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D Vaira

Publications and source records attributed to D Vaira.

At least 19 recordsLinked to original sources
PubMed2005

Accuracy of breath tests using low doses of 13C-urea to diagnose Helicobacter pylori infection: a randomised controlled trial.

BACKGROUND: The 13C-urea breath test (UBT) for detecting Helicobacter pylori infection is a non-invasive method based on the organism's urease activity. Since its first description, the method has been extensively modified. However, only the dose of 13C-urea and the measurement equipment are directly related to the cost of the test. AIMS: (1) To assess the diagnostic accuracy before eradication therapy of three UBTs using 25, 15, and 10 mg of 13C-urea, respectively; and (2) to determine diagnostic performance in the post-eradication setting showing the highest values for sensitivity and specificity with the lowest dose of 13C-urea. METHODS: Three hundred consecutive patients were randomised to be tested with one of the three UBTs. All patients underwent upper endoscopy with biopsies. A total of 222 more patients were enrolled to evaluate the second aim. Infected patients were offered treatment and asked to return 4-6 weeks after the end of therapy to perform endoscopic follow up and to carry out 13C-UBT. RESULTS: In the pretreatment setting, 13C-UBT 25 mg had a sensitivity of 100% (95% confidence interval (CI) 91.8-100) and a specificity of 100% (95% CI 93.7-100); 13C-UBT 15 mg had a sensitivity of 96.1% (95% CI 86.8-98.9) and a specificity of 100% (95% CI 92.6-100); and 13C-UBT 10 mg had a sensitivity of 89.1% (95% CI 77-95.3) and a specificity of 100% (95% CI 93.3-100). As the test with the best performance and the lowest dose of 13C-urea was 13C-UBT 15 mg, it was evaluated after treatment, reporting a sensitivity of 100% (95% CI 79.6-100) and a specificity of 98.9% (95% CI 94.3-99.8). DISCUSSION: UBTs using 25 and 15 mg of 13C-urea were both accurate in the diagnosis of H pylori infection in untreated patients. 13C-UBT 15 mg was also accurate for follow up of patients after treatment.

Adult↗
PubMed2005

A 10-day levofloxacin-based triple therapy in patients who have failed two eradication courses.

BACKGROUND: A standard third-line treatment is lacking, and European guidelines recommend performing culture in these patients. However, the use of this procedure as 'routine practice' is definitively not feasible. AIM: To evaluate the eradication rate of a 10-day levofloxacin-based triple therapy in patients who have failed two eradication courses for Helicobacter pylori. METHODS: A total of 151 patients with persistent Helicobacter pylori infection after two treatments were studied. Patients were considered positive if two of three endoscopic tests were positive. Susceptibility testing was also performed. Patients received a standard dose of proton-pump inhibitors twice daily, levofloxacin 250 mg twice daily and amoxicillin 1 g twice daily, for 10 days. Endoscopic follow-up was carried out 4-6 weeks after the end of eradication therapy. RESULTS: About 76% (95% CI: 68.8-82.3), and 85% (95% CI: 77.5-89.7) of patients were eradicated according to intention-to-treat and per-protocol analysis, respectively. Eradication rates of the strains showed as 92% (95% CI: 83.2-96.7) of those resistant to both metronidazole and clarithromycin but susceptible to levofloxacin. CONCLUSIONS: In patients who failed previous regimens, the 10-day levofloxacin-based triple therapy is safe and effective, allowing eradication in almost 80% of the patients.

Amoxicillin↗
PubMed2005

High rate of Helicobacter pylori eradication with sequential therapy in elderly patients with peptic ulcer: a prospective controlled study.

