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 breathingtest and stool antigen test are most widely used noninvasive 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.

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.

Application of Stool-PCR test for diagnosis of Helicobacter pylori infection in children

AIM： To evaluate the usefulness of stooI-PCR test for diagnosis of Helicobacter pylori （H pylon） infection in pediatric populations. METHODS： Based on endoscopic features （including nodular gastritis, erosive duodenitis and ulcer） and/or a positive rapid urease test （RUT） obtained during endoscopy, 28 children from a group of children admitted to the Children＇s Medical Center of Tehran for persistent upper gastrointestinal problems were selected to compare biopsy-based tests with stool- PCR. Their gastric activity and bacterial density were graded by the updated Sydney system, and their first stool after endoscopy was stored at -70℃. Biopsies were cultured on modified campy-blood agar plates and identified by gram-staining, biochemical tests, and PCR. Two methods of phenol-chloroform and boiling were used for DNA extraction from H pylori isolates. Isolation of DNA from stool was performed using a stool DNA extraction kit （Bioneer Inc, Korea）. PCR was performed using primers for detection of vacA, cagA, and 16srRNA genes in both isolates and stool. RESULTS： Sixteen out of 28 child patients （57%） were classified as H pylori positive by biopsy-based tests, of which 11 （39%） were also positive by stool- PCR. Sensitivity and specificity of stool-PCR was 62.5% and 92.3% respectively. H pylori was observed in histological sections for 10 out of 11 stool-positive patients. Association was observed between higher score of H pylori in histology and positivity of stool- PCR. Also association was observed between the more severe form of gastritis and a positive stool-PCR. CONCLUSION： Association between higher score of H pylori in histology and a positive stool-PCR make it a very useful test for detection of H pylori active infection in children. We also suggest that a simple stool-PCR method can be a useful test for detection of Hpylori virulence genes in stool.

Stool antigen tests in the diagnosis of Helicobacter pylori infection before and after eradication therapy

Aim： To evaluate two enzyme immunoassay-based stool antigen tests, Premier Platinum HpSA and Amplified IDEIA HpStAR, and one rapid test, ImmunoCard SLAT! HpSA, in the primary diagnosis of Helicobacter pylon （H pylori） infection and after eradication therapy. METHODS： Altogether 1 574 adult subjects were screened with a whole-blood H pylori antibody test and positive results were confirmed with locally validated serology and ^13C-urea breath test. All 185 subjects, confirmed to be H pylori positive, and 97 H pylorinegative individuals, randomly selected from the screened study population and with negative results in serology and UBT, were enrolled. After eradication therapy the results of 182 subjects were assessed. RESULTS： At baseline, the sensitivity of HpSA and HpStARwas 91.9% and 96.2%, respectively, and specificity was 95.9% for both tests. ImmunoCard had sensitivity of 93.0% but specificity of only 88.7%. After eradication therapy, HpSA and HpStAR had sensitivity of 81.3% and 100%, and specificity of 97.0% and 97.6%, respectively. ImmunoCard had sensitivity of 93.8% and specificity of 97.0%. HpSA, HpStAR, and ImmunoCard had PPV 77%, 80%, and 75%, and NPV 98%, 100%, and 99%, respectively. CONCLUSION： In primary diagnosis, the EIA-based tests performed well. After eradication therapy, negative results were highly accurate for all the three tests. HpStAR had the best overall performance.

Limitations of urease test in diagnosis of pediatric Helicobacter pylori infection

The diagnosis of Helicobacter pylori(H. pylori) infection is usually based on the results of urease test and histology. The urease test known as a simple and cheap method does not need special skills to perform or to read the result. The time needed for the test to turn positive depends on the concentration of bacteria, and the accuracy is up to the density of H. pylori density in the biopsy sample, which is generally lower in children than adolescents and adults. Therefore, there are debates about the sensitivity of the urease test in children. The reason for lower sensitivity of the urease test in children was not identified, but might be related to the low density and patchy distribution of bacteria. In this review, we discuss the limitations of the urease test in children according to age, histology, number of biopsy samples, and biopsy site. In children under 5 years old, the differences in positivity rate when the urease test used one or three biopsy samples, and samples from the antrum or the gastric body, were larger than those in children aged 5-15 years. Thus, three or more biopsy samples from both the antrum and body would improve the sensitivity of H. pylori infection diagnosis in children under 5 years old.

