Detection of Helicobacter pylori in Gastric Aspirates Using a Monoclonal Antibody-Based Test

Background/Aims

The objective of this study was to evaluate a monoclonal antibody-based test to detect Helicobacter pylori-specific antigen in gastric aspirates from humans.

Methods

Sixty-one volunteers were enrolled in the study. All of the subjects underwent a ¹³C-urea breath test (UBT) before esophagogastroduodenoscopy. Gastric aspirates were analyzed for pH and ammonia and used for polymerase chain reaction (PCR), culture, and monoclonal antibody-based detection of H. pylori. Multiple biopsies of the gastric antrum and body were obtained for a rapid urease test (RUT) and histological evaluation.

Results

Thirty-six subjects were H. pylori-positive and 25 were H. pylori-negative according to the UBT results. Compared with the H. pylori-negative subjects, H. pylori-positive subjects had a higher pH (4.77±1.77 vs 3.49±1.30, p<0.05) and ammonia level (1,130.9±767.4 vs 184.2±126.3, p<0.0001). The sensitivities and specificities of the PCR test, RUT, culture test, and monoclonal antibody-based test were 100% and 72%, 89% and 100%, 47% and 100%, and 78% and 100%, respectively.

Conclusions

The monoclonal antibody-based test for diagnosing H. pylori infection in gastric aspirates has increased sensitivity compared with the culture test and specificity as high as that of the RUT. The test may be useful as an additive test for examining gastric aspirates.     

Significant decrease in prevalence of Helicobacter pylori in the Czech Republic

AIM: To study possible decrease in prevalence of Helicobacter pylori (H. pylori) infection in the Czech Republic within a 10-year period.METHODS: A total of 22 centres entered the study. The catchment areas of these centres covered cities and towns with more than 20 000 inhabitants, smaller towns (≤ 20 000 inhabitants) with surrounding villages and rural areas, and were spread over the whole country, corresponding well to the geographical distribution of the Czech population. A total of 1 837 subjects (aged 5-98 years) took part in the study, randomly selected out of 38 147 people from the general population. H. pylori infection was investigated by means of a ¹³C-urea breath test. Breath samples in duplicates were analysed using isotope ratio mass spectrometry. The cut-off point was 3.5. Social and demographic characteristics were based on data from self-completed questionnaires.RESULTS: The overall prevalence of H. pylori infection was 23.5% (430/1826), and 4.8% (20/420) in children aged 15 or less. There was no statistically significant difference in prevalence between males (24.3%; 208/857) and females (22.9%, 222/969, P = 0.494). H. pylori infection was strongly associated with higher age, among subjects aged 55+ years, prevalence of H. pylori infection was 39.8% (252/633, P < 0.001). The highest prevalence of H. pylori infection was found among persons aged 55-64 years (43.9%, 97/221) and 75+ years (37.9%, 58/153). Among study subjects aged 15+ years, prevalence of H. pylori infection was significantly increased in those with lowest education (odds risk 3.19, 95% CI 1.87-5.47). Compared to never married (14.1%), the prevalence of H. pylori infection was statistically significantly higher among married (35.4%, 246/694, P < 0.001), divorced (36.8%, 49/133, P < 0.001) and widowed study subjects (40.2%, 45/112, P < 0.001), both in minimally and fully adjusted analysis. There was no significant difference in the prevalence of H. pylori infection between married and widowed subjects (35.4%, 246/694 vs 40.2%, 45/112, P = 0.389). There was little variation in smoking prevalence across categories of smoking and there was no evidence of an increased risk of H. pylori infection among current or past smokers in our data (odds risk 1.04 with 95% CI 0.78-1.40 for current smokers; odds ratio 0.83 with 95% CI 0.60-1.16 for former smokers). The current prevalence of H. pylori in 2011 was significantly lower compared to the prevalence reported from identical geographical areas in 2001 (23.5% vs 41.7%, P < 0.001).CONCLUSION: The overall prevalence of H. pylori infection in the general population has fallen substantially in the Czech Republic over the past 10 years.     

Accuracy of Rapid Urease Test in Diagnosing Helicobacter pylori Infection in Patients using NSAIDs

Background/Aim:

This study aimed to determine the effect of nonsteroidal anti-inflammatory drugs (NSAIDs) on the results of rapid urease test (RUT).