BACKGROUND: Helicobacter pylori eradication rates with triple therapies are decreasing, and few data in elderly patients are available. A 10-day sequential regimen succeeded in curing such H. pylori infection in unselected patients. AIM: To compare this sequential regimen and the standard triple therapy for H. pylori eradication in geriatric patients with peptic ulcer. METHODS: Overall, 179 H. pylori-infected patients with peptic ulcer were enrolled (mean age: 69.5 years; range: 65-83). Patients were randomized to 10-day sequential therapy (rabeprazole 20 mg b.d. plus amoxicillin 1 g b.d. for the first 5 days, followed by rabeprazole 20 mg, clarithromycin 500 mg and tinidazole 500 mg, all b.d., for the remaining 5 days) or standard 7-day triple regimen (rabeprazole 20 mg, clarithromycin 500 mg and amoxicillin 1 g, all b.d.). Helicobacter pylori status was assessed by histology and rapid urease test at baseline and 4-6 weeks after completion of treatment. RESULTS: The sequential regimen achieved eradication rates significantly higher in comparison with the standard regimen at both intention-to-treat (94% vs. 80%; P = 0.008) and per-protocol (97% vs. 83%; P = 0.006) analyses. In both treatment groups, compliance to the therapy was high (> 95%), and the rate of mild side-effects was similarly low (< 12%). At repeated upper endoscopy, peptic ulcer lesions were healed in 97% patients, without a statistically significant difference between the sequential regimen and the standard triple therapy. CONCLUSIONS: In elderly patients with peptic ulcer disease, the 10-day sequential treatment regimen achieved significantly higher eradication rates in comparison with standard triple therapy.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2005

Twice-daily standard dose of omeprazole achieves the necessary level of acid inhibition for Helicobacter pylori eradication. A randomized controlled trial using standard and double doses of omeprazole in triple therapy.

Antibiotic resistances and level of acid inhibition may affect the outcome of eradicating regimens for H. pylori. To evaluate the impact of different degrees of acid inhibition on the efficacy of triple treatment, we treated 323 patients with H. pylori infection with clarithromycin and tinidazole plus omeprazole, either 20 mg bid or 40 mg bid. Gastric biopsies and antimicrobial susceptibility testing were performed. Eradication was evaluated by means of breath test. Eradication rates were (intention to treat and per protocol) 83.3 and 84.3% in patients receiving 40 mg omeprazole and 81.9 and 84.1% in those receiving 80 mg omeprazole. Culture was successful in 218 patients (68.7%). Resistance to clarithromycin and metronidazole were found in 13.7 and 20.6%, respectively. Eighteen further patients (8.2%) presented double resistance. Resistance was comparable across the two groups. In resistant patients the eradication rate was significantly lower (66.6% [95% CI, 56-76%], vs 86% [95% CI, 78-91%]; P = 0.001). Antibiotic resistance (OR, 2.73; 95% CI, 1.4-5.3) and smoking (OR, 2.68; 95% CI, 1.4-5.2) were independent predictors of eradication failure. Omeprazole, 20 mg bid, achieves the optimal acid inhibition in H. pylori eradication. Increasing antisecretory activity does not significantly enhance cure rates.

Adult↗
PubMed2005

Diagnostic accuracy of a new rapid urease test (Pronto Dry), before and after treatment of Helicobacter pylori infection.

