Detection of Helicobacter pylori infection in children using rapid urease and histologic methods of diagnosis.

Objective: The study aimed to detect the presence of Helicobacter pylori infection in children using two investigative methods: the rapid urease test and histological methods. It also examined the relationship between socioeconomic status and Helicobacter pylori infection. Design: This was a cross-sectional study conducted in the paediatric theatre at Korle Bu Teaching Hospital in Accra, Ghana. Participants: Children who were scheduled for upper gastrointestinal endoscopy were recruited into the study. Main outcome measures: The presence of Helicobacter pylori in gastric biopsies was measured using a rapid urease test and histology. Results: Seventy-three children aged 2 years to 16 years were seen during the period. Both tests were positive at the same time in 36 (49.3%) out of the 73 children (p<0.0001). The positivity rates for the rapid urease test and histology were 57.5% and 53.4 %, respectively. Significant predictors of the histology presence of H. pylori were a large household size of at least 6 members (AOR: 4.03; p<0.013) and the presence of pets at home (AOR: 3.23; p<0.044). Conclusions: Substantial agreement was found between the rapid urease test and histology examination of gastric biopsies for the presence of H. pylori. Children from large households and those with pets at home appear to have increased odds of having H. pylori infection of the gastric mucosa. Funding: None declared.

Prospective Evaluation of a New Liquid-Type Rapid Urease Test Kit for Diagnosis of Helicobacter pylori.

BACKGROUND/AIMS: Rapid and accurate diagnostic tools are essential for the timely recognition of Helicobacter pylori (H. pylori) in clinical practice. The rapid urease test (RUT) is a comparatively accurate and time-saving method recommended as a first-line diagnostic test. The primary objective of conducting the RUT is to obtain rapid results, thus enabling the initiation of an eradication therapy based on clarithromycin resistance testing. This study aimed to assess the reaction time and accuracy of a new liquid-type RUT. METHOD: In this prospective study, consecutive dyspeptic or check-up patients referred to our clinic for endoscopy were assessed to evaluate the rapidity and accuracy of a novel liquid-type RUT (Helicotest®, WON Medical, Bucheon, Republic of Korea) compared with another commercial RUT kit (HP kit, Chong Kun Dang, Seoul, Republic of Korea) and a real-time quantitative PCR-based assay (Seeplex® H.pylori-ClaR Detection, Seegene, Republic of Korea). RUTs were analyzed at 10 min, 30 min, 60 min, and 120 min. RESULTS: Among the 177 enrolled patients, 38.6% were infected with H. pylori. The positivity rates of the liquid-type RUT were 26.1, 35.8, 39.2%, and 41.5% at 10, 30, 60, and 120 min, respectively. When compared with the HP kit test, the time needed to confirm positivity was significantly reduced by 28.6 min (95% CI, 16.60-39.73, p < 0.0001). Helicotest® had a greater accuracy (96.02 ± 1.47), sensitivity (98.53 ± 1.46) and NPV (99.03 ± 0.97) compared to the HP kit. CONCLUSIONS: Compared to the commonly used RUT, the new liquid-type RUT presented faster and reliable results. Such findings could improve H. pylori treatment outcomes, particularly in outpatient clinical settings.

Upper gastrointestinal bleeding: Diagnosis of Helicobacter pylori infection-Descriptive study.