Patients and Methods:

The study evaluated 210 consecutive patients for the diagnosis of Helicobacter pylori (H. pylori) infection. They were divided into case and control groups based on history of NSAID use (n=70 each). Two biopsy specimens were collected from antrum and corpus of stomach during endoscopy and sent for rapid urease testing and histopathology. Sensitivity, specificity, and accuracy rate of RUT test were compared against histology.

Results:

The average age was 55.2±12.9 and 43.3±12.1 years in the case and control groups, respectively. Among NSAID users, RUT sensitivity, specificity and accuracy rate were all 100%. The sensitivity, specificity and accuracy rate of RUT in patients without history of NSAID use were 97.37, 98.57 and 98.14%, respectively. The overall sensitivity, specificity and accuracy rate of RUT were 98.57, 99.29, and 99.04%, respectively.

Conclusion:

Our study shows that sensitivity, specificity and accuracy rate of RUT are not affected by NSAID use. Rapid urease test remains a reliable test for diagnosis of H. pylori in patients on NSAIDs.     

Helicobacter pylori eradication in patients with chronic immune thrombocytopenic purpura

AIM:To assess the effect of Helicobacter pylori(H.pylori)eradication on platelet counts in patients with chronic immune thrombocytopenic purpura(cITP).METHODS:A total of 36 cITP patients were included in the study.The diagnosis of H.pylori was done by rapid urease test and Giemsa staining of the gastric biopsy specimen.All H.pylori positive patients received standard triple therapy for 14 d and were subjected for repeat endoscopy at 6 wk.Patients who continued to be positive for H.pylori on second endoscopyreceived second line salvage therapy.All the patients were assessed for platelet response at 6 wk,3rd and 6th months.RESULTS:Of the 36 patients,17 were positive for H.pylori infection and eradication was achieved in16 patients.The mean baseline platelet count in the eradicated patients was 88615.38±30117.93/mm3and platelet count after eradication at 6 wk,3 mo and6 mo was 143230.77±52437.51/mm3(P=0.003),152562.50±52892.3/mm3(P=0.0001),150187.50±41796.68/mm3(P=0.0001)respectively and in the negative patients,the mean baseline count was71000.00±33216.46/mm3 and at 6 wk,3rd and 6th month follow up was 137631.58±74364.13/mm3(P=0.001),125578.95±71472.1/mm3(P=0.005),77210.53±56892.28/mm3(P=0.684)respectively.CONCLUSION:Eradication of H.pylori leads to increase in platelet counts in patients with cITP and can be recommended as a complementary treatment with conventional therapy.     

Dual-priming oligonucleotide-based multiplex PCR using tissue samples in rapid urease test in the detection of Helicobacter pylori infection

AIM:To investigate whether tissue samples processed by the rapid urease test(RUT)kit are suitable for dualpriming oligonucleotide-based multiplex polymerase chain reaction(DPO-PCR)to detect Helicobacter pylori(H.pylori).METHODS:A total of 54 patients with specific gastrointestinal symptom were enrolled in this study.During endoscopy,gastric biopsy specimens were taken for histology,RUT,and DPO-PCR.DPO-PCR was performed on gastric biopsy samples and tissue samples that were analyzed by RUT at 2 separate institutes.In detecting H.pylori,the concordance rate of the DPO-PCR tests between the tissue samples that had been submitted to RUT and the gastric biopsy samples was investigated.RESULTS:H.pylori co-occurred with 76.0%(19/25)of gastric ulcers,64.3%(9/14)of duodenal ulcers,and 33.3%(4/12)of gastritis cases.H.pylori infection was found in 100%(3/3)of the patients with both gastric and duodenal ulcers.Overall,H.pylori was detected in 35 of 54(64.8%)patients.The diagnostic sensitivities of histology,RUT,and DPO-PCR were85.7%(30/35),74.3%(26/35),and 97.1%(34/35),respectively(P=0.02).The positive predictive value(PPV)of DPO-PCR was 94.4%,whereas the negative predictive value(NPV)was 94.7%.In the rapid urease test(CLOtest)-negative cases,the frequency of positive DPO-PCR and histologic results was 20.0%(7/35).The concordance rate of the DPO-PCR tests between the tissue samples from the RUT kit and the gastric biopsy samples was 94.4%(51/54).The rate of DPOPCR and silver stain positivity in the RUT-negative cases was 20.0%(7/35).CONCLUSION:In diagnosing H.pylori infection,DPO-PCR can be performed on tissue samples that have been processed by the RUT kit.Particularly,in patients with RUT-negative results,DPO-PCR on these tissue samples could be helpful in detecting of H.pylori infection.     

