Analysis of eight different methods for the detection of Helicobacter pylori infection in patients with dyspepsia

Associations of Interleukin-1β with H. pylori-Induced Gastric Atrophy and Syndrome of Dampness-Heat in the Spleen and Stomach in Subjects with H. pylori-Related Gastric Diseases

H. pylori-related gastric diseases (HPGD) are a series of gastric mucosal benign and malignant lesions associated with H. pylori infection. Exploring the pathogenesis of HPGD will be of great significance to prevent and treat gastric malignancy. Traditional Chinese medicine (TCM) syndrome is the essence of TCM, reflecting the state of whole body. Potential similarities of TCM syndrome may provide a new perspective in understanding development and treatment of diseases. To seek an early warning signal for gastric malignant pathology and similarities of TCM syndrome from the viewpoint of molecular biology, we examined the relationships among H. pylori, gastric pathology, and TCM syndrome and effects of Interleukin-1β (IL-1β) gene polymorphisms and expression on gastric pathology and TCM syndrome in HPGD. The results indicated that detection of H. pylori with differentiation of TCM syndrome may have a predictive function to gastric pathology. H. pylori may lead to gastric atrophy via enhancing IL-1β mRNA expression, and IL-1β mRNA overexpression in gastric mucosa may be one of the generality characteristics for H. pylori-negative subjects with syndrome of dampness-heat in the spleen and stomach.

Imprint cytology: a useful screening test for diagnosis of Helicobacter pylori in resource poor settings

Objective

The study aimed to compare the usefulness of two staining methods for imprint cytology for diagnosis of Helicobacter pylori infection. Gastric biopsy specimens (from dyspeptic patients attending routine upper gastrointestinal endoscopy) were placed on glass slides to obtain imprints. The imprints were stained with Toluidine blue and Giemsa stains separately and observed under ×400 magnification using a light microscope. Imprinted biopsies were sectioned and stained with H & E stain and Giemsa stain for histological analysis. Diagnosis of H. pylori infection in both imprint and histological sections were confirmed by a consultant pathologist. The sensitivity, specificity, positive predictive value and negative predictive value of each stain were calculated and benchmarked against histological diagnosis.

Results

Of the 55 dyspeptic patients enrolled in the study, 5 were positive for H. pylori by Toluidine blue stain and 4 by Giemsa stain. The sensitivity of Toluidine blue stain (57.1%) was higher than Giemsa stain (42.9%) while the specificity of both stains was equal (97.9%). Giemsa stain gave a better discrimination for identification of H. pylori bacteria among the mucosal background. Imprint cytology is a rapid, simple and cost effective diagnosis method that can supplement histological diagnosis.

Electronic supplementary material

The online version of this article (10.1186/s13104-018-3592-2) contains supplementary material, which is available to authorized users.

Assessment of Helicobacter pylori eradication in patients on NSAID treatment

Background

In this post-hoc analysis of a randomized, double blind, placebo controlled trial, we measured the sensitivity and specificity of Helicobacter pylori IgG-antibody titer changes, hematoxylin and eosin (H&E) stains, immunohistochemical (IHC) stains and culture results in NSAID using patients, following H. pylori eradication therapy or placebo.

Methods

347 NSAID using patients who were H. pylori positive on serological testing for H. pylori IgG-antibodies were randomized for H. pylori eradication therapy or placebo. Three months after randomization, gastric mucosal biopsies were taken for H. pylori culture and histological examination. At 3 and 12 months, blood samples were taken for repeated serological testing. The gold standard for H. pylori infection was based on a positive culture or both a positive histological examination and a positive serological test. Sensitivity, specificity and receiver operating curves (ROC) were calculated.

Results

H. pylori eradication therapy was successful in 91% of patients. Culture provided an overall sensitivity of 82%, and 73% after eradication, with a specificity of 100%. Histological examination with either H&E or IHC stains provided sensitivities and specificities between 93% and 100%. Adding IHC to H&E stains did not improve these results. The ROC curve for percent change in H. pylori IgG-antibody titers had good diagnostic power in identifying H. pylori negative patients, with an area under the ROC curve of 0.70 (95 % CI 0.59 to 0.79, P = 0.085) at 3 months and 0.83 (95% CI 0.76 to 0.89, P < 0.0001) at 12 months. A cut-off point of at least 21% decrease in H. pylori IgG-antibody titers at 3 months and 58% at 12 months provided a sensitivity of 64% and 87% and a specificity of 81% and 74% respectively, for successful eradication of H. pylori.

