Value of a new stick-type rapid urine test for the diagnosis of Helicobacter pylori infection in the Vietnamese population

AIM:To assess the value of a new test for the diagnosis of Helicobacter pylori(H.pylori) infection,Rapirun H.pylori Antibody Stick(Rapirun Stick),in a Vietnamese population.METHODS:Eligible patients without previous history of H.pylori eradication were recruited.Rapid urease test(RUT) and histologic examination were used to diagnose the H.pylori infection.Patients were considered H.pylori positive when the RUT results were positive and/or the bacteria were detected histologically.Rapirun Stick tests were performed using urine samples,and the results were compared with the other 2 methods.RESULTS:We enrolled 200 patients with a mean age of 36(range,18-76) years.There were 116 females and 84 males.Of the 200 patients,111(55.5%) were diagnosed as being H.pylori positive.The sensitivity,specificity,and accuracy of the Stick test were 84.7%,89.9%,and 87.0%,respectively.There were 17(8.5%) falsenegative patients and 9(4.5%) false-positive patients.CONCLUSION:The Rapirun Stick test has high sensitivity,specificity,and accuracy for the diagnosis of H.pylori infection in the Vietnamese population.The test can be clinically applied in Vietnamese populations.     

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.     

Detection of anti-Helicobacter pyloriantibodies in serum and duodenal fluid in peptic gastroduodenal disease

AIM:To study the diagnosis of Helicobacter pylori(H pylori)infection through the determination of serum levels of anti-H pylori IgG and IgA antibodies,and the levels of anti-H pyloriIgA antibodies in duodenal fluid.METHODS:Data were collected from 93 patients submittedto upper digestive endoscopy due to dyspeptic symptoms.The patients were either negative(group A)or positive(group B)to H pylori by means of both histological detectionand urease tests.Before endoscopy,peripheral blood wascollected for the investigation of anti-H pylori IgG andIgA antibodies.To perform the urease test,biopsies wereobtained from the gastric antrum.For the histologicalevaluation,biopsies were collected from the gastric antrum(greater and lesser curvatures)and the gastric body.Following this,duodenal fluid was collected from the firstand second portions of the duodenum.For the serologicalassaying of anti-Hpylori IgG and IgA,and anti-Hpylori IgAin duodenal fluids,the ELISA method was utilized.RESULTS:The concentration of serum IgG showed sensitivityof 64.0%,specificity of 83.7%,positive predictive value of82.0%,negative predictive value of 66.6% and accuracyof 73.1% for the diagnosis of H pylori infection.For thesame purpose,serum IgA showed sensitivity of 72.0%,specificity of 65.9%,positive predictive value of 72.0%,negative predictive value of 67.4% and accuracy of 69.8%.If the serological tests were considered together,i.e.whenboth were positive or negative,the accuracy was 80.0%,sensitivity was 86.6%,specificity was 74.2%,positivepredictive value was 74.2% and negative predictive valuewas 86.6%.When values obtained in the test for detectingIgA in the duodenal fluid were analyzed,no significantdifference(P=0.43)was observed between the valuesobtained from patients with or without H pylori infection.CONCLUSION:The results of serum IgG and IgA tests forH pylori detection when used simultaneously,are moreefficient in accuracy,sensitivity and negative predictive value,than those when used alone.The concentration of IgAantibodies in duodenal fluid is not useful in identifying patientswith or without H pylori.     

Capsule 13C-urea breath test for the diagnosis of Helicobacter pylori infection

AIM: To compare the accuracy of capsule 13C-urea breath test (UBT) with conventional invasive methods for the diagnosis of Helicobacter pylori infection. METHODS: One hundred patients received CLO test, histological examination, culture and 100- or 50-mg capsule UBT for the diagnosis of H pylori infection. H pylori infection was defined as those with positive culture or positive results from both histology and CLO test. RESULTS: Both the sensitivity and specificity of the 100-mg capsule UBT (n=50) were 100%. The sensitivity and specificity of the 50-mg capsule UBT (n = 50) were 96.4 and 100%, respectively. Taken together, the accuracy of capsule UBT (n =100) was higher than that of CLO test, histology and culture (100% vs 92%, 91% and 89%, respectively; P= 0.035, 0.018 and 0.005, respectively). Our data showed that the optimal timing of sampling for 100-and 50-mg capsule UBT was 15-30 and 6-15 min, respectively. CONCLUSION: Capsule UBT has a higher accuracy compared with biopsy-based tests. It is an ideal method for the diagnosis of H pylori infection.     

