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Vaira D, Ricci C, Perna F, Gatta L, Tampieri A, Miglioli M. Diagnosis of Helicobacter pylori infection: which is the best test? The stool test. Dig Liver Dis 2000; 32 Suppl 3:S193-5. [PMID: 11245293 DOI: 10.1016/s1590-8658(00)80276-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Savarino V, Landi F, Dulbecco P, Ricci C, Tessieri L, Biagini R, Gatta L, Miglioli M, Celle G, Vaira D. Isotope ratio mass spectrometry (IRMS) versus laser-assisted ratio analyzer (LARA): a comparative study using two doses of. Dig Dis Sci 2000; 45:2168-74. [PMID: 11215733 DOI: 10.1023/a:1026605021484] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
This study was carried out to compare the measurements and the diagnostic accuracy of the traditional expensive IRMS and the new economical LARA system using two doses of [13C]urea + two different test meals in patients undergoing upper gastrointestinal endoscopy, both before and after anti-Helicobacter treatment. A total of 354 dyspeptic patients underwent endoscopy with gastric biopsies to diagnose H. pylori infection by CLO-test and histology. No patients had taken antibiotics, bismuth, or antisecretory drugs in the 4 weeks before testing. After overnight fasting, breath samples were collected simultaneously in both plastic and glass tubes at baseline and at 30 and 60 min after urea ingestion. In 237 patients 100 mg [13C]urea + Ensure and in 117 patients 75 mg [13C]urea + citric acid were given. The test was also performed with the two urea dosages and meals in 67 and 64 infected patients, respectively, four weeks after anti-Helicobacter therapy. H. pylori was considered eradicated when both biopsy-based tests were negative. A delta value >5 per thousand was considered positive. Breath samples with insufficient CO2 levels at both 30 and 60 min were excluded from final analysis (N = 37 in pre- and N = 8 in posttreatment). There was excellent agreement between overall delta values of the two machines with both [13C]urea 100 mg + Ensure and [13C]urea 75 mg + citric acid. The 95% CI of the difference against the mean was wider with the former (mean -1.3, +6.3, and -9.4) than with the latter urea dosage and test meal (mean -1.2, +5.2 and -8.1). LARA and IRMS were equally effective (P = NS) in distinguishing infected from uninfected patients before therapy using both doses of [13C]urea and test meals (sensitivity ranged from 95% to 99% and specificity from 95% to 97%). This good performance was maintained in the posttreatment phase (sensitivity ranged from 90% to 100% and specificity from 90% to 97%), without any statistical difference among the various combinations (P = NS). The LARA system is a valid alternative to IRMS in the diagnosis of H. pylori infection. Both machines provide highly reliable results after 30 min, so that the 60 min sample can be avoided. The dose of 75 mg + citric acid suffices to ensure an accurate UBT. The test performed with both devices and [13C]urea dosages is very effective also for posttherapy evaluation of H. pylori status.
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Gérard C, Vaira D, Delwaide J, Lamproye A, Maggipinto G, Sondag D, Rorive G, Belaïche J, Rentier B. Does HCV screening of blood donors affect transmission of hepatitis G virus in dialysed patients? Vox Sang 2000; 75:77. [PMID: 9779566 DOI: 10.1046/j.1423-0410.1998.7510077.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
MESH Headings
- Belgium/epidemiology
- Blood Donors
- Blood Transfusion/standards
- Cohort Studies
- Comorbidity
- Evaluation Studies as Topic
- Flaviviridae/immunology
- Hepatitis B/epidemiology
- Hepatitis B Surface Antigens/blood
- Hepatitis C/complications
- Hepatitis C/diagnosis
- Hepatitis C/epidemiology
- Hepatitis C Antibodies/blood
- Hepatitis, Viral, Human/complications
- Hepatitis, Viral, Human/epidemiology
- Hepatitis, Viral, Human/prevention & control
- Hepatitis, Viral, Human/transmission
- Humans
- Kidney Failure, Chronic/epidemiology
- Kidney Failure, Chronic/therapy
- Mass Screening
- Prevalence
- RNA, Viral/blood
- Renal Dialysis
- Reverse Transcriptase Polymerase Chain Reaction
- Transfusion Reaction
- Viremia/diagnosis
- Viremia/epidemiology
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Vaira D, Holton J, Menegatti M, Ricci C, Gatta L, Geminiani A, Miglioli M. Review article:invasive and non-invasive tests for Helicobacter pylori infection. Aliment Pharmacol Ther 2000; 14 Suppl 3:13-22. [PMID: 11050483 DOI: 10.1046/j.1365-2036.2000.00096.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
There are two general ways in which a diagnosis of infection by Helicobacter pylori can be made: by using either an invasive or non-invasive procedure. The invasive procedures involve an endoscopy and biopsy. A biopsy is essential because often the mucosa may appear macroscopically normal but nevertheless be inflamed. A biopsy is obtained by histological examination, culture, polymerase chain reaction or detection of the presence of urease activity in biopsy material. The non-invasive tests that can be used to diagnose the infection are serology, detection of labelled metabolic products of urea hydrolysis in the breath (13CO2, 14CO2), the urine or the blood, and detection of H, pylori antigen in a stool specimen. At present no single test can be relied upon to detect definitely colonization by H. pylori, and a combination of two is recommended if this is feasible. The choice of the test to be used is not straightforward and may vary according to the clinical condition and local expertise.