AIM: The diagnosis of Helicobacter pylori infection can be made easily by the rapid urease test during endoscopy. The mainly commercial rapid urease test available in routine practice, is in liquid phase, need to be stored at 4 degrees C and generally they are not ready to use. Recently a new rapid urease test, the Pronto Dry, has been reported to be faster in the final reading, ready to use, and it can be stored at room temperature. Aim of the study was to evaluate the diagnostic accuracy and the reaction time of Pronto Dry vs liquid phase-rapid urease test, before and after treatment of Helicobacter pylori infections. METHODS: A total of 315 untreated dyspeptic patients and 323 post-treatment patients, were enrolled in this study. At endoscopy, 5 biopsy samples were obtained from the antrum and from the corpus for histology; culture and rapid urease tests (liquid phase and Dry test). Helicobacter pylori status was defined according to European guidelines. Sensitivity and specificity of both rapid urease test were assessed at 5, 15, 30 minutes, and 3 and 24 hours after the endoscopy. RESULTS: One hundred and eleven out of 315 untreated dyspeptic patients were found to be positive for Helicobacter pylori infection, and 56/323 patients were found still positive after treatment. Sensitivity at 5, 15, 30 minutes, and 3 and 24 hours in untreated patients were 45%, 71.2%, 81.1%, 90.1% and 91.9% respectively for the Pronto Dry vs 6.3%, 31.5%, 51.3%, 78.4% and 90.1% for liquid phase rapid urease test. Sensitivity at the same times in not eradicated patients were 33.9%, 66.1%, 85.7%, 92.8 and 92.8% respectively for the Pronto Dry vs 3.6%, 37.5%, 55.3%73.2%, 92.8% for liquid phase rapid urease test. CONCLUSIONS: Pronto Dry showed to have higher sensitivity in pre and post treatment setting compared to liquid phase-rapid urease test within 3 hours of incubation time.

Clinical Enzyme Tests↗
PubMed2004

A rapid immunochromatographic assay for Helicobacter pylori in stool before and after treatment.

BACKGROUND: Current guidelines recommend non-invasive testing and treatment of young dyspeptic patients without alarm symptoms. AIM: To evaluate the accuracy of a new rapid immunochromatographic stool test to diagnose Helicobacter pylori infection before and after treatment compared with a gold standard. METHODS: Prospective, single-blind study, performed in a tertiary care hospital. A total of 303 consecutive dyspeptic patients underwent endoscopy with multiple biopsies. Infected patients were offered a treatment and invited to come back 4-6 weeks after the end of therapy to repeat the endoscopy. Patients were also asked to provide a stool sample before and after therapy. RESULTS: About 149 patients were H. pylori infected. The sensitivity and specificity before treatment were 91.3 and 93.5%; after treatment 92 and 100%. The likelihood ratios were robust enough to produce significant changes from pretest to post-test probability both in pre-treatment (LR+ = 14, LR- = 0.093) and post-treatment (LR+ = 19.6, LR- = 0.095). CONCLUSIONS: The novel immunochromatographic stool test is fast, easy to perform and provides good differentiation between positive and negative results. It might become a rapid near patients test easily performed in the doctor office.

Antigens, Bacterial↗
PubMed2004

Helicobacter pylori infection: anything new should we know?

Over the past year, 2003-4, there have been a number of studies consolidating previous work in relation to pathogenesis of disease, diagnosis and management of Helicobacter pylori. Studies into the pathogenesis of disease have identified the main adhesin of H. pylori as an important virulence marker and as a potential target for therapy. Molecular investigations of both the strain and host variations have identified the action of several of the virulence factors, e.g. cagA, vacA, on disrupting host cell signalling and the consequences in respect of the release of chemokines from the damaged gastric epithelium and the effect on apoptosis. Over the past year, there have been further diagnostic kits developed based on modifications of current technology. Two promising areas of research for diagnosis are the use of host/strain genome polymorphisms as a means of identifying high-risk patients who may develop severe disease and the use of proteomics to identify potential antigens of diagnostic (or therapeutic) use. The three main antibiotics that are used in first-line eradication regimens are clarithromycin, metronidazole and amoxycillin. Of these, metronidazole has the highest prevalence of resistance, followed by clarithromycin; amoxycillin resistance is only rarely reported. The decreasing success of current first-line therapy is the driving force for the development of new antibiotic combinations and a search for novel sources for chemotherapeutic agents and novel therapeutic targets.

Adhesins, Bacterial↗
PubMed2003

European multicentre validation trial of two new non-invasive tests for the detection of Helicobacter pylori antibodies: urine-based ELISA and rapid urine test.