Typical and atypical symptoms of gastro esophageal reflux disease: Does Helicobacter pylori infection matter?

AIM: To analyze whether the presence of Helicobacter pylori(H. pylori) infection could affect the quality of symptoms in gastro-esophageal reflux disease(GERD) patients. METHODS: one hundred and forty-four consecutive patients referred to our Unit for suspected GERD were recruited for the study. All patients underwent esophageal p H-metric recording. For those with a positive test, C13 urea breath test was then performed to assess the H. pylori status. GERD patients were stratified according to the quality of their symptoms and classified as typical, if affected by heartburn and regurgitation, and atypical if complaining of chest pain, respiratory and ears, nose, and throat features. H. pylori-negative patients were also asked whether they had a previous diagnosis of H. pylori infection. If a positive response was given, on the basis of the time period after successful eradication, patients were considered as "eradicated"(E) if H. pylori eradication occurred more than six months earlier or "recently eradicated" if the therapy had been administered within the last six months. Patients without history of infection were identified as "negative"(N). χ2 test was performed by combining the clinical aspects with the H. pylori status.RESULTS: one hundred and twenty-nine of the 144 patients, including 44 H. pylori-positive and 85 H. pylori-negative(41 negative, 21 recently eradicated, 23 eradicated more than 6 mo before), were eligible for the analysis. No difference has been found between H. pylori status and either the number of reflux episodes(138 ± 23 vs 146 ± 36, respectively, P = 0.2, not significant) or the percentage of time with pH values 4(6.8 ± 1.2 vs 7.4 ± 2.1, respectively, P = 0.3, not significant). The distribution of symptoms was as follows: 13 typical(30%) and 31 atypical(70%) among the 44 H. pylori-positive cases; 44 typical(52%) and 41 atypical(48%) among the 85 H. pylori-negative cases,(P = 0.017 vs H. pylori +; OR = 2.55, 95%CI: 1.17-5.55). Furthermore, clinical signs in patients with recent H. pylori eradication were similar to those of H. pylori-positive(P = 0.49; OR = 1.46, 95%CI: 0.49-4.37); on the other hand, patients with ancient H. pylori eradication showed a clinical behavior similar to that of H. pylori-negative subjects(P = 0.13; OR = 0.89, 95%CI: 0.77-6.51) but different as compared to the H. pylori-positive group(P 0.05; OR = 3.71, 95%CI: 0.83-16.47).CONCLUSION: Atypical symptoms of GERD occur more frequently in H. pylori-positive patients than in H. pylori-negative subjects. In addition, atypical symptoms tend to decrease after H. pylori eradication.     

Centralized isolation of Helicobacter pylori from multiple centers and transport condition influences

AIM:To evaluate the efficacy of centralized culture and possible influencing factors.METHODS:From January 2010 to July 2012,66452 patients with suspected Helicobacter pylori(H.pylori) infection from 26 hospitals in Zhejiang and Jiangsu Provinces in China underwent gastrointestinal endoscopy.Gastric mucosal biopsies were taken from the antrum for culture.These biopsies were transported under natural environmental temperature to the central laboratory in Hangzhou city and divided into three groups based on their transport time:5,24 and 48 h.The culture results were reported after 72 h and the positive culture rates were analyzed by a χ2 test.An additional 5736 biopsies from H.pylori-positive patients(5646 rapid urease test-positive and 90 14C-urease breath test-positive) were also cultured for quality control in the central laboratory setting.RESULTS:The positive culture rate was 31.66%(21036/66452) for the patient samples and 71.72%(4114/5736) for the H.pylori-positive quality control specimens.In the 5 h transport group,the positiveculture rate was 30.99%(3865/12471),and 32.84%(14960/45553) in the 24 h transport group.In contrast,the positive culture rate declined significantly in the 48 h transport group(26.25%; P 0.001).During transportation,the average natural temperature increased from 4.67 to 29.14℃,while the positive culture rate declined from 36.67%(1462/3987) to 24.12%(1799/7459).When the temperature exceeded 24℃,the positive culture rate decreased significantly,especially in the 48 h transport group(23.17%).CONCLUSION:Transportation of specimens within 24 h and below 24℃ is reasonable and acceptable for centralized culture of multicenter H.pylori samples.     