Assessing GastroPanel serum markers as a non-invasive method for the diagnosis of atrophic gastritis and <i>Helicobacter pylori</i>infection

Gastric colonization by Helicobacter pylori increases the risk of gastric disorders, including atrophic gastritis which can be diagnosed based on levels of serum biomarkers like Gastrin and Pepsinogen. We therefore examined the efficacy of a serological-based method namely GastroPanel Blood kit, in diagnosing and scoring gastritis associated to Helicobacter pylori infection. Patients with dyspeptic symptoms were prospectively recruited on voluntary basis at the Yaounde Central Hospital and University Teaching Hospital, from March to July 2011. The degree of atrophy was classified according to levels in patient serum of pepsinogens I and II (PGI and PGII) and Gastrin 17 (G17) and compared with histological profiles as reference method. A specific ELISA test was used for the detection of H. pylori IgG antibodies. In total, 86 volunteers from 21 to 83 years old (mean = 46.4 ± 3.3) were enrolled, including 74.4% of women and 25.6% of men. The prevalence of gastritis was statistically similar between Gastro Blood Panel test and histology used as reference method (89.5% versus 83.7%: p > 0.20). Diagnosis based on serum makers showed high sensitivity (93.1%) in comparison with the reference method. However, the serological based method has diagnosed more atrophic gastritis than the reference (17.4% versus 7.0%: p 0.05). Furthermore, the prevalence of H. pylori infection did not differ significantly between serological method (84.9%) and reference method (81.4%). These results suggest that diagnosis of atrophic gastritis and H. pylori infection obtained with an optional serological method (GastroPanel) is in a strong agreement with the biopsy findings, and thus can be a useful non endoscopic assessment of stomach mucosal atrophy in patients with dyspepsia.

Current situation and prospect of artificial intelligence application in endoscopic diagnosis of Helicobacter pylori infection

With the appearance and prevalence of deep learning,artificial intelligence(AI)has been broadly studied and made great progress in various fields of medicine,including gastroenterology.Helicobacter pylori(H.pylori),closely associated with various digestive and extradigestive diseases,has a high infection rate worldwide.Endoscopic surveillance can evaluate H.pylori infection situations and predict the risk of gastric cancer,but there is no objective diagnostic criteria to eliminate the differences between operators.The computer-aided diagnosis system based on AI technology has demonstrated excellent performance for the diagnosis of H.pylori infection,which is superior to novice endoscopists and similar to skilled.Compared with the visual diagnosis of H.pylori infection by endoscopists,AI possesses voluminous advantages:High accuracy,high efficiency,high quality control,high objectivity,and high-effect teaching.This review summarizes the previous and recent studies on AI-assisted diagnosis of H.pylori infection,points out the limitations,and puts forward prospect for future research.

Is Helicobacter pylori infection protective against esophageal cancer?

Helicobacter pylori(H.pylori)infection affects a substantial proportion of the global population and causes various gastric disorders,including gastric cancer.Recent studies have found an inverse relationship between H.pylori infection and eso-phageal cancer(EC),suggesting a protective role against EC.This editorial focuses on the possible mechanisms underlying the role of H.pylori infection in EC and explores the role of gut microbiota in esophageal carcinogenesis and the prac-ticality of H.pylori eradication.EC has two major subtypes:Esophageal squamous cell carcinoma(ESCC)and esophageal adenocarcinoma(EAC),which have different etiologies and risk factors.Gut microbiota can contribute to EC via inflammation-induced carcinogenesis,immunomodulation,lactagenesis,and genotoxin production.H.pylori infection is said to be inversely related to EAC,protecting against EAC by inducing atrophic gastritis,altering serum ghrelin levels,and triggering cancer cell apoptosis.Though H.pylori infection has no significant association with ESCC,COX-2-1195 polymorphisms and endogenous nitrosamine production can impact the risk of ESCC in H.pylori-infected in-dividuals.There are concerns regarding a plausible increase in EC after H.pylori eradication treatments.However,H.pylori eradication is not associated with an increased risk of EC,making it safe from an EC perspective.