Conclusions

In NSAID using patients, following H. pylori eradication therapy or placebo, histological examination of gastric mucosal tissue biopsies provided good sensitivity and specificity ratios for evaluating success of H. pylori eradication therapy. A percentual H. pylori IgG-antibody titer change has better sensitivity and specificity than an absolute titer change or a predefined H. pylori IgG-antibody titer cut-off point for evaluating success of H. pylori eradication therapy.

Evaluation of diagnostic methods for the detection of Helicobacter pylori in gastric biopsy specimens of dyspeptic patients

Helicobacter pylori infects nearly 50% of the world’s population. This microorganism is accepted as the most important agent of gastritis and as a risk factor for peptic ulcer disease and gastric adenocarcinoma. Currently many diagnostic methods exist for detecting H. pylori, however they all have limitations, thus it is recommend a combination of at least two methods. The aim of this study was to evaluate diagnostic methods, such as in-house urease test, culture and Polymerase Chain Reaction (PCR), for the detection of the H. pylori in gastric biopsy specimens of 144 dyspeptic patients, using as gold standard the association between histology and rapid urease test. According to the gold standard used in this study, 48 (33.3%) patients were infected with H. pylori, while 96 (66.7%) were classified as not infected. The in-house urease test and the PCR were the most sensitive methods (100%), followed by culture (85.4%). However, the inhouse urease test and the culture were the most specific (100%), followed by PCR (75%). In conclusion, this study showed that, in comparison with the combination of histology and rapid urease test, the in-house urease test and the PCR presented 100% of sensitivity in the diagnosis of gastric infection by H. pylori, while the in-house urease test and the culture reached 100% of specificity. These finding suggest that the combination of two or more methods may improve the accuracy of the H. pylori detection.

Comparison of three methods based on endoscopic gastric biopsies for diagnosis of Helicobacter pylori active infection in a clinical setting

CONTEXT

The correct diagnosis and effective treatment of Helicobacter pylori gastric infection are essential in controlling this infection.

OBJECTIVE

To compare the diagnostic value of three tests based in endoscopic gastric biopsies histopathological evaluation with hematoxylin-eosin (H-E) staining, urease rapid test and microbiological culture for detecting Helicobacter pylori active infection, in order to make recommendations for daily clinical practice.

METHODS

Gastric biopsies from 115 adult patients (85 female/30 male) were obtained by upper gastrointestinal endoscopy and studied by histopathological evaluation with H-E (antrum-corpus), urease test in 2 hours (antrum) and microbiological culture (antrum).

RESULTS

Helicobacter pylori active infection was diagnosed in 67% of patients. Helicobacter pylori active infection was detected by histopathological evaluation with H-E, urease test and microbiological culture in 87%, 79% and 70% of the positive cases, respectively. There were significant differences when histopathological evaluation with H-E and urease test rapid test when compared with microbiological test (P<0.01). There was no significant difference between histopathological evaluation with H-E and urease test (P = 0.7). The kappa index of agreement for histopathological evaluation with H-E/urease test was 0.56, histopathological evaluation with H-E/microbiological culture 0.6, and urease test/microbiological culture 0.64.

CONCLUSIONS

In a hospital setting like the one studied, histopathological evaluation with H-E and urease test are the most recommended tests for diagnosis of Helicobacter pylori active infection based in endoscopic biopsies. If pathological information of gastric lesions will be required, histopathological evaluation with H-E is essential. Urease test is mandatory if a prompt diagnosis is necessary. Microbiological culture can be used in cases of persistent or complicated infection, which may require studies on Helicobacter virulence or antimicrobial susceptibility. Selected cases might demand a combination of several tests. The three tests exhibit a good concordance level for Helicobacter pylori active infection diagnosis.

Molecular Basis of pathogenicity in Helicobacter pylori clinical isolates

This study identified pathogenicity genes in 40 Helicobacter pylori clinical isolates. The cagA, vacA, and iceA genes were detected in 65%, 97.5%, and 97.5% of the isolates, respectively. The cagA, iceA1, and vacAs1a/m1 genes were related to erosive gastritis, whereas the vacAs2/m2 and iceA2 genes were associated with enanthematous gastritis.