Helicobacter pylori infection is associated with gallstones: Epidemiological survey in China

AIM: To elucidate the prevalence and risk factors for gallstones, primarily focusing on Helicobacter pylori(H. pylori) infection. METHODS: A total of 10016 Chinese subjects, who had undergone physical examination, fasting 13 C urea breath test and abdominal ultrasonography, had sufficient blood test data, and had finished a questionnaire, were included in this cross-sectional study. Participants(n = 1122) who had previous eradication of H. pylori were studied separately. RESULTS: Gallstones were discovered in 9.10% of men and 8.58% of women, with no significant sex difference. Multivariate analyses displayed that age, aspartate aminotransferase, total cholesterol, H. pylori infection, hepatitis C virus(HCV) infection, and fattyliver had a significant association with gallstones(P 0.05). Successive multiple logistic regression analysis including index of odds ratio(OR) and standardized coefficient(β) indicated that older age(OR/β = 1.056/0.055), H. pylori infection(OR/β = 1.454/0.109), HCV infection(OR/β = 1.871/0.123), and fatty liver(OR/β = 1.947/0.189) had a significant positive association with gallstones. After age stratification, H. pylori infection and fatty liver still had a significant positive association with gallstones in any age-specific groups, whereas HCV infection had a significant positive association in patients aged 40 years. The prevalence of gallstones among H. pylori-positive, H. pylori-eradicated, and H. pylori-negative subjects was 9.47%, 9.02%, and 8.46%, respectively. The matched analysis showed that gallstones among H. pylori eradicated subjects was significantly lower compared with H. pylori-positive subjects(P 0.05).CONCLUSION: H. pylori infection and fatty liver have a significant positive association with gallstones. H. pylori eradication may lead to prevention of gallstones.     

Simple animal model of Helicobacter pylori infection

Helicobacter pylori(H.pylori)has become accepted as a human pathogen for the development of gastritis and gastroduodenal ulcer.To develop a simple rat model of chronic H.pylori infection,male Sprague-Dawley rats were pretreated with streptomycin suspended in tap water(5 mg/mL)for 3 d.The rats were inoculated by gavage at 1 mL/rat with H.pylori suspension(5×108-5×1010 CFU/mL)twice daily at an interval of 4 h for three consecutive days.Two weeks after inoculation,rats were sacrificed and the stomachs were removed.Antral biopsies were performed for urease test and the stomachs were taken for histopathology.Successful H.pylori inoculation was defined as a positive urease test and histopathology.We reported a 69.8%-83.0%success rate for H.pylori infection using the urease test,and hematoxylin and eosin staining confirmed the results.Histopathological analysis detected bacteria along the mucous lining of the surface epithelium and crypt lumen and demonstrated mild to moderate gastric inflammation in successfully inoculated rats.We developed a simple rat model of chronic H.pylori infection for research into gastric microcirculatory changes and therapy with plant products.     

High rate of Helicobacter pylori reinfection in Lithuanian peptic ulcer patients

AIM: To evaluate the frequency of Helicobacter pylori(H. pylori) reinfection in peptic ulcer patients during 9 years after H. pylori eradication.METHODS: We invited 117 peptic ulcer patients in whom eradication of H. pylori was confirmed 1 year after eradication treatment both by histology and by rapid urease test. In total, 57 patients were available for the study procedures: 34(59.6%) male, 23(40.4%) female; mean age 52.3 ± 13.0 years. There were 45(78.9%) patients with duodenal ulcer and 12(21.1%) with gastric ulcer. H. pylori was diagnosed by a rapid urease test and histology if endoscopy was performed. If endoscopy was refused, H. pylori was diagnosed by the C14-urea breath test and serology. H. pylori was established if at least one of the tests was positive.RESULTS: The mean follow-up was 8.9 ± 1.0 years(range, 6-12). H. pylori was established in 15 patients. In 2 H. pylori-negative patients, H. pylori was established during the follow-up period and eradicated. Therefore, we consider that reinfection occurred in 17 patients. In the per protocol analysis, reinfection was established in 17 of 57(29.8%; 95%CI: 19.2-42.2) patients during the follow-up period. The annual rate of infection was 3.36%. If all non-responders were considered H. pylori-negative, reinfection would be 14.5%(17/117), the annual ratebeing 1.63%. The mean age of patients with reinfection was 51.8 ± 14.0 years, and without reinfection was 52.5 ± 13.0 years, P 0.05; the mean body mass index of patients with reinfection was 27.2 ± 4.1 kg/m2, and without reinfection was 25.7 ± 4.2 kg/m2, P 0.05. There were no differences in the reinfection rates according the location of the peptic ulcer, the eradication regimen used, and smoking status.CONCLUSION: The reinfection rate of H. pylori is relatively high in Lithuania and probably related to the high prevalence of H. pylori, what may reflect differences in the socioeconomic status between Western and Eastern European countries.     