Background and Aim: The presence of blood in the stomach has been thought to affect the performance of diagnostic tests used in detecting Helicobacter pylori (H. pylori) in the stomach. This study evaluates the effect of upper gastrointestinal bleeding on the efficacy of a rapid urease test (RUT) and compares the results with the pathologic method. Methods: In this descriptive study, 100 patients presented with upper gastrointestinal bleeding, confirmed from endoscopy, referred to Shahid Rahimi Hospital in Khorramabad were enrolled. Antral biopsy was performed in all the patients and the samples were extracted for histopathology and RUT. A questionnaire was used to collect rapid urease test outcomes and associated parameters (antibiotic, bismuth, and proton pump inhibitors), histology and demographic data. Histopathology was used as the gold standard for diagnosis of H. pylori. Results: Of the 52 patients who were reported positive for H. pylori in pathology, 36 had RUT-positive H. pylori, sensitivity 69.2%, and of 48 patients whose pathology was negative, 25 had negative RUT, specificity 52.1%. Of 59 RUT, 36 had positive pathology, positive predictive value was 61% and from 41 with negative RUT, 25 had negative pathology, negative predictive value was 61%. The prevalence of H. pylori infection was significantly associated with the age of 50 years and above, p = 0.042, and previous history of bleeding, p = 0.019. Conclusion: Gastrointestinal bleeding can reduce the sensitivity of RUT. The negative results of these tests in acute upper gastrointestinal bleeding should therefore be interpreted carefully.

Diagnostic Approaches to Helicobacter pylori: A Comparative Study of Detection in Gastric Biopsy and Aspirates.

Background Helicobacter pylori is one of the most common bacterial pathogens in humans. It is a microaerophilic bacteria with multiple unipolar flagella. It is associated with the development of various lesions like chronic gastritis, gastric ulcers, adenocarcinoma, and mucosa-associated lymphomas. The aim of this study was a comparative evaluation of the rapid urease test (RUT) and polymerase chain reaction (PCR) in gastric biopsy and aspirates for the detection of H. pylori infection and to further determine the sensitivity and specificity of RUT and PCR. Method Endoscopic guided biopsy tissue and gastric aspirate specimens were collected from 110 patients with symptoms like gastritis, dyspepsia, etc., and subjected to RUT and PCR for detection of H. pylori infection. Results A total of 110 samples, including both biopsy tissue (77) and gastric aspirate (33) were subjected to RUT and PCR. RUT for biopsy tissue showed the highest sensitivity (97.18%), compared to gastric aspirate (78.94%). Comparing RUT with PCR, the sensitivity and specificity of PCR were 93.33% and 90.0%, respectively. The positive predictive value (PPV) of PCR was 97.67%, the negative predictive value (NPV) was 75.0%, and the accuracy was 92.73%. Conclusion The present study showed that RUT is a rapid and accurate invasive test for the detection of Helicobacter pylori infection in biopsy tissue as compared to gastric aspirate specimens, which are more sensitive to PCR. The study also showed that biopsy tissue was found to be a superior specimen for the detection of Helicobacter pylori as compared to gastric aspirate.

Retrospective analysis of discordant results between histology and other clinical diagnostic tests on helicobacter pylori infection.

BACKGROUND: A reliable test is essential for diagnosing Helicobacter pylori (H. pylori) infection, and crucial for managing H. pylori-related diseases. Serving as an excellent method for detecting H. pylori infection, histologic examination is a test that clinicians heavily rely on, especially when complemented with immunohistochemistry (IHC). Additionally, other diagnostic tests for H. pylori, such as the rapid urease test (CLO test) and stool antigen test (SA), are also highly sensitive and specific. Typically, the results of histology and other tests align with each other. However, on rare occasions, discrepancy between histopathology and other H. pylori diagnostic tests occurs. AIM: To investigate the discordance between histology and other H. pylori tests, the underlying causes, and the impact on clinical management. METHODS: Pathology reports of gastric biopsies were retrieved spanning August 2013 and July 2018. Reports were included in the study only if there were other H. pylori tests within seven days of the biopsy. These additional tests include CLO test, SA, and H. pylori culture. Concordance between histopathology and other tests was determined based on the consistency of results. In instances where histology results were negative while other tests were positive, the slides were retrieved for re-assessment, and the clinical chart was reviewed. RESULTS: Of 1396 pathology reports were identified, each accompanied by one additional H. pylori test. The concordance rates in detecting H. pylori infection between biopsy and other tests did not exhibit significant differences based on the number of biopsy fragments. 117 discrepant cases were identified. Only 20 cases (9 with CLO test and 11 with SA) had negative biopsy but positive results in other tests. Four cases initially stained with Warthin-Starry turned out to be positive for H. pylori with subsequent IHC staining. Among the remaining 16 true discrepant cases, 10 patients were on proton pump inhibitors before the biopsy and/or other tests. Most patients underwent treatment, except for two who were untreated, and two patients who were lost to follow-up. CONCLUSION: There are rare discrepant cases with negative biopsy but positive in SA or CLO test. Various factors may contribute to this inconsistency. Most patients in such cases had undergone treatment.