Predictive power of serum pepsinogen tests for the development of gastric cancer in comparison to the histologic risk index

BACKGROUND AND AIM

The selection of a high-risk group of gastric cancer is important. This study was performed to compare the efficacy of non-invasive gastric cancer screening through the measurement of pepsinogen (PG) I/II ratio and endoscopic screening using histologic criteria (Meining's risk index for gastric cancer) in Korean patients.

METHODS

Included in the study were 460 gastric cancer patients and 460 control cases who underwent upper endoscopy between June 2003 and July 2008 at Seoul National University Bundang Hospital. Serum PG I/II ratio and histologic characteristics were evaluated for each participant. Multivariate logistic regression was performed to compare the predictive power for gastric cancer of both the PG II/I ratio (the inverse form of PG I/II ratio) and the histologic gastric cancer risk index.

RESULTS

A higher PG II/I ratio was significantly associated with a higher risk for gastric cancer (odds ratio of highest quartile for cancer vs. lowest quartile, 3.51; 95% confidence interval, 2.29-5.36) in the multivariate logistic model. The validity (in terms of calibration and discrimination) of the PG-including multivariate logistic model was comparable to the histologic gastric cancer risk index model. The results were similar regardless of the staging of the cancer, Lauren's histologic classification, and the location of the cancer.

CONCLUSIONS

These results suggest that non-invasive measurement of serum PG I/II ratio is as effective as Meining's histologic gastric cancer risk index in predicting gastric cancer occurrence.

Immunoglobulin G antibody against Helicobacter pylori is an accurate test for atrophic gastritis

BACKGROUND

Enzyme-linked immunosorbent assay (ELISA) is the most commonly used serologic test for Helicobacter pylori. This study aimed to investigate the effects of age and atrophic gastritis on the diagnostic accuracy of an immunoglobulin G (IgG) antibody test against H. pylori in adults.

METHODS

One hundred and seventy dyspeptic patients (age range, 20-70 years) were evaluated. H. pylori infection was diagnosed when culture or both urease and histological tests were positive. Serum pepsinogen-I (P-I) and pepsinogen-II (P-II) levels were measured. Atrophic gastritis was defined when P-I < or = 70 microg/L and P-I/P-II < or = 3. A quantitative ELISA test (HEL-pTEST II) was used for IgG antibodies against H. pylori.

RESULTS

The H. pylori prevalence rate was 62.1%. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of ELISA were 93.5%, 94.4%, 95.6%, 91.9%, and 93.9% in patients aged < 45 years, and 100%, 81.3%, 94.3%, 100%, and 95.6% in patients aged > or = 45 years, respectively. Twenty-six patients had atrophic gastritis. There was 100% sensitivity and 86.7% specificity in atrophic gastritis and 96.5% sensitivity and 91.9% specificity in non-atrophic gastritis.

CONCLUSION

The quantitative ELISA test is a good noninvasive test even in older age groups and is a suitable test in patients with atrophic gastritis due to its excellent sensitivity.

Detection of Helicobacter pylori by phenotypic and genotypic methods

AIMS

This research evaluated the utilization of a urease in-house test, culture and molecular method (ureA PCR) as a diagnostic tool for Helicobacter pylori infection. Furthermore, we assessed the presence of the cagA gene in the specimens and in isolated strains that were positive for ureA by PCR positive.

RESULTS

Sensitivity and specificity, respectively, were 100 and 95.8% for the urease in-house test 93.3 and 95.8 for the ureA PCR assay of the specimen and 100 and 100% for the culture. The presence of the cagA gene was observed in eight (53%) ureA-positive samples.

CONCLUSIONS

In this study, we found that the PCR technique has applicability in the study of cagA, and other genes related to the H. pylori pathogen. This method can be applied to samples directly from biopsy or isolated from the bacteria.

Endoscopic tests for the diagnosis of Helicobacter pylori infection in children: Validation of rapid urease test

BACKGROUND

Rapid urease test (CLO-test) is an inexpensive and quick method for diagnosis of Helicobacter pylori infection with controversial results in children. We evaluated the performance of CLO-test in relation to endoscopic and histological findings in children with H. pylori infection.

MATERIALS AND METHODS

We studied the medical records of children with H. pylori infection who were diagnosed between 1989 and 2009. Noninfected children were used as controls. H. pylori infection was defined by positive culture or by two other positive tests (histology and CLO-test, or urea breath test when a single test was positive). All children had histology together with CLO-test. Tissue culture was performed whenever possible.

