Detection ofHelicobacter pylori DNA in gastric juice by the polymerase chain reaction: Comparison with findings in bacterial culture and the detection of tissue IgA and serum IgG antibodies againstHelicobacter pylori

The detection ofHelicobacter pylori in gastric juice by the polymerase chain reaction (PCR) was undertaken in 124 patients with peptic ulcer or chronic gastritis. PCR products were evaluated by agarose gel electrophoresis and Southern hybridization ofH. pylori-specific DNA sequences. Positive and negative results of the PCR analysis in 72 examinations were compared with those from bacterial culture, and with the detection of tissue IgA antibody againstH. pylori by enzyme-linked immunosorbent assay ELISA; Serion, Wuerzburg, Germany, and detection of serum IgG antibody againstH. pylori by ELISA; Radim Pomezia, Italy. Thirty-four PCR-positive samples evaluated by electrophoresis and hybridization coincided with positive samples in 56% of bacterial cultures, 59% of tissue IgA antibody identifications, and 94% of serum IgG antibody evaluations; 26 PCR-negative samples coincided with negative samples in 96% of bacterial cultures, 81% of tissue IgA antibody evaluations, and 38% of serum IgG assessments. We compared the detection achieved with theH. pylori PCR assay in gastric juice with that in biopsies taken from the antrum and upper corpus in 90 examinations, and found them to be both positive in 34 (38%) and 36 (40%) of specimens, both negative in 37 (41%) and 30 (33%) specimens, gastric juice-positive but biopsynegative in 10 (11%) and 12 (13%) specimens, and vice versa in 9 (10%) and 12 (13%) specimens, when detected by electrophoresis and hybridization, respectively, showing equivalent detection rates. In relation to the type of disease, the positive PCR assay results with gastric juice, evaluated by electrophoresis and hybridization, respectively, were: gastric ulcer 34/53 (64%) and 39/53 (74%), duodenal ulcer 23/38 (61%) and 25/38 (66%), and chronic gastritis 20/33 (61%) and 23/33 (70%), showing no significant difference in positive rates between peptic ulcer and chronic gastritis. Of the samples of 16 patients withH. pylori-positive gastric juice by the PCR assay, 7 were negative by PCR assay analyzed by electrophoresis and hybridization after the completion of treatmentH. pylori. However, after treatment, 3 were negative on electrophoresis but still had positive results with hybridization, indicating that a minimal number of bacilli may have still remained. Detection ofH. pylori in gastric juice has potential advantages for examiningH. pylori infection in the entire stomach and for follow up after treatment for the eradication ofH. pylori. This study was supported by Grants-in-Aid for Cancer Research from the Ministry of Health and Welfare, Japan.     

Detection of clarithromycin resistance in Helicobacter pylori following noncryogenic storage of rapid urease tests for 30 days

OBJECTIVE: Traditional Helicobacter pylori (H. pylori) eradication therapy has been undermined by increasing antimicrobial, especially clarithromycin, resistance. Susceptibility testing in some areas is difficult to achieve or unavailable. We aimed to determine whether gastric biopsy specimens stored at room temperature for rapid urease test (RUT) were suitable for clarithromycin susceptibility testing of H. pylori. METHODS: After 30 days of storage at room temperature, DNA was extracted from gastric biopsies present in RUTs (Hpfast). H. pylori status and clarithromycin susceptibility were evaluated using H. pylori‐specific polymerase chain reaction (PCR) for ureA, vacA, and allele‐specific primer‐PCR of the 23S rRNA genes. The PCR results were compared with histology, RUT, and culture results. H. pylori positive was defined as RUT and either culture or histology positive; H. pylori negative as RUT, culture and histology negative. RESULTS: Samples from 31 patients were evaluated; 11 were H. pylori positive including 9 by culture; seven of which had allele‐specific primer‐PCR results from the RUT specimen for the detection of mutations of the 23S rRNA gene. When both tests were available, culture and PCR results were concordant in 7 cases. In 15 of the 20 histology, RUT and culture negative patients, three PCR were negative. In one patient, all of the three tests were positive; and in three only the 23S rRNA was positive and in one only ureA was positive. CONCLUSION: Gastric biopsy specimens stored in the gel of RUT for 30 days can be used for molecular testing to confirm the diagnosis of H. pylori infection and test for clarithromycin susceptibility.     