Isolation and diagnosis of Helicobacter pylori by a new method: Microcapillary culture

AIM:To investigate the performance of the microcapillary culture method(MCM) in Helicobacter pylori(H.pylori) isolation and diagnosis.METHODS:Microcapillary culture(MC),classical culture(CC),rapid urease(CLO) test,and histopathologic examination(HE) were performed with biopsy samples.Homogenized biopsy samples were loaded into capillary tubes and incubated for 48 h at 37 ℃ without providing a microaerophilic environment.Additionally,three or four loops of the homogenized sample were inoculated in a ready-to-use selective medium(Becton Dickinson,Helicobacter Agar,Modified) specific for the isolation of H.pylori and incubated at 37 ℃ in a microaerophilic atmosphere provided by Campy Gen(Becton Dickinson,Gas Pack).Bacteria reproducing in microcapillary tubes were evaluated in an inverted microscope and also were evaluated after performing a CC with the content.Results obtained by CC,CLO test,and HE were compared with those of MC.The diagnostic performances of the methods used in this study were evaluated for specificity,sensitivity,positive predictive value(PPV),negative predictive value(NPV),and CI.RESULTS:H.pylori was found positive by CLO test +HE and/or CC culture in 26 patient antrum and corpus biopsy samples.In 25(25/26) patient biopsy samples,H.pylori was isolated by MCM,whereas in only 14(14/26) patient biopsy samples,H.pylori was isolatedby CC.CLO test and HE were found positive in 17(17/26) patient biopsy samples.Comparing the results of the isolation of H.pylori by MCM,CC,CLO test,and HE,the sensitivity of the MCM was found as 96%,the specificity as 80%,the PPV as 83%,the NPV as 95%,and the 95%CI as 0.76(χ2 =31.51,P < 0.01) whereas the sensitivity of the CC was found as 54%(χ2 =19.15,P < 0.01),and the sensitivity of the CLO test and HE were found as 65%(χ2 =25.26,P < 0.01).CONCLUSION:This new microcapillary cultivation method for H.pylori has high diagnostic sensitivity compared with CC,HE,and CLO tests.     

Predictive value of neutrophil infiltration as a marker of Helicobacter pylori infection

AIM: To evaluate the predictive value of neutrophil infiltration as a marker of Helicobacter pylori (H. pylori) infection.METHODS: A total of 315 patients with dyspepsia symptoms who underwent upper gastrointestinal endoscopy were enrolled in this study. Biopsies were evaluated using the updated Sydney system. The medication history of all patients in the preceding 4 wk was recorded. The diagnosis of H. pylori infection was based on ¹³C-urea breath test at least 4 wk after withdrawal of antisecretory drugs, antibiotics and related drugs. For the patients with subtotal gastrectomy, the diagnosis of H. pylori infection was based on anti-H. pylori immunoglobulin G (IgG) antibody. Serum anti-H. pylori IgG antibody was measured by enzyme-linked immunosorbent assays (Biohit, Finland).RESULTS: The sensitivity, specificity, positive predictive value and negative predictive value of neutrophil infiltration in the diagnosis of H. pylori infection were 92.3%, 83.5%, 77.4% and 94.7%, respectively. Neutrophil infiltration of gastric mucosa in the histological analysis was strongly associated with H. pylori infection (77.4% vs 5.3% in the neutrophil infiltration negative group, P = 0.000). Moderate neutrophil infiltration was more frequent in H. pylori infection when compared to mild infiltration (81.8% and 75%, respectively), but did not reach statistical significance. For those patients with negative rapid urease test, H. pylori was detected in 73.2% of patients with positive neutrophil infiltration on histology. In patients with subtotal gastrectomy, the diagnostic accuracy of neutrophil infiltration in H. pylori infection was 50%.CONCLUSION: Neutrophil infiltration is closely associated with H. pylori and may be recognized as a sign of this infection.     

