Jordi Sánchez-Delgado

Accuracy of Diagnostic Tests for Helicobacter pylori: A Reappraisal

BACKGROUND Despite many changes, no large studies comparing the different diagnostic tests for Helicobacter pylori have been performed in the past 10 years. In this time, monoclonal stool antigen immunoassays and in-office 13C-urea breath tests (UBTs) have appeared. The aim of this study was to evaluate the accuracy of invasive and noninvasive tests in a large series of dyspeptic patients. METHODS A total of 199 dyspeptic patients who had not previously been treated for H. pylori infection were prospectively enrolled. Noninvasive analyses included a commercial infrared-based UBT and a commercially available stool test. Biopsy-based tests included histological examination and a rapid urease test. A patient was considered to be infected when at least 2 test results were positive. Sensitivity, specificity, positive and negative predictive values, and 95% confidence intervals were calculated. The test results were compared using the McNemar test. RESULTS Rates of positive test results were similar (54%) for the rapid urease test, histopathological examination, and the stool test. By contrast, 75% of UBT results were positive, and the UBT was associated with a very low specificity (60%). For this reason, the delta cutoff value for the UBT was recalculated as 8.5%. Sensitivities and specificities with this new cutoff value were 95% and 100%, respectively, for the rapid urease test; 94% and 99%, respectively, for histopathological examination; 90% and 93%, respectively, for the stool test; and 90% and 90%, respectively, for the UBT. CONCLUSIONS Histological examination and rapid urease testing showed excellent diagnostic reliability. The stool test seems to be a good, noninvasive alternative to endoscopy-based tests. By contrast, the infrared-based UBT evaluated in our study showed a lower than expected performance, which was partially corrected when the cutoff value for the test was recalculated.

Ten-Day Sequential Treatment for Helicobacter pylori Eradication in Clinical Practice

BACKGROUND:Cure rates of Helicobacter pylori infection with standard triple therapy are disappointingly low. A very effective, new sequential treatment schedule has recently been described. However, all studies published to date were performed in Italy; it is mandatory to confirm these results in other settings.AIM:To assess the cure rate and the acceptability of a new sequential treatment regimen through a pilot study.METHODS:A hundred and thirty-nine patients (60% men, mean age 49.6 ± 15.7 yr) were recruited from six centers. H. pylori status was assessed by histology, urease test or urea breath test. Sequential regime consisted of a 10-day treatment including a proton pump inhibitor (PPI) b.d. plus amoxicillin 1 g b.d. for the first 5 days, followed by a PPI b.d. clarithromycin 500 mg b.d. and metronidazole 500 mg b.d for the next 5 days. Eradication was determined 8 wk after the end of treatment by urea breath test or histology. Eradication rates were calculated both per protocol and by intention-to-treat.RESULTS:Eradication was achieved in 117 out of 129 patients who returned for a follow-up test. The intention-to-treat eradication rate was thus 84.2% (95%CI: 77%–90%) and the per-protocol cure rate 90.7% (95%CI: 84%–95%). The treatment was well tolerated. Only 14 patients complained of mild side effects.CONCLUSIONS:Sequential treatment seems highly effective for eradicating H. pylori.

Has H. pylori prevalence in bleeding peptic ulcer been underestimated? A meta-regression.

