Novel monoclonal antibody-based Helicobacter pylori stool antigen test

What Is New in Helicobacter pylori Diagnosis. An Overview

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

Clinical Performance of the Automated LIAISON® Meridian H. pylori SA Stool Antigen Test

Background

Antigens derived from Helicobacter pylori can be used as stool biomarkers to assist in the diagnosis of H. pylori infection. Since current assays have variable performance, we assessed the clinical performance of the automated LIAISON® Meridian H. pylori infection. Since current assays have variable performance, we assessed the clinical performance of the automated LIAISON® Meridian

Methods

This prospective multisite study enrolled patients undergoing an esophagogastroduodenoscopy with collection of biopsy and stool specimens. Adult patients (≥22 years) participated in the study from February 2017 to August 2018. Specimens of the stomach were tested by three methods, known as the Composite Reference Method: (1) histological evaluation, (2) culture of the organism, and (3) rapid urease detection test. H. pylori infection. Since current assays have variable performance, we assessed the clinical performance of the automated LIAISON® Meridian H. pylori infection. Since current assays have variable performance, we assessed the clinical performance of the automated LIAISON® Meridian

Results

277 patients (63% female) were included in the study. The prevalence of infected subjects was 24.2% in this study cohort. Clinical performance assessed against the Composite Reference Method showed very good agreement (Cohen′s kappa = 0.922), with good sensitivity (95.5%) and specificity (97.6%). Reproducibility study results showed total imprecision ranging from 3.1% to 13.9% CV.

Conclusion

The automated LIAISON® Meridian H. pylori SA assay brings reliable noninvasive testing for H. pylori to the laboratory that is in very good agreement with the current, more invasive biopsy-based methods such as histology, culture, or rapid urease test. The clinical trial identifiers are NCT03060746 (pretherapy) and NCT03060733 (posttherapy).H. pylori infection. Since current assays have variable performance, we assessed the clinical performance of the automated LIAISON® Meridian H. pylori infection. Since current assays have variable performance, we assessed the clinical performance of the automated LIAISON® Meridian

Twice-a-day PPI, tetracycline, metronidazole quadruple therapy with Pylera® or Lactobacillus reuteri for treatment naïve or for retreatment of Helicobacter pylori. Two randomized pilot studies

BACKGROUND

Bismuth is no longer available in Europe except as part of combination therapy. Lactobacillus reuteri has also been used as an adjuvant for Helicobacter pylori therapy. We aimed to investigate the efficacy of a b.i.d. quadruple therapy containing Pylera® or L reuteri for H pylori infection.

MATERIALS AND METHODS

We performed two open-label randomized pilot studies. Adult patients positive for H pylori were randomly assigned to b.i.d therapy with quadruple therapy containing bismuth (2 capsules of Pylera® plus 250 mg each of tetracycline and metronidazole for a total of 500 mg of each), or the same dose of antibiotics plus 2 × 10⁸  CFU L reuteri DSM 17 938 plus 2 × 10⁸  CFU L reuteri ATCC PTA 6475 (Gastrus®) once daily and pantoprazole 20 mg b.i.d. Regimens were given with meals for 10 days. Cure was defined by negative 13C-UBT or stool antigen test.

RESULTS

A total of 99 subjects (29% men) were enrolled; 92 completed the study. In the Pylera® group, H pylori infection was cured in 95.7%; 95% CI = 85%-99% (44/46) PP and 88%; 95% CI = 75%-95% (44/50) ITT vs. 84.8%; 95% CI = 71%-95% (39/46) PP and 79.6%; 95% CI = 65%-89% (39/49) ITT in the Gastrus® group, respectively. Cure rates in naїve patients were 100%; 95% CI = 85%-100% (25/25) PP with Pylera®, and 89.7%; 95% CI = 72%-97% (26/29) with Gastrus®. Compliance was excellent and side effects mild with both regimens.

CONCLUSIONS

B.i.d. bismuth quadruple therapy was highly effective for H pylori eradication in treatment of naïve patients in Sardinia. Replacement of bismuth with Gastrus® might be considered when bismuth is contraindicated or unavailable.

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.

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.