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Checchi L, Felice P, Acciardi C, Ricci C, Gatta L, Polacci R, Holton J, Vaira D. Absence of Helicobacter pylori in dental plaque assessed by stool test. Am J Gastroenterol 2000; 95:3005-6. [PMID: 11051403 DOI: 10.1111/j.1572-0241.2000.03230.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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106
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Menegatti M, Figura N, Farinelli S, Landi F, Acciardi C, Ricci C, Holton J, Gatta L, Crosatti M, Polacci R, Miglioli M, Vaira D. Helicobacter pylori seroconversion in asymptomatic blood donors: a five-year follow-up. Dig Dis Sci 2000; 45:1653-9. [PMID: 11007120 DOI: 10.1023/a:1005589700652] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
Several techniques have been developed to diagnose Helicobacter pylori infection and two noninvasive methods are available: carbon 13-urea breath test (UBT) and serology. Measurement of IgG serum antibodies by enzyme-linked immunosorbent assay (ELISA) is a reliable and inexpensive method for detection of infection. The aim of this study was to assess the seroconversion by different techniques after five to eight years. In 1990, 588 of 1,010 asymptomatic donors were found to be seronegative by ELISA, based on an H. pylori whole-cell suspension lysate (sensitivity and specificity: 92% and 97%). In 1995 serum samples from 418 of 588 seronegative donors were collected and retested using the same antigen. 411 of 418 samples were frankly negative, and 7 donors were found to be seroconverted. This group of seven sera represents the object of the study. They were retested by ELISA and western blotting using a different antigen (NCTC). To standardize our techniques, sera from 43 H. pylori positive and 47 H. pylori negative patients according to culture, histology, urease test, and UBT were used. The cutoff for ELISA-NCTC was 0.53 AI (absorbance index) (mean value + 2 SD), and for western blotting was negativity for CagA or <10 bands (sensitivity and specificity: 95% and 96%; 98% and 81% for ELISA and western blotting respectively). According to the results obtained in 1990 and 1995, seven donors were found to be seroconverted by ELISA using sonicated antigen; in five the seroconversion was confirmed by ELISA using NCTC antigen and in two there was concordance with WB. Four of the seven donors were contacted and asked to undergo UBT and a further serum sample was drawn to be reassessed in 1998. A seroconversion was found in all four donors by ELISA, while WB and UBT confirmed the seroconversion in only three of four donors. In conclusion the in-house ELISA used performed well compared to other theoretically better serologic assays and confirmed the low seroconversion rate for H. pylori infection in adult populations living in developed countries.
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Muyldermans G, Debaisieux L, Fransen K, Marissens D, Miller K, Vaira D, Vandamme AM, Vandenbroucke AT, Verhofstede C, Schuurman R, Zissis G, Lauwers S. Blinded, multicenter quality control study for the quantification of human immunodeficiency virus type 1 RNA in plasma by the Belgian AIDS reference laboratories. Clin Microbiol Infect 2000; 6:213-7. [PMID: 11168110 DOI: 10.1046/j.1469-0691.2000.00048.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE In order to evaluate the interlaboratory variation of HIV-1 RNA measurements in plasma, the Belgian AIDS reference laboratories organized a blinded multicenter quality control study. METHODS Atest panel of coded spiked HIV-1 plasma samples reflecting the dynamic range of the assay was composed and distributed. The HIV-1 RNA concentration of these samples was determined by the eight Belgian AIDS reference laboratories by means of the Amplicor HIV-1 Monitor version 1.5 assay. RESULTS Analysis of the results demonstrated that there was little interlaboratory variation for the high concentration range (4.0-5.7 log10 copies/mL), never exceeding 0.2 log10 copies/mL. However the standard deviation for the low concentration range (2.6-3.9 log10 copies/mL) reached up to 0.22 log10 copies/mL. CONCLUSIONS Since interlaboratory variability never reached 0.5 log10 copies/mL and each of the laboratories was able to detect four-fold differences in plasma HIV-1 RNA levels, the Amplicor assay can be used in multicenter studies without a centralized analysis of samples. Furthermore, this well-characterized proficiency panel of spiked plasma samples could be used as a standard in the study of interassay comparisons.
