Evaluation of the PyloriTek test for detection of Helicobacter pylori infection in cases with and without eradication therapy

OBJECTIVE: The accuracy of the PyloriTek test (a 1-h rapid urease test) used after eradication therapy of Helicobacter pylori (H. pylori) has not been well clarified. This study was done to evaluate the accuracy of the PyloriTek test results for cases with and without eradication therapy, using culture and histology as gold standard methods, and to establish the suitable timing of the PyloriTek test after eradication treatment. METHODS: One hundred sixty-three patients undergoing upper endoscopy were randomly selected; 100 patients had not received eradication therapy and 63 had. Three biopsy specimens each were obtained from the gastric antrum and the body for examination by PyloriTek, culture, and histology. The absence of H. pylori was established with negative results from both culture and histology. RESULTS: In cases without eradication therapy, PyloriTek, correctly identified 66 of 67 H. pylori-positive cases and 30 of 33 H. pylori-negative cases, yielding 98.5% sensitivity and 90.9% specificity. In cases with eradication therapy, PyloriTek gave correct diagnoses in 10 of 17 H. pylori-positive cases and in 45 of 46 H. pylori-negative cases, for 58.8% sensitivity and 97.8% specificity. However, when PyloriTek was used more than 4 months after the end of eradication therapy, both the sensitivity and the specificity increased to 100%. CONCLUSION: Considering time and cost, the use of PyloriTek alone may be satisfactory for detecting H. pylori infection in cases without eradication therapy. When patients are examined more than 4 months after intervention, the use of PyloriTek alone may be sufficient for correctly diagnosing H. pylori infections.     

p53 expression is of independent predictive value in lymph node-negative breast carcinoma

OBJECTIVES: To compare the diagnostic accuracy of the most widely available tests for diagnosis of Helicobacter pylori infection after antibiotic treatment. METHODS: A total of 59 H. pylori-positive, duodenal ulcer patients (mean age, 40.7 +/- 11.7 yr; 40 male and 19 female) were treated for 2 wk with either amoxicillin-metronidazole (n = 36) or omeprazole-amoxicillin-tinidazole (n = 23), and after 4 wk, were tested for H. pylori infection by [14C]urea breath test (UBT), serum IgG antibody level, and multiple antral biopsies for rapid urease testing, histology, Warthin-Starry stain, and polymerase chain reaction to detect H. pylori DNA. Infection status was established by a concordance of test results. RESULTS: H. pylori was eradicated in 47 patients (80%). UBT and rapid urease testing had the best sensitivity and specificity, although not statistically different to Warthin-Starry stain and polymerase chain reaction. Serology and histology had little diagnostic value in this setting due to high proportion of false-positive results. CONCLUSIONS: Noninvasive UBT is as accurate in predicting H. pylori status after antibiotic treatment as rapid urease testing and Warthin-Starry stain. Especially for duodenal ulcer patients, UBT could be considered the gold standard to confirm eradication of H. pylori.     

Taking the low (stretch) road

Helicobacter pylori infection can be detected by several invasive tests based on gastroscopy and by noninvasive methods such as serologic assays. Noninvasive tests can be used not only in addition to invasive tests but also by themselves to screen for H. pylori infection in patients who are not in urgent need of endoscopy. Lately, rapid qualitative serologic tests have been developed. In the present study, the accuracy of a novel rapid whole-blood test, Pyloriset Screen, detecting immunoglobulin G (IgG) and IgA antibodies against H. pylori was evaluated. A total of 207 consecutive adult outpatients referred for upper endoscopy were enrolled. Gastric biopsy specimens were taken from the antrum and corpus for histologic examination and rapid urease testing. Cultures were available for 113 patients. Serum samples collected from all patients were tested for H. pylori antibodies by two enzyme immunoassays (EIAs) (Pyloriset EIA and an in-house EIA), a rapid latex agglutination test (Pyloriset Dry), and Pyloriset Screen. Patients were considered H. pylori positive if helicobacters were seen on histologic examination (77 patients) or, if in combination with histologically verified (although helicobacter-negative) gastritis, their IgG antibody titers were elevated in the two EIAs (five patients). The Pyloriset Screen test had a sensitivity of 95%, a specificity of 94%, a positive predictive value of 91%, and a negative predictive value of 97%. Among 63 patients under the age of 45 years, the Pyloriset Screen test did not miss a single H. pylori diagnosis, and only 1 patient had a false-positive result. Pyloriset Screen could be used reliably to screen for H. pylori infection.     

