was excellent when "any combination of three positive tests" was used as the gold standard (sensitivity 96%, specificity 100%, positive predictive value 100% [false positivity 0%], negative predictive value 99% [false-negative results 1%]). The results of invasive and noninvasive tests were comparable. When culture was considered as "gold standard," the sensitivity of serology and 13C-urea breath test was 96%; the specificity was 96% and 93%, respectively; the positive predictive value was 89% and 83% (false-positive results in 11% and 17%); and the negative predictive value for both was 99% (false-negative results in 1%). It is concluded that culture can be used as gold standard, but that non-invasive tests such as serology and/or 13C-urea breath test can be used to diagnose H pylori infection in children, since each has at least 95% sensitivity and 92% specificity.     

Histologic Findings in '“Ex– Helicobacter pylori'” Gastric Biopsies of Pediatric Patients

Long-term sequelae of Helicobacter pylori–associated chronic gastritis (HpCG) have been described in adult patients. In the present study we report the histology of gastric mucosa biopsies in 6 asymptomatic pediatric patients (5 male and 1 female; mean age 9.5 years) with previous HpCG. Preceding H. pylori was histologically proved and confirmed by culture, direct visualization, and/or serology before delivering treatment. In 5 of 6 cases the HpCG followed a protracted clinical course, with various therapeutic series needed before H. pylori eradication. Time from final treatment for HpCG to actual biopsy ranged from 3 months to almost 3 years. Gastric mucosa showed mild chronic gastritis with absence of H. pylori organisms (6 of 6), focal loss of gland units with collagenous replacement (6 of 6), serrated foveolae (3 of 6), regenerative changes at elongated glandular necks with cells having enlarged and hyperchromatic nuclei (5 of 6), lymphoid aggregates (2 of 6), and presence of sulfomucins in isolated epithelial cells of glands and foveolae (2 of 6). None of these features were noticed in 10 normal gastric mucosa biopsies used as controls. The referred findings in “ex– H. pylori” pediatric patients may represent very early sequelae from HpCG at this age.     

Helicobacter pylori colonization in children with peptic ulcer disease III. Diagnostic value of the 13C-urea breath test to detect gastric H. pylori colonization

The efficiency of the ¹³C-Urea Breath Test (¹³C-UBT) for the detection of Helicobacter pylori colonization in gastric mucosa was evaluated. The ¹³C-UBT was performed in five pediatric and six adult subjects who had had upper gastrointestinal endoscopy within 2 weeks. H. pylori colonization was confirmed in two pediatric and three adult subjects with peptic ulcer combined with antral gastritis, by histological examination of antral biopsy specimens. When an individual with H. pylori colonization ingested a solution containing ¹³C-urea, a significant amount of ¹³CO₂ appeared in the respiratory CO₂ within 10 min. The mean cumulative percentage dose of ¹³C recovered in the breath over 30 min in the cases with H. pylori colonization was significantly higher than that in those who were not colonized (4.91 vs 0.41, P <0.001). In addition, the effect of antibiotic on the eradication of H. pylori from gastric mucosa was monitored by ¹³C-UBT in two cases. The values of cumulative percentage dose of ¹³C over 30 min fell to the same levels as those observed in H. pylori negative subjects after just 2 weeks treatment with amoxicillin; however, positive results were obtained again 1 month after the withdrawal of amoxicillin. In summary, ¹³C-UBT is a simple, reliable, non-invasive method in the diagnosis of gastric H. pylori colonization especially for pediatric patients.     

Primary gastric burkitt lymphoma: a rare cause of intraabdominal mass in childhood

Primary gastric lymphoma in the pediatric population is rare and the role of Helicobacter Pylori (H. Pylori) in its pathogenesis is unclear. In this report, we describe a case of non-Hodgkin’s lymphoma (Burkitt’s type) coexisting with H. pylori and discuss the potential relationship between H. Pylori and gastric Burkitt lymphoma.     

Helicobacter pylori antigens in stool specimens of gastritis children before and after treatment

BACKGROUND: Various testing methods are successfully applied to the diagnosis of Helicobacter pylori infection, but noninvasive techniques are still needed for therapeutic monitoring, especially in children. In the search for new noninvasive techniques for the diagnosis of H. pylori infection, the authors evaluated an enzyme immunoassay for the detection of H. pylori antigen in stool (HpSA). METHODS: The authors studied 62 H. pylori-positive children with chronic gastritis and 45 control subjects. H. pylori infection was diagnosed using cultures and histology of gastric biopsy specimens and a stool antigen test before treatment (clarithromycin, amoxicillin, omeprazole for 7 days) and 4 weeks to 6 weeks after treatment. RESULTS: Before therapy, antigen in stool was detected in 55 of 62 H. pylori-positive patients, which indicates that the sensitivity of the HpSA test was 88.7%. Of the 45 control subjects (with negative culture and histology results), 43 had negative results for H. pylori in the stool test (specificity, 95.5%). After completion of therapy, eradication was obtained (and confirmed by culture and histology) in 53 of the 62 H. pylori-positive children (85.5%). Four weeks to 6 weeks after eradication therapy, the sensitivity, specificity, positive predictive value, and negative predictive value of the stool antigen (HpSA) test were 88.9%, 96.2%, 80%, and 98%, respectively. CONCLUSIONS: The accuracy of the HpSA test for the detection of H. pylori in human stool 4 weeks to 6 weeks after treatment is comparable with the accuracy of the culture results. The stool antigen (HpSA) test was found to be a useful method for posttreatment eradication testing of infection in children.     