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Vaira D, Malfertheiner P, Mégraud F, Axon AT, Deltenre M, Gasbarrini G, O'Morain C, Pajares Garcia JM, Quina M, Tytgat GN. Noninvasive antigen-based assay for assessing Helicobacter pylori eradication: a European multicenter study. The European Helicobacter pylori HpSA Study Group. Am J Gastroenterol 2000; 95:925-9. [PMID: 10763939 DOI: 10.1111/j.1572-0241.2000.01931.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE In a recently published multicenter study involving 501 patients undergoing esophagogastroduodenoscopy (EGD) throughout Europe, we showed the high accuracy of a recently developed simple test (HpSA) to detect Helicobacter pylori (H. pylori) antigens in stools of untreated patients. The aim of this study was to assess the diagnostic usefulness of HpSA compared with 13C UBT shortly after H. pylori eradication treatment. METHODS Of the 501 patients enrolled in the validation study, 279 were found to be H. pylori-positive. These patients were given H. pylori eradicating regimen and asked to return for follow-up EGD with biopsies, 13C UBT and HpSA testing 4 wk after therapy. Follow-up results were available for 235 patients. Of these, 162 consented to all testing and 73 consented only to 13C UBT and HpSA testing. We assessed sensitivity and specificity of both HpSA and 13C UBT compared with biopsy-based methods in the 162 patients, who accepted follow-up EGD. We also assessed sensitivity and specificity of HpSA compared with 13C UBT, arbitrarily chosen as the gold standard, in the whole population of 235 patients. RESULTS Sensitivity and specificity in 162 patients who consented to a second EGD were 93.8% (CI: 85.4-100%) and 96.9% (CI: 93.9-99.9%) for HpSA, and 90.6% (CI: 80.5-100%) and 99.2% (CI: 97.7-100%) for UBT. Using EGD-based methods as the gold standard, 130 of the 162 treated patients' H. pylori infection were eradicated (125 HpSA-negative, one borderline, and four false-positive; 129 13C UBT-negative, one false-positive), and 32 remained H. pylori-infected (30 HpSA-positive, two false-negative, 29 13C UBT-positive, three false negative). The overall eradication rate was 80.2%. The sensitivity and specificity of HpSA relative to UBT as the gold standard in the overall population (n = 235) were 95.6% (CI: 89.6-100%) and 94.7% (CI: 91.5-97.9%), respectively. CONCLUSIONS HpSA has proven to be a useful method in posttreatment eradication testing for H. pylori. Its ease of use, speed, and noninvasive nature make HpSA testing an ideal method for post-treatment monitoring where a second EGD may not be justified.
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Reinhard J, Basset C, Holton J, Binks M, Youinou P, Vaira D. Image analysis method to assess adhesion of Helicobacter pylori to gastric epithelium using confocal laser scanning microscopy. J Microbiol Methods 2000; 39:179-87. [PMID: 10670764 DOI: 10.1016/s0167-7012(99)00118-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
We have used confocal scanning microscopy of FITC-labelled bacteria to assess binding of Helicobacter pylori to stomach sections and to assess the effect of inhibitors on binding to the Lewis antigens. We have quantified the binding using an image manipulation package that is readily available on the web. Our results demonstrate heterogeneity of binding of Helicobacter pylori to tissue sections and that binding can be inhibited using synthetic Lewis B oligosaccharide.