Association between central serous chorioretinopathy and Helicobacter pylori infection: a systematic review and Meta-analysis

AIM:To investigate the association between central serous chorioretinopathy(CSC)and Helicobacter pylori(Hp)by summarizing all available evidence.METHODS:The Scopus,Embase,EBSCO,PubMed,Web of Science,and Cochrane Library databases for all relevant studies published from inception to October 2022 were searched,and manually searched for relevant reference lists as a supplement.Studies investigating the association between CSC and Hp infection were included.Finally,8 case-control studies were included in the Meta-analysis after study selection.RESULTS:The results showed no significant correlation between Hp infection and CSC[odds ratio(OR)1.89,95%confidential interval(CI)0.58–6.15,I2=96%,P=0.29].After subgroup analysis based on the degree of development of the study(developing/developed countries),it was found that the results of the two subgroups were the same as the whole,and no significant difference between the two subgroups existed.Meta-regression showed that the effect of sample size on heterogeneity among studies was more prominent(P<0.01,adjusted R^(2)=89.72%),which can explain 89.72%of the sources of heterogeneity.CONCLUSION:This Meta-analysis reveals no significant correlation between Hp infection and CSC,which still warrants further well-designed extensive sample studies to reach a more reliable conclusion and promote a better understanding of the treatment of CSC.

Evaluation of urea breath test as a diagnostic tool for Helicobacter pylori infection in adult dyspeptic patients

In this editorial,we discuss the article in the World Journal of Gastroenterology.The article conducts a meta-analysis of the diagnostic accuracy of the urea breath test(UBT),a non-invasive method for detecting Helicobacter pylori(H.pylori)infection in humans.It is based on radionuclide-labeled urea.Various methods,both invasive and non-invasive,are available for diagnosing H.pylori infection,inclu-ding endoscopy with biopsy,serology for immunoglobulin titers,stool antigen analysis,and UBT.Several guidelines recommend UBTs as the primary choice for diagnosing H.pylori infection and for reexamining after eradication therapy.It is used to be the first choice non-invasive test due to their high accuracy,specificity,rapid results,and simplicity.Moreover,its performance remains unaffected by the distribution of H.pylori in the stomach,allowing a high flow of patients to be tested.Despite its widespread use,the performance characteristics of UBT have been inconsistently described and remain incompletely defined.There are two UBTs available with Food and Drug Administration approval:The 13C and 14C tests.Both tests are affordable and can provide real-time results.Physicians may prefer the 13C test because it is non-radioactive,compared to 14C which uses a radioactive isotope,especially in young children and pregnant women.Although there was heterogeneity among the studies regarding the diagnostic accuracy of both UBTs,13C-UBT consistently outperforms the 14C-UBT.This makes the 13C-UBT the preferred diagnostic approach.Furthermore,the provided findings of the meta-analysis emphasize the significance of precise considerations when choosing urea dosage,assessment timing,and measurement techniques for both the 13C-UBT and 14C-UBT,to enhance diagnostic precision.

Urea breath test for Helicobacter pylori infection in adult dyspeptic patients: A meta-analysis of diagnostic test accuracy

BACKGROUND Helicobacter pylori(H.pylori)infection has been well-established as a significant risk factor for several gastrointestinal disorders.The urea breath test(UBT)has emerged as a leading non-invasive method for detecting H.pylori.Despite numerous studies confirming its substantial accuracy,the reliability of UBT results is often compromised by inherent limitations.These findings underscore the need for a rigorous statistical synthesis to clarify and reconcile the diagnostic accuracy of the UBT for the diagnosis of H.pylori infection.AIM To determine and compare the diagnostic accuracy of 13C-UBT and 14C-UBT for H.pylori infection in adult patients with dyspepsia.METHODS We conducted an independent search of the PubMed/MEDLINE,EMBASE,and Cochrane Central databases until April 2022.Our search included diagnostic accuracy studies that evaluated at least one of the index tests(^(13)C-UBT or ^(14)C-UBT)against a reference standard.We used the QUADAS-2 tool to assess the methodo-logical quality of the studies.We utilized the bivariate random-effects model to calculate sensitivity,specificity,positive and negative test likelihood ratios(LR+and LR-),as well as the diagnostic odds ratio(DOR),and their 95%confidence intervals.We conducted subgroup analyses based on urea dosing,time after urea administration,and assessment technique.To investigate a possible threshold effect,we conducted Spearman correlation analysis,and we generated summary receiver operating characteristic(SROC)curves to assess heterogeneity.Finally,we visually inspected a funnel plot and used Egger’s test to evaluate publication bias.endorsing both as reliable diagnostic tools in clinical practice.CONCLUSION In summary,our study has demonstrated that ^(13)C-UBT has been found to outperform the ^(14)C-UBT,making it the preferred diagnostic approach.Additionally,our results emphasize the significance of carefully considering urea dosage,assessment timing,and measurement techniques for both tests to enhance diagnostic precision.Nevertheless,it is crucial for researchers and clinicians to evaluate the strengths and limitations of our findings before implementing them in practice.