Simple and accurate 13C-urea breath test for detection of Helicobacter pylori in the remnant stomach after surgery

Background The efficacy of the ¹³C-urea breath test (UBT) for diagnosis of Helicobacter pylori (H. pylori) infection in the remnant stomach after surgery is a matter of controversy. We report a simple and accurate method of ¹³C-UBT for diagnosis of H. pylori infection in the remnant stomach after gastrectomy. Methods Eighty patients who had undergone gastrectomy with or without subsequent H. pylori eradication therapy were examined a total of 134 times for H. pylori infection by the ¹³C-UBT. ¹³C-Urea, 10mg per test, was used in powdered form or in the form of film-coated tablets. Breath samples were collected before and 10, 20, and 3min after ingestion. Mucosal biopsy specimens for bacterial culture and histological examination of the remnant stomach were collected endoscopically after each ¹³C-UBT test. Results Factors that confounded the ¹³C-UBT results in the remnant stomach were oral bacteria, posture, and residual food. Lying horizontally on the left side was the best position, and film-coated tablets indicated no necessity for use of mouthwash. The method of anastomosis had no significant effect on the results of the ¹³C-UBT. Thirty minutes and a cutoff of 4.5‰ were optimal conditions for detection of H. pylori in the remnant stomach. Under these conditions, sensitivity, specificity, and accuracy were 79.4% (27/34 cases), 95.7% (44/46 cases), and 88.8% (71/80 cases), respectively, in ordinary H. pylori diagnosis, and 100% (2/2 cases), 93.3% (14/15 cases), and 94.1% (16/17 cases), respectively, in evaluating eradication at 4 weeks after treatment of H. pylori. Conclusions Having the patient lie horizontally on the left side, using a film-coated ¹³C-urea tablet without using mouthwash, and measurement at 3min provided a simple and accurate method of ¹³C-urea breath test for detection of H. pylori in the remnant stomach after gastrectomy.     

Comparison of the Clinical Feasibility of Three Rapid Urease Tests in the Diagnosis of <Emphasis Type="Italic">Helicobacter pylori</Emphasis> Infection

Rapid urease tests (RUTs) are a fast, accurate, and inexpensive method to diagnose H. pylori infection in the endoscopy suite. Of these, the CLO test is both common and widely used. The aim of our study was to evaluate the accuracy and positive reaction times of two new rapid urease tests (ProntoDry and HpONE) in comparison with the CLO test. Fifty-one patients (26 men, 25 women; mean age, 52.4 years) were included in this study, and all underwent esophagogastroduodenoscopy (EGD). None of the patients had received any prior H. pylori eradication therapy. H. pylori infection status was evaluated by histology, culture, ¹³C–UBT, and RUT. H. pylori infection was considered to be positive if the culture was positive or if two of the other three tests (histology, RUT, and ¹³C–UBT) were positive. If culture was negative and only one of the other three tests was positive, or if all four tests were negative, the result was interpreted as negative. Of these 51 patients, 2 were excluded and 29 (59.1%) were infected with H. pylori. The sensitivities, specificities, positive predictive values, and negative predictive values of the three RUTs were not significantly different. The mean positive reaction times of the three RUTs (CLO test, ProntoDry, and HpONE) were 67.8 ± 12.0, 16.5 ± 2.2, and 17.8 ± 2.1 min, respectively. ProntoDry (P < 0.001) and HpONE (P < 0.001) had significantly faster reaction times than the CLO test, but there was no significant difference between ProntoDry and HpONE. Different media of RUTs may influence the rapidity of a positive reaction time. Both ProntoDry and HpONE were superior to the CLO test in terms of accuracy, reaction time, and cost-effectiveness.     

Comparison between the <Superscript>13</Superscript>C-urea breath test and stool antigen test for the diagnosis of childhood <Emphasis Type="Italic">Helicobacter pylori</Emphasis> infection