Accuracy of gastric nodule combined with rapid urease test prediction in diagnosing Helicobacter pylori infection in children.

BACKGROUND: The diagnosis of Helicobacter pylori (H. pylori) infection in children remains challenging with the lack of a rapid, cost-effective, and highly accurate diagnostic method. Consequently, this study aimed to investigate the accuracy of the combination of gastric nodule and rapid urease test (RUT) as a diagnostic method for H. pylori infection in children. METHODS: The study included participants who underwent a thorough examination, including gastroscopy, a 13C breath test, RUT, and pathological methylene blue staining, with the gold standard for diagnosing of H. pylori infection being a positive result from both pathological methylene blue staining and 13C breath test. The sensitivity, specificity, positive and negative predictive values, and accuracy of the diagnostic methods were calculated. RESULTS: The accuracy of the different tests for H. pylori infection was evaluated in 2202 participants. A total of 730 (33.2%) children were diagnosed with H. pylori infection (pathological methylene blue staining and 13C breath test, both positive). Gastric nodule had a sensitivity of 87.1% and a specificity of 93.1%, whereas combining gastric nodule and RUT in parallel had the higher accuracy of 95.4%. The accuracy of gastric nodule diagnosis was higher in younger age groups and increased after excluding patients with a history of anti-H. pylori treatment. CONCLUSIONS: The findings of this study suggest that gastric nodules, particularly when combined with RUT, can be a valuable predictor of H. pylori infection in children, offering a simple and feasible alternative to other invasive methods.

New strategies for Helicobacter pylori isolation and sequencing analysis for virulence genes contributing to its pathogenicity.

BACKGROUND: Helicobacter pylori is a fastidious pathogen that is required a complicated medium for growth. Invading epithelial cells of the stomach. H. pylori virulence factors are classified by function, acidic resistivity, adhesion, chemotaxis and motility, molecular mimicry, immunological invasion and modulation, and toxins formation such as cytotoxin-associated genes A (cagA) and vacuolating cytotoxin A (vacA). This study aims to determine a simple and innovative technique to isolate H. pylori from gastric biopsies and assess pathogenicity by virulence factor gene detection. METHODS: A total of 200 patients who were suspected of having H. pylori infection had two antral gastric biopsies undertaken. A rapid urease test (RUT) was used for one, and Brain Heart Infusion broth (BHI) was used to cultivate the other. The molecular study included diagnostics utilizing the 16sRNA housekeeping gene along with the identification of the virulence factors genes (cagA, cagT, and vacA) and sequencing, RESULT: Of the 200 antral gastric biopsies collected, 135 were positive rapid urease tests, and 17 H. pylori isolates were successfully obtained from 135 biopsies. The 16SrRNA as a housekeeping gene is confirmed, and about 53%, 70.5%, and 82.3% of the 17 isolates show carrying cagA, cagT, and vacA genes, respectively. All peptic ulcer isolates have the cagA gene, while Gastroesophageal Reflux Disease (GERD) and non-peptic ulcer disease (NPUD) isolates show the lack of the cagA gene. All bacteria, which were isolated from peptic ulcer, nodular gastritis, and gastritis patients, have a vacA gene. CONCLUSION: The effective method for isolating H. pylori is centrifuging the transport broth after 24 h of incubation. The cagA toxin causes peptic ulcer while vacA toxin induces several histopathological changes in the stomach. Three virulence genes were present in all peptic ulcer-causing bacteria, while only one or none were present in the GERD and NPUD biopsy isolates.