Effect of acacetin on inhibition of apoptosis in Helicobacter pyloriinfected gastric epithelial cell line

BACKGROUND Helicobacter pylori(H.pylori)infection can cause extensive apoptosis of gastric epithelial cells,serving as a critical catalyst in the progression from chronic gastritis,gastrointestinal metaplasia,and atypical gastric hyperplasia to gastric carcinoma.Prompt eradication of H.pylori is paramount for ameliorating the pathophysiological conditions associated with chronic inflammation of the gastric mucosa and the primary prevention of gastric cancer.Acacetin,which has multifaceted pharmacological activities such as anti-cancer,anti-inflammatory,and antioxidative properties,has been extensively investigated across various domains.Nevertheless,the impact and underlying mechanisms of action of acacetin on H.pylori-infected gastric mucosal epithelial cells remain unclear.AIM To explore the defensive effects of acacetin on apoptosis in H.pylori-infected GES-1 cells and to investigate the underlying mechanisms.METHODS GES-1 cells were treated with H.pylori and acacetin in vitro.Cell viability was assessed using the CCK-8 assay,cell mortality rate via lactate dehydrogenase assay,alterations in cell migration and healing capacities through the wound healing assay,rates of apoptosis via flow cytometry and TUNEL staining,and expression levels of apoptosis-associated proteins through western blot analysis.RESULTS H.pylori infection led to decreased GES-1 cell viability,increased cell mortality,suppressed cell migration,increased rate of apoptosis,increased expressions of Bax and cle-caspase3,and decreased Bcl-2 expression.Conversely,acacetin treatment enhanced cell viability,mitigated apoptosis induced by H.pylori infection,and modulated the expression of apoptosis-regulatory proteins by upregulating Bcl-2 and downregulating Bax and cleaved caspase-3.CONCLUSION Acacetin significantly improved GES-1 cell viability and inhibited apoptosis in H.pylori-infected GES-1 cells,thereby exerting a protective effect on gastric mucosal epithelial cells.

From immunology to artificial intelligence: revolutionizing latent tuberculosis infection diagnosis with machine learning

Latent tuberculosis infection(LTBI)has become a major source of active tuberculosis(ATB).Although the tuberculin skin test and interferon-gamma release assay can be used to diagnose LTBI,these methods can only differentiate infected individuals from healthy ones but cannot discriminate between LTBI and ATB.Thus,the diagnosis of LTBI faces many challenges,such as the lack of effective biomarkers from Mycobacterium tuberculosis(MTB)for distinguishing LTBI,the low diagnostic efficacy of biomarkers derived from the human host,and the absence of a gold standard to differentiate between LTBI and ATB.Sputum culture,as the gold standard for diagnosing tuberculosis,is time-consuming and cannot distinguish between ATB and LTBI.In this article,we review the pathogenesis of MTB and the immune mechanisms of the host in LTBI,including the innate and adaptive immune responses,multiple immune evasion mechanisms of MTB,and epigenetic regulation.Based on this knowledge,we summarize the current status and challenges in diagnosing LTBI and present the application of machine learning(ML)in LTBI diagnosis,as well as the advantages and limitations of ML in this context.Finally,we discuss the future development directions of ML applied to LTBI diagnosis.

Estimate the Prevalence of Helicobacter pylori Infection among Diabetes & Non-Diabetes Mellitus Patients and Its Correlation with Malignant Gastritis Patients Attending in Lower Shabelle Region (Somalia)

Background: Several conducted studies have reported a higher and more frequent Helicobacter pylori infection rate in type 2 diabetes mellitus (T2DM). The aim of this study was to estimation the prevalence of H. pylori and its association between H. pylori infection and T2DM. Materials and Methods: A sectional-cross study was conducted based on 200 patients studded with socioeconomic characteristics through a questionnaire & H. pylori was diagnosed by serum anti-H. pylori immunoglobulin G (IgG) and IgA. Furthermore, patients were investigated for fasting blood glucose (FBG) levels, glycosylated hemoglobin (HbA1c), serum cholesterol, and other biochemistry parameters. Results: The findings showed The prevalence of Hp positive infection was significantly higher in the total sample was 134 with (67%). While 66 out of 200 patients with (33%) was H. pylori negative infection. of H. pylori. Further, the mean values were statistically significant for diabetes with H. pylori infection for IgG > 300 titer and IgA > 250 titer, regarding, HbA1C (7.52 ± 0.41) (P Conclusions: The current study revealed that H. pylori prevalence infections were significantly higher in diabetic patients studied compared to non-diabetic patients. Furthermore, T2DM patients infected with H. pylori positive reported a higher prevalence rate of symptoms than H. pylori negative.