Clinical value of Helicobacter pylori stool antigen test,Immuno Card STAT HpSA,for detecting Hpylori infection

AIM:To evaluate the reliability of the Helicobacter pyloristool antigen test,ImmunoCard STAT HpSA,for detectingH pylori infection.METHODS:Stool specimens were collected from 53 patientswho received upper endoscopy examination due togastrointestinal symptoms.ImmunoCard STAT HpSA wasused to detect H pyloristool antigens.Hpyloriinfection wasdetected based on three different tests:the urease test,Warthin-Starry staining and culture.H pylori status wasdefined as positive when both the urease test and histologyor culture alone was positive.RESULTS:Sensitivity,specificity,positive predictive andnegative predictive values and the total accuracy ofImmunoCard STAT HpSA for the diagnosis of Hpyloriinfectionwere 92.6% (25/27),88.5% (23/26),89.3% (25/28),92%(23/25) and 90.6% (48/531),respectively.CONCLUSION:The stool antigen test,ImmunoCard STATHpSA,is a simple noninvasive and accurate test for thediagnosis of H pylori infection.     

New fecal test for non-invasive Helicobacter pylori detection: A diagnostic accuracy study

AIM To assess the diagnostic accuracy of a new fecal test for detecting Helicobacter pylori(H. pylori), using ~(13)Curea breath test as the reference standard, and explore bacterial antibiotic resistance. METHODS We conducted a prospective two-center diagnostic test accuracy study. We enrolled consecutive people≥ 18 years without previous diagnosis of H. pylori infection, referred for dyspepsia between February and October 2017. At enrollment, all participants underwent 13 C-urea breath test. Participants aged over 50 years were scheduled to undergo upper endoscopy with histology. Participants collected stool samples 1-3 d after enrollment for a new fecal investigation(THD fecal test). The detection of bacterial 23 S rRNA subunit gene indicated H. pylori infection. We also used the index diagnostic test to examine mutations conferring resistance to clarithromycin and levofloxacin. Independent investigators analyzed index test and reference test standard results blinded to the other test findings. We estimated sensitivity, specificity, positive(PPV) and negative(NPV) predictive value, diagnostic accuracy, positive and negative likelihood ratio(LR), together with 95% confidence intervals(CI).RESULTS We enrolled 294 consecutive participants(age: Median 37.0 years, IQR: 29.0-46.0 years; men: 39.8%). Ninetyfive(32.3%) participants had a positive ~(13)C-urea breath test. Twenty-three(7.8%) participants underwent upper endoscopy with histology, with a full concordance between ~(13)C-urea breath test and histology in detecting H. pylori infection. Four(1.4%) out of the 294 participants withdrew from the study after the enrollment visit and did not undergo THD fecal testing. In the 290 participants who completed the study, the THD fecal test sensitivity was 90.2%(CI: 84.2%-96.3%), specificity 98.5%(CI:96.8%-100%), PPV 96.5%(CI: 92.6%-100%), NPV 95.6%(CI: 92.8%-98.4%), accuracy 95.9%(CI: 93.6%-98.2%), positive LR 59.5(CI: 19.3-183.4), negative LR 0.10(CI: 0.05-0.18). Out of 83 infected participants identified with the THD fecal test, 34(41.0%) had bacterial genotypic changes consistent with antibiotic-resistant H. pylori infection. Of these, 27(32.5%) had bacterial strains resistant to clarithromycin, 3(3.6%) to levofloxacin, and 4(4.8%) to both antibiotics. CONCLUSION The THD fecal test has high performance for the non-invasive diagnosis of H. pylori infection while additionally enabling the assessment of bacterial antibiotic resistances.     