Background As noninvasive tests for Helicobacter pylori infection, the ¹³C-urea breath test (UBT) and stool antigen test have been widely used. In children, however, there are few studies reporting which test shows superior performance. The purpose of this study was to compare the ¹³C-UBT and stool antigen test for their accuracy in diagnosing H. pylori infection in children.Methods A total of 123 Japanese children, ages 2 to 17 years (mean, 12 years) who underwent gastric biopsies for H. pylori infection were studied. The diagnoses included gastritis (n = 55), gastric ulcer (n = 5), duodenal ulcer (n = 20), iron-deficiency anemia (n = 7), and other conditions (n = 36). The cutoff value of the ¹³C-UBT was defined to be 3.5. The stool antigen test was performed using the HpSA enzyme-linked immunosorbent assay (ELISA) (Premier Platinum HpSA). In 16 patients who received eradication therapy, the ¹³C-UBT and HpSA were repeated 2 months after treatment.Results Based on biopsy tests, 60 children were infected with H. pylori and 63 children were not. For the ¹³C-UBT, the sensitivity, specificity, and accuracy were 95.0% (95% confidence interval [CI], 86.1%–99.0%), 98.4% (95% CI, 91.5%–100%), and 96.4% (95% CI, 93.6%–99.9%), respectively. For the HpSA, the sensitivity, specificity, and accuracy were 98.3% (95% CI, 90.8%–100%), 98.4% (95% CI, 91.2%–100%), and 98.3% (95% CI, 96.0%–100%), respectively. There were no significant differences between the performance of these two tests. In the assessment of H. pylori eradication, the results of ¹³C-UBT and HpSA agreed with those of biopsy tests.Conclusions The ¹³C-UBT and the HpSA are equally accurate for the diagnosis of active H. pylori infection in Japanese children.Kazuie Iinuma, for the Japanese Pediatric Helicobacter study Group     

Accuracy of IgG Serology and Other Tests in Confirming Helicobacter pylori Eradication

Background: In this study we assessed the accuracy of IgG serology and other tests in confirming Helicobacter pylori eradication. Methods: The outcome of anti-H. pylori therapy was established by at least two of the following tests: rapid urease test (RUT), culture, ¹⁴C urea breath test (non-capsule or capsule UBT), and IgG serology (Orion Diagnostica Pyloriset New EIA-G). Results: Successful H. pylori eradication was confirmed in 698 of 794 patients (88%). The percentage decrease in IgG antibody titre was related to the patients' pre-treatment IgG titre and time interval after treatment. A decrease in IgG titres of 40% or more confirmed H. pylori eradication with 100% specificity, whereas the sensitivity was 82%, 90%, 98%, and 98% 3, 4, 5, and 6 months after therapy, respectively. The 40% cut-off confirmed eradication 3 to 6 months after therapy in 328 of 339 patients (97%) with pre-treatment IgG titres of &gt;700, in 36 of 45 patients (80%) with pre-treatment titres of 300-700, and in 5 of 12 patients (42%) with pre-treatment titres of &lt;300. The sensitivity and specificity of the other tests 2 months after treatment were as follows: RUT, 84% and 100%; culture, 88% and 100%; non-capsule UBT, 100% and 89%; and capsule UBT, 100% and 97%. Conclusion: A decrease in IgG antibody titre of 40% or more 3 to 6 months after therapy and the capsule ¹⁴C UBT at the 2-month follow-up were both highly accurate in confirming H. pylori eradication.     

Role ofHelicobacter pylori serology in evaluating treatment success

Duodenal ulcer recurrence and gastritis are reduced with successfulHelicobacter pylori treatment. Serology is accurate in the diagnosis ofH. pylori, but its value in determining eradication is unproved. To evaluate the usefulness of serology in monitoring treatment, we measured serial serum antibodies in three patient groups: eradication success (N=57), eradication failure (N=19), and untreated patients (N=24). Eradication was determined by Warthin Starry staining of antral biopsies and repeat¹³C breath tests at six weeks. Subsequent¹³C breath tests were then performed at three-month intervals to monitor eradication. IgG antibody concentrations toH. pylori were determined by a commercially available ELISA kit. Serology concentrations remained constant throughout the study period in the untreated patients. IgG concentrations decreased slightly in the treatment failure group at six weeks but thereafter remained at baseline values. In the eradicated group, serum IgG concentrations decreased 26% by three months, 43% by six months and 55% at nine and 12 months (P<0.001). A 20% reduction in IgG concentrations by six months was associated with successful treatment (sensitivity 86% and specificity 88%). We conclude that serology is a potentially useful way to monitorH. pylori treatment success.This work was presented in part in a poster at the May 1992 meeting of the American Gastroenterology Association.[¹³C]urea was kindly provided by Cambridge Isotope Laboratories, Boston, Massachusetts. Reagents and equipment to perform ELISA supplied by Bio Whittaker, Inc., Walkersville, Maryland.     