Diagnosis of ''Helicobacter pylori infection of the gastric biopsy'' by rapid urease test, histopathology and Raman spectroscopy.

This study aim to investigate the diagnostic potential of Raman spectroscopy in comparison with rapid urease test and histopathology in diagnosis of H. pylori infection. A comparative study was conducted at Pathology Laboratory and a total of 94 samples were collected from patients based on Rome IV criteria. Sensitivity, specificity and accuracy of histopathology, rapid urease test and for Raman spectroscopy were investigated. Rapid urease test showed 23 false negative results of H. pylori as compared to Raman spectroscopy and histopathology. We concluded that Raman spectroscopy showed sensitivity (94.5%), accuracy (94.0%) and specificity of (87.5%) in the diagnosis of H. pylori infection. However rapid urease test showed specificity of 92.5% while low sensitivity 75%, and 78% accuracy as compared to Raman spectroscopy and histopathology . This study illustrates the applicability of Raman spectroscopy as a potent innovative detection tool for the molecular detection of H. pylori infection in gastritis.

Gastric mucosal swab as an alternative to biopsy for Helicobacter pylori detection.

BACKGROUND AND AIMS: Gastric mucosal swab may be a more sensitive sampling method than a biopsy since Helicobacter pylori (H. pylori) resides within the mucus layer. We compared the diagnostic performance of the rapid urease test (RUT) and bacterial load of H. pylori between swabs and tissue biopsy. METHODS: Overall, 276 RUTs (138 swab-RUTs (S-RUT) and 138 tissue-RUTs (T-RUT)) were performed. To diagnose H. pylori infection, RUT, H. pylori PCR, and 16S ribosomal RNA gene sequencing of tissue and swab were used, and its infection was defined as at least two positives of the six test results. The diagnostic performances of RUTs and the H. pylori bacterial load using qPCR were compared between swab and biopsy. RESULTS: The positivity rates of S-RUT and T-RUT were 35.5% (49/138) and 25.4% (35/138), respectively. The sensitivity, specificity, and accuracy of S-RUT were 98.0%, 100.0%, and 99.2%, while those of T-RUT were 70.0%, 100%, and 89.1%, respectively. The sensitivity and accuracy were significantly higher for S-RUT than for T-RUT (p < 0.05). In the patients with atrophic gastritis and intestinal metaplasia, S-RUT showed significantly higher sensitivity than T-RUT. qPCR showed that the swab contained a significantly higher H. pylori bacterial load than tissue biopsy (22.92-fold and 31.61-fold in the antrum and body (p < 0.05), respectively). CONCLUSIONS: Gastric mucosal swabs showed higher RUT accuracy and H. pylori bacterial load than a tissue biopsy. This may be an alternative to a biopsy when diagnosing H. pylori infection during endoscopy is necessary. (ClinicalTrials.gov, NCT05349578).

The first 5 years of Helicobacter pylori research-With an emphasis on the United Kingdom.