Mucosal polymerase chain reaction for diagnosing Helicobacter pylori infection in patients with bleeding peptic ulcers

AIM: Helicobacter pylori (H pylon) has been linked to chronic gastritis, peptic ulcers, gastric cancer and MALT-lymphoma. Conventional invasive tests are less sensitive than non-invasive tests in diagnosing H pylori infection in patients with bleeding peptic ulcers. Polymerase chain reaction is a sensitive and accurate method for diagnosing H pylori infection. The aim of this study was to evaluate the diagnostic role of mucosai polymerase chain reaction for H pylori infection in patients with bleeding peptic ulcers. METHODS: In patients with bleeding, non-bleeding peptic ulcers and chronic gastritis, we checked rapid urease test, histology, bacterial culture and mucosai polymerase chain reaction fordetecting H pylori infection. Positive H pylori infection was defined as positive culture or both a positive histology and a positive rapid urease test. For mucosai polymerase chain reaction of H pylori, we checked vacA (s1a, s1b, s1c, s2, m1, m1T, m2), iceA1, iceA2. and cag A. RESULTS: Between October 2000 and April 2002,88 patients with bleeding peptic ulcers (males/females: 60/28, gastric ulcers/duodenal ulcers: 55/33), 81 patients with non-bleeding peptic ulcers (males/females: 54/27, gastric ulcers/duodenal ulcers: 45/36) and 37 patients with chronic gastritis (males/ females: 24/13) were enrolled in this study. In patients with bleeding peptic ulcers, non-bleeding peptic ulcers and chronic gastritis, 45 patients (51%), 71 patients (88%) and 20 patients (54%) respectively were found to have positive H pylori infection (P<0.001). In patients with bleeding peptic ulcers, non-bleeding peptic ulcers and chronic gastritis, polymerase chain reaction for H pylori infection was positive in 54 patients (61%), 70 patients (86%) and 20 patients (54%) respectively (P<0.001). The sensitivity, positive predictive value and diagnostic accuracy of mucosai polymerase reaction for H pylori infection were significantly lower in patients with bleeding peptic ulcers (84%, 79% and 81%) than in patients with non-bleeding peptic ulcers (99%, 99% and 98%) (P<0.001, P<0.01 and P<0.001 respectively). The sensitivity, negative predictive value and diagnostic accuracy of mucosal polymerase reaction for H py/ori were significantly lower in patients with bleeding peptic ulcers (84%, 83% and 81%) than in patients with chronic gastritis (100%, 100% and 100%) (P= 0.02, P= 0.02 and P=0.001). CONCLUSION: Mucosal polymerase chain reaction for detecting H pylori infection is not reliable in patients with bleeding peptic ulcers.     

Comparison of invasive methods and two different stool antigen tests for diagnosis of H pylori infection in patients with gastric bleeding

AIM: To compare two different H pylori stool antigen tests as noninvasive diagnostic methods. METHODS: The study population consisted of 22 upper gastrointestinal system bleeding patients. Urea breath test (UBT), rapid urease test (RUT) and histopathological examination were applied to all patients. Stool specimens from these patients were examined by rapid STRIP!HpSA and one step simple H pylori antigen cassette test for the detection of H pylori antigens. RESULTS: For these 22 patients, 15 (68.2%) were diagnosed as positive and seven (31.8%) were diagnosed negative for H pylori infection by the gold standard methods. Whereas 10 (45.5%) were positive and 12 (54.5%) were diagnosed negative by the rapid STRiP!HpSA test. The sensitivity, specificity, positive and negative predictive values were 60%, 86%, 90% and 50%, respectively. When compared to the gold standard methods, these differences were not significant. However, six patients (27.3%) were positive, and 16 (72.7%) were negative by the simple H pylori stool antigen cassette test. The sensitivity, specificity, positive and negative predictive values were 33%, 86%, 83% and 38%, respectively. Compared to the gold standard methods, the simple H pylori stool antigen cassette test results were significantly different (P = 0.012). CONCLUSION: Rapid STRIP! HpSA test could be used as a routine diagnostic tool in the microbiology laboratory for assessing clinical significance and eradication control of H pylori in upper gastrointestinal system bleeding patients.     