Management of febrile infants under 3 years old

BACKGROUND: Rapid ureas tests (RUTs) provide a simple, sensitive method of detecting Helicobacter pylori infection. OBJECTIVES: Our aim, therefore, was to determine whether the yield of detecting H. pylori infection by RUT varied depending on the site of gastric biopsy. MATERIALS AND METHODS: Gastric biopsies were obtained from 50 patients for RUT by use of hpfast (GI Supply, Camp Hill, PA). Biopsies were taken from the prepyloric greater curve antrum, from the gastric angle, and from the greater curve in mid-corpus. One biopsy specimen was placed in the RUT gel, and the biopsy from the adjacent mucosa was placed in formalin for subsequent histological evaluation by using the Genta stain. RUTs were examined and scored at intervals of 5, 10, 15, 30, and 45 minutes and after 1, 2, 4, and 24 hours. RESULTS: Fifty patients were entered in the rest (150 RUTs), 32 having H. pylori infection. There were no false-positive RUTs (specificity, 100%). The gastric angle site was positive in 100%. The prepyloric site was positive in 87%, and the corpus site was positive in 84.4% (p < .052 for angle or prepyloric antrum versus corpus). The most common pattern was for all to be positive (74%). The median time to positivity was similar with angle and prepyloric sites (37.5 and 60 minutes, respectively, p = not significant) and shorter than the corpus biopsy (180 minutes); (p < .05 for angle or prepyloric antrum versus corpus). CONCLUSION: The maximum probability for detecting H. pylori infection using a RUT is to obtain a biopsy from the gastric angle. To prevent missing a positive result when intestinal metaplasia is present, we recommend that (at a minimum) biopsies be taken from both the angle and the corpus.     

Evaluation of the FlexSure HP whole blood antibody test for diagnosis of Helicobacter pylori infection

OBJECTIVE: Rapid, inexpensive, reliable tests are needed to facilitate the diagnosis of Helicobacter pylori infection. We evaluated the accuracy of the new FlexSure HP whole blood test (SmithKline Diagnostics, Inc.), a rapid, qualitative in-office test for the detection of antibodies to H. pylori utilizing whole blood obtained from a fingerstick. METHODS: Five North American sites enrolled patients not previously treated for H. pylori who underwent upper endoscopy. Patients had not received antibiotics, bismuth, or proton pump inhibitors within 4 wk before study enrollment. Bacterial infection was established by the presence of H. pylori in gastric biopsies (minimum of two) or positive rapid urease test of antral tissue. The presence of IgG antibodies was determined using FlexSure HP whole blood tests with blood obtained by fingerstick and FlexSure HP serum and ELISA (HM-CAP) tests with serum obtained from venipuncture. RESULTS: Three hundred ninety-three patients were enrolled (56% male; mean age, 46.8 +/- 16.0 yr). H. pylori infection was present in 187 (48%). Compared with the standard of histology and rapid urease test, sensitivity for FlexSure HP whole blood, FlexSure HP serum, and HM-CAP EIA were, respectively, 84%, 90%, and 95% (p < 0.05 compared with FlexSure HP whole blood). There were no statistical differences in specificity or overall accuracy between the three tests. CONCLUSIONS: FlexSure HP whole blood demonstrated an accuracy not significantly different from the FlexSure HP serum test but had sensitivity significantly lower than the HM-CAP EIA. FlexSure HP whole blood may be useful for in-office H. pylori diagnosis.     