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

Helicobacter pylori (H. pylori) affects nearly half of the world&#x02019;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&#x02019;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.

Infections with Helicobacter pylori and challenges encountered in Africa

Helicobacter pylori(H.pylori)is the causative agent of gastritis,peptic ulcer disease,mucosa associated lymphoid tissue lymphoma and gastric cancer(GC).While this bacterium infects 50%of the world’s population,in Africa its prevalence reach as high as 80%as the infection is acquired during childhood.Risk factors for H.pylori acquisition have been reported to be mainly due to overcrowding,to have infected siblings or parent and to unsafe water sources.Despite this high H.pylori prevalence there still does not exist an African guideline,equivalent to the Maastricht V/Florence Consensus Report of the European Helicobacter and Microbiota Study Group for the management of this infection.In this continent,although there is a paucity of epidemiologic data,a contrast between the high prevalence of H.pylori infection and the low incidence of GC has been reported.This phenomenon is the so-called“African Enigma”and it has been hypothesized that it could be explained by environmental,dietary and genetic factors.A heterogeneity of data both on diagnosis and on therapy have been published.In this context,it is evident that in several African countries the increasing rate of bacterial resistance,mainly to metronidazole and clarithromycin,requires continental guidelines to recommend the appropriate management of H.pylori.The aim of this manuscript is to review current literature on H.pylori infection in Africa,in terms of prevalence,risk factors,impact on human health,treatment and challenges encountered so as to proffer possible solutions to reduce H.pylori transmission in this continent.

Diagnosing Helicobacter pylori infection in vivo by novel endoscopic techniques

Infection with Helicobacter pylori(H.pylori)is a worldwide problem.Endoscopic observation of H.pylori infection in vivo would be helpful to obtain an immediate diagnosis.The aim of this review is to describe recent advances in endoscopic technology and to review the available literature pertaining to its clinical application in H.pylori infection.Endoscopic visualization of H.pylori infection is not always feasible using conventional endoscopy.Thus,advanced endoscopic techniques have been developed with the aim of providing a precise and‘‘real-time’’endoscopic diagnosis.Recently,new endoscopic techniques such as magnifying endoscopy,narrow band imaging,I-Scan,endocytoscopy and endomicroscopy help focus examination of the stomach to diagnose disease in a time-efficient manner,and the analysis of mucosal surface details is beginning to resemble histologic examination.The new detailed images have enabled endoscopists to observe microscopic structures,such as gastric pit patterns,microvessels and cell morphology.Accordingly,endoscopic prediction of H.pylori infection is possible by analysis of surface architecture of the mucosa,which influences the clinical management.These endoscopic techniques might lead us to easier diagnosis and treatment of H.pylorirelated diseases.

Early genetic diagnosis of clarithromycin resistance in Helicobacter pylori

BACKGROUND The drug resistance rate of clinical Helicobacter pylori(H.pylori)isolates has increased.However,the mechanism of drug resistance remains unclear.In this study,drug-resistant H.pylori strains were isolated from different areas and different populations of Chinese for genomic analysis.AIM To investigate drug-resistant genes in H.pylori and find the genes for the early diagnosis of clarithromycin resistance.METHODS Three drug-resistant H.pylori strains were isolated from patients with gastritis in Bama County,China.Minimal inhibitory concentrations of clarithromycin,metronidazole,and levofloxacin were determined and complete genome sequencing was performed with annotation.Hp1181 and hp1184 genes were found in these strains and then detected by reverse transcription polymerase chain reaction.The relationships between hp1181 or hp1184 and clarithromycin resistance were ascertained with gene mutant and drug-resistant strains.The homology of the strains with hp26695 was assessed through complete genome detection and identification.Differences in genome sequences,gene quantity,and gene characteristics were detected amongst the three strains.Prediction and analysis of the function of drug-resistant genes indicated that the RNA expression of hp1181 and hp1184 increased in the three strains,which was the same in the artificially induced clarithromycin-resistant bacteria.After gene knockout,the drug sensitivity of the strains was assessed.RESULTS The strains showing a high degree of homology with hp26695,hp1181,and hp1184 genes were found in these strains;the expression of the genes hp1184 and hp1181 was associated with clarithromycin resistance.CONCLUSION Hp1181 and hp1184 mutations may be the earliest and most persistent response to clarithromycin resistance,and they may be the potential target genes for the diagnosis,prevention,and treatment of clarithromycin resistance.CONCLUSION Hp1181 and hp1184 mutations may be the earliest and most persistent response to clarithromycin resistance,and they may be the potential target genes for the diagnosis,prevention,and treatment of clarithromycin resistance.