RESULTS

Five hundred thirty infected children (10.4 +/- 3.0 years) and 1060 controls (7.3 +/- 4.4 years) were studied. Sensitivity of CLO-test was 83.4% (95% CI, 79.9-86.3%), of culture 84.6% (95% CI, 78.7-89.1%), of histology 93.2% (95% CI, 90.7-95.1%), and specificity 99% (95% CI, 98.2-99.4%), 100%, and 100% respectively. CLO-test positivity was correlated with higher bacterial density (p < .001), activity (p < .001) and severity of gastritis (p < .01), older age (p < .01), and the presence of antral nodularity (p < .001). When CLO-test was positive, the concordance with histology and culture was high (95.5 and 89.2% respectively), whereas low concordance was observed when CLO-test was negative (17.05 and 45.83% respectively).

CONCLUSIONS

CLO-test had lower sensitivity and comparable specificity with histology. Both tests should be performed concurrently to accurately diagnose H. pylori infection in children.

Helicobacter pylori isolates recovered from gastric biopsies of patients with gastro-duodenal pathologies in Cameroon: current status of antibiogram

OBJECTIVE

To determine the prevalence of Helicobacter pylori in patients with gastro-duodenal pathologies and the susceptibility patterns of isolates to the currently recommended antibiotic treatment regimen used in Cameroon.

METHODS

Consecutive dyspeptic patients referred to Douala General Hospital, Cameroon for endoscopy were recruited in the study. Gastric biopsies were collected from the patients and H. pylori isolated and identified following standard microbiology and biochemical techniques. Antibiotic susceptibility was determined by disk diffusion and agar dilution methods against clarithromycin, tetracycline, amoxicillin and metronidazole. Data were analysed using chi-square test and significance considered at P < 0.05.

RESULTS

Seventy-one (92.2%) of the 77 patients (mean age 44.5 +/- 15.7, range 15-77 years) were positive for H. pylori. The antibiotic susceptibility rates were 56% for tetracycline, 55.3% for clarithromycin, 14.4% for amoxicillin and 6.8% for metronidazole. The prevalence of clarithromycin resistance in males vs. females was 42.1%vs. 46.7%, while for metronidazole it was 89.5%vs. 94.7% (P > 0.05). Antimicrobial susceptibility results also revealed 12 antibiotypes based on resistance to the antimicrobial agents investigated. The resistance pattern, amoxicillin and metronidazole (AMR(R) MET(R)) was the most common (23.7%) amongst the isolates. More than 60% of the isolates exhibited multi-drug resistance to three or four antibiotics.

CONCLUSION

Multi-drug resistance is common against the current treatment regimen in Cameroon and, therefore, calls for urgent studies involving newer and broad spectrum antibiotics to address the problem.

In vitro anti-Helicobacter pylori activity of extracts of selected medicinal plants from North West Cameroon

ETHNOPHARMACOLOGICAL RELEVANCE

Helicobacter pylori, a gram negative microaerophilic bacterium is a major etiological agent in duodenal, peptic and gastric ulcers. The growing problem of antibiotic resistance by the organism demands the search for novel compounds from plant based sources.

AIM OF STUDY

The present study is aimed at evaluating the antimicrobial activity of some selected medicinal plants on clinical isolates of H. pylori circulating in Cameroon in a bid to identify potential sources of cheap starting materials for the synthesis of new drugs.

MATERIALS AND METHODS

Gastric biopsy samples were obtained from patients presenting with gastroduodenal complications. H. pylori was isolated from the specimens following standard microbiology procedures. The disk diffusion method was used to determine the susceptibility of 15 isolates to ten methanol plant extracts (Ageratum conyzoides, Scleria striatinux, Lycopodium cernua, Acanthus montanus, Eryngium foetidium, Aulutandria kamerunensis, Tapeinachilus ananassae, Euphorbia hirta, Emilia coccinea and Scleria verrucosa). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for the most active plant extracts were also determined by the agar dilution method. Results were analyzed statistically by the Fisher's exact test.