In the 1970s, 1% of the UK population consulted with dyspepsia; fiberoptic gastroscopy allowed biopsy specimens under direct vision enabling systematic histopathology. Steer et al described clusters of flagellated bacteria closely apposed to the gastric epithelium associated with chronic active gastritis. The first UK series of Helicobacter pylori following Marshall's 1983 visit to Worcester confirmed the association of H. pylori with gastritis. UK researchers completed much early helicobacter research as there were many UK campylobacteriologists. Steer and Newell proved the Campylobacter-like organisms grown on culture were the same as those seen in the gastric mucosa using antiserum raised by inoculating rabbits with H. pylori from cultures. Wyatt, Rathbone, and others showed a strong correlation between the number of organisms, type and severity of acute gastritis, immunological response, and bacterial adhesion similar to enteropathogenic E coli. Seroprevalence studies indicated H. pylori increased with age. Histopathologists also showed peptic duodenitis was in effect "gastritis in the duodenum" caused by H. pylori, unifying its role in the pathogenesis of both gastritis and duodenal ulceration. These bacteria were initially called Campylobacter pyloridis and then C. pylori. However, electron microscopy suggested that the bacteria were not campylobacters, and this was supported by differences in fatty acid and polyacrylamide electrophoresis profiles. In-vitro tests indicated that H. pylori was susceptible to penicillins, erythromycin, and quinolones, but not trimethoprim or cefsulodin allowing development of selective media for culture. Monotherapy with erythromycin ethylsuccinate was ineffective, and patients treated with bismuth subsalicylate initially responded with clearance of H. pylori and the associated gastritis, but then many relapsed. Thus, pharmacokinetic and treatment studies were important to direct suitable dual and triple treatments. Work optimized serology, and the rapid biopsy urease and urea breath tests. The link between H.pylori and gastric cancer was established in large seroprevalence studies, and H. pylori test and treat for dyspepsia became routine.

Intraprocedural gastric juice analysis as compared to rapid urease test for real-time detection of Helicobacter pylori.

BACKGROUND: Endofaster is an innovative technology that can be combined with upper gastrointestinal endoscopy (UGE) to perform gastric juice analysis and real-time detection of Helicobacter pylori (H. pylori). AIM: To assess the diagnostic performance of this technology and its impact on the management of H. pylori in the real-life clinical setting. METHODS: Patients undergoing routine UGE were prospectively recruited. Biopsies were taken to assess gastric histology according to the updated Sydney system and for rapid urease test (RUT). Gastric juice sampling and analysis was performed using the Endofaster, and the diagnosis of H. pylori was based on real-time ammonium measurements. Histological detection of H. pylori served as the diagnostic gold standard for comparing Endofaster-based H. pylori diagnosis with RUT-based H. pylori detection. RESULTS: A total of 198 patients were prospectively enrolled in an H. pylori diagnostic study by Endofaster-based gastric juice analysis (EGJA) during the UGE. Biopsies for RUT and histological assessment were performed on 161 patients (82 men and 79 women, mean age 54.8 ± 19.2 years). H. pylori infection was detected by histology in 47 (29.2%) patients. Overall, the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value (NPV) for H. pylori diagnosis by EGJA were 91.5%, 93.0%, 92.6%, 84.3%, and 96.4%, respectively. In patients on treatment with proton pump inhibitors, diagnostic sensitivity was reduced by 27.3%, while specificity and NPV were unaffected. EGJA and RUT were comparable in diagnostic performance and highly concordant in H. pylori detection (κ-value = 0.85). CONCLUSION: Endofaster allows for rapid and highly accurate detection of H. pylori during gastroscopy. This may guide taking additional biopsies for antibiotic susceptibility testing during the same procedure and then selecting an individually tailored eradication regimen.

Real-Time Polymerase Chain Reaction for the Detection of Helicobacter pylori and Clarithromycin Resistance.

Background/Aims: Real-time polymerase chain reaction (RT-PCR) is a fast and simple method for the simultaneous detection of clarithromycin (CLR) resistance and Helicobacter pylori. We evaluated the effectiveness of RT-PCR compared to that of the rapid urease test (RUT) and assessed its value in verifying CLR resistance. Methods: A total of 70 specimens with confirmed H. pylori infection in culture were enrolled and analyzed in this prospective study. All specimens were subjected to RT-PCR assay using fluorescence melting peak signals to detect H. pylori infection and CLR resistances caused by either A2142G or A2143G mutations in the 23S ribosomal RNA gene (23S rRNA). The results were compared to those of RUT and antimicrobial susceptibility culturing tests to investigate the efficacy of RT-PCR. Results: Among the 70 specimens analyzed, the positivity rate was 97.1% (68/70) with RT-PCR and 82.9% (58/70) with RUT. CLR resistance (minimum inhibitory concentration >1.0 µg/mL) was confirmed in 18.6% (13/70), and fluorescence melting curve analysis showed that 84.6% (11/13) had point mutations in 23S rRNA. Ten specimens had only A2143G mutation, and one specimen contained both A2142G and A2143G mutations. Conclusions: RT-PCR assay was found to be more efficient than RUT in detecting H. pylori infection and could effectively verify CLR resistance compared to the antimicrobial susceptibility culturing test. Considering the high sensitivity and accessibility of RT-PCR method, it could be used to easily detect CLR-resistant H. pylori, thus helping clinicians select suitable treatment regimen and improve the eradication rate.