Dyspepsia: When and How to Test for Helicobacter pylori Infection

Dyspepsia is defined as symptoms related to the upper gastrointestinal tract. Approximately 25% of western populations complain of dyspeptic symptoms each year. 70% of them do not have an organic cause and symptoms are related to the so-called functional dyspepsia, characterized by epigastric pain, early satiety, and/or fullness during or after a meal occurring at least weekly and for at least 6 months according to ROME III criteria. In order to avoid invasive procedures and adverse effects, to minimize costs, to speed up diagnosis, and to provide the most appropriate treatments, primary care physicians need to recognize functional dyspepsia. Because symptoms do not reliably discriminate between organic and functional forms of the disease, anamnesis, family history of peptic ulcer and/or of gastric cancer, medication history, especially for nonsteroidal anti-inflammatory drugs, age, and physical examination could help the physician in discerning between functional dyspepsia and organic causes. For patients without alarm symptoms, noninvasive testing for H. pylori, with either carbon-13-labeled urea breath testing or stool antigen testing, is recommended as a first-line strategy. In this review, we provide recommendations to guide primary care physicians for appropriate use of diagnostic tests and for H. pylori management in dyspeptic patients.

The Relation between Helicobacter pylori Infection and Acute Bacterial Diarrhea in Children

Background. H. pylori infection leads to chronic gastritis in both children and adults. But recently, there are arising theories of its protective effect in diarrheal diseases. Aim. To explore the prevalence of H. pylori infection in children with bacterial diarrhea and compare it with healthy controls. Patients and Methods. Two matched groups consisted of 122 consecutive children, aged 24–72 months old, with acute bacterial diarrhea, who had Shigellosis (N = 68) and Salmonellosis (N = 54) as patients group and 204 healthy asymptomatic children as control group enrolled in this study. Results. The prevalence of H. pylori infection in healthy control children was significantly higher than in patients group, (odds ratio = 3.6, 95% CI: 1.33–9.5, P = 0.007). In our study, only 2/54 Salmonella infected patients and 3/68 of Shigellosis had evidence of H. pylori infection, while normal control children had 27/204 infected individuals. Conclusion. H. pylori infection may play a protective role against bacterial diarrhea in children. So it is important to consider all of the positive and negative aspects of H. pylori infection before its eradication.

Immunodot blot assay to detect Helicobacter pylori using monoclonal antibodies against the 26 kDa protein

Development of a specific immunoassay to detect Helicobacter pylori infection in stool samples requires monoclonal antibody against the specific antigen. The aims of this study were to establish monoclonal antibodies against the 26 kDa protein of H. pylori and develop an immunodot blot for their application to recognize H. pylori infection using stool samples. Mice were immunized intraperitoneally with homogenized gel containing the 26 kDa band of cell surface proteins of H. pylori in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The monoclonal antibodies were produced using the hybridoma technique. Reactivity of monoclonal antibodies was tested with the purified 26 kDa antigen and cell surface proteins from cultured H. pylori by ELISA. Furthermore reactivity of monoclonal antibodies was tested on negative and positive stool samples for H. pylori and suspensions of several major bacteria in stool by immunodot blot assay. Five stable hybridoma monoclones were obtained. The concordant reactivity of the monoclonal antibodies with H. pylori present in the stool samples, which had been tested previously using an ACON ELISA kit for H. pylori stool antigen testing, and unreactivity with several different major fecal bacteria in immunodot blotting indicates high specificity of the immunodot blot based on the reaction of produced monoclonal antibodies with the H. pylori antigen in stools. The findings indicate that the novel immunodot blot developed based on new monoclonal antibodies for stool antigens would be useful as a noninvasive method of diagnosing H. pylori infection.

Validation of a rapid stool antigen test for diagnosis of Helicobacter pylori infection

The aim of this study was to validate the rapid lateral flow Helicobacter pylori stool antigen test (One step H. pylori antigen test, ACON laboratories, San Diego, USA; Prime diagnostics, São Paulo), using 13C-Urea Breath Test as the gold standard for H. pylori infection diagnosis. A total of 98 consecutive patients, asymptomatic or dyspeptic, entered the study. Sixty-nine were women, with a mean age of 45.76 ± 14.59 years (14 to 79 years). In the H. pylori-positive group, the rapid stool antigen test detected H. pylori antigen in 44 of the 50 positive patients (sensitivity 88%; 95% CI: 75.7-95.5%), and six false-negative; and in the H. pylori-negative group 42 presented negative results (specificity 87.5%; 95% CI: 74.7-95.3%), and six false-positive, showing a substantial agreement (Kappa Index = 0.75; p < 0.0001; 95% CI: 0.6-0.9). Forty four of fifty patients that had positive stool antigen were H. pylori-positive, the PPV of the stool antigen test was 88% (95% CI: 75.7-95.5%), and 42 patients with negative stool antigen test were H. pylori-negative, the NPV of the stool antigen test was 87.5% (95% CI: 74.7-95.3%). We conclude that the lateral flow stool antigen test can be used as an alternative to breath test for H. pylori infection diagnosis especially in developing countries.