Accuracy of Seven Different Tests for the Diagnosis of Helicobacter pylori Infection and the Impact of H2-Receptor Antagonists on Test Results

Background: In this study we compared the accuracy of seven diagnostic tests in diagnosing Helicobacter pylori infection. Methods: Over 1 year 351 consecutive dyspeptic patients were tested for H. pylori infection by means of antral biopsy specimens for the rapid urease test (RUT), culture, microscopy (acridine stain), and the laboratory urease test (LUT) and, in addition, with ¹⁴C urea breath test (UBT), IgG serology, and IgA serology (Orion Diagnostica Pyloriset New EIA-G and New EIA-A). The criterion for H. pylori infection was a minimum of three positive tests. Before being tested, 38% of the patients had used an H₂-receptor antagonist (H₂RA). Results: Two-hundred and twenty-four patients (64%) were H. pylori-positive. The sensitivity and specificity of the tests were as follows (percentages): RUT, 85, 99; culture, 93, 100; microscopy, 81, 98; LUT, 80, 100; UBT, 95, 95; IgG serology, 99, 91; and IgA serology, 88, 91. The accuracy of the RUT and LUT was reduced in patients receiving HRA therapy (P = 0.04 and 0.01, respectively). Conclusions: Culture, UBT, and IgG serology were all superior to the other four tests in diagnosing H. pylori infection. Invasive urease-based tests were less accurate in patients receiving HRAs.     

Analysis of the 13C-urea breath test for detection of Helicobacter pylori infection based on the kinetics of Δ-13CO2 using laser spectroscopy

We have previously reported on laser spectroscopy as a simple alternative to mass spectrometry. To validate a simplified ¹³C-urea breath test (UBT) with laser spectroscopy for the detection of Helicobacter pylori in clinical use, we evaluated the optimal time of breath sample collection. The ¹³C-UBT was carried out on each of 102 infected and 70 non-infected subjects (32 without eradication and 38 after eradication therapy). Breath samples were taken at five time points within 60 min followed by 100 mg of ¹³C-urea administration. The ratio of ¹³CO₂ to ¹²CO₂ was measured using laser spectroscopy and the recovery of tracer in the exhaled breath was calculated. Results were compared with histological and culture examinations of gastric biopsies to establish the infection status. For statistical evaluation of ¹³C-UBT, the optimal timing of breath sample collection was examined on the basis of the kinetics of Δ-¹³CO₂. In 32 H. pylori-negative patients (without therapy), the mean ± 2SD of Δ-¹³CO₂ was at its minimum 20 min after urea ingestion whereas in H. pylori-positive patients, the mean ± SD Δ-¹³CO₂ was maximum at 20 min. In addition, receiver operating characteristic (ROC) curve analysis showed that the cut-off value was estimated between 2.5–3.0 per mil (‰) at 20 min before therapy. Based on the histology and culture results, the sensitivity, specificity and positive and negative predictive values were 98.0%, 100%, 100% and 94.1%, respectively. In conclusion, ¹³C-UBT with laser spectroscopy is a non-invasive, simple, sensitive and specific test to determine H. pylori status. Our findings suggest that in clinical use, measurements made at 20 min after substrate administration could be recommended for most sensitive and specific ¹³C-UBT results.     

Efficacy and Tolerability of Rifampicin-Based Rescue Therapy for Helicobacter Pylori Eradication Failure in Peptic Ulcer Disease