Detection of helicobacter pylori infection by helicobacter pylori IgG serology test in pediatric patients at the Philippine General Hospital

Objective@#To determine the validity of serum H. pylori IgG in the detection of H. pylori-associated gastroduodenitis in patients with gastrointestinal symptoms. @*Methods@#Cross-sectional study which included consecutive patients 1-18 years old with upper gastrointestinal symptoms who underwent esophagogastroduodenoscopy. H. pylori infection was diagnosed by positive tests for both rapid urease test (RUT) and Giemsa stain of gastric biopsies. H. pylori IgG (ELISA) serology was also performed.@*Results@#Twenty-five patients [Mean (SD) age: 12 (4.5) years, 68% females] were included. Majority presented with epigastric pain (64%) and had endoscopic gastritis (84%). Four patients had ulcers (1 antral, 3 duodenal). Giemsa stain was positive in 16 (64%) patients and RUT in one. Prevalence of H. pylori infection was 4%. Serum H. pylori IgG test was positive in two; borderline in three with a 100% sensitivity, 80% specificity, and a positive and negative likelihood ratio of 10.9 and 0.6.@*Conclusion@#The present study showed a low prevalence of H. pylori infection, thus, the validity of the H. pylori serology could not be adequately evaluated. We presently could not recommend the serum IgG in the detection of H. pylori gastroduodenitis in our setting.

The high sensitivity and specificity of rapid urease test in diagnosis of Helicobacter pylori infection in Moroccan children.

Background and Objectives: Infesting nearly 50% of the world's population, Helicobacter pylori are thought to cause peptic ulcers, as well as gastric adenocarcinoma. Several diagnostic methods are available to detect this bacterium; however, at least two must be used together for an accurate diagnosis. This study evaluated the use of rapid urease test for diagnosis of H. pylori infection in a pediatric population. Materials and Methods: Five gastric biopsies were taken from children during a 2-year period for the purpose of histological, molecular, bacteriological culture, and rapid urease testing. Results: Among 83 children, 38 were male, and 45 were female with an age ranging of 2 to 15 years. The infected group represented 31%. The rapid urease test had a sensitivity of 88.5%, a negative predictive value of 94%, a specificity of 84.2%, and a positive predictive value of 72%. Conclusion: A rapid urease test may be appropriate for ruling out H. pylori infection after a negative result. The positive results however, may be confirmed by a second invasive test.

Diagnosis and Comparison of Three Invasive Detection Methods for Helicobacter pylori Infection.

Background: The purpose of this study was to compare different invasive methods for Helicobacter pylori (H. pylori) detection, namely PCR for H. pylori specific ureC gene, Rapid urease test (RUT), and histopathological examination by modified Giemsa staining. Methodology: Endoscopic gastroduodenal biopsy materials were collected from dyspeptic patients who underwent endoscopic examination upon fulfilling the inclusion criteria. Three to four samples were collected from each patient after taking informed consent and proper clinical history. A rapid urease test (RUT) was done on spot with in-house RUT media from 1 specimen. One to two specimens were preserved in 10% formaldehyde for histopathology and PCR for ureC gene was done from 1 specimen. Collected biopsy specimens from gastric and duodenal mucosa of 142 patients were categorized as H. pylori-positive cases and H. pylori-negative cases based on the case definition used in the study upon positivity of 3 diagnostic tests. Results: Among 142 biopsy specimens, 34.5% were categorized as H. pylori-positive cases, 35.2% as H. pylori-negative cases, and finally 30.2% as doubtful or indeterminate cases. Rapid urease test was the most sensitive method, closely followed by ureC gene PCR and histopathology, with a sensitivity of 94.2%, 83.0%, and 76.5%, respectively. Whereas histology was the most specific, having 98.0% specificity followed by 83.0% in PCR. RUT was the least specific, with 55.5% specificity. Conclusion: While histopathology could detect H. pylori infection with the highest specificity, for definitive diagnosis combination of any 2 methods should be used, if available.