Effect of posture on 13C-urea breath test in partial gastrectomy patients

AIM: To investigate whether posture affects the accuracy of ¹³C-urea breath test (¹³C-UBT) for Helicobacter pylori (H. pylori) detection in partial gastrectomy patients.METHODS: We studied 156 consecutive residual stomach patients, including 76 with H. pylori infection (infection group) and 80 without H. pylori infection (control group). H. pylori infection was confirmed if both the rapid urease test and histology were positive during gastroscopy. The two groups were divided into four subgroups according to patients’ posture during the ¹³C-UBT: subgroup A, sitting position; subgroup B, supine position; subgroup C, right lateral recumbent position; and subgroup D, left lateral recumbent position. Each subject underwent the following modified ¹³C-UBT: 75 mg of ¹³C-urea (powder) in 100 mL of citric acid solution was administered, and a mouth wash was performed immediately; breath samples were then collected at baseline and at 5-min intervals up to 30 min while the position was maintained. Seven breath samples were collected for each subject. The cutoff value was 2.0‰.RESULTS: The mean delta over baseline (DOB) values in the subgroups of the infection group were similar at 5 min (P > 0.05) and significantly higher than those in the corresponding control subgroups at all time points (P < 0.01). In the infection group, the mean DOB values in subgroup A were higher than those in other subgroups within 10 min and peaked at the 10-min point (12.4‰ ± 2.4‰). The values in subgroups B and C both reached their peaks at 15 min (B, 13.9‰ ± 1.5‰; C, 12.2‰ ± 1.7‰) and then decreased gradually until the 30-min point. In subgroup D, the value peaked at 20 min (14.7‰ ± 1.7‰). Significant differences were found between the values in subgroups D and B at both 25 min (t = 2.093, P = 0.043) and 30 min (t = 2.141, P = 0.039). At 30 min, the value in subgroup D was also significantly different from those in subgroups A and C (D vs C: t = 6.325, P = 0.000; D vs A: t = 5.912, P = 0.000). The mean DOB values of subjects with Billroth I anastomosis were higher than those of subjects with Billroth II anastomosis irrespectively of the detection time and posture (P > 0.05).CONCLUSION: Utilization of the left lateral recumbent position during the procedure and when collecting the last breath sample may improve the diagnostic accuracy of the ¹³C-UBT in partial gastrectomy patients.     

Quadruple therapy with moxifloxacin and bismuth for first-line treatment of Helicobacter pylori

AIM: To compare triple therapy vs quadruple therapy for 10 d as first-line treatment of Helicobacter pylori (H. pylori) infection.METHODS: Consecutive H. pylori positive patients never treated in the past for this infection were randomly treated with triple therapy of pantoprazole (PAN) 20 mg bid, amoxicillin (AMO) 1 g bid and moxifloxacin (MOX) 400 mg bid for 10 d (PAM) or with quadruple therapy of PAN 20 mg bid, AMO 1 g bid, MOX 400 mg bid and bismuth subcitrate 240 mg bid for 10 d (PAMB). All patients were found positive at 13 C-Urea breath test (UBT) performed within ten days prior to the start of the study. A successful outcome was confirmed with an UBT performed 8 wk after the end of treatment. χ² analysis was used for statistical comparison. Per protocol (PP) and intention-to-treat (ITT) values were also calculated.RESULTS: Fifty-seven patients were enrolled in the PAM group and 50 in the PAMB group. One patient in each group did not return for further assessment. Eradication was higher in the PAMB group (negative: 46 and positive: 3) vs the PAM group (negative: 44 and positive: 12). The H. pylori eradication rate was statistically significantly higher in the PAMB group vs the PAM group, both with the PP and ITT analyses (PP: PAMB 93.8%, PAM 78.5%, P < 0.02; ITT: PAMB 92%, PAM 77.1 %, P <0.03).CONCLUSION: The addition of bismuth subcitrate can be considered a valuable adjuvant to triple therapy in those areas where H. pylori shows a high resistance to fluoroquinolones.     