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Menegatti M, Vaira D, Figura N, Palli D, Miglioli M. Age, Helicobacter pylori, and/or CagA antibodies as a pre-endoscopic screening policy. Am J Gastroenterol 2000; 95:320-1. [PMID: 10638619 DOI: 10.1111/j.1572-0241.2000.01724.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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111
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Figura N, Di Cairano G, Lorè F, Guarino E, Gragnoli A, Cataldo D, Giannace R, Vaira D, Bianciardi L, Kristodhullu S, Lenzi C, Torricelli V, Orlandini G, Gennari C. The infection by Helicobacter pylori strains expressing CagA is highly prevalent in women with autoimmune thyroid disorders. JOURNAL OF PHYSIOLOGY AND PHARMACOLOGY : AN OFFICIAL JOURNAL OF THE POLISH PHYSIOLOGICAL SOCIETY 1999; 50:817-26. [PMID: 10695561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
UNLABELLED H. pylori infection is putatively associated with extra-digestive disorders and may also play a role in the development of autoimmune thyroid diseases (ATD). It was recently found that monoclonal antibodies to an H. pylori strain with cagA-positivity reacted with follicular cells of the thyroid gland, and that an H. pylori organism possessing the cag pathogenicity island carried a gene encoding for an endogenous peroxidase. The aims of this study was (1); To ascertain whether the infection by strains endowed with an increased inflammatory potential (those expressing CagA) could further enhance the risk of developing ATD (2); To verify the possible existence of an immune cross-reactivity between autoantibodies to peroxidase and thyroglobulin and H. pylori antigens (3). To establish whether thyroid colloid antigens could cross-react with an anti-H. pylori serum. The study was partly designed retrospectively. We examined 41 consecutive women with ATD, and, as a control, 33 consecutive age- and socio-economic class-matched women without autoimmune thyroid disorders, living in the same area as patients, occurred at the same institution in the same period (six months). Both patients and controls were examined serologically for H. pylori infection and CagA status by Western blotting. Some serum samples were absorbed with H. pylori to determine whether the antibody levels decreased. Colloid proteins were resolved electrophoretically and matched with a hyperimmune serum raised in rabbits against a CagA-positive H. pylori. Thirty-two patients (78.0%) tested seropositive for H. pylori infection, vs. 16 controls (48.4%) (P = 0.008, OR = 3.78, RR = 1.61). The prevalence of anti-CagA antibodies was 71.8% in infected patients, and 50% in infected controls (P = 0.161, n.s.). The overall prevalence of infection by CagA-positive H. pylori was significantly higher in patients with ATD (23/41, or 56.0%) than that in controls (8/33, or 24.2%) (P = 0.006, OR = 3.99, RR = 2.31). The other tests gave negative or inexplicable results. IN CONCLUSION CagA-positive H. pylori infection increases the risk of ATD development.
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Vaira D, Malfertheiner P, Megraud F, Axon AT. Diagnosis of Helicobacter pylori infection by HpSA test. European Helicobacter pylori HpSA Study Group. Lancet 1999; 354:1732. [PMID: 10568603 DOI: 10.1016/s0140-6736(05)76722-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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113
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Van Der Hulst RW, Lamouliatte H, Megraud F, Pounder RE, Stolte M, Vaira D, Williams M, Tytgat GN. Laser assisted ratio analyser 13C-urea breath testing, for the detection of H. pylori: A prospective diagnostic European multicentre study. Aliment Pharmacol Ther 1999; 13:1171-7. [PMID: 10468698 DOI: 10.1046/j.1365-2036.1999.00594.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
BACKGROUND Novel technology based on laser optogalvanic spectroscopy called the LARA (Laser Assisted Ratio Analyser) system was developed to measure 12C/13C ratios in breath samples using stable 13C isotopes, to detect Helicobacter pylori infection. AIM To determine the sensitivity and specificity of the 13C-LARA-urea breath test in the detection of H. pylori infection in a prospective European multicentre trial; FDA-and EMEA-approved. METHODS Consecutive dyspeptic patients underwent diagnostic gastroscopy with biopsies for culture and histopathology, to detect H. pylori infection (gold standard). Subsequently, the LARA-urea breath test was performed using either a system without a cold trap (part I) or a system with a cold trap (part II). In both instances baseline, 30-min and 60-min breath samples were collected. The optimum cut-off level for 12C/13C ratios was determined by Receiver Operator Characteristics analysis. RESULTS In part I, 544 out of 604 patients were evaluable (low CO2: 47; withdrawn: 13). 284 out of 544 patients (52%) were H. pylori-positive according to the gold standard. The sensitivity of the LARA-urea breath test was 95% and the specificity 94%. In part II, 257 out of 272 were evaluable (low CO2: 14; withdrawn: 1). Sensitivity and specificity were 93% and 96%, respectively. CONCLUSION The LARA-technology represents an accurate and non-invasive testing system for the detection of H. pylori infection. Its major advantages are the use of stable 13C isotope, the high throughput of samples and the easy means of collecting, storing and transporting the samples, thus making the system convenient to both patient and clinician.