Detection methods of Helicobacter pylori: accuracy and costs

A variety of methods exist for determining gastric colonization with Helicobacter pylori, which has been implicated in the development of peptic ulcer disease. The goal of this study was to evaluate four of the current methods available in a clinical surgical practice setting through a prospective evaluation of 40 consecutive patients undergoing upper diagnostic endoscopy. All patients underwent six antral gastric biopsies for use with the following detection methods: histologic demonstration of organisms (hematoxylin and eosin stain), direct detection of urease activity (Remel Selective Rapid Urea, Lenexa, KS), and culture of H. pylori. All patients also had measurement of serum immunoglobulin G for H. pylori by the enzyme-linked immunosorbent assay method (Corning Clinical Laboratories, St. Louis, MO). The infection status was established by a concordance of test results. The results show that H. pylori can be assessed equally well with histology, a rapid urease test, and serology, with all three tests having good sensitivity (92-100%) and specificity (85-96%). The culturing of the organism had poor sensitivity (42%). The benefits of the urease test are a much more rapid response time and a much lower cost as compared to histologic and serologic testing. In conclusion, the rapid urease test is the method of choice to detect H. pylori in those patients undergoing endoscopy in whom the identification of H. pylori will change their management.     

Transmission electron and atomic force microscopic observation of polysomes on carbon-coated grids prepared by surface spreading

BACKGROUND: A number of noncommercial preparations of urease test have been described. The present prospective study evaluated the accuracy of one such preparation for the diagnosis of Helicobacter pylori infection. METHODS: From February 1996 to November 1996, all patients undergoing elective upper endoscopy in a single endoscopy facility were included. Three antral biopsy specimens were taken. Two specimens were subjected to histologic examination, and one specimen was placed into a "locally made rapid urease test" (LRUT). Results of histologic examinations were taken as standards for comparison. The final result of LRUT was obtained on scrutiny of color changes at 4 hours after the start of the test. RESULTS: Two thousand three hundred sixteen patients (male/female = 1.5:1) with a mean age of 56.7 +/- 0.4 years were included. Five hundred sixty-two patients (24.3%) had a history of eradication treatment for H. pylori. Nine hundred fifty-three patients (41.1%) were found to be positive for H. pylori on histologic examination. In patients in whom a history of eradication therapy was absent, the sensitivity, specificity, and positive and negative predictive values of the LRUT were 92.8%, 97.6%, 97.5%, and 93.0%, respectively. In patients with a history of eradication treatment, the corresponding figures were 76.1%, 99.6%, 96.2%, and 96.9%. CONCLUSIONS: The locally made rapid urease test provides a simple, safe, rapid, inexpensive, and accurate test for the diagnosis of H. pylori infection.     

Evaluation of a new urease reagent strip for detection of Helicobacter pylori in gastric biopsy specimens

OBJECTIVES: Determine sensitivity and specificity of a new urease reagent strip (URS) test for detection of Helicobacter pylori in gastric biopsy specimens. METHODS: Six paired biopsy specimens were obtained from the greater curvature of the distal antrum, the lesser curvature near the incisura, and the corpus along the greater curvature during 66 procedures on 59 patients with endoscopic findings of gastric antral mucosal erythema or erosions, or gastric or duodenal ulcers. One biopsy from each site was tested with the URS. The second was evaluated with histology. A final antral biopsy was evaluated with a urea/gel test. RESULTS: Twenty-eight of the 66 cases were histologically positive, with H. pylori observed in at least one of the three biopsy sites. The URS test correctly identified all 28. Of 193 individual biopsy specimens, 78 were positive for H. pylori. The URS correctly identified 77. Sensitivity was 0.99, specificity 0.95, positive predictive value 0.93, negative predictive value 0.99, and kappa 0.92. Average time to positive was 20 min. Twenty-seven antral biopsies were histologically positive for H. pylori. The URS test correctly identified all 27, whereas the urea/gel test correctly identified 21. For antral sites, URS sensitivity was 1.00 and specificity 0.95 versus urea/gel test sensitivity of 0.75 and specificity of 1.00. CONCLUSIONS: In this sample, the URS test is as accurate as histology in diagnosing H. pylori infections, and it provides results in less time and at a lower cost than histology.     

