Economic impact of inflammatory bowel disease in Catalonia: a population-based analysis.

Background: Inflammatory bowel disease (IBD) has a major economic impact on healthcare costs. Objectives: The aim of this study was to evaluate the current healthcare expenditure associated with IBD in a population-wide study in Catalonia. Design: Retrospective observational study. Methods: All patients with IBD included in the Catalan Health Surveillance System (CHSS) were considered eligible. The CHSS compiles data on more than 7 million individuals in 2020 (34,823 with IBD). Data on the use of healthcare resources and its economic impact were extracted applying the International Classification of Diseases, 10th revision, Clinical Modification codes (ICD-10-CM codes). Health expenditure, comorbidities, and hospitalization were calculated according to the standard costs of each service provided by the Department of Health of the Catalan government. The data on the IBD population were compared with non-IBD population adjusted for age, sex, and income level. IBD costs were recorded separately for Crohn's disease (CD) and ulcerative colitis (UC). Results: Prevalence of comorbidities was higher in patients with IBD than in those without. The risk of hospitalization was twice as high in the IBD population. The overall healthcare expenditure on IBD patients amounted to 164M€. The pharmacy cost represents the 60%. The average annual per capita expenditure on IBD patients was more than 3.4-fold higher (IBD 4200€, non-IBD 1200€). Average costs of UC were 3400€ and 5700€ for CD. Conclusion: The risk of comorbidities was twice as high in patients with IBD and their use of healthcare resources was also higher than that of their non-IBD counterparts. Per capita healthcare expenditure was approximately 3.4 times higher in the population with IBD. Trial registration: The study was not previously registered.

Economic impact of inflammatory bowel disease in Catalonia The manuscript includes data of the most recent epidemiologic data about the high economic impact of IBD in Catalonia.

Incidence of Myelotoxicity and Other Adverse Effects Related to Thiopurine Starting in Patients with Inflammatory Bowel Disease: Retrospective Observational Study in a Third-Level Hospital.

BACKGROUND AND OBJECTIVES: Thiopurines are an effective treatment for the maintenance of remission in inflammatory bowel disease (IBD). They can present adverse effects (AEs), with myelotoxicity being the most relevant. This study aims to determine the incidence of AEs related to the starting of thiopurines in our centre. METHODOLOGY: Retrospective study. The AEs in patients that were started on thiopurines between January 2016 and June 2020 were registered, with a two-year follow-up. The mean and standard deviation were used to describe the quantitative variables, and percentages and confidence intervals were used for the qualitative variables. The statistical significance was set at a p-value < 0.05. RESULTS: 98 patients were included, with 64 AEs detected in 48 patients (49%). Most of the AEs appeared in the first 6 months. The most relevant were: 21 neutropenia (21.4%), 19 hypertransaminasemia (19.4%), 13 digestive intolerances (13.2%), 6 acute pancreatitis (6.12%), 3 phototoxicity (3%), and 2 unknown origin fevers (2%). In 29 patients (29.4%) the treatment had to be suspended due to AEs