Mucosal polymerase chain reaction for diagnosing Helicobacter pylori infection in patients with bleeding peptic ulcers

AIM: Helicobacter pylori (H pylon) has been linked to chronic gastritis, peptic ulcers, gastric cancer and MALT-lymphoma. Conventional invasive tests are less sensitive than non-invasive tests in diagnosing H pylori infection in patients with bleeding peptic ulcers. Polymerase chain reaction is a sensitive and accurate method for diagnosing H pylori infection. The aim of this study was to evaluate the diagnostic role of mucosai polymerase chain reaction for H pylori infection in patients with bleeding peptic ulcers. METHODS: In patients with bleeding, non-bleeding peptic ulcers and chronic gastritis, we checked rapid urease test, histology, bacterial culture and mucosai polymerase chain reaction fordetecting H pylori infection. Positive H pylori infection was defined as positive culture or both a positive histology and a positive rapid urease test. For mucosai polymerase chain reaction of H pylori, we checked vacA (s1a, s1b, s1c, s2, m1, m1T, m2), iceA1, iceA2. and cag A. RESULTS: Between October 2000 and April 2002,88 patients with bleeding peptic ulcers (males/females: 60/28, gastric ulcers/duodenal ulcers: 55/33), 81 patients with non-bleeding peptic ulcers (males/females: 54/27, gastric ulcers/duodenal ulcers: 45/36) and 37 patients with chronic gastritis (males/ females: 24/13) were enrolled in this study. In patients with bleeding peptic ulcers, non-bleeding peptic ulcers and chronic gastritis, 45 patients (51%), 71 patients (88%) and 20 patients (54%) respectively were found to have positive H pylori infection (P<0.001). In patients with bleeding peptic ulcers, non-bleeding peptic ulcers and chronic gastritis, polymerase chain reaction for H pylori infection was positive in 54 patients (61%), 70 patients (86%) and 20 patients (54%) respectively (P<0.001). The sensitivity, positive predictive value and diagnostic accuracy of mucosai polymerase reaction for H pylori infection were significantly lower in patients with bleeding peptic ulcers (84%, 79% and 81%) than in patients with non-bleeding peptic ulcers (99%, 99% and 98%) (P<0.001, P<0.01 and P<0.001 respectively). The sensitivity, negative predictive value and diagnostic accuracy of mucosal polymerase reaction for H py/ori were significantly lower in patients with bleeding peptic ulcers (84%, 83% and 81%) than in patients with chronic gastritis (100%, 100% and 100%) (P= 0.02, P= 0.02 and P=0.001). CONCLUSION: Mucosal polymerase chain reaction for detecting H pylori infection is not reliable in patients with bleeding peptic ulcers.

Assessment of gastroesophageal reflux disease by serodiagnosis of Helicobacter pylori-related chronic gastritis stage

AIM:To evaluate the association of Helicobacter pylori(H.pylori)-related chronic gastritis stage with upper gastro-intestinal symptoms and gastro-eso-phageal reflux disease(GERD).METHODS:Subjects underwent upper gastrointestinal endoscopy,a questionnaire using a frequency scale for symptoms of GERD(FSSG),and measurements of serum H.pylori-antibody and pepsinogen(PG)levels.They were classified into the following 4 groups in terms of H.pylori-related chronic gastritis stage:Group A(n = 219),H.pylori(-)PG(-);Group B(n = 310),H.pylori(+)PG(-);Group C(n = 279),H.pylori(+)PG(+);and Group D(n = 17),H.pylori(-)PG(+).RESULTS:Reflux esophagitis occurred in 30.6% of Group A,14.5% of Group B,6.8% of Group C,and 0% of Group D(P < 0.001).Scores for acid reflux sympto-ms decreased significantly with chro-nic gastritis stage(from Group A to D)(P < 0.05),while scores for dysmotility symptoms did no-t differ significantly.The prevalence of nonerosive reflux disease(NERD)did not differ amo-ng groups.However,in subjects with GERD,the prevalence of NERD tended to increase with chronic gastritis stage(P = 0.081).CONCLUSION:Acid reflux sympto-ms and the prevalen-ce of reflux esophagitis can be assessed by measuring both serum H.pylori-antibody and PG levels.