AIM: Non-invasive tests for the assessment of Helicobacter pylori status are now an integral part of the management strategies for patients with dyspepsia. The aim of this study was to evaluate a urine based antibody ELISA and a near patient urine test for the diagnosis of H. pylori infection in a European population. METHODS: Urine samples were collected from 449 patients (240 females, 209 males, mean age 54 years), with dyspeptic symptoms but no previous H. pylori eradication therapy, at five centres in four European countries. All patients underwent GI endoscopy and biopsies were taken for H. pylori diagnosis. Urine samples were analysed using an IgG ELISA (URINELISA) and a near patient urine test (RAPIRUN). In addition, a serum IgG ELISA (Pyloriset-EIA-GIII), a whole blood test (Pyloriset-Screen) and a 13C-urea breath test were performed. RESULTS: The sensitivity of the urine based ELISA and the near patient urine test was 90% and 82%, and the specificity 68% and 83%, respectively. The accuracy of the serum ELISA and the whole blood test was comparable with the urine based test. CONCLUSION: The urine based ELISA and the near patient urine test are just as accurate as the serological tests. This comparable accuracy and complete non-invasiveness of the former gives it an advantage over blood based tests. This limits the application of these tests in general practice.

Antibodies, Bacterial↗
PubMed2003

A rapid, low-dose, 13C-urea tablet for the detection of Helicobacter pylori infection before and after treatment.

BACKGROUND: A new urea breath test (UBT) has been described which uses a tablet formulation of 13C-urea with citric acid and allows breath sampling to be performed as early as 10 min after ingestion of the tablet. AIM: To assess the diagnostic accuracy of tablet-based 13C-UBTs (50 and 100 mg 13C-urea) before and after Helicobacter pylori eradication treatment, compared with an endoscopy gold standard and a conventional 13C-UBT (75 mg 13C-urea). METHODS: Two hundred dyspeptic patients underwent endoscopy, followed by tablet-based 13C-UBTs (50 and 100 mg 13C-urea) and a conventional 13C-UBT (75 mg 13C-urea). H. pylori-infected patients were prescribed treatment and asked to return 4-6 weeks after the end of therapy for repeat endoscopy and 13C-UBTs. RESULTS: One hundred and thirteen patients were infected with H. pylori. The sensitivity and specificity of the conventional 13C-UBT were both 100%; the sensitivity and specificity of the 100-mg tablet-based 13C-UBT were 100% and 98.85%, respectively. For the 50-mg tablet-based 13C-UBT, cut-off values of the difference over baseline of between 1.65 and 3.15 provided a sensitivity and specificity of 100%. At follow-up, the sensitivity and specificity of the conventional and 100-mg tablet-based 13C-UBTs were both 100%. For the 50-mg tablet-based 13C-UBT, cut-off values of the difference over baseline of between 1.49 and 1.56 gave a sensitivity and specificity of 100%. CONCLUSIONS: New 10-min 13C-UBTs using tablet formulations of 13C-urea with citric acid are reliable for the assessment of H. pylori status pre- and post-treatment.

Biopsy↗
PubMed2003

High eradication rates of Helicobacter pylori with a new sequential treatment.

BACKGROUND: Eradication rates of Helicobacter pylori with standard triple therapy are disappointing, and studies from several countries confirm this poor performance. AIM: To assess the eradication rate of a new sequential treatment regimen compared with conventional triple therapy for the eradication of H. pylori infection. METHODS: One thousand and forty-nine dyspeptic patients were studied prospectively. H. pylori-infected patients were randomized to receive 10-day sequential therapy [rabeprazole (40 mg daily) plus amoxicillin (1 g twice daily) for the first 5 days, followed by rabeprazole (20 mg), clarithromycin (500 mg) and tinidazole (500 mg) twice daily for the remaining 5 days] or standard 7-day therapy [corrected] [rabeprazole (20 mg), clarithromycin (500 mg) and amoxicillin (1 g) twice daily]. H. pylori status was assessed by histology, rapid urease test and 13C-urea breath test at baseline and 6 weeks or more after completion of treatment. RESULTS: Higher eradication rates were found with the sequential regimen compared to the standard regimen (intention-to-treat: 92% vs. 74%, P < 0.0001; per protocol: 95% vs. 77%, P < 0.0001). Higher eradication rates were also seen in patients with peptic ulcer disease and non-ulcer dyspepsia. In both treatments, compliance was similar (> 90%), as was the rate of side-effects, which were mild. CONCLUSIONS: This 10-day sequential treatment regimen achieves high eradication rates in peptic ulcer disease and non-ulcer dyspepsia.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2003