In vitro activity of rifampicin has been shown against H. pylori. It has also been reported that the prevalence of H. pylori is low in patients with tuberculosis treated with rifampicin. Clinical trials are required to establish the efficacy of rifampicin as a salvage therapy for eradication of H. pylori. We aimed to evaluate the efficacy of rifampicin-based salvage therapy for eradication of H. pylori in patients with peptic ulcer disease. Twenty-eight patients with peptic ulcer disease who either had failed eradication of H. pylori or had a recurrence of H. pylori following successful eradication were included in the prospective study. The inclusion criteria included one or more failed attempts at eradication and presence of H. pylori infection as evidenced by positivity of at least two of three tests: rapid urease test (RUT), ¹⁴C urea breath test (UBT), and histology. The subjects were treated with a 10-day regimen consisting of rifampicin, 450 mg od, tetracycline, 1 g bd, and esomeprazole, 40 mg bd. Four weeks after completion of therapy, H. pylori status was assessed by RUT, ¹⁴C, UBT, and histology. Liver function tests were done before and at the end of therapy. The study subjects included 25 males and 3 females with a mean age of 33.7 ± 8.92 years (range: 22–65 years). The median duration of symptoms was 42 months, with a range of 1–180 months. The median number of eradication attempts was two, with one prior attempt in 6 (21.4%), two attempts in 19 (67.9%), and three attempts in 3 (10.7%) patients. Successful H. pylori eradication as defined by concomitant negativity of RUT, UBT, and histology with special stains was achieved in 32.1% (9/28) of patients by intention-to-treat and 33.3% (9/27) of patients by per-protocol analysis. This pilot study suggests that rifampicin-based regimes have no role as salvage eradication therapy in refractory cases of H. pylori infection with peptic ulcer disease.     

A newly developed PCR assay ofH. pylori in gastric biopsy,saliva, and feces

We have recently developed a new PCR assay for the detection ofH. pylori. In this study, the polymerase chain reaction (PCR) assay was used to detectH. pylori in 88 gastric biopsy, 85 saliva, and 71 fecal specimens from 88 patients.H. pylori infection was confirmed in 71 of 88 patients by culture and/or histological stain of gastric biopsies. Serum IgG antibody toH. pylori was also measured and resulted in 97% sensitivity and 94% specificity.H. pylori DNA was detected by the PCR assay in gastric biopsy specimens from all 71 patients (100% sensitivity) with proven gastricH. pylori infection but not from 17 noninfected patients (100% specificity). In saliva specimens,H. pylori DNA was identified in 57 of the 68 patients (84%) with proven gastricH. pylori infection and in three of the 17 patients without gastricH. pylori infection. However, the PCR assay was only able to detectH. pylori DNA in the feces from 15 of 61 patients (25%) with proven gastricH. pylori infection and one of the 10 patients without gastricH. pylori infection. The results show that the PCR assay is reliable for detecting the presence ofH. pylori in gastric biopsy and saliva specimens. The data indicate thatH. pylori exists in a higher prevalence in saliva than feces and that the fecal-oral route may be an important means of transmission of this infection in developing countries but not as significant as previously suspected in the developed countries. It is likely that the oral-oral route is more prominent.     

Elevated <Superscript>13</Superscript>C Urea Breath Test Values Females Infected With <Emphasis Type="Italic">Helicobacter pylori</Emphasis>

¹³C-urea breath test (UBT) for the diagnosis of Helicobacter pylori requires a high density and active bacteria and has the potential to provide a noninvasive index of bacterial growth. We describe the gender differences in δ over baseline ¹³C-UBT values in 7373 patients (4531 females and 2842 males) who underwent ¹³C-UBT test for the diagnosis of H. pylori infection. A significantly (P<.001) higher mean ± SD excess delta ¹³CO₂ excretion was recorded in females (24.7±17.4) compared to males (17.6±11.8) aged 10–80 years. The age-adjusted difference between sexes was 7.1 (95% confidence interval, 6.4–7.9). Our analysis demonstrates quantitatively for the first time gender associated differences in H. pylori host interaction. This study suggests that infected females have a higher bacterial load and therefore may potentially infect their children at a higher degree than males.     

Detection of Chlamydiae pneumoniae but not Helicobacter pylori DNA in atherosclerosis plaques

Chronic infections have been associated with cardiovascular disease. We used bacterial culture, polymerase chain reaction (PCR), and immunohistochemical staining with anti-vacA and anticagA antibodies to search for Helicobacter pylori and Chlamydiae pneumoniae in atherosclerotic plaques obtained at endarterectomy. Serum IgG antibodies to H. pylori and C. pneumoniae were also determined. Thirty-two patients were enrolled. Anti-H. pylori and anti-C. pneumoniae IgG were present in 72% and 81%, respectively. Culture and PCR for H. pylori of vessel walls and plaques were negative. Atherosclerotic plaque and normal vessel sections from H. pylori-negative and- positive patients showed reactivity with anti-vacA and anti-cagA antibodies. C. pneumoniae DNA was amplified in three atherosclerotic lesions. These findings suggest that the association between H. pylor infection and atherosclerosis does not result from continuing direct effects of H. pylori antigens in the vessel walls. Antigens within vessel atherosclerotic plaques cross-react with H. pylori virulence factors and could act as cofactors in determining instability for the atherosclerotic plaques.     