Validity and cost comparison of ~(14)carbon urea breath test for diagnosis of H Pylori in dyspeptic patients

AIM: To validate and compare the cost of microdose 14C urea breath test (UBT) with histology and rapid urease test for the diagnosis of H Pylori. METHODS: Ninety-four consecutive patients with dyspeptic symptoms undergoing gastroscopy were enrolled. Gastric biopsies were taken for histology and rapid urease test. UBT was performed after gastroscopy by microdose 14C urea capsules. Sensitivity, specificity and accuracy of UBT were calculated and compared with histology and rapid urease test. Cost comparison of these tests was also performed. RESULTS: H pylori was diagnosed by histology and rapid urease test in 66 (70%) and 61 (65%) patients, while 14C UBT detected infection in 63 (67%). Accuracy of UBT was 93% in comparison with histology while its positive and negative predictive values were 97% and 84%, respectively. Comparison of 14C UBT with rapid urease test gives an accuracy of 96%, with positive and negative predictive values of 95% and 97%, respectively. These results were highly reproducible with a Kappa test (P value < 0.001). Cost of histology or rapid urease test with gastroscopy was 110 USD or 95 USD respectively while the cost of UBT was 15 USD. CONCLUSION: Microdose 14C UBT was comparable to histology and rapid urease test. 14C UBT is an economical, self sufficient and suitable test to diagnose active H pylori infection in less developed countries.     

Extremely high prevalence of Helicobacter pylori infection in Bhutan

AIM: To revealed the prevalence of Helicobacter pylori (H. pylori ) infection in the Bhutanese population. METHODS: We recruited a total of 372 volunteers (214 females and 158 males; mean age of 39.6 ± 14.9 years) from three Bhutanese cities (Thimphu, Punaka, and Wangdue). The status of H. pylori infection was determined based on five different tests: the rapid urease test (CLO test), culture, histology, immunohistochemistry (IHC), and serum anti H. pylori -antibody. RESULTS: The serological test showed a significantly higher positive rate compared with the CLO test, culture, histology and IHC (P < 0.001, P < 0.001, P=0.01, and P=0.01, respectively). When the subjects were considered to be H. pylori positive in the case of at least one test showing a positive result, the overall prevalence of H. pylori infection in Bhutan was 73.4%. The prevalence of H. pylori infection significantly decreased with age (P < 0.01). The prevalence of H. pylori infection was lower in Thimphu than in Punakha and Wangdue (P=0.001 and 0.06, respectively). The prevalence of H. pylori infection was significantly higher in patients with peptic ulcers than in those with gastritis (91.4% vs 71.3%, P=0.003). CONCLUSION: The high incidence of gastric cancer in Bhutan may be attributed to the high prevalence of H. pylori infection.     

幽门螺杆菌粪便抗原试验的多中心研究

目的：评估幽门螺杆菌（H.pylori)粪便抗原（HpSA)试验诊断H.pylori感染的准确性。方法：应用酶免疫反应原理进行HpSA试验，在大样本、多中心研究中进行HpSA试验的评估。995例因消化不良症状接受胃镜检查者纳入本研究，所有患者均以HpSA试验、快速尿素酶试验（RUT）和组织学（或培养）方法检测H.pylori。以RUT和组织学（或培养）联合检测作为“金标准”，两项试验均阳性者定为H.pylori感染。结果：以光密度值≥0.16为阳性，HpSA检测诊断H.pylori感染的敏感性为93.5%(478/511)，特异性为94.2%(456/484)，阳性预测值为94.5%(478/506)，阴性预测值为93.3%(456/489)，总的检测准确性为93.9%(934/995)。结论：HpSA试验是一种简便、准确的非侵入性H.pylori感染检测方法。     

How useful is the detection kit for antibody to Helicobacter pylori in urine (URINELISA) in clinical practice?

