F. Perna

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.

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.

Primary antibiotic resistance in Helicobacter pylori strains isolated in northern and central Italy

Background  Helicobacter pylori resistance to antibiotics is increasing worldwide, and it reduces the efficacy of therapy.

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.

Phenotypic and genotypic Helicobacter pylori clarithromycin resistance and therapeutic outcome: benefits and limits

INTRODUCTION Primary clarithromycin resistance is increasing worldwide, and it has been regarded as the main factor reducing the efficacy of Helicobacter pylori therapy. However, the clinical consequence of either phenotypic or genotypic resistance still remains unclear. This study aimed to evaluate: (i) the concordance between phenotypic (culture) and genotypic (real-time PCR) tests in assessing primary clarithromycin resistance; and (ii) the role of both in therapeutic outcome. METHODS A post hoc subgroup study was selected from a double-blind, placebo-controlled trial, enrolling 146 patients with dyspepsia or peptic ulcers never previously treated. Real-time PCR and Etest on bacterial culture for assessing clarithromycin resistance were performed. [(13)C]urea breath test (UBT), histology and rapid urease tests at entry and UBT after 4-8 weeks were used to assess infection and eradication. All patients received a 10 day therapy. RESULTS Prevalence of clarithromycin phenotypic resistance was significantly lower as compared with genotypic resistance (18.4% versus 37.6%, P < 0.001). A concordance between the two methods was present in 71.2% of cases. A significant difference in the eradication rate was seen between clarithromycin-susceptible and -resistant strains, when assessed with either Etest (92.4% versus 55.5%, P < 0.001) or a PCR-based method (94.5% versus 70.9%; P < 0.001). Of note, the eradication rate showed the lowest value (30.7%) when phenotypic bacterial resistance was genetically linked to the A2143G point mutation. CONCLUSIONS This study showed that: (i) there is a relevant discordance between the two methods; and (ii) phenotypic clarithromycin resistance markedly reduces H. pylori eradication when it is linked to a specific point mutation.

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.

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.

Accuracy of a new ultrafast rapid urease test to diagnose Helicobacter pylori infection in 1000 consecutive dyspeptic patients

Background  Rapid diagnostic tools for Helicobacter pylori are important in endoscopy.

Helicobacter pylori infection from pathogenesis to treatment – a critical reappraisal

The main areas of this review are Helicobacter pylori and disease pathogenesis; the relationship of H. plyori to lower gastrointestinal diseases, liver disease and extra‐gastrointestinal conditions; the relationship of H. plyori to gastro‐oesophageal reflux disease; infection in the very young and very old; diagnostic techniques; and management of H. plyori infections with particular emphasis on eradication regimens and antibiotic resistance.

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.