L. Gatta

High eradication rates of Helicobacter pylori with a new sequential treatment

Background :u2002Eradication rates of Helicobacter pylori with standard triple therapy are disappointing, and studies from several countries confirm this poor performance.

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

Background :u2002A 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.

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

Background :u2002Helicobacter 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.

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.METHODS: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.RESULTS: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.

Meta-analysis: the efficacy of proton pump inhibitors for laryngeal symptoms attributed to gastro-oesophageal reflux disease

Many investigators have proposed an association between gastro‐oesophageal reflux disease and laryngo‐pharyngeal symptoms, suggesting that medical or surgical therapy for reflux may be useful.

Diagnosis of Helicobacter pylori infection

Helicobacter pylori (H.u2003pylori) infection can be diagnosed by invasive techniques requiring endoscopy and biopsy (histological examination, culture, polymerase chain reaction) and by noninvasive techniques (serology, urea breath test, urine or blood, detection of H.u2003pylori antigen in stool specimen). At present, no single test can be absolutely relied upon to detect colonization by H.u2003pylori, and a combination of two tests is recommended if feasible. The tests used should depend on the clinical circumstances, the likelihood ratio of positive and negative tests, the cost‐effectiveness of the testing strategy, and the availability of the tests. Some clinical circumstances warrant invasive studies, principally patients with alarm symptoms (bleeding, weight loss, etc.) as well as older patients with new‐onset dyspepsia. Endoscopy may also be advisable in patients who have failed eradication therapy and need culture and antimicrobial sensitivity testing to determine an appropriate regimen. Recent studies have also demonstrated that a strategy to `test and treat for H.u2003pylori in uninvestigated, young (<u200350 years), dyspeptic patients in primary care is safe and reduces the need for endoscopy. Indeed, a number of clinical guidelines recommend noninvasive testing followed by treatment of H.u2003pylori for dyspeptic patients in primary care based on clinical and economic analyses.

Invasive and non-invasive tests for Helicobacter pylori infection

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.

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 10u2003min after ingestion of the tablet.

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.

Blood tests in the management of Helicobacter pylori infection. Italian Helicobacter pylori Study Group

There are three main types of blood test available for the management of Helicobacter pylori infection: those that detect an antibody response; tests of the pathophysiological state of the stomach; and those that indicate an active infection. Enzyme linked immunosorbent assay (ELISA) based kits are the most numerous of the commercially available tests. Originally the kits used crude antigen preparations but many of the newer kits use a more purified antigen preparation giving increased specificity but a lower sensitivity. The sensitivity, specificity, and predictive values of the tests can also be affected by the population under test and coexistent disease in the patients. Near patient test kits are based on either latex agglutination or immunochromatography. Generally, they have low sensitivities compared with laboratory tests. Commercial western blotting kits have also been developed and are used to detect the presence of specific virulence markers. The exact role of serology in the management of Helicobacter infection has still to be defined, although there is evidence that, used as a screening procedure, it can reduce endoscopy cost and workload. Gastrin and pepsinogen blood concentrations may provide valuable information on the pathophysiological state of the stomach--for example, the presence of inflammation or gastric atrophy. A combination of serology and serum concentrations of gastrin and pepsinogen may be used effectively to detect serious gastroduodenal disease in patients.