13C-Urea breath test, using a new compact nondispersive isotope-selective infrared spectrophotometer: comparison with mass spectrometry

Background The ¹³C-urea breath test (¹³C-UBT) is the most commonly used noninvasive method of detecting Helicobacter pylori infection. The isotope ratio mass spectrometer (IRMS) is the most commonly used device for this test, but the UBiT-IR300 infrared spectrophotometer, which, by comparison, is a more compact, less expensive, and easier to use analytical device, has now become widely used in the clinical setting in Japan. The objective of this study was to examine the diagnostic performance of the ¹³C-UBT, using the UBiT-IR300.Methods A multicenter open-label study was performed, in which the ¹³C-UBT was conducted using 100mg of ¹³C-urea. Analysis of ¹³CO₂ in the expired breath was performed by infrared spectroscopy and mass spectrometry, and assessment of H. pylori infection was performed by culture, histological examination, and rapid urease test.Results In 255 cases of H. pylori infection diagnosed by biopsy methods, the ¹³C-UBTs, performed with two different ¹³C-ruea formulations, and using infrared spectroscopy for evaluation, showed a sensitivity of 97.7%, specificity of 98.0%, and accuracy of 97.8% (total number of evaluable cases, n = 505). The rate of agreement in the assessment of H. pylori infection between infrared spectroscopy and mass spectrometry was 100% (n = 505). The regression equation for infrared spectroscopy to mass spectrometry was y = 0.9822x – 0.0809 (n = 2542), with a correlation coefficient of r = 0.99989 (P = 0.0001).Conclusions Diagnosis of H. pylori infection can be performed using infrared spectroscopy as well as mass spectrometry.     

Studies of 13C-urea breath test for diagnosis of Helicobacter pylori infection in Japan

In recent years Helicobacter pylori infection has been implicated in the etiology of a variety of upper gastrointestinal diseases. The aim of this multi-center trial was to search for the cut-off value of the simple ¹³C-urea breath test (¹³C-UBT) for diagnosis of H. pylori infection, and to examine the sensitivity and specificity of ¹³C-UBT for culture, the rapid urease test (CLO test), histology, and serological tests. Two hundred and forty-eight patients participated in this study after giving their informed consent. Endoscopic biopsy specimens were taken from gastric antrum and corpus for culture (190 patients), CLO test (222 patients), and histology (98 patients). A serological test was carried out for all patients. H. pylori infection was established when culture was positive or more than two of the tests, histology, CLO test, and serological test, were positive, and non-infection status was established when the all tests more than two tests were negative. After baseline breath samples were taken, the patients (who had fasted) were given 100 mg of ¹³C-urea in 100 ml water while sitting; they washed out the mouth with water. They were then placed in the left lateral decubitus position for 5 min, and additional breath samples were taken 10, 20, 30, 45, and 60 min after urea administration, with patients in the sitting position. One hundred and sixty-five of the 248 patients were infected, 48 were not infected, and H. pylori infection status was not evaluated in 35 by endoscopic and serological tests. Breath samples at 20 min were employed to determine the cut-off value. Using the receiver operating characteristic (ROC) curve, we determined the cut-off value for a positive UBT at 2.5 Δ‰. The sensitivities of UBT for culture, CLO test, histology, and serological test were 98.4%, 98.6%, 100.0%, and 92.5%, and the specificities were 78.8%, 82.5%, 83.3%, and 87.3%, respectively. The cut-off value of 13C-UBT for the diagnosis of H. pylori infection was 2.5 Δ‰; this test is a simple and non-invasive method for the diagnosis of this infection and has high sensitivity and specificity. Received Nov. 18, 1996; accepted June 20, 1997     

Complete regression of primary gastric plasmacytoma following<Emphasis Type="Italic"> Helicobacter pylori</Emphasis> eradication

We describe the first case of a primary gastric plasmacytoma stage I completely regressed following Helicobacter pylori (H.pylori) eradication. The patient, a 61-year-old man, had a long history of chronic gastritis and gastric ulcers with recurrent gastrointestinal hemorrhage. Diagnosis of H.pylori infection was based on the positive urease breath test, the elevated titers of serum anti-H.pylori antibodies, and the detection of the bacterium in gastric mucosa biopsy specimens. Diagnosis of gastric plasmacytoma was based on the findings of histopathology, immunocytochemistry and in situ hybridization. Eradication of H.pylori with antibiotics was followed by disappearance of endoscopic and histopathologic features of the gastric tumor 3 months after the completion of the treatment. No relapse has been documented 20 months after the initial diagnosis of plasmacytoma. A possible causal relationship between the tumor and the underlying H.pylori infection is discussed.     