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Fusconi M, Vaira D, Menegatti M, Farinelli S, Figura N, Holton J, Ricci C, Corinaldesi R, Miglioli M. Anti-CagA reactivity in Helicobacter pylori-negative subjects: a comparison of three different methods. Dig Dis Sci 1999; 44:1691-5. [PMID: 10492154 DOI: 10.1023/a:1026647918258] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Emerging evidence suggests that infection by CagA-positive Helicobacter pylori strains is related to the development of more serious gastroduodenal diseases, thus conferring to the determination of anti-CagA antibodies a relevant clinical significance in serological screenings. The detection of anti-CagA positivity in sera negative for anti-H. pylori antibodies raises the question of whether this apparently nonsense result is merely due to a false positive reaction. To address this issue, we compared three different methods for the detection of anti-CagA antibodies. In all, 272 selected sera from patients with precisely defined H. pylori status (positive or negative concordance of five tests, ie, histology by Giemsa in both antrum and corpus, rapid urease test, culture, [13C]urea breath test, IgG ELISA) were tested for anti-CagA reactivity by three different techniques (western immunoblotting, ELISA, and recombinant immunoblotting assay). In order to assess the sensibility and specificity of each tests, we considered as "true" anti-CagA positive sera those with two out of three positive results. Sera from 70% of H. pylori-positive patients and 10% from H. pylori-negative patients turned out to be "true" positives for anti-CagA antibodies. The three methods showed similar excellent results, in terms of both sensitivity and specificity, always over 93%. It is confirmed that a proportion of patients with a negative conventional serology against H. pylori possess anti-CagA antibodies in their sera. In this paper we demonstrate that it can happen even in patients without any biological signs of actual H. pylori infection. The possibility that this can be due to a false positive laboratory result is very likely ruled out by the accuracy of the three methods used. The clinical management of these patients needs further study on larger series.
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Ali' A, Menegatti M, Gatta L, Landi F, Ricci C, Acciardi C, Miglioli M, Vaira D, Holton J. A second-line anti-Helicobacter pylori therapy in patients with previously failed treatment. Am J Gastroenterol 1999; 94:2321-3. [PMID: 10445583 DOI: 10.1111/j.1572-0241.1999.02321.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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116
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Vaira D, Malfertheiner P, Mégraud F, Axon AT, Deltenre M, Hirschl AM, Gasbarrini G, O'Morain C, Garcia JM, Quina M, Tytgat GN. Diagnosis of Helicobacter pylori infection with a new non-invasive antigen-based assay. HpSA European study group. Lancet 1999; 354:30-3. [PMID: 10406362 DOI: 10.1016/s0140-6736(98)08103-3] [Citation(s) in RCA: 266] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND Helicobacter pylori is a common human pathogen implicated in certain gastrointestinal diseases. In the search for new non-invasive techniques to diagnose H. pylori infection, we evaluated an EIA for H. pylori antigen in stool (HpSA). METHODS In a prospective multicentre study, stool specimens from 501 patients (276 men, 225 women; age range 17-88 years, mean 52) undergoing gastroscopy in 11 centres throughout Europe were tested with HpSA and the carbon-13-urea breath test. At endoscopy, four biopsy samples were taken for histology (haematoxylin and eosin) and H. pylori detection (giemsa in both antrum and corpus, culture and rapid urease test). Patients were defined as positive for H. pylori if histology (antrum, corpus, or both) and urease test were positive, or if culture was positive. Patients classified as having H. pylori infection received an eradication regimen; 107 were reassessed 4 weeks after therapy. FINDINGS Of 272 patients with H. pylori infection by the predefined criteria, 256 were positive by HpSA (sensitivity 94.1% [95% CI 90.6-96.6]). Of 219 patients without infection, 201 were negative by HpSA (specificity 91.8% [87.3-95.1]). INTERPRETATION The stool assay was a reliable and easy-to-use tool for diagnosis of H. pylori infection. The test was accurate even shortly after treatment.
