Evaluation of Invasive and Noninvasive Methods for the Diagnosis of Helicobacter Pylori Infection

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.

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 (13C-UBT or 14C-UBT) against a reference standard. We used the QUADAS-2 tool to assess the methodological 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.

RESULTS

The titles and abstracts of 4621 studies were screened; 79 articles were retrieved and selected for full-text reading. Finally, 60 studies were included in the diagnostic test accuracy meta-analysis. Our analysis demonstrates superior diagnostic accuracy of 13C-UBT over 14C-UBT, indicated by higher sensitivity (96.60% vs 96.15%), specificity (96.93% vs 89.84%), likelihood ratios (LR+ 22.00 vs 10.10; LR- 0.05 vs 0.06), and area under the curve (AUC; 0.979 vs 0.968). Notably, 13C-UBT's DOR (586.47) significantly outperforms 14C-UBT (DOR 226.50), making it the preferred diagnostic tool for dyspeptic individuals with H. pylori infection. Correlation analysis revealed no threshold effect (13C-UBT: r = 0.48; 14C-UBT: r = -0.01), and SROC curves showed consistent accuracy. Both 13C-UBT and 14C-UBT showed high AUC values (13C-UBT 0.979; 14C-UBT 0.968) near 1.00, reinforcing their excellent accuracy and endorsing both as reliable diagnostic tools in clinical practice.

CONCLUSION

In summary, our study has demonstrated that 13C-UBT has been found to outperform the 14C-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.

A Comparison Between Histology and Rapid Urease Test in the Diagnosis of Helicobacter Pylori in Gastric Biopsies: A Systematic Review

Helicobacter pylori (H. pylori) is a gram-negative aerobic pathogen that primarily colonizes the gastric mucosa. Peptic ulcer disease, atrophic gastritis, gastric cancer, and mucosal-associated lymphoid tissue lymphoma have all been linked to chronic H. pylori infection. Hence, it is critical to diagnose and treat it as early as possible. There are both invasive and noninvasive tests available to detect it. In this review, the diagnostic abilities of two invasive tests - histology and the rapid urease test (RUT) - are compared in a variety of clinical situations. This systematic review was carried out using the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) 2020 checklist. We performed a literature search using the PubMed and Google Scholar databases in accordance with the eligibility criteria and ultimately selected eight articles for final analysis. The Newcastle-Ottawa scale adapted for cross-sectional studies, the Scale for the Assessment of Narrative Review Articles (SANRA), and the PRISMA 2020 checklist were used to assess the quality of selected articles for cross-sectional studies, traditional literature reviews, and systematic reviews, respectively. According to the findings of the review, both histology and the RUT have high sensitivity and specificity in diagnosing H. pylori though this varies depending on the clinical situation, making one test superior to the other. Neither of these tests can be considered the gold standard method on its own. Hence, using at least two diagnostic tests at the same time is critical for ensuring high sensitivity and specificity while accurately diagnosing the pathogen.

Comparison of invasive histological and molecular methods in the diagnosis of Helicobacter pylori from gastric biopsies of Sudanese patients: a cross-sectional study

Background: The continuous rise in the number of patients suffering from Helicobacter pylori is probably due to the changes in modern life. Nowadays, patients suffering from gastrointestinal problems are diagnosed through invasive and non-invasive techniques. The choice of a diagnostic test is influenced by factors such as the tests' sensitivity and specificity, the clinical conditions, and the cost-effectiveness of the testing strategy. This study aimed to compare molecular detection methods of H. pylori by polymerase chain reaction (PCR) targeting the 16S rRNA, ureA and glmM genes with an invasive histopathological technique. Methods: 290 gastric biopsies were collected using gastrointestinal endoscopy from patients with gastritis symptoms in different hospitals in Khartoum state. Two gastric biopsies were collected from each patient for PCR and histopathology. Results: A total of 103 (35.5%) samples were positive by histopathological examination, 88 (30.3%) by 16S rRNA, 39 (13.4%) by glmM gene, and 56 (19.3%) by ureA gene. The highest sensitivity was observed in 16S rRNA (46.6%), followed by glmM (24.3%) and ureA (23.3%). While the best specificity was observed in glmM gene (92.5%), followed by ureA (82.3%) and 16S rRNA (78.6%). Conclusion: PCR test targeting the 16S rRNA gene exhibited the best results for molecular detection of H. pylori compared to other genes.

Accuracy of H. pylori fecal antigen test using fecal immunochemical test (FIT)

BACKGROUND

Gastric and colorectal cancer (CRC) are both one of the most common cancers worldwide. In many countries fecal immunochemical tests (FIT)-based CRC screening has been implemented. We investigated if FIT can also be applied for detection of H. pylori, the main risk factor for gastric cancer.