The source of Helicobacter pylori infection in the neonatal period

AIMS

To investigate the transmission of Helicobacter pylori in the perinatal period.

METHODS

H. pylori status of 180 women was preliminarily screened by serology and stool antigen test (SAT) within the fourth day after delivery and a positive value was confirmed by (13)C-urea breath test. Infants were analyzed by SAT at 1, 6, 12 and 18 months of age. H. pylori status was also investigated in the medical and paramedical staff of the Neonatology Unit.

RESULTS

H. pylori infection was found in 34.4% of the women. At the 1(st) month of age, 5 out of 172 newborns (2.9%) were H. pylori positive by SAT. Three out of the five positive infants were born to H. pylori non-infected mothers. Formula feeding (P=0.02) and admission in intermediate-risk neonatal unit (P=0.01) were significantly related to a positive H. pylori result. Medical and paramedical staff of the neonatology unit was found H. pylori positive in 34.8% of cases. All five H. pylori positive children spontaneously cleared the infection.

CONCLUSIONS

Perinatal H. pylori SAT positive status is low in our area, and it may be found both in infants from infected or non-infected mothers. Formula feeding and admission in intermediate-risk neonatal unit appear to be related with H. pylori infection.

Diagnosis of Helicobacter pylori infection in a high-prevalence pediatric population: a comparison of 2 fecal antigen testing methods and serology

OBJECTIVES

Accurate methods for diagnosing active Helicobacter pylori infection in children have been limited to invasive or time-consuming techniques. Recently, fecal antigen testing has been used successfully for the diagnosis of H pylori infection in the pediatric population. We compared 2 monoclonal fecal antigen diagnostic methods in a population of children with a suspected high prevalence of H pylori infection. We also assessed the diagnostic performance of H pylori immunoglobulin G serology.

MATERIALS AND METHODS

In a cross-sectional study of African refugee children (<16 years) we compared an immunochromatographic technique (ICT) and serology with a monoclonal fecal antigen enzyme immunoassay (MFAT) method for the detection of active H pylori infection. Following the manufacturer's instructions, an optical density of >or=0.190 was used as a cutoff for MFAT. Sensitivity, specificity, and positive and negative predictive values were calculated.

RESULTS

Of the 193 eligible children enrolled, active H pylori infection was detected in 149 of 182 (81.9%) in whom MFAT was performed. The prevalence of active infection increased with age; children with active infection were significantly older, and there were no sex differences. ICT and serology underperformed in comparison with MFAT (ICT sensitivity 74.6%, specificity 63.6%, positive predictive value 89.8%, negative predictive value 36.8%; and serology sensitivity 57.9%, specificity 77.4%, positive predictive value 92.0%, negative predictive value 29.9%).

CONCLUSIONS

Monoclonal enzyme immunoassay fecal antigen testing is a practical and feasible alternative to traditional invasive diagnostic methods in high-prevalence pediatric populations. Neither immunochromatography nor serology is useful for the diagnosis of active H pylori infection in these children.

Accuracy of monoclonal stool antigen test for the diagnosis of H. pylori infection: a systematic review and meta-analysis

OBJECTIVE

To perform a systematic review and a meta-analysis of accuracy of monoclonal stool antigen test (SAT) for the diagnosis of Helicobacter pylori infection.

SELECTION OF STUDIES

assessing the accuracy of monoclonal SAT for the diagnosis of H. pylori infection.

SEARCH STRATEGY

electronic and manual bibliographical searches.

DATA EXTRACTION

independently done by two reviewers.

DATA SYNTHESIS

meta-analyses combining the sensitivities, specificities, and likelihood ratios (LRs) of the individual studies.

RESULTS

Twenty-two studies, including 2,499 patients, evaluated the monoclonal SAT before eradication therapy. Pooled sensitivity, specificity, LR+, and LR- were: 0.94 (95% CI 0.93-0.95), 0.97 (0.96-0.98), 24 (15-41), and 0.07 (0.04-0.12). The accuracy of both monoclonal and polyclonal SAT was evaluated together in 13 pretreatment studies, and higher pooled sensitivity was demonstrated with the monoclonal technique (0.95 vs 0.83). Twelve studies, including 957 patients, assessed the monoclonal SAT to confirm eradication after therapy. Pooled sensitivity, specificity, LR+, and LR- were 0.93 (0.89-0.96), 0.96 (0.94-0.97), 17 (12-23), and 0.1 (0.07-0.15). Both tests were evaluated together in eight post-treatment studies and, again, the monoclonal technique showed higher sensitivity (0.91 vs 0.76). Heterogeneity among studies disappeared when a single outlier study was excluded. Subanalysis depending on the reference method, the study population, or the study quality showed similar results.