OBJECTIVES:It has been suggested that prevalence of Helicobacter pylori (Hp) in peptic ulcer bleeding (PUB) is lower than that in non-complicated ulcers. As Hp infection is elusive in PUB, we hypothesized that this low prevalence could be related to an insufficiently intensive search for the bacteria. The aim of the study was to evaluate whether the prevalence of Hp in PUB depends on the diagnostic methods used in a given study.METHODS:A systematic review was performed of studies assessing the prevalence of Hp infection in patients with PUB. Data were extracted in duplicate. Univariate and multivariate random-effects meta-regression analyses were performed to determine the factors that explained the differences in Hp prevalence between studies.RESULTS:The review retrieved 71 articles, including 8,496 patients. The mean prevalence of Hp infection in PUB was 72%. The meta-regression analysis showed that the most significant variables associated with a high prevalence of Hp infection were the use of a diagnostic test delayed until at least 4 weeks after the PUB episode—odds ratio: 2.08, 95% confidence interval: 1.10–3.93, P=0.024—and a lower mean age of patients—odds ratio: 0.95 per additional year, 95% confidence interval: 0.92–0.99, P=0.008.CONCLUSIONS:Studies that performed a delayed test and those including younger patients found a higher prevalence of Hp, approaching that recorded in cases of non-bleeding ulcers. These results suggest that the low prevalence of Hp infection described in PUB may be related to the methodology of the studies and to patients’ characteristics, and that the true prevalence of Hp in PUB is still to be determined. Our data also support the recent recommendations of the International Consensus on Non-Variceal Upper Gastrointestinal Bleeding regarding the performance of a delayed diagnostic test when Hp tests carried out during the acute PUB episode are negative.Am J Gastroenterol advance online publication, 8 February 2011; doi:10.1038/ajg.2011.2

Effects of intravenous albumin in patients with cirrhosis and episodic hepatic encephalopathy: A randomized double-blind study

BACKGROUND & AIMS Episodic hepatic encephalopathy is frequently precipitated by factors that induce circulatory dysfunction, cause oxidative stress-mediated damage or enhance astrocyte swelling. The administration of albumin could modify these factors and improve the outcome of hepatic encephalopathy. The aim of this study is to assess the efficacy of albumin in a multicenter, prospective, double-blind, controlled trial (ClinicalTrials.gov number, NCT00886925). METHODS Cirrhotic patients with an acute episode of hepatic encephalopathy (grade II-IV) were randomized to receive albumin (1.5g/kg on day 1 and 1.0g/kg on day 3) or isotonic saline, in addition to the usual treatment (laxatives, rifaximin 1200mg per day). The primary end point was the proportion of patients in which encephalopathy was resolved on day 4. The secondary end points included survival, length of hospital stay, and biochemical parameters. RESULTS Fifty-six patients were randomly assigned to albumin (n=26) or saline (n=30) stratified by the severity of HE. Both groups were comparable regarding to demographic data, liver function, and precipitating factors. The percentage of patients without hepatic encephalopathy at day 4 did not differ between both groups (albumin: 57.7% vs. saline: 53.3%; p>0.05). However, significant differences in survival were found at day 90 (albumin: 69.2% vs. saline: 40.0%; p=0.02). CONCLUSIONS Albumin does not improve the resolution of hepatic encephalopathy during hospitalization. However, differences in survival after hospitalization suggest that the development of encephalopathy may identify a subgroup of patients with advanced cirrhosis that may benefit from the administration of albumin.

Systematic review and meta-analysis: susceptibility-guided versus empirical antibiotic treatment for Helicobacter pylori infection

BACKGROUND The cure rate of standard triple therapy for Helicobacter pylori infection is unacceptably low. Susceptibility-guided therapies (SGTs) have been proposed as an alternative to standard empirical treatments. The aim of this study was to perform a systematic review and meta-analysis evaluating the efficacy of SGTs. METHODS A systematic search was performed in multiple databases. Randomized controlled trials comparing cure rates of SGTs versus those of empirical therapy were selected and analysed separately for first- and second-line treatments. A meta-analysis was performed using risk ratio (RR) and number needed to treat (NNT) to measure the effect. RESULTS Twelve studies were included in the meta-analysis. In first-line treatment, SGT was more efficacious than empirical 7-10 day triple therapy (RR 1.16, 95% CI 1.10-1.23, I (2) = 33%; NNT = 8). Most studies used a 7-10 day triple therapy and randomized the patients after endoscopy and/or culture, thus precluding the comparison of SGT versus non-invasive testing and empirical treatment in clinical practice. For second-line therapy, only four studies were found. Results were highly heterogeneous and no significant differences were found (RR 1.11, 95% CI 0.82-1.51, I (2) = 87%). CONCLUSIONS Once endoscopy and culture have been performed, SGT is superior to empirical 7 or 10 day triple therapy for first-line treatment. Further studies are needed to evaluate the effectiveness of SGT in clinical practice, especially when compared with currently recommended first-line quadruple therapies.