Symptomatology of Helicobacter pylori infection in children

In a retrospective evaluation we reviewed the symptomatology of 143 children (age 2–15 years, mean 8.9 years) who were referred to us for upper gastrointestinal endoscopy because of recurrent abdominal pain with a duration of 6 weeks or longer. Helicobacter pylori infection was diagnosed in 36 out of 143 patients (25.2%). No statistically significant differences could be detected between the symptoms experienced by the 36 H. pylori-infected children and those experienced by the remaining 107 H.pylori-negative pediatric patients (p = 0.18–0.60). We conclude that no specific symptoms are associated with H. pylori gastritis in children. Our observations suggest that the recurrent abdominal complaints found in children with H. pylori infection seem to be caused by the secondary gastroduodenal pathology, rather than by H. pylori infection itself.     

Severe iron‐deficiency anaemia in adolescents: Consider Helicobacter pylori infection

Aim: This article describes the association of severe iron‐deficiency anaemia with Helicobacter pylori gastritis. Results: We report three children who had symptomatic iron‐deficiency anaemia with no obvious clinical cause and refractory to iron replacement therapy. All three underwent a diagnostic endoscopy and were found to have H. pylori gastritis. Histopathology confirmed inflammatory changes consisting of dense bands of clusters of plasma cells within the lamina propria and two of the three adolescents were noted to have numerous H. pylori in gastric crypts and glands. Two of the three cases had a urease positive test. Iron deficiency was successfully corrected following antibiotic eradication of H. pylori infection. Conclusions: This case series highlights the importance of considering H. pylori infection as a cause of refractory iron‐deficiency anaemia in adolescents, even in the absence of gastrointestinal symptoms.     

Accurate diagnosis of Helicobacter pylori infection by stool antigen test and 6 other currently available tests in children

Invasive and noninvasive tests have been developed for the diagnosis of Helicobacter pylori infection. Because H pylori infection is acquired in childhood and adolescence, accurate diagnosis of the infection in the pediatric population is important. We conducted a study to compare invasive tests: culture, biopsy urease test, histology, and polymerase chain reaction on gastric biopsy specimens, with noninvasive tests: serology, (13)C-urea breath test, and a new diagnostic modality, stool antigen test to diagnose H pylori infection. A total of 53 children with symptoms were enrolled in this study, and all had completed the 7 diagnostic tests for H pylori. All the diagnostic tests except serology were excellent methods of diagnosing H pylori infection in children; the diagnostic accuracy was as follows: stool antigen test 96.2%, biopsy urease test 96.2%, histology 98.1%, polymerase chain reaction 94.3%, culture 98.1%, (13)C-urea breath test 100%, and serology 84.9%. The stool antigen test, being highly sensitive and specific, will be potentially very helpful in diagnosing H pylori infection in children.     

Evaluation of stool antigen test for Helicobacter pylori infection in asymptomatic children from a developing country using 13C-urea breath test as a standard

OBJECTIVE: Prevalence of asymptomatic Helicobacter pylori infection is very high in infants and children in developing countries. C urea breath test (UBT) is a reliable non-invasive diagnostic test for H. pylori infection in children that avoids invasive endoscopy. We compared a newly introduced H. pylori stool antigen test (with a high sensitivity and specificity in symptomatic children) with UBT in asymptomatic children mostly 1-5 years old, from a population with a high prevalence of infection. METHOD: Eighty six asymptomatic children (42 boys and 44 girls) were tested for H. pylori infection using the UBT and a stool antigen test (HpSA) based on a sandwich enzyme immunoassay for antigen detection. RESULTS: Forty five of the eighty-six (52.3%) children tested positive for H. pylori using the breath test. In 34 of these forty-five children, H. pylori antigen was detected in stool (sensitivity = 75.6%, 95% CI = 63 to 88%). Of the 50 of 86 (58%) children positive by HpSA test, 34 were positive for breath test. Of the 41 children with negative UBT test 25 were negative for stool antigen test (specificity = 61%, 95% CI = 46 to 76%). CONCLUSION: The sensitivity and specificity of the new stool antigen test are lower in asymptomatic children with high H. pylori prevalence rate compared to those reported for children with gastrointestinal symptoms. Its usefulness is limited for diagnosis in an asymptomatic child with H. pylori infection.     

Evaluation of a novel stool native catalase antigen test for Helicobacter pylori infection in asymptomatic North American children

Rapid immunochromatographic tests for Helicobacter pylori infection have been developed to allow "near-patient" testing. We therefore performed a pilot study to test a rapid immunochromatographic stool antigen test for the diagnosis of H. pylori infection in asymptomatic children. We tested stool specimens collected from children participating in a cohort study in the United States and Mexico. H. pylori-positive status was defined by positivity on at least 2 tests: a commercial H. pylori stool antigen enzyme immunoassay, an immunoglobulin G antibody enzyme immunoassay, and the C-urea breath test. Negative H. pylori status was defined by negative findings of all of these tests. Of 52 children (22 girls, 30 boys) 25 were H. pylori-positive, 19 H. pylori-negative, and 8 uncertain (eg, presumably negative; positive findings on 1 of the 3 noninvasive tests). The sensitivity and specificity of the new stool antigen test for those with definite H. pylori status were 100% (exact 95% CI 86.3%-100% and 82.4%-100%, respectively). This rapid stool antigen test may prove useful for point-of-care testing and epidemiological field studies. Larger prospective studies are needed in symptomatic and asymptomatic children for more precise estimates.