OBJECTIVE: Increased knowledge of the significance of Helicobacter pylori (H. pylori) infection in gastric disorders has accelerated the trend of screening patients with dyspepsia for its infection. Serological examination of antibody for H. pylori has been widely performed. Recently, a urine-based enzyme-linked immunosorbent assay (URINELISA) kit for detection of antibody for H. pylori has been developed. Accordingly, we evaluated its diagnostic accuracy in clinical practice. METHODS: Subjects of this study were 132 patients who presented at our university hospital because of dyspeptic symptoms (81 men, 51 women; age, 41.5+/-1.4 yr). 13C urea breath test, blood drawing for serological antibody for H. pylori infection by four different kits, and urine collection for the URINELISA test for detection of the antibody were performed. Diagnostic accuracy of the commercially available antibodies in serum and in urine were investigated using the results of the 13C urea breath test as the gold standard. RESULTS: Sensitivity, specificity, and accuracy of URINELISA were 86.3% (95% confidence intervals [CI], 76-93%), 91.5% (95% CI, 81-97%), and 88.6% (95% CI, 82-93%), respectively, which were comparable to those of imported serological kits. CONCLUSIONS: The URINELISA kit for detecting anti-H. pylori antibody in urine provides diagnostic accuracy comparable to that of imported kits for detecting antibodies in serum and is considered to be clinically useful for the diagnosis of H. pylori infection.     

Breath test is very reliable for diagnosis of Helicobacter pylori infection in real clinical practice

AIMS: To determine the accuracy of the most common available tests for the diagnosis of Helicobacter pylori infection in an unselected and untreated population of patients. PATIENTS AND METHODS: Prospective study including 314 unselected patients from a population of 814 patients referred for upper endoscopy at one hospital. H. pylori infection was diagnosed by rapid urease test (RUT), histology, culture and 13C-urea-breath test (UBT) and serum IgG (EIA). H. pylori infection was defined as positive if culture or at least two of the other tests were positive. RESULTS: The prevalence of H. pylori infection in this population was 72%. The diagnostic test with the greatest combination of sensitivity (97%) and specificity (100%) was the UBT. EIA had a good sensitivity (96%), but it was the test with the least specificity (71%). RUT, histology and culture showed a high specificity (>98%) but a sensitivity lower than 90%. In elderly patients (>65 years old, n=120), UBT was also the test with the greatest combination of sensitivity (94%) and specificity (100%). CONCLUSIONS: In conditions of real clinical practice the 13C-urea-breath test is a reliable test for H. pylori diagnosis, both in young and elderly patients.     

Enzyme-linked immunosorbent assay for serodiagnosis of Helicobacter pylori in dyspeptic patients and volunteer blood donors

Helicobacter pylori, an important etiological agent in the development of gastritis, peptic ulcer and gastric carcinoma, can be detected by the enzyme-linked immunosorbent assay (ELISA). Our objectives were: (1) to evaluate the efficacy of a commercial ELISA kit (Pyloriset EIA-G III) in sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for diagnosis of H. pylori infection in Thai dyspeptic patients in Khon Kaen Thailand; and (2) to examine the seroprevalence of H. pylori among blood donors at Srinagarind Hospital's Blood Bank, Khon Kaen University, by the commercial ELISA. Gastric biopsies obtained from 137 dyspeptic patients were diagnosed by culture, rapid urease test (RUT) and histology. Serum samples from the same dyspeptic patients and 100 healthy blood donors were assayed using the commercial ELISA. H. pylori infection in dyspeptic patients was considered positive when the culture or both RUT and histology were positive. Using a cut-off value at a titer of 20 U/ml (as recommended by the manufacturer), we found the commercial ELISA kit had a sensitivity of 93.3%, specificity of 75.3%, PPV of 74.7%, NPV of 93.5% and accuracy of 83.2%. The overall H. pylori seroprevalence in the healthy blood donors was 57%. Of the 100 healthy blood donors, 39 (60.9%) of the males and 18 (50.0%) of the females were seropositive.     

Evaluation of endoscopy-based diagnostic methods for the detection of Helicobacter pylori.