Real-Time PCR Improves Helicobacter pylori Detection in Patients with Peptic Ulcer Bleeding

Background and Aims Histological and rapid urease tests to detect H. pylori in biopsy specimens obtained during peptic ulcer bleeding episodes (PUB) often produce false-negative results. We aimed to examine whether immunohistochemistry and real-time PCR can improve the sensitivity of these biopsies. Patients and Methods We selected 52 histology-negative formalin-fixed paraffin-embedded biopsy specimens obtained during PUB episodes. Additional tests showed 10 were true negatives and 42 were false negatives. We also selected 17 histology-positive biopsy specimens obtained during PUB to use as controls. We performed immunohistochemistry staining and real-time PCR for 16S rRNA, ureA, and 23S rRNA for H. pylori genes on all specimens. Results All controls were positive for H. pylori on all PCR assays and immunohistochemical staining. Regarding the 52 initially negative biopsies, all PCR tests were significantly more sensitive than immunohistochemical staining (p<0.01). Sensitivity and specificity were 55% and 80% for 16S rRNA PCR, 43% and 90% for ureA PCR, 41% and 80% for 23S rRNA PCR, and 7% and 100% for immunohistochemical staining, respectively. Combined analysis of PCR assays for two genes were significantly more sensitive than ureA or 23S rRNA PCR tests alone (p<0.05) and marginally better than 16S rRNA PCR alone. The best combination was 16S rRNA+ureA, with a sensitivity of 64% and a specificity of 80%. Conclusions Real-time PCR improves the detection of H. pylori infection in histology-negative formalin-fixed paraffin-embedded biopsy samples obtained during PUB episodes. The low reported prevalence of H. pylori in PUB may be due to the failure of conventional tests to detect infection.

Comparative Accuracy of 3 Monoclonal Stool Tests for Diagnosis of Helicobacter pylori Infection among Patients with Dyspepsia

BACKGROUND Well-devised studies comparing new but different monoclonal fecal tests for diagnosing Helicobacter pylori infection are scarce. The objective of this study was to compare the diagnostic accuracy of 3 monoclonal stool tests: 2 rapid in-office tools-RAPID Hp StAR and ImmunoCard STAT! HpSA-and an enzyme immunoassay test-Amplified IDEIA Hp StAR-for diagnosing H. pylori infection prior to eradication treatment. METHODS Diagnostic reliability was evaluated in 199 untreated consecutive patients with dyspeptic symptoms. The gold standard for diagnosing H. pylori infection was defined as the concordance of the rapid urease test, histopathology, and urea breath test. Readings of immunochromatographic tests were performed by 2 different observers. Sensitivity, specificity, positive and negative predictive values, and 95% confidence intervals were calculated. Sensitivity and specificity were compared using the McNemar test. RESULTS The sensitivity and specificity of Amplified IDEIA Hp StAR were 90% and 89%, respectively. This enzyme immunoassay test was significantly more sensitive than ImmunoCard STAT! HpSA and more specific than RAPID Hp StAR. The sensitivity and specificity of RAPID Hp StAR were 91% and 80%, respectively, according to observer 1, and 92% and 76%, respectively, according to observer 2. It was significantly more sensitive and less specific than ImmunoCard STAT! HpSA. The sensitivity and specificity of ImmunoCard STAT! HpSA were 69% and 90%, respectively, according to observer 1, and 74% and 89%, respectively, according to observer 2. CONCLUSIONS Amplified IDEIA Hp StAR seems to be the most accurate stool test for diagnosing H. pylori for patients with dyspeptic symptoms. The currently available in-office tests obtain slightly less reliable results.