Association of Helicobacter Pylori in Carcinoma Stomach at Maharaja Krishna Chandra Gajapat Medical College: A Prospective Study.

Introduction Gastric cancer is the fourth most common type of cancer and the second leading cause of cancer-related death in the world. The etiology of gastric cancer includes Helicobacter pylori infection, diet, lifestyle, tobacco, alcohol, and genetic susceptibility. Upper gastrointestinal endoscopy (UGIE) is the most effective method for examining the upper gastrointestinal tract as compared to the other examination tools. Objective To study the histopathological finding of upper gastrointestinal endoscopic biopsies and its association with H. pylori in cases of carcinoma stomach. Materials and methods This was a hospital-based observational study carried out in the Department of Surgery, at Maharaja Krushna Chandra Gajapati Medical College, Berhampur, a tertiary care hospital in Eastern India. Study population consisted of 106 patients for a period of 2 years from July 2019 to June 2021, after due consideration of the inclusion and exclusion criteria. Endoscopic location and pathological types of the gastric lesion were noted, and all biopsy specimens were investigated to see the presence of H. pylori by rapid urease test (RUT) and histological examination in the form of Giemsa and H&E stain. Results In the present study of 106 cases, 62 cases (58.49%) were found to be positive for H. Pylori by RUT and 72 cases (67.92%) were positive for H. pylori by smear staining. In histopathological study, 72 cases (67.92%) were of intestinal type of carcinoma and 34 cases (32.07%) were of diffuse type of carcinoma. Smear for H . pylori was positive in 56 cases (77.78%) among the 72 cases of intestinal type of carcinoma stomach. Whereas only 16 cases (47.05%) were found to be smear-positive for H. pylori among the 34 cases of diffuse type of lesion. Irrespective of histological type, H. pylori was positive in 67.92% of patients with carcinoma stomach. This association was statistically significant (p<0.001) and indicates its role in intestinal type of gastric carcinoma. Conclusion There is a high frequency of H. pylori infection in cases of stomach cancer. This study confirmed the higher association of H. pylori infection with gastric cancer. Its association with the intestinal histological variety of stomach cancer is more common than diffuse type. The prevalence of H. pylori infection in distal stomach carcinoma is higher than proximal.

Diagnostic approach to Helicobacter pylori-related gastric oncogenesis.

Helicobacter pylori (H. pylori) is a causative agent of peptic ulcer disease and plays an important role in the development of various other upper and lower gastrointestinal tract and systemic diseases; in addition to carcinogenesis and the development of mucosa-associated lymphoid tissue lymphoma, extragastric manifestations of H. pylori are increasingly being unraveled. Therefore, prompt and accurate diagnosis is essential. Within this narrative review we present an overview of the current trend in the diagnosis of H. pylori infection and its potential oncogenic sequelae, including gastric mucosa atrophy, intestinal metaplasia, dysplasia and gastric cancer. Signs of H. pylori-related gastric cancer risk can be assessed by endoscopy using the Kyoto classification score. New technology, such as optical or digital chromoendoscopy, improves diagnostic accuracy and provides information regarding H. pylori-related gastric preneoplastic and malignant lesions. In addition, a rapid urease test or histological examination should be performed, as these offer a high diagnostic sensitivity; both are also useful for the diagnosis of sequelae including gastric and colon neoplasms. Culture is necessary for resistance testing and detecting H. pylori-related gastric dysbiosis involved in gastric oncogenesis. Likewise, molecular methods can be utilized for resistance testing and detecting H. pylori-related gastric cancer development and progression. Noninvasive tests, such as the urea breath and stool antigen tests, can also be implemented; these are also suitable for monitoring eradication success and possibly for detecting H. pylori-related gastric malignancy. Serological tests may help to exclude infection in specific populations and detect gastric and colon cancers. Finally, there are emerging potential diagnostic biomarkers for H. pylori-related gastric cancer.