BACKGROUND: Helicobacter pylori is an etiological factor in duodenal ulcer. Few studies have objectively assessed the accuracy of diagnostic methods for the detection of H. pylori. METHODS: The sensitivity and specificity of histology, touch smear, rapid urease test (RUT) and brush cytology of endoscopic antral biopsy from patients with duodenal ulcer were compared. Forty-nine patients were evaluated before, and 34 after, eradication therapy. Each time, sampling was done for all 4 tests. The infection status for each sample was established by a positive concordance of results of three of four tests. RESULTS: The highest degree of agreement was between RUT and cytology (kappa = 0.69). Brush cytology (100%) followed by RUT (94.5%) were the most sensitive tests. Histology had the highest specificity (89.3%). A combination of RUT or brush cytology with histology had the maximum chance of detecting H. pylori. As single tests, brush cytology and touch smear had high diagnostic accuracies with a Youdin J value of 1.79 and 1.78, respectively. CONCLUSION: The best method for diagnosis of H. pylori is a combination of the rapid urease test or brush cytology with histology. Brush cytology or touch smear are diagnostic tests of choice if a single test is desired.     

The clinical utility of string-PCR test in diagnosing Helicobacter pylori infection

BACKGROUND/AIMS: Non-invasive string test has been reported as being convenient and capable of yielding bacteria by means of gastric juice sampling in the diagnosis of Helicobacter pylori infection. Molecular methods, such as polymerase chain reaction for the amplification of DNA, are desirable for the detection of minute quantities of H. pylori. We planned to evaluate the diagnostic efficiency of the combination of the string test and polymerase chain reaction and determine whether the string polymerase chain reaction test could obtain more information in conditions where the bacterial load is so low that other diagnostic tests fail to confirm the presence of H. pylori. METHODOLOGY: We enrolled 48 dyspeptic patients, including 29 males and 19 females, with a mean age of 52.5 years. Each patient received endoscopy and biopsy-based tests, including RUT (rapid urease test), cultures, and histology, followed by 13C-UBT (13Carbon urea breath test). We used the string test, (Entero-Test H. pylori, HDC Corporation, CA, US), for gastric juice sampling. The specimen was further analyzed by polymerase chain reaction for the presence of H. pylori with the primer for cagA gene, which is highly prevalent in Taiwan. H. pylori infection was considered as positive when either culture yield was positive, or when two of the other three tests, including RUT, histology, and 13C-UBT, were positive. RESULTS: Of the total 48 patients, 34 patients were H. pylori-positive, and 14 were H. pylori-negative. A fragment of 349 bp of polymerase chain reaction products was detected by agarose gel electrophoresis in 32 out of 34 patients who was classified as H. pylori-positive. The sensitivity, specificity, positive predictive value, and negative predictive value of the string polymerase chain reaction test were 94.12%, 96.97%, 92.86%, and 86.67%, respectively. These results are comparable to 13C-UBT and RUT, and better than histology and culture. One subject, who tested as H. pylori-negative according to the diagnostic criteria, had positive 13C-UBT and string polymerase chain reaction test results. Further sequencing of the DNA obtained from the results of polymerase chain reaction product was performed and it showed 98% identities with the known sequence of cagA strain H. pylori (GenBank accession number: AF249275). CONCLUSIONS: The string polymerase chain reaction test is non-invasive and provides direct bacterial yields. Its diagnostic efficiency is comparable with 13C-UBT and RUT in detecting H. pylori infection. Also, with the assistance of polymerase chain reaction and DNA sequencing, we can diagnose H. pylori infection even when the bacterial load is low. Further application of string polymerase chain reaction test in the genetic analysis of virulent and resistant strains seems promising.     