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Vaira D, Holton J, Menegatti M, Ricci C, Landi F, Ali' A, Gatta L, Acciardi C, Farinelli S, Crosatti M, Berardi S, Miglioli M. New immunological assays for the diagnosis of Helicobacter pylori infection. Gut 1999; 45 Suppl 1:I23-7. [PMID: 10457032 PMCID: PMC1766658 DOI: 10.1136/gut.45.2008.i23] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
Abstract
There are several types of immunological tests available for the diagnosis and management of Helicobacter pylori infection. Most commercially available serological kits use the enzyme linked immunosorbent assay (ELISA) test format. Originally the kits used crude antigen preparations although many of the newer kits use a more purified antigen preparation, with often increased specificity but lower sensitivity. Near patient test kits are based either on latex agglutination or immunochromatography. Generally they have low sensitivities compared with laboratory tests. Western blotting, ELISA, and recombinant immunoblot assays (RIBA) have also been developed into commercially available kits and can be used to indicate the presence of specific virulence markers. An antigen detection kit has been developed for the detection of Helicobacter pylori in faeces. Immunological reagents have also been combined with other diagnostic modalities to develop immunohistochemical stains and DNA immunoassays. Helicobacter pylori is now recognised as the cause of gastritis and most cases of peptic ulcer disease (PUD); its long term carriage increases the risk of gastric adenocarcinoma sixfold and it is designated as a class I carcinogen. H pylori has also been implicated as a cause of gastric mucosa associated lymphoid tissue lymphomas. Its relation to non-ulcer dyspepsia remains controversial. Additionally, long term carriage of the organism may be associated with short stature in young girls and, in the general population, as a possible risk factor for the development of vasospastic disorders and possibly skin immunopathology such as urticaria. With the recognition of H pylori as an important human pathogen, it has become one of the growing number of organisms to have its complete genome sequence mapped. Serology is an important method of determining colonisation status and can be used for diagnosis, as a screening procedure, or to follow the efficacy of eradication regimens. Most serological assays are in the ELISA format although some are based on the latex agglutination reaction. These latter are used principally as near patient assays. Most assays detect IgG in serum although some detect serum IgA. More recently developed assays detect IgA in saliva and the production of affinity purified antibodies has led to the development of an antigen detection assay for faecal specimens. Serological reagents have also been used in immunocytochemistry and to speed up the detection of amplified products of the polymerase chain reaction (PCR)-DNA immunoassays.
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Dore MP, Bilotta M, Vaira D, Manca A, Massarelli G, Leandro G, Atzei A, Pisanu G, Graham DY, Realdi G. High prevalence of Helicobacter pylori infection in shepherds. Dig Dis Sci 1999; 44:1161-4. [PMID: 10389689 DOI: 10.1023/a:1026676223825] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
It has been suggested that Helicobacter pylori infection may, in some instances, be a zoonosis. The aim of this study was to evaluate the prevalence of H. pylori infection in Sardinian shepherds and their families in relation to exposure to sheep and sheep dogs. Sardinian shepherds and a control group of blood donors completed detailed questionnaires regarding demographics, childhood and current economic status, and the presence of symptoms related to the upper gastrointestinal tract. H. pylori status was determined by a sensitive ELISA for anti-H. pylori IgG and by western blot for anti-CagA IgG. A subgroup of shepherds had upper gastrointestinal endoscopy with biopsy to assess the severity of the gastritis. H. pylori infection in Sardinian shepherds approached 100% and was positively related to animal contact (98% of shepherds, 73% of family members without regular direct animal contact compared to 43% of blood donors) (P < 0.001). Importantly, the family members shared the same childhood with the shepherds but choose different careers (e.g., teachers, nurses, business) and did not have regular contact with sheep. In conclusion, the prevalence of H. pylori infection in Sardinian shepherds is among the highest in the world and is associated with direct contact with sheep and sheep dogs. These results suggest that the cycle of H. pylori infection might, in certain circumstances, include phases in the environment, animals (sheep or dogs) and human beings.