METHODS

This prospective study included participants over 18 years of age referred for urea breath test (UBT). Patients were excluded if they had used antibiotics/bismuth in the past 4 weeks, or a proton pomp inhibitor (PPI) in the past 2 weeks. Participants underwent UBT, ELISA stool antigen test in standard feces tube (SAT), ELISA stool antigen test in FIT tube (Hp-FIT), and blood sampling, and completed a questionnaire on user friendliness. UBT results were used as reference.

RESULTS

A total of 182 patients were included (37.4% male, median age 52.4 years (IQR 22.4)). Of these, 60 (33.0%) tested H. pylori positive. SAT and Hp-FIT showed comparable overall accuracy 71.1% (95%CI 63.2-78.3) vs. 77.6% (95%CI 70.4-83.8), respectively (p = 0.97). Sensitivity of SAT was 91.8% (95%CI 80.4-97.7) versus 94.2% (95%CI 84.1-98.9) of Hp-FIT (p = 0.98). Serology scored low with an overall accuracy of 49.7% (95%CI 41.7-57.7). Hp-FIT showed the highest overall user convenience.

CONCLUSIONS

FIT can be used with high accuracy and sensitivity for diagnosis of H. pylori and is rated as the most convenient test. Non-invasive Hp-FIT test is highly promising for combined upper and lower gastrointestinal (pre-) cancerous screening. Further research should investigate the clinical implications, benefits and cost-effectiveness of such an approach.

Detection of Helicobacter Pylori infection by invasive and non-invasive techniques in patients with gastrointestinal diseases from Iraq: A validation study

There is still no agreement on the gold standard technique for diagnosing of H. Pylori in Iraq, as well as a paucity of data on the validity of different diagnostic techniques. This study aimed to investigate the prevalence of this bacterium with different methods and compare them to the quantitative polymerase chain reaction (qPCR) as a golden standard technique among Iraqi patients. In total, 115 Iraqi patients strongly suspected of H. pylori infection were enrolled in the current study. Invasive techniques including rapid urease testing (RUT) and gastric tissue culture in addition to non-invasive techniques including ¹⁴C-Urea breath test (¹⁴C-UBT), stool antigen test (SAT), CagA-IgG serology, and qPCR were performed to confirm the H. pylori infection. The qPCR was used as the gold standard to estimate the sensitivity, specificity, positive and negative predictive values for the studied diagnostic tests. Overall, the prevalence rate of H. pylori in Iraqi patients was ranged from 47.8 to 70.4% using different methods. The positive results for each test were as follows: qPCR 81, (70.4%) UBT 79 (68.7%), SAT 77 (67%), RUT 76 (66.1%), Cag-IgG 61 (53%), and culture 55 (47.8%). The ¹⁴C-UBT showed the highest overall performance with 97.5% sensitivity, 97% specificity, and total accuracy of 97.3% followed by SAT, RUT, Cag-IgG, and culture method. Based on the accuracy of the studied methods for H. pylori detection, they can be arranged in order as follows: qPCR > UBT > SAT > RUT> CagA IgG > culture. Since a universal gold standard assay for the diagnosis of H. pylori has not yet been established in Iraq, the UBT may be recommended as first choice due to its higher performance compared to other methods.

Evaluation of Better Staining Method among Hematoxylin and Eosin, Giemsa and Periodic Acid Schiff-Alcian Blue for the Detection of Helicobacter pylori in Gastric Biopsies

Background

This study was undertaken to evaluate the preferred method (Giemsa or periodic acid Schiff-Alcian blue [PAS-AB] stains) of detecting Helicobacter pylori (H. pylori) in gastric mucosal biopsies in terms of sensitivity, specificity and applicability. To the best of my knowledge, this is the first report comparing Giemsa and PAS-AB staining for the detection of H. pylori in such biopsies.

Methods

The formalin-fixed paraffin-embedded blocks of 49 gastric biopsies from different patients were collected from the archive of anatomical pathology at King Abdulaziz Medical City, National Guard, Riyadh, Saudi Arabia. From each block, three slides were prepared and analysed using the hematoxylin and eosin (H&E), Giemsa and PAS-AB stains to detect the presence/absence of H. pylori, and the results were compared in terms of sensitivity, specificity and applicability.

Results

The majority of the biopsies in this study showed antrum-type gastric mucosa. Only 15 biopsies showed active gastritis, whereas the rest showed chronic gastritis. Three biopsies showed intestinal metaplasia. All were detected by PAS-AB stain, but only two-thirds were detected by H&E stain. Fifteen gastric biopsies showed H. pylori infection in general and in 13 of them, active gastritis cases were discovered. Fourteen out of these 15 H. pylori infection cases were detected by Giemsa stain, whereas only 13 cases were detected by H&E stain. PAS-AB stain showed the worst results since it demonstrated only 40% sensitivity and 67.65% specificity in H. pylori detection.

Conclusion

Giemsa stain has better sensitivity and specificity in gastric H. pylori infection detection than PAS-AB. Therefore, using PAS-AB stain to detect H. pylori infection is not recommended.