Review article: diagnosis and treatment of Helicobacter: a 2002 updated review.

The year 2002 saw advances on many fronts in the study of Helicobacter and gastroduodenal disease. Several studies have confirmed endoscopy as a valuable management procedure with confirmation of the diagnostic utility of the rapid urease test and the description of a new formulation of the test, which is more rapid in giving a result. Serology has been re-confirmed as a useful investigation in selected populations. Some commercial kits for near patient testing have also been assessed and although generally regarded as less accurate than laboratory based tests some have shown acceptable accuracy. The recent exciting development in diagnostic serology is the availability of the faecal antigen test; further studies have confirmed its usefulness as recommended screening tests. There have been several studies demonstrating that a test and treat policy has a significant patient benefit, both economic and medical, although there is some doubt if eradication of Helicobacter leads to regression of atrophy and metaplasia. However, in low Helicobacter-prevalence areas the test and treat policy is being challenged as an effective management strategy. Further studies have shown that compliance with treatment regimens is an important determinant of successful eradication. Finally several new eradication regimens have been reported particularly for use in patients who have had previous unsuccessful eradication attempts.

Biopsy↗
PubMed2003

Non-invasive techniques for the diagnosis of Helicobacter pylori infection.

Helicobacter pylori infection can be diagnosed by invasive techniques requiring endoscopy and biopsy (histologic examination, culture, polymerase chain reaction), and non-invasive techniques (serology, urea breath test, urine or blood, detection of H. pylori antigen in stool specimen). However, recent studies have demonstrated that a strategy of 'testing and treating' for H. pylori in uninvestigated, young (<50 years), dyspeptic patients in primary care is safe and reduces the need for endoscopy. Indeed, a number of clinical guidelines recommend non-invasive testing in dyspeptic patients followed by treatment of H. pylori in primary care based on clinical and economic analyses. Several non-invasive tests are currently available on the market. The choice depends on the clinical circumstances, the likelihood ratio of positive and negative tests, the cost-effectiveness of the testing strategy, and, finally, the availability of the tests. Nevertheless, two non-invasive tests are commonly used: the urea breath test, and the stool antigen test.

Bacterial Typing Techniques↗
PubMed2003

Best cut-off values for [14C]-urea breath tests for Helicobacter pylori detection.

BACKGROUND: The 'test and treat' strategy for Helicobacter pylori is recommended in dyspeptic patients under 55 years of age with no alarm symptoms. Reliable non-invasive tests are therefore needed. The aim of this study was to assess the pre- and post-treatment accuracy of a low dose (1 microCi [37kBq]), short collecting time [14C]-UBT (urea breath test) in diagnosing H pylori infection, examining different methods to analyse the best cut-off points. METHODS: The study included 119 patients. Endoscopy and [14C]-UBT were performed in the pre- and post-treatment setting. [14C]-UBT results were expressed in three different ways: 1) the measured disintegrations per minute (dpm) at sample time, 2) the difference (D) in dpm between sample time and the dpm at T0, 3) the ratio of dpm at sample time to dpm at T0. RESULTS: Seventy-six out of the 119 patients (63.9%; 95% CI: 54.9 to 71.9) were infected. Seventy-three (96%) patients completed the follow-up. The most accurate results in both pre- (sensitivity 95.9%; specificity 97.7%) and post-treatment (sensitivity 90.9%; specificity 100%) were obtained using the difference (D) in dpm between sample time at T0 and at T12.5. CONCLUSION: A low dose [14C]-UBT, with a short collecting time, is a reliable method to evaluate H. pylori infection in both the pre- and post-treatment setting.