The Diagnostic Yield of Various Tests for Helicobacter pylori Infection in Patients on Acid-Reducing Drugs

The diagnostic yield of various tests for Helicobacter pylori infection in patients on acid-reducing drugs, such as proton pump inhibitors (PPI) and histamine-2 receptor blocker (H2RB), was compared. Seventy-four consecutive patients on acid-reducing drugs were enrolled: 34 (46%) were on PPIs, 20 (27%) were on H2RBs and 20 (27%) were not on medications. For those patients on PPIs, RUT and histology results from antrum were negative in 28 (82%) and 17 (50%) patients, respectively (OR: 4.7; 95% CI: 1.4–16.6; P = 0.004), while those from the corpus were negative in was 28 (82%) and 18 (53%) patients, respectively (OR: 4.4, 95% CI: 1.3–15.5; P = 0.006). For patients on H2RBs, RUT and histology results from the antrum were negative in 12 (60%) and six (30%) patients, respectively (OR: 3.5; 95% CI: 0.8–16.1; P = 0.05), while those from the corpus were negative in 12 (60%) and nine (45%) patients, respectively (OR: 1.8; 95% CI: 0.4–7.8; P = 0.342). For those patients on PPIs, the diagnostic yield of both RUT and histology was reduced from both the antrum and corpus. In these patients, PCR for H. pylori is more sensitive than RUT and histology.     

Significance of rapid urease test for identification ofHelicobacter pylori in comparison with histological and culture studies

Helicobacter pylori in the stomach is an etiological factor of gastritis and peptic ulcer. It is now considered that gastric cancer can be, at least in some cases, a late complication ofH. pylori infection. In 123 consecutive endoscopic antral biopsies obtained from patients with the OkamotsoHospital, the specimens were subjected to the rapid urease test (RUT), histology (H&E stain), and culture, for the identification ofH. pylori. The results of these methods were compared semi-quantitatively in order to evaluate these detection methods for identifyingH. pylori. The results of these methods were found to agree well, with the Spearman's rank correlation coefficient between RUT and culture being 0.90 (P<0.01) and that between histology and culture being 0.80 (P<0.01). RUT is considered to be a very simple, sensitive, and highly specific test which enables the endoscopist to diagnoseH. pylori infection.     

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.     

Comparison of a monoclonal with a polyclonal antibody-based enzyme immunoassay stool test in diagnosing Helicobacter pylori infection after eradication therapy

Background  Recently, a novel Helicobacter pylori stool antigen test (Testmate pylori antigen EIA) using monoclonal antibodies against H. pylori catalase has been developed commercially. This study assessed the diagnostic usefulness of the stool antigen test compared with a polyclonal enzyme immunoassay (HpSA test) after H. pylori eradication. Methods  A total of 150 patients with H. pylori infection were treated by triple therapy with PPI and amoxicillin with either clarithromycin or metronidazole. H. pylori stool antigen was tested 4 and 8 weeks after eradication. The outcome of H. pylori eradication was assessed by urea breath test (UBT) 8 weeks after the end of therapy. Discordant results were followed by endoscopic examination. Results  Of 150 patients enrolled, H. pylori status was negative in 122 cases and positive in 28 cases, assessed by the ¹³C-UBT. On the other hand, the monoclonal stool antigen test results were negative in 126 cases and positive in 24. The polyclonal stool test results were negative in 126 cases and positive in 22. The overall sensitivity and specificity of the monoclonal stool antigen test were 91.6% (95% CI 85.9–97.3%) and 98.4% (95% CI 97.3–99.5%). The overall sensitivity and specificity of the polyclonal stool antigen test were 87.0% (95% CI 86.9–94.0%) and 97.5% (95% CI 96.1–98.9%). Conclusion  The new stool antigen test using monoclonal antibody is useful for the diagnosis of H. pylori eradication 4 weeks after the end of treatment.