Comparison of two rapid whole-blood tests for Helicobacter pylori infection in Chinese patients

Consecutive Chinese patients undergoing endoscopy for dyspepsia were tested for Helicobacter pylori infection by two rapid whole-blood tests: FlexPack HP (Abbott Laboratories) and Helisal One-Step (Cortecs Diagnostics). Biopsy-based tests (rapid urease test and histology) and the [13C]urea breath test were used as the "gold standard." One hundred sixty-one consecutive patients were studied, and 88 (54.7%) were confirmed to have H. pylori infection. The sensitivities, specificities, and positive and negative predictive values were 81.8%, 83.6% (P = 0.008), 85.7% (P = 0.04), and 79.2% for FlexPack HP and 84.1%, 63.0% (P = 0.008), 73.3% (P = 0.047), and 76.7% for Helisal One-Step, respectively.     

A comprehensive analysis of complex traits in problem 2A

Helicobacter pylori infection is mainly acquired in childhood, and studies on the epidemiology of this infection depend on the availability of a noninvasive diagnostic test for use in children. The aim of this study was to determine whether the carbon 13-labeled urea breath test (UBT) can be used in children by evaluating: (1) its sensitivity and specificity compared with either culture or both rapid urease test and histologic examination, (2) whether a test meal or a prolonged fast is required, (3) the usefulness after treatment for H. pylori. Eighty-eight children (mean age, 10.6 +/- 4.19 years) who were undergoing upper endoscopy were studied while fasting, not fasting, and after treatment. Children were given 50 mg of 13C-urea if they weighed less than 50 kg or 75 mg of 13C-urea if they weighed more than 50 kg with 50 mg of a glucose polymer solution in 7.5 ml of water. Breath samples were collected at baseline and at 15, 30, 45, and 60 minutes. In 63 fasting children the UBT was 100% sensitive and 97.6% specific at 30 minutes with a cutoff value of 3.5 delta 13CO2 per mil. Nonfasting tests in 23 children, performed between 1 and 2 hours after their usual meal, were 100% sensitive and 91.6% specific. In 13 children fed directly before the UBT, the sensitivity of the test was reduced to 50%. Thirty minutes was the optimal sampling time. There was a significant decrease in specificity when samples were obtained at 15 minutes, possibly caused by the interference of oral urease-producing organisms. The test was 100% sensitive and specific in 20 children after treatment for H. pylori infection. The UBT is a highly sensitive and specific test for the diagnosis of H. pylori infection in children. Neither a prolonged fast nor a test meal is required.     

Amoxycillin resistance is one reason for failure of amoxycillin-omeprazole treatment of Helicobacter pylori infection

BACKGROUND: The efficacy of omeprazole and amoxycillin dual therapy to treat Helicobacter pylori infection has been inconsistent, suggesting the presence of host or bacterial factors influencing treatment success. The aim of this study was to assess the role of pre-treatment amoxycillin resistance in the efficacy of omeprazole and amoxycillin dual therapy. METHODS: We studied 43 consecutive dyspeptic patients with H. pylori infection. Pre-treatment H. pylori infection was established by the combination of positive rapid urease test, culture and histology. Amoxycillin susceptibility testing was performed by an Epsilometer test (E-test) method and amoxycillin resistance was defined as minimum inhibitory concentration greater than 8 microg/mL. Patients received 20 mg omeprazole twice daily for 28 days and amoxycillin 1000 mg twice daily for 2 weeks. Adverse effects were documented using a questionnaire. H. pylori status was reassessed 6-8 weeks after the end of treatment by rapid urease testing and histological examination of gastric biopsies. RESULTS: Forty-two dyspeptic patients completed the study, and one patient dropped out. H. pylori infection was cured in 2 3 of 42 patients (55%). The cure rate was higher in patients harbouring amoxycillin-sensitive organisms than in those with resistant strains: 66% (19/29) vs. 31% (4/13), respectively (P = 0.049). No significant differences in cure rates were evident in relation to age, sex, smoking habits or compliance. CONCLUSIONS: The effectiveness of amoxycillin-omeprazole dual therapy was greatly reduced in the presence of pre-treatment amoxycillin-resistant H. pylori. The success rate in patients with amoxycillin-sensitive H. pylori was only 66%, suggesting the presence of additional factors affecting the efficacy of this therapy.     