14C-尿素呼气试验对幽门螺杆菌感染的诊断价值

目的：评估^14C-尿素呼气试验（^14C-UBT）对幽门螺杆菌（HP）感染的诊断价值。方法：对2000例1月内未曾使用可能影响HP检测结果的药物者同步完成快速尿酶试验（RUT）、病理、^14C-UBT检测，以病理（HE染色）、RUT均阳性为诊断HP感染的标准，评价^14C-UBT对HP感染的诊断价值。结果：^14C-UBT的敏感性89.7％，特异性98.4％，阳性预测值98.4％，准确性93.4％，阴性预测值88.1％。结论：^14C-UBT是HP感染无创伤、敏感而特异的诊断方法。     

Immunological rapid urease test using monoclonal antibody for Helicobacter pylori

BACKGROUND AND AIM: The current diagnostic methods for detecting Helicobacter pylori infection include rapid urease test (RUT), urea breath test (UBT), histology, culture, and serum antibody detection. The present study evaluated the efficacy of a novel highly specific test, an immunological RUT (IRUT), that uses a monoclonal antibody against H. pylori urease. METHODS: The clinical evaluation of the IRUT was performed in 100 subjects. Each gastric mucus sample obtained during endoscopic examination was incubated for 15 min with a solid tip coated with monoclonal antibody for H. pylori urease, and then the tip was introduced into a pH-monitoring cell containing urea solution. The change in pH of the solution after the enzymatic reaction (delta pH) was measured. The performance of the IRUT was compared with culture, histology, RUT, and UBT. RESULTS: Of the 47 H. pylori-positive subjects, 43 were IRUT positive (sensitivity, 91.5%), and of the 53 H. pylori-negative subjects, 52 were negative (specificity, 98.1%). Compared with the usual diagnostic methods, IRUT had high sensitivity and specificity for the detection of H. pylori and was no less efficient. CONCLUSIONS: IRUT is a sensitive, specific and very rapid (within 20 min) method of detecting H. pylori infection.     

Efficacy of the urine antibody test for detection of Helicobacter pylori: comparison with serum antibody tests]

A urine-based enzyme-linked immunosorbent assay kit (URINELISA) for detection of the antibody for H. pylori has recently been developed. We evaluated the diagnostic capability of the URINELISA test in comparison with two serum IgG antibody kits (HM-CAP and Helico G) for H. pylori infection. The subjects of this study were 173 patients. H. pylori was detected by means of culture, immunohistochemical staining and rapid urease test of endoscopically obtained biopsy specimens. A positive diagnosis of H. pylori was when at least one of three tests was positive and a negative diagnosis when all three were diagnosed as H. pylori positive and 23 as negative. We also examined the diagnostic potential of the antibodies in urine and in serum by using the results of the bioptic methods as the gold standard. The sensitivity of both URINELISA and HM-CAP was 93.3% and that of Helico G 94.7%, while their respective specificities were 47.8%, 65.2% and 52.2%. The URINELISA kit thus showed high sensitivity but relatively low specificity. The latter was due to sampling errors in the bioptic procedure because the subjects of this study included many elderly patients with atrophic gastritis. The level of the antibody in urine decreased markedly after 2 months of eradication therapy. We conclude that the URINELISA kit is as effective as serum antibody kits for the diagnosis of H. pylori infection.     

Clinical value of Helicobacter pylori stool antigen test,ImmunoCard STAT HpSA，for detecting Hpylori infection

AIM: To evaluate the reliability of the Helicobacter pylori stool antigen test, ImmunoCard STAT HpSA, for detecting H pylori infection. METHODS: Stool specimens were collected from 53 patients who received upper endoscopy examination due to gastrointestinal symptoms. ImmunoCard STAT HpSA was used to detect H pylori stool antigens. H pylori infection was detected based on three different tests: the urease test, Warthin-Starry staining and culture. H pylori status was defined as positive when both the urease test and histology or culture alone was positive. RESULTS: Sensitivity, specificity, positive predictive and negative predictive values and the total accuracy of ImmunoCard STAT HpSA for the diagnosis of H pylori infection were 92.6% (25/27), 88.5% (23/26), 89.3% (25/28), 92% (23/25) and 90.6% (48/53), respectively.CONCLUSION: The stool antigen test, ImmunoCard STAT HpSA, is a simple noninvasive and accurate test for the diagnosis of H pylori infection.