High-dose, ten-day esomeprazole, amoxicillin and metronidazole triple therapy achieves high Helicobacter pylori eradication rates

Strong acid inhibition using esomeprazole increases cure rates with triple therapy and 10‐day treatments are more effective than 7‐day ones. The combination of amoxicillin plus metronidazole at full doses, and using a physiologically‐correct schedule three times a day, and has been shown to overcome metronidazole resistance and to achieve good eradication rates.

Systematic review: third-line susceptibility-guided treatment for Helicobacter pylori infection

Background: Susceptibility-guided therapies (SGTs) have been proposed as preferable to empirical rescue treatments after two treatment failures. The aim of this study was to perform a systematic review and meta-analysis evaluating the effectiveness and efficacy of SGT as third-line therapy. Methods: A systematic search was performed in multiple databases. Studies reporting cure rates of Helicobacter pylori with SGT in third-line therapy were selected. A qualitative analysis describing the current evidence and a pooled mean analysis summarizing the cure rates of SGT in third-line therapy was performed. Results: No randomized controlled trials or comparative studies were found. Four observational studies reported cure rates with SGT in third-line treatment, and three studies which mixed patients with second- and third-line treatment also reported cure rates with SGT. The majority of the studies included the patients when culture had been already obtained, and so the effectiveness of SGT and empirical therapy has never been compared. A pooled mean analysis including four observational studies (283 patients) showed intention-to-treat and per-protocol eradication rates with SGT of 72% (95% confidence interval 56–87%; I2: 92%) and 80% (95% confidence interval 71–90%; I2: 80%), respectively. Conclusions: SGT may be an acceptable option as rescue treatment. However, cure rates are, at best, moderate and this approach has never been compared with a well-devised empirical therapy. The evidence in favor of SGT as rescue therapy is currently insufficient to recommend its use.

Manejo de la infección por Helicobacter pylori en atención primaria en España

Resumen Introduccion Las indicaciones sobre cuando y como diagnosticar y tratar la enfermedad ulcerosa y la infeccion por Helicobacter pylori son razonablemente claras en la actualidad. El objetivo fue analizar el manejo de la infeccion por H. pylori y el acceso a las pruebas diagnosticas de la infeccion en atencion primaria. Material y metodos Estudio observacional, transversal, realizado mediante cuestionario anonimo administrado a medicos de atencion primaria de todo el territorio espanol.Las indicaciones y los tratamientos se analizaron evaluando su adecuacion a las recomendaciones de consenso sobre lainfeccion por H. pylori . Resultados Se recogieron 991 encuestas. El 87,7% de los medicos realizo uno o mas tratamientos erradicadores en el ultimo ano, el 79,9% en ulcera duodenal, el 75,3% en ulcera gastrica y el 18,3% en enfermedad por reflujo. El 74,7% indico una pauta de tratamiento erradicador cuya composicion fue correcta. El 29% la indico con una duracion superior a la recomendada (14 dias). El 67% no indico tratamiento erradicador en el paciente ulceroso bien controlado con antisecretores y continua el tratamiento antisecretor de mantenimiento. El 64,7% de los medicos tiene acceso a la endoscopia, el 67,4% al test del aliento, el 59,6% a la serologia y el 11,9% a la prueba de deteccion de antigeno de H. pylori en heces. Se detectaron variaciones importantes entre las diversas comunidades autonomas en el acceso a las pruebas diagnosticas. Conclusiones El porcentaje de adecuacion a las recomendaciones es razonable. Sin embargo, se observa una notable variabilidad geografica e importantes restricciones en el acceso a pruebas diagnosticas, lo que dificulta la aplicacion de las recomendaciones.