Clonidine and vasomotion physiology

BACKGROUND: Serological rapid whole-blood tests for the detection of H. pylori are presently being promoted for use in primary care. We conducted a multi-center study to investigate the diagnostic accuracy of the Boehringer Mannheim Helicobacter pylori test (BM test), which is identical with the Cortecs Helisal test. PATIENTS AND METHODS: A previous diagnosis of H. pylori, a history of peptic ulcer diseases, or proton-pump inhibitor, bismuth or antibiotic use during the preceding month were exclusion criteria. The BM test was performed prior to endoscopy by 7 primary care physicians, 5 practicing gastroenterologists, or a single physician in the university hospital outpatient service. During endoscopy, antral and corpus biopsies were obtained for histology and rapid urease testing (RUT). H. pylori positivity was defined by histology and/or RUT as reference methods. H. pylori IgG-ELISA was performed additionally. RESULTS: Of the 203 patients included, 151 were H. pylori-positive by reference methods (74.4%). The overall accuracy of the BM test was 77.3%. Eight BM tests were indeterminate, and in the other 195 patients the test performed as follows: sensitivity 80.3%, specificity 81.3%, positive predictive value 92.9%, negative predictive value 57.4%. Using IgG-ELISA as reference, the BM test performance was similar. It also did not differ substantially among the three groups of physicians involved. CONCLUSIONS: We found the performance of the BM test to be insufficiently accurate, as both over- and underdiagnosis of H. pylori infection were not infrequent. This test needs to be improved before its use in primary care can be recommended.     

Eradication of Helicobacter pylori with lansoprazole, roxithromycin and metronidazole--an open pilot study

BACKGROUND: The most extensively studied Helicobacter pylori eradication regimen comprises omeprazole, clarithromycin and metronidazole. Macrolide antibiotics other than clarithromycin should achieve similar efficacy, but they have not yet been thoroughly tested. AIM: To determine the efficacy and safety of a triple therapy regimen using lansoprazole, roxithromycin, and metronidazole on the basis of multicentre outpatient care in an open pilot study. METHODS: 163 patients with duodenal ulcer and proven H. pylori infection received lansoprazole 30 mg b.d., roxithromycin 300 mg b.d. and metronidazole 500 mg b.d. for 7 days followed by another 7 days of lansoprazole 30 mg once daily. H. pylori status was determined by urease quick test, histology, microbiology and 13C-urea breath test before starting and at least 4 weeks after completing treatment. RESULTS: 150 patients were available for evaluation; H. pylori was successfully eradicated in 84.7% (127/ 150) as determined by urease quick test, 78.0% (117/150) by histology, 81.3% (109/134) by 13C-urea breath test; and in 75.3% (113/150), at least two tests were negative. Side-effects were reported in 34 patients (most commonly diarrhoea and changes in liver function tests), in two cases the study medication was interrupted. Prior to treatment, 23% of the H. pylori isolates were resistant against metronidazole and 3.4% against roxithromycin. After unsuccessful treatment, 84% of the isolates were resistant against metronidazole and 21% against roxithromycin. Primary resistance to metronidazole increased the chance of treatment failure approximately sevenfold (7% vs. 53%). CONCLUSIONS: For H. pylori eradication, the combination of lansoprazole, roxithromycin and metronidazole proved to be as safe as other current triple therapy regimens, while a comparison of efficacy rates yet remains to be assessed in prospective controlled trials. The metronidazole-resistant H. pylori is not rare in Germany and, in the present study, has strongly influenced treatment success.     