Objective Interpretation of the Rapid Urease Test for Helicobacter pylori Infection Using Colorimetry.

BACKGROUND: The rapid urease test (RUT) is a major diagnostic tool for detecting Helicobacter pylori infection. This study aimed to establish an objective method for measuring the color changes in the RUT kit to improve the test's diagnostic accuracy. METHODS: A UV-visible spectrophotometer was selected as the colorimeter; experiments were conducted in three stages to objectively identify the color changes in the RUT kit. RESULTS: First, the urea broth solution showed an identifiable color change from yellow to red as the pH increased by 0.2. The largest transmittance difference detected using the UV-visible spectrophotometer was observed at a 590-nm wavelength. Second, the commercialized RUT kit also showed a gradual color change according to the pH change detected using the UV-visible spectrophotometer. Third, 13 cases of negative RUT results with a biopsy specimen and 16 of positive RUT results were collected. The transmittance detected using the UV-visible spectrophotometer showed a clear division between the positive and negative RUT groups; the largest difference was observed at a 559-nm wavelength. The lowest transmittance in the negative RUT group was 64, while the highest in the positive RUT group was 56, at the 559-nm wavelength. The UV-visible spectrophotometry reading showed a consistency of 92.7% compared with that of manual reading. CONCLUSION: A transmittance of 60 at a 559-nm wavelength detected using UV-visible spectrophotometer can be used as a cutoff value for interpreting RUT results; this will help develop an automatic RUT kit reader with a high accuracy.

Technical Note: Comparative Analysis and Evaluation of the Polymerase Chain Reaction and Rapid Urease Test for Diagnosing Helicobacter pylori Infection.

This study was conducted in order to compare the performance of the rapid urease test (RUT) with that of the polymerase chain reaction (PCR) for H. pylori diagnosis. Of 536 patients, 81% were concordant between RUT and PCR, 16% were concordant between two PCR assays but not between RUT and PCR, and the remaining 3% showed discrepant results between two PCR assays evaluated. Low bacterial load was shown to be a significant factor associated with false-negative diagnosis by RUT, and non-H. pylori urease activity or bacterial alkaline-generating activity was the cause of false-positive diagnosis. Disagreement between the PCR assays was due to single nucleotide polymorphisms in primers or probes causing decreased amplification efficiency and false-negative diagnosis when the bacterial load in the samples was low.

Helicobacter pylori infection in non-ulcer dyspepsia: A cross-sectional study.

Background: Helicobacter pylori infection has been known to be associated with dyspepsia for more than two decades; however, studies on this topic in India are limited. This study was carried out to estimate the Helicobacter pylori infection rates in non-ulcer dyspepsia. Methods: Helicobacter pylori infection rates detected by rapid urease test (RUT) positivity were analyzed in 235 patients presenting to a tertiary care center with dyspepsia having no evidence of peptic ulcer disease on esophagogastroduodenoscopy. Results: In this study, the prevalence of Helicobacter pylori infection diagnosed by the RUT was found to be 40.85%. Gender-based prevalence was found to be 40.14% and 41.93% for men and women, respectively. The highest prevalence was found in the age group of 30-39 years. The most common area of involvement was the isolated antrum of the stomach as seen in 93 patients. Conclusion: This study shows a modest RUT positivity rate for Helicobacter pylori infection with the commonest site of involvement being the antrum of the stomach. Further studies will be needed to assess the prevalence of Helicobacter pylori in the community to analyze the extent of infection.