CONCLUSION

Monoclonal SAT is an accurate noninvasive method both for the initial diagnosis of H. pylori infection and for the confirmation of its eradication after treatment. The monoclonal technique has higher sensitivity than the polyclonal one, especially in the post-treatment setting.

Helicobacter pylori infection is not associated with an increased hemorrhagic risk in patients in the intensive care unit

Introduction

The potential role of Helicobacter pylori in acute stress ulcer in patients in an intensive care unit (ICU) is controversial. The aim of this study was to determine the frequency of H. pylori infection in ICU patients by antigen detection on rectal swabs, and to analyze the potential relationship between the presence of H. pylori and the risk of digestive gastrointestinal bleeding.

Methods

In this prospective, multicenter, epidemiological study, the inclusion criteria were as follows: patients admitted to the 12 participating ICU for at least two days, who were free of hemorrhagic shock and did not receive more than four units of red blood cells during the day before or the first 48 hours after admission to the ICU. Rectal swabs were obtained within the first 24 hours of admission to the ICU and were tested for H. pylori antigens with the ImmunoCard STAT! HpSA kit. The following events were analyzed according to H. pylori status: gastrointestinal bleeding, unexplained decline in hematocrit, and the number of red cell transfusions.

Results

The study involved 1,776 patients. Forty-nine patients (2.8%) had clinical evidence of upper digestive bleeding. Esophagogastroduodenoscopy was performed in 7.6% of patients. Five hundred patients (28.2%) required blood transfusion. H. pylori antigen was detected in 6.3% of patients (95% confidence interval 5.2 to 7.5). H. pylori antigen positivity was associated with female sex (p < 0.05) and with a higher Simplified Acute Physiology Score II (SAPS II; p < 0.05). H. pylori antigen status was not associated with the use of fiber-optic gastroscopy, the need for red cell transfusions, or the number of red cell units infused.

Conclusion

This large study reported a small percentage of H. pylori infection detected with rectal swab sampling in ICU patients and showed that the patients infected with H. pylori had no additional risk of gastrointestinal bleeding. Thus H. pylori does not seem to have a major role in the pathogenesis of acute stress ulcer in ICU patients.

Immunity markers in patients with Helicobacter pylori infection: effect of eradication

BACKGROUND

Helicobacter pylori is a microorganism able to stimulate a robust inflammatory and systemic immune response.

AIM

The aim of our study was to evaluate autoimmune markers in dyspeptic patients positive for H. pylori infection compared to a control group of non-H. pylori-infected subjects. The kinetics of cryoglobulins and autoantibodies was evaluated after treatment of the infection.

PATIENTS AND METHODS

Dyspeptic patients with active H. pylori infection and age- and sex-matched healthy H. pylori-negative controls were studied. Markers of immunity were compared, in H. pylori-infected patients before, 6 months and 1 year after the end of therapy. Results were also compared between those with and without successful eradication therapy.

RESULTS

Eighty-six individual were entered (43 H. pylori-infected). H. pylori-infected patients had higher levels of IgG and/or IgA and/or IgM (22/43 versus 2/43). Circulating immune complexes and cryoglobulins were detected in patients more often than controls (p < .05 for both). Autoantibodies were observed in 13 patients (30% versus 5% in controls) and antithyroid antibodies in 12 (p < .04 versus controls). Lower levels of C3 and/or C4 complement fractions were observed in infected patients with respect to controls (7/43 versus 1/43; p = .014). After 1 year of follow-up, the markers of autoimmunity dramatically improved in patients eradicated for H. pylori infection compared to those in whom therapy failed. No patient developed a clinical autoimmune disorder.

CONCLUSIONS

Additional studies are necessary to ascertain the clinical significance of the modifications of autoimmune markers in patients with H. pylori infection.

Diagnosis of Helicobacter pylori Infection

A large number of studies on diagnostic tests have been published this year. New tests were proposed for the detection of Helicobacter pylori antigens in stools and new molecular methods (real-time polymerase chain reaction) to look for antimicrobial susceptibility. The other standard tests have been applied in different situations to improve the diagnosis of the infection.