Midazolam improves postoperative epidural analgesia with continuous infusion of local anaesthetics

BACKGROUND: A number of triple drug regimens using proton pump inhibitors and two antibiotics have been evaluated in the West and reported to achieve Helicobacter pylori eradication rates of over 90%. In developing countries however, these combinations have neither been well evaluated, nor the optimum treatment for H. pylori infection well defined. AIM: To compare the combination of a proton pump inhibitor with a nitroimidazole and another antibiotic in eradicating H. pylori infection and healing duodenal ulcer. METHODS: Sixty consecutive patients with active duodenal ulcer who were positive for H. pylori (by rapid urease test and 14C-urea breath test) were randomized into three treatments groups: (1) LAS (n=21): lansoprazole 30 mg o.m., amoxycillin 500 mg q.d.s. and secnidazole 2 g on alternate days for 2 weeks; (2) LCS (n=18): lansoprazole 30 mg o.m., clarithromycin 500 mg b.d. and secnidazole 2 g on alternate days for 1 week; (3) LPS (n=21): lansoprazole 30 mg o.m., pefloxacin 400 mg o.m. and secnidazole 2 g on alternate days for 2 weeks. Urease and breath tests were performed at 0, 6 and 12 weeks to check for H. pylori eradication. RESULTS: Intention-to-treat eradication rates were as follows: LAS 86%, LCS 83%, LPS 71%; the overall ulcer healing rate was 90% at 6 weeks. CONCLUSIONS: High H. pylori eradication rates were achieved using the amoxycillin- and clarithromycin-based therapies. Fewer side-effects, better compliance and low cost favoured the amoxycillin-based therapy.     

Use of a gastric juice-based PCR assay to detect Helicobacter pylori infection in culture-negative patients

A gastric juice-based PCR assay was compared with culture, microscopy, and a rapid urease test with specimens from 114 subjects. The PCR and conventional tests were positive for 76 and 62% of the subjects, respectively. The prevalence of gastroduodenal disease and seropositivity for anti-Helicobacter pylori immunoglobulin G were similarly high among conventional-test-positive and PCR-only-positive subjects compared to all-negative ones. The PCR assay is recommended to confirm the H. pylori status of culture-negative peptic-ulcer patients.     

Touch cytology. A reliable and cost-effective method for diagnosis of Helicobacter pylori infection

A variety of reliable methods are available for detecting Helicobacter pylori (Hp) during upper gastrointestinal endoscopy. We evaluated the clinical utility and cost-effectiveness of rapid urease test (RUT), touch cytology (TC), and histology (H). Two hundred thirty-eight consecutive patients (178 without previous medical treatment and 60 formerly treated with anti-Hp therapy) were tested for Hp infection by RUT, TC, and H (H&E stain). The infection status for each patient was established by a concordance of two test results. The time to carry out the three tests and their cost were also calculated. Sensitivity of TC (100%) was significantly higher than that of RUT (86.8%; P < 0.001), but not than that of H (94.9%). RUT was significantly more specific than H (100% vs 95.6%; P < 0.05), but not than TC (96.4%). Hp infection was more frequent in the patients with chronic active gastritis than in those with chronic nonactive gastritis (P < 0.001). No Hp infection was detected in absence of chronic antral inflammation. RUT resulted the cheapest method and H the most expensive; TC is faster and cheaper than H. When additional information about the severity of mucosal damage or the presence of cell atypias is not necessary, histologic examination can be omitted, and a cost-effective strategy for assessing Hp status might consist in taking two antral biopsies, the former for performing RUT and the latter for preparing a slide by TC, which should be stained and examined only when the RUT result is negative.     

Can the C-14 urea breath test replace follow-up endoscopic biopsies in patients treated for Helicobacter pylori infection?