MGMT and MLH1 methylation in Helicobacter pylori-infected children and adults

AIM:To evaluate the association between Helicobacter pylori(H.pylori) infection and MLH1 and MGMT methylation and its relationship with microsatellite instability(MSI).METHODS:The methylation status of the MLH1 and MGMT promoter region was analysed by methylation specific methylation-polymerase chain reaction(MSPPCR) in gastric biopsy samples from uninfected or H.pylori-infected children(n = 50),from adults with chronic gastritis(n = 97) and from adults with gastric cancer(n = 92).MLH1 and MGMT mRNA expression were measured by real-time PCR and normalised to a constitutive gene(β actin).MSI analysis was performed by screening MSI markers at 4 loci(Bat-25,Bat-26,D17S250 and D2S123) with PCR;PCR products were analysed by single strand conformation polymorphism followed by silver staining.Statistical analyses were performed with either the χ 2 test with Yates continuity correction or Fisher’s exact test,and statistical significance for expression analysis was assessed using an unpaired Student’s t-test.RESULTS:Methylation was not detected in the promoter regions of MLH1 and MGMT in gastric biopsy samples from children,regardless of H.pylori infection status.The MGMT promoter was methylated in 51% of chronic gastritis adult patients and was associated with H.pylori infection(P < 0.05);this region was methylated in 66% of gastric cancer patients,and the difference in the percentage of methylated samples between these patients and those from H.pylori-infected chronic gastritis patients was statistically significant(P < 0.05).MLH1 methylation frequencies among H.pylori-infected and non-infected chronic gastritis adult patients were 13% and 7%,respectively.We observed methylation of the MLH1 promoter(39%) and increased MSI levels(68%) in samples from gastric cancer patients in comparison to samples from H.pylori-infected adult chronic gastritis patients(P < 0.001 and P < 0.01,respectively).The frequency of promoter methylation for both genes was higher in gastric cancer samples than in H.pylori-positiv     

Seroepidemiology of Helicobacter pylori infection in elderly people in the Beijing region,China

AIM:To investigate seroepidemiology of cagA+and vacA+strains of Helicobacter pylori(H.pylori)in an elderly population in Beijing and to determine risk factors for seropositivity.METHODS:A total of 2006 elderly persons(>60years)were selected using a random cluster sampling method in different parts of the Beijing area(urban,suburban and mountainous districts).Structured questionnaires were completed during home visits,including history of H.pylori infection,history of gastrointestinal diseases,diet types,hygiene habits,occupation and economic status.Blood samples(2 mL)were collected from each participant,and serum IgG antibodies to cagA,vacA and H.pylori urease antigens were measured by immunodetection.RESULTS:The prevalence of H.pylori infection in elderly subjects was 83.4%and the typeⅠH.pylori strain infection rate was 56%.The seroprevalence for typeⅠH.pylori strain infection in urban and suburbandistricts was higher than that in the mountainous areas(P<0.001).Elderly subjects who had previously performed manual labor or were in the young-old age group(age<75 years)had a higher seroprevalence of H.pylori infection than those who had previously performed mental labor or were in the oldest-old age group(age≥75 year)(P<0.05).The typeⅠH.pylori strain infection rate in the elderly with vegetarian diets was higher than in those eating high-protein foods(P<0.001).There was no significant difference in the prevalence of H.pylori strains between male and female elderly participants(P>0.05).CONCLUSION:TypeⅠH.pylori seroprevalence is higher in elderly people.The distribution of strains of H.pylori is significantly affected by age,area and dietary habits.     