RESULTS

All the plants tested demonstrated antimicrobial activity with zone diameters of inhibition ranging from 0-30mm. Of these, A. conyzoides, S. striatinux and L. cernua showed very potent antibacterial activity on the isolates. The lowest MIC and MBC recorded were 0.032mg/mL and 0.098mg/mL respectively. However, the MIC of the extracts ranged from 0.032-1.0mg/mL for S. striatinux; 0.063-0.5mg/mL for L. cernua and 0.063-1.0mg/mL for A. conyzoides. The MBC of the extracts ranged from 0.098-15.0mg/mL for S. striatinux; 0.098-12.5mg/mL for A. conyzoides, and 0.195-12.5mg/mL for L. cernua. The extracts had a wide spectrum of activity. The three most potent extracts possessed significant (P<0.05) inhibitory activities.

CONCLUSION

The plant extracts may contain compounds with therapeutic activity.

Diagnosis of Helicobacter pylori: invasive and non-invasive tests

Helicobacter pylori infection can be diagnosed by invasive techniques requiring endoscopy and biopsy (e.g. histological examination, culture and rapid urease test) and by non-invasive techniques, such as serology, the urea breath test, urine/blood or detection of H. pylori antigen in stool specimen. Some non-invasive tests, such as the urea breath test and the stool antigen test, detect active infection: these are called 'active tests'. Non-invasive tests (e.g. serology, urine, near-patient tests) are markers of exposure to H. pylori but do not indicate if active infection is ongoing; these are 'passive tests'. Non-invasive test-and-treat strategies are widely recommended in the primary care setting. The choice of appropriate test depends on the pre-test probability of infection, the characteristics of the test being used and its cost-effectiveness.

Detection of H pylori infection by ELISA and Western blot techniques and evaluation of anti CagA seropositivity in adult Turkish dyspeptic patients

AIM: To detect H pylori infection and to evaluate the anti CagA seropositivity in adult Turkish dyspeptic patients.

METHODS: We evaluated anti-H pylori IgA, IgG and anti-CagA antibodies using commercial enzyme-linked immunoassay (ELISA) and Western blot in dyspeptic Turkish patients. H pylori status was determined by histology and rapid urease testing.

RESULTS: Fifty-six patients were entered. Forty-eight (85.7%) out of the 56 patients were positive for H pylori. H pylori IgG seropositivity was 82.1%, IgA seropositivity 48.2%. CagA ELISA showed that IgG was positive in 50% and IgA in 30.4% of those with H pylori infections. Western blot showed that IgG seropositivity was 80.4% and IgA seropositivity 33.9%. Western blot detected IgG antibodies with reactivity to CagA in 50%, VacA in 62.5%, UreB in 87.5%, UreA in 80.4%, and OMP in 57.1%. None of the tests had a sensitivity and specificity above 80%.

CONCLUSION: None of these commercial tests seems clinically useful for H pylori detection in adult dyspeptic patients, while Western blot can give seropositivity and determine anti-CagA, VacA virulence factor status of Turkish dyspeptic patients in the Izmir region.

Local and systemic immune and inflammatory responses to Helicobacter pylori strains

Colonization with Helicobacter pylori eventuates in varied clinical outcomes, which relate to both bacterial and host factors. Here we examine the relationships between cagA status, serum and gastric juice antibody responses, and gastric inflammation in dyspeptic patients. Serum, gastric juice, and gastric biopsy specimens were obtained from 89 patients undergoing endoscopy. H. pylori colonization and cagA status were determined by histology, culture, and PCR methods, and acute inflammation and chronic inflammation in the gastric mucosa were scored by a single pathologist. Serum and gastric juice antibodies to H. pylori whole-cell and CagA antigens were determined by enzyme-linked immunosorbent assay. Relationships between variables were sequentially analyzed using univariate and multivariate statistical methods. Of the 89 subjects, 62 were colonized by H. pylori. By univariate analyses, levels of serum immunoglobulin G (IgG) and IgA and gastric juice IgA antibodies against whole-cell and CagA antigens each were significantly higher in the H. pylori-positive group than in the H. pylori-negative group (P<0.001). H. pylori and CagA sero-positivities were both significantly associated with enhanced inflammation in gastric antrum and body (P<0.02). The presence of gastric juice antibodies to H. pylori antigens was associated with more severe gastric inflammation. However, in multivariate analyses, only the presence of serum antibodies against CagA and, to a lesser extent, whole-cell antigens remained significantly associated with acute and chronic inflammation in antrum and body (P<0.05). Thus, serum antibody response to CagA correlates with severity of gastric inflammation. Furthermore, given the relationships demonstrated by multivariate analysis, determination of gastric juice antibodies may provide a better representation of serum, rather than secretory, immune response.