BACKGROUND: The C-14 urea breath test (UBT) is the most specific noninvasive test to detect Helicobacter pylori, with reported sensitivity and specificity rates of 90% and 95%, respectively. This test has not been evaluated for eradication after a therapeutic trial. The goal of this study was to assess the accuracy of C-14 UBT in the diagnosis and eradication of H. pylori infection in patients with duodenal ulcer who were treated with a triple drug regimen. METHODS: Sixty patients with active duodenal ulcers who tested positive for the rapid urease test had a C-14 UBT at 0 weeks (at enrollment) and at 6 and 12 weeks using 5 microCi (185 KBq) of C-14 urea. A single breath sample was collected at 15 minutes for UBT. H. pylori was eradicated using lansoprazole and two antibiotics. RESULTS: Receiver operator characteristic curves showed that, using a value of 400 counts per minute (cpm), UBT had a sensitivity rate of 91%, specificity rate of 93%, positive predictive value of 77%, and a negative predictive value of 97% in the prediction of H. pylori eradication. The mean + 3 SD of H. pylori-negative patients was 380.1 cpm; at this cutoff value, the sensitivity and specificity rates were 91.3% and 92.8%, respectively. CONCLUSION: The C-14 UBT was an accurate, rapid, and easily administered test to diagnose initial H. pylori infection and to monitor its eradication, thereby obviating the need for repeated endoscopic biopsies.     

The importance of increasing the number of gastric biopsies in the diagnosis of Helicobacter pylori

BACKGROUND/AIMS: The role of Helicobacter pylori in various gastroduodenal diseases is universally accepted. In this study, we aimed to determine the proper number and sites of the gastric biopsies in order to achieve the highest diagnostic yield through the use of a urease test and histopathology. We also compared the histological findings encountered in patients who had Helicobacter pylori (H. pylori) colonization. METHODOLOGY: Fifty patients referred for upper gastrointestinal endoscopy for dyspeptic complaints were included in the study. Our mapping protocol included 2 biopsies from antrum and 2 biopsies from corpus. We obtained 2 biopsies from each biopsy site for urease test and histopathological assessment. Golden standard positivity for the presence of H. pylori colonization was defined as concomitantly positive urease test and histologically detected bacteria found at the same biopsy site. RESULTS: Forty-three patients had H. pylori colonization. Colonization rates of H. pylori, sensitivities of urease testing, and histopathology in 4 biopsy sites were not statistically different. Sensitivity of urease testing was 81.4% for 1 biopsy and 100% for 4 cumulative biopsies. Sensitivities of histological assessment were 93% and 100% for 1 and 4 biopsies, respectively. CONCLUSIONS: Results of this study suggest that 2 biopsies for urease testing and 1 biopsy for histopathology obtained from the antrum or corpus of the stomach were sufficient to obtain the highest statistically significant diagnostic sensitivity.     

Detection of Helicobacter pylori gene by means of immunomagnetic separation-based polymerase chain reaction in feces

BACKGROUND: Detection of Helicobacter pylori is usually performed by culture, polymerase chain reaction (PCR), histology, or urease test on gastric biopsy samples. Although methods based on feces are non-invasive, their sensitivity has been relatively low. In this study, to improve its sensitivity, immunomagnetic separation (IMS) was used as a pre-PCR step for direct detection of H. pylori in feces. METHODS: Fresh fecal samples were taken from 72 patients attending for endoscopy. Of these, 57 patients had a positive H. pylori status according to the results of culture, histology, and PCR on gastric biopsy samples. Anti-H. pylori antibody-sensitized immunomagnetic beads were used to concentrate the bacteria. PCR was then performed to detect the H. pylori urease A-encoding gene. RESULTS: Of the 57 H. pylori-positive patients, 35 (61.4%) had positive fecal samples by IMS-based PCR method. None of the 15 H. pylori-negative patients had positive fecal samples. The sensitivity of this method was 61.4%, and the specificity 100.0%. CONCLUSIONS: This study confirms that non-invasive diagnosis of H. pylori infection could be made from feces by using IMS-based PCR.     

Usefulness of Leifson staining method in diagnosis of Helicobacter pylori infection

The Leifson staining method was used to diagnose Helicobacter pylori infection and was compared to histology, culture, and the rapid urease test (RUT). Histology gave the best sensitivity (98%), compared to Leifson staining (97%), culture (92%), and RUT (85%) (P < 0.005). Leifson staining is a sensitive, rapid, economical method for diagnosis of H. pylori infection in dyspeptic patients.