Helicobacter pylori infection as a cause of iron deficiency anaemia of unknown origin

AIM: To assess the aetiological role of Helicobacter pylori (H. pylori) infection in adult patients with ironrefractory or iron-dependent anaemia of previously unknown origin. METHODS: Consecutive patients with chronic irondeficient anaemia (IDA) with H. pylori infection and a negative standard work-up were prospectively evaluated. All of them had either iron refractoriness or iron dependency. Response to H. pylori eradication was assessed at 6 and 12 mo from follow-up. H. pylori infection was considered to be the cause of the anaemia when a complete anaemia resolution without iron supplements was observed after eradication. RESULTS: H. pylori was eradicated in 88 of the 89 patients. In the non-eradicated patient the four eradicating regimens failed. There were violations of protocol in 4 patients, for whom it was not possible to ascertain the cause of the anaemia. Thus, 84 H. pylori eradicated patients (10 men; 74 women) were available to assess the effect of eradication on IDA. H. pylori infection was considered to be the aetiology of IDA in 32 patients (38.1%; 95%CI: 28.4%-48.8%). This was more frequent in men/postmenopausal women than in premenopausal women (75% vs 23.3%; P < 0.0001) with an OR of 9.8 (95%CI: 3.3-29.6). In these patients, anaemia resolution occurred in the first follow-up visit at 6 mo, and no anaemia or iron deficiency relapse was observed after a mean follow-up of 21 ± 2 mo. CONCLUSION: Gastric H. pylori infection is a frequent cause of iron-refractory or iron-dependent anaemia of previously unknown origin in adult patients.     

Blood pressure and stature in Helicobacter pylori positive and negative persons

To evaluate vital signs and body indices in Helicobacter pylori(H.pylori)positive and negative persons.A total of 22 centres entered the study.They were spread over the whole country,corresponding well to the geographical distribution of the Czech population.A total of 1818 subjects(aged 5-98 years)took part in the study,randomly selected out of 38147 subjects.H.pylori infection was investigated by means of a 13Curea breath test.Data on height,weight,systolic and diastolic blood pressure and heart rate were collected at the clinics of general practitioners.The overall prevalence of H.pylori infection was 30.4%(402/1321)in adults(≥18 year-old)and 5.2%(26/497)in children and adolescents(≤17 year-old).Once adjusted for age and gender,only a difference in body mass index remained statistically significant with H.pylori positive adults showing an increase of 0.6 kg/m2 in body mass index.Once adjusted for age and gender,we found a difference in height between H.pylori positive and H.pylori negative children and adolescents.On further adjustment for place of residence,this difference became statistically significant,with H.pylori positive children and adolescents being on average 3.5 cm shorter.H.pylori positive adults were significantly older compared to H.pylori negative subjects.Once adjusted for age and gender,H.pylori infection had no impact on body weight,body mass index and vital signs either in adults or children and adolescents.Chronic H.pylori infection appeared to be associated with short stature in children.H.pylori infection did not influence blood pressure,body weight and body mass index either in adults or children and adolescents.     

Helicobacter pylori infection is not associated with nonalcoholic fatty liver disease

AIM: To determine whether Helicobacter pylori(H. pylori) infection confers a higher risk of Nonalcoholic fatty liver disease(NAFLD).METHODS: Healthy people who underwent health screening were analyzed retrospectively. Inclusion criteria were age ≥ 20 years, history of H. pylori infection, and recorded insulin level. Participants were classified as H. pylori positive or negative according to 13 C urea breath tests. NAFLD was defined using the hepatic steatosis index(HSI) and NAFLD liver fat score(NAFLD-LFS). Those with an HSI 36 or NAFLD-LFS -0.640 were considered to have NAFLD. Multivariable logistic regression was performed to identify risk factors for NAFLD.RESULTS: Three thousand six hundred and sixtythree people were analyzed and 1636(44.7%) were H. pylori positive. H. pylori infection was associated with older age, male gender, hypertension, higher body mass index, and a dyslipidemic profile. HSI differed significantly between H. pylori positive and negative subjects(median 33.2, interquartile range(IQR) 30.0-36.2 for H. pylori-positive vs median 32.6, IQR 29.8-36.0 for negative participants, P = 0.005), but NAFLD-LSF did not [median-1.7, IQR-2.4--0.7 vs median-1.8, IQR-2.4-(-0.7), respectively, P = 0.122]. The percentage of people with NAFLD did not differbetween infected and uninfected groups: HIS, 26.9% vs 27.1%, P = 0.173; NAFLD-LFS, 23.5% vs 23.1%, P = 0.778. H. pylori infection was not a risk factor, but C-reactive protein concentration and smoking were significant risk factors for NAFLD.CONCLUSION: H. pylori infection is not a risk factor for NAFLD as indicated by HSI or NAFLD-LFS. Prospective, large-scale studies involving liver biopsies should be considered.