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Figura N, Perrone A, Gennari C, Orlandini G, Bianciardi L, Giannace R, Vaira D, Vagliasinti M, Rottoli P. Food allergy and Helicobacter pylori infection. ITALIAN JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY 1999; 31:186-91. [PMID: 10379477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
BACKGROUND Most antigens reach the immune system through mucosae. Gastrointestinal mucosa is a barrier for alimentary antigens. Inflammatory processes, such as Helicobacter pylori-associated gastritis, could alter the integrity of the gastric barrier, increase the mucosal permeability, and enhance crossing of food antigens which may stimulate allergic reactions. PURPOSE The aim of this study was to establish whether patients with symptomatic food allergy and detectable immunoglobulin E (IgE) to alimentary antigens were infected by Helicobacter pylori more often than controls, and to determine the phenotype of the infecting Helicobacter pylori. PATIENTS AND METHODS Thirty-eight consecutive patients with symptomatic food allergy and serum IgE to alimentary antigens, and 53 consecutive age-matched controls (subjects without food allergy and detectable levels of IgE anti-alimentary antigens) living in the same area and attending the same institution were investigated serologically to determine the prevalence of Helicobacter pylori infection, and an immune response to CagA, a marker of the most pathogenic strains. IgE to alimentary allergens were measured by a commercial kit. RESULTS The prevalence of Helicobacter pylori infection in patients with food allergy and controls was similar (42.1% and 47.1%, respectively). Anti-CagA antibodies in Helicobacter pylori-infected persons were detected in 62.5% of patients with food allergy, and 28.0% of controls (p = 0.030, odds ratio = 4.29, RR = 2.23). The mean IgE level to the most common alimentary antigens was increased in CagA-positive, with respect to the CagA-negative, patients. CONCLUSIONS The enhanced mucosal and inflammatory lesions commonly found in individuals infected by CagA-positive Helicobacter pylori strains could increase the epithelial permeability and render non-selective the passage of allergens which, in atopic persons, could directly stimulate an IgE response. Infection by CagA-positive Helicobacter pylori may increase the risk of food allergy.
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Salardi S, Cacciari E, Menegatti M, Landi F, Mazzanti L, Stella FA, Pirazzoli P, Vaira D. Helicobacter pylori and type 1 diabetes mellitus in children. J Pediatr Gastroenterol Nutr 1999; 28:307-9. [PMID: 10067733 DOI: 10.1097/00005176-199903000-00017] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Helicobacter pylori is a recognized gastroduodenal pathogen and H. pylori infection is one of the most common bacterial infections, usually acquired during childhood. However, diabetes mellitus is characterized by an increased susceptibility to infections. METHODS We compared the prevalence of H. pylori infection as well as cytotoxin-associated gene A-CagA-and vacuolating cytotoxin gene A-VacA-positivity in 103 children and adolescents with type 1 diabetes mellitus and in 236 nondiabetic children. We used a novel Recombinant ImmunoBlot Assay-Strip (RIBA SIA) with individual band for whole H. pylori lysate and recombinant CagA and VacA. RESULTS H. pylori-positive subjects, both diabetics and controls, were significantly older than negative subjects. In the whole group of diabetic patients the prevalence of each of the three reactivities was higher than in control subjects, reaching significance only for lysate. Only diabetic patients over 12 years of age, with a longer disease duration, had a higher prevalence of positive cases, although not significantly so. CONCLUSIONS In the first few years of disease, diabetic children do not differ from the nondiabetic population. Subsequently they show an H. pylori seroprevalence tendentially higher than that of controls of the same age. Therefore, H. pylori infection acquired in childhood and lasting several years, could be one of the causes of chronic atrophic gastritis, which is more frequent in longstanding diabetes mellitus.
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Cacciari E, Menegatti M, Salardi S, Ali A, Stella FA, Figura N, Landi F, Holton J, Farinelli S, Cuccaro V, Miglioli M, Vaira D. Helicobacter pylori infection and cytotoxic antigen associated gene "A" status in short children. J Pediatr Endocrinol Metab 1999; 12:197-201. [PMID: 10392367 DOI: 10.1515/jpem.1999.12.2.197] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Helicobacter pylori is now an accepted gastroduodenal pathogen and is being investigated for possible implications in nongastroenterological conditions such as growth impairment. Subjects infected by cytotoxic Cag-A positive strains seem more likely to develop serious gastroduodenal diseases but the possible role of Cag-A positive strains in non gastroenterological diseases has not been fully investigated. OBJECTIVE 1) To evaluate the prevalence of Helicobacter pylori infection and Cag-A positivity in short children compared to auxologically normal children. All the subjects were without gastro-intestinal symptoms and were not obese or significantly underweight. 2) To verify the reliability of the ELISA assay for H. pylori. SUBJECTS H. pylori infection was assessed in 338 children, 182 auxologically normal and 156 short children, with and without deficiency in growth hormone, by the determination of specific IgG antibody. In 79 subjects (all seropositive and a random sample of seronegative children), 13C-urea breath test and cytotoxic Cag-A positive strains were examined. RESULTS The overall seroprevalence of H. pylori infection by IgG antibody was 18/156 (11.5%) and 13/182 (7.1%) in short and auxologically normal children respectively. The 13C-urea breath test was positive in 29 children: 17 (10.9%) short and 12 (6.6%) auxologically normal. Western blotting documented infection by cytotoxic Cag-A positive strains in 12/17 (70.6%) and 8/12 (66.6%) of short and auxologically normal children respectively. None of the differences between the two groups were significant. CONCLUSIONS 1) We found a similar prevalence of H. pylori infection and Cag-A positivity in two large pediatric populations of short or auxologically normal children. Therefore: 1) Our data did not confirm a role of H. pylori infection in short stature in children. 2) We found a high reliability of ELISA assay for the detection of IgG antibodies compared to breath test.