Adult↗
PubMed2003

The clinical role of cytochrome p450 genotypes in Helicobacter pylori management.

OBJECTIVE: The aim of this pharmacogenomics study was to investigate the influence of different cytochrome P450 (CYP) genotypes in Helicobacter pylori eradication therapy. METHOD: The study involved 143 consecutive Italian Caucasian patients with H. pylori infection diagnosed and treated with 1-wk triple therapy according to European Helicobacter Pylori Study Group guidelines. Using human genomic DNA, CYP2C19 (*2 and *3) and CYP3A4 alleles (*1B, *2, and *3) were evaluated by polymerase chain reaction-restriction fragment length polymorphism assays and confirmed by sequencing the amplicons. RESULT: According to the endoscopy-based gold standard, 93 patients achieved H. pylori eradication. Regarding CYP2C19 genotype, the 50 patients who remained infected were all homozygous or heterozygous extensive metabolizers (homEM or hetEM). Carriers of homEM fared significantly less well than those of hetEM; homEM genotype was also predictive of failure at univariate/multivariate analysis. Carriers of CYP3A4 polymorphisms achieved favorable eradication rates similar to patients bearing CYP2C19. All four patients with single CYP3A4*2 polymorphism achieved eradication, and only 29% (5/17) of all CYP3A4*1B carriers did not achieve eradication. All nine patients carrying CYP3A4 polymorphisms in the CYP2C19 hetEM subgroup were cured, suggesting the possibility of a positive synergism between CYP3A4 and CYP2C19. CONCLUSIONS: This first pharmacogenomics study on the influence of different CYP genotypes on H. pylori therapy suggests that, as in Asian populations, CYP2C19 genotype patterns are probably also relevant in Caucasians receiving H. pylori eradication regimens that include omeprazole. The possibility of a favorable drug interaction mediated by CYP2C19 and CYP3A4 requires investigation.

Adult↗
PubMed2003

Effect of Helicobacter pylori eradication on development of dyspeptic and reflux disease in healthy asymptomatic subjects.

BACKGROUND AND AIM: There are few data on the course of Helicobacter pylori infection in asymptomatic subjects. The aim of this study was to assess the effect of eradication therapy on the development of dyspeptic and gastro-oesophageal reflux disease in a cohort of asymptomatic individuals observed over a prolonged period. METHODS: A total of 169 blood donors infected with H pylori who had volunteered for studies on eradication in 1990 formed the cohort. To be included in this cohort subjects had to have no symptoms, as determined by a validated symptom questionnaire at the baseline visit. Eighty eight subjects were infected with H pylori while 81 had successfully undergone eradication therapy. Subjects were followed up (annually) using the same symptom questionnaire and in 2000 they underwent repeat endoscopy. RESULTS: Thirteen subjects developed symptoms during follow up. The incidence of symptoms in H pylori positive subjects was 1.893/100 person-years of follow up and in H pylori negative individuals 0.163/100 person-years of follow up. H pylori infected subjects were significantly more likely to develop symptoms (log rank test, p=0.003) as well as those infected with CagA positive strains (log rank test, p=0.017). The development of symptomatic gastro-oesophageal reflux disease was no different in individuals with and without eradication (odds ratio 0.57 (95% confidence interval 0.26-1.24); p=0.163). CONCLUSIONS: H pylori eradication prevents the development of dyspeptic symptoms and peptic ulcer disease in healthy asymptomatic blood donors and is not associated with an increase in the incidence of symptomatic gastro-oesophageal reflux disease.

Antibodies, Bacterial↗