High Prevalence of Helicobacter pylori in Liver Cirrhosis (Relationship with Clinical and Endoscopic Features and the Risk of Peptic Ulcer)

In 153 consecutive patients with cirrhosis weassessed: (1) the prevalence of IgG to Helicobacterpylori and compared it with that found in 1010 blooddonors resident in the same area; and (2) therelationships of IgG to Helicobacter pylori with clinical andendoscopic features and with the risk of peptic ulcer.The IgG to Helicobacter pylori prevalence of cirrhoticswas significantly higher than in blood donors (76.5% vs 41.8%; P < 0.0005) and was notassociated with sex, cirrhosis etiology, Child class,gammaglobulins and hypertensive gastropathy. In bothgroups, the prevalence of IgG to Helicobacter pylori was significantly higher in subjects over 40. Amongpatients with cirrhosis a significantly higherprevalence of Helicobacter pylori was found in patientswith previous hospital admission (P = 0.02) and/or upper gastrointestinal endoscopy (P = 0.01) andpatients with peptic ulcer (P = 0.0004). Multivariateanalysis identified increasing age and male sex as riskfactors for a positive Helicobacter pylori serology and no independent risk factors for pepticulcer. The high prevalence of Helicobacterpylori-positive serology found in the present series isrelated to age and sex and might also be explained byprevious hospital admissions and/or uppergastrointestinal endoscopy. Our results do not confirmthe role of Helicobacter pylori as risk factor forpeptic ulcer in patients with liver cirrhosis.     

Helicobacter pylori antigen stool test and 13C-urea breath test in patients after eradication treatments

OBJECTIVES: Current guidelines recommend either the urea breath test (UBT) or the Helicobacter pylori antigen stool test (HpSA) for monitoring H. pylori infection. The aim of this study was to evaluate the agreement between the two tests in patients after treatment. METHODS: After eradication treatments, patients were tested with both UBT and HpSA. Cut-off values (delta value over baseline at 30') for UBT were positive (> or = 5 per thousand), indeterminate (3.01-4.99 per thousand), and negative (< or = 3 per thousand). Cut-off values (absorbance at 450 nm) for HpSA test were positive (> or = 0.160), indeterminate (0.159-0.140), and negative (< 0.140). Patients with either discordant or indeterminate tests underwent repeat endoscopy with multiple gastric biopsies for rapid urease test (RUT), culture, histology, and immunohistochemistry to detect H. pylori and to assess the ratio between coccoid and bacillary forms. RESULTS: A total of 458 patients were studied. Of these, 422 (92.2%) had concordant tests, three (0.6%) indeterminate tests (one on UBT and two on HpSA), and 33 (7.2%) discordant tests. A total of 28 patients (25 with discordant and three with indeterminate tests) underwent endoscopy. The HpSA was inaccurate in 24 cases (18 false negative, four false positive, and two indeterminate results), whereas the UBT was inaccurate in four cases (two false positive, one false negative, and one indeterminate results). Biopsy-based tests showed no bacillary or coccoid forms in all five endoscoped patients who were negative on UBT and positive on HpSA, but in one in whom the ratio between coccoid and bacillary forms was 3:1 in the antrum and corpus. CONCLUSIONS: UBT and HpSA test give discordant or indeterminate results in nearly 8% of patients after treatment. The HpSA test is less accurate than the UBT. Coccoid forms do not cause false positive HpSA results.     

Isotope Ratio Mass Spectrometry (IRMS) Versus Laser-Assisted Ratio Analyzer (LARA)

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 value >5 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 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.     

Comparison of Cytomegalovirus (CMV) Enzyme-Linked Immunosorbent Spot and CMV Quantiferon Gamma Interferon-Releasing Assays in Assessing Risk of CMV Infection in Kidney Transplant Recipients

Assessing cytomegalovirus (CMV)-specific cell-mediated immunity (CMI) represents an appealing strategy for identifying transplant recipients at risk of infection. In this study, we compared two gamma interferon-releasing assays (IGRAs), Quantiferon-CMV and CMV enzyme-linked immunosorbent spot (ELISPOT), to determine the ability of each test to predict protective CMV-specific T-cell responses. Two hundred twenty-one Quantiferon-CMV and ELISPOT tests were conducted on 120 adult kidney transplant recipients (KTRs), including 100 CMV-seropositive transplant recipients (R⁺) and 20 CMV-seronegative transplant recipients of a CMV-positive donor (D⁺/R⁻). As a control cohort, 39 healthy adult subjects (including 33 CMV-seropositive and 6 CMV-seronegative subjects) were enrolled. CMV IgG serology was used as a reference for both tests. In the CMV-seropositive individuals, the ELISPOT and Quantiferon-CMV assays provided 46% concordance with the serology, 12% discordance, 18% disagreement between ELISPOT or Quantiferon-CMV and the serology, and 24% gray areas when one or both tests resulted in weak positives. None of the CMV-seronegative subjects showed detectable responses in the ELISPOT or the Quantiferon-CMV test. In transplant recipients, both the ELISPOT and Quantiferon-CMV assays positively correlated with each other and negatively correlated with CMV DNAemia in a significant way (P < 0.05). During the antiviral prophylaxis, all 20 D⁺/R⁻ KTRs we examined displayed undetectable Quantiferon-CMV and ELISPOT results, and there was no evidence of CMV seroconversion. The receiving operator curve (ROC) statistical analysis revealed similar specificities and sensitivities in predicting detectable viremia (areas under the curve [AUC], 0.66 and 0.62 for Quantiferon-CMV and ELISPOT, respectively). ELISPOT and Quantiferon-CMV values of >150 spots/200,000 peripheral blood mononuclear cells (PBMCs) and >1 to 6 IU gamma interferon (IFN-γ) were associated with protection from CMV infection (odds ratios [OR], 5 and 8.75, respectively). In transplant recipients, the two tests displayed similar abilities for predicting CMV infection. Both the ELISPOT and Quantiferon-CMV assays require several ameliorations to avoid false-negative results.