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Delwaide J, Gérard C, Vaira D, Maggipinto G, Rentier B, Belaiche J. Hepatitis C virus transmission following invasive medical procedures. J Intern Med 1999; 245:107-8. [PMID: 10095825 DOI: 10.1046/j.1365-2796.1999.0444f.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Lamproye A, Delwaide J, Vaira D, Maggipinto G, Gérard C, Sondag-Thull D, Rentier B, Rorive G, Belaïche J. Prevalence of hepatitis G virus in a haemodialysis unit. Acta Gastroenterol Belg 1999; 62:13-5. [PMID: 10333594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
BACKGROUND Recently, a novel blood-borne virus has been identified and named hepatitis G virus. Transfusion is the main route of transmission. It is known that patients on maintenance dialysis are more susceptible to infections with parenterally-transmitted viruses than the general population. The aim of the present study was to determine the prevalence of hepatitis G infection in a Belgian dialysis unit. METHODS The entire population of our dialysis unit (82 patients) was tested for the presence of hepatitis G virus (HGV) by reverse transcriptase polymerase chain reaction. History of transfusion or renal transplantation, coinfections with hepatitis B and C viruses, and serum aminotransferase levels were also tested. RESULTS Thirteen patients (16%) were found positive for HGV-RNA. Among these patients, 69.2% were infected by the G virus alone, 15.4% were coinfected with B virus, and 15.4% with C virus. All but one patient had a history of transfusion. Ten of the thirteen infected patients (77%) had normal aminotransferase (< 30 UI/l). Three patients had elevated aminotransferase levels (23%); one was coinfected with B virus, one with C virus, and the last one had a diabetes-induced fatty liver infiltration. No liver biopsies were performed. CONCLUSIONS It is concluded that infection with G virus is common among dialyzed patients. This high rate of infection could be related to previous transfusions, but may as well be due to nosocomial transmission. In our series, at least one patient has been contaminated by another road than transplantation or transfusion. Finally, it does not appear clearly that chronic infection with hepatitis G virus induces liver disease, as defined by elevated aminotransferase level.
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Neri M, Vaira D, Palli D, Menegatti M, Landi F, Saieva C, Ricci C, Gatta L, Miglioli M. Symptoms and Helicobacter pylori: any link? The Italian Helicobacter pylori Study Group. Am J Gastroenterol 1998; 93:2633-4. [PMID: 9860456 DOI: 10.1111/j.1572-0241.1998.2633a.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Ricci C, Gatta L, Miglioli M, Vaira D. Therapeutic news on Helicobacter pylori from Budapest and Wien. ITALIAN JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY 1998; 30:648-62. [PMID: 10076792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Helicobacter pylori is the most common infection in the world and is associated with some of the most prevalent gastroduodenal diseases. There is now considerable evidence that Helicobacter pylori eradication not only heals duodenal ulcer, but also prevents ulcer recurrences and probably ulcer complication. It is, therefore, universally accepted that, all patients with duodenal ulcer disease should receive eradication therapy. This review represents an attempt to summarize and analyse all the regimens proposed in September at the last International Meetings in Budapest and Wien in which different anti Helicobacter pylori regimens have been used. Despite the large number of clinical trials which had been performed, no significant advances have been made in relation to Helicobacter pylori therapy, so the "optimal" eradication treatment still remains a matter of debate. More than 10,000 patients were treated and most of them (around 5000) were found to have peptic ulcer disease which represents no more than 10-15% of our endoscopic findings. The proton pump inhibitor regimens are definitely the most representative drug policy appearing in the literature and despite several attempts (proton pump inhibitor given for less, one, or more than one week) the short one-week regimen (The Maastricht regimen) has been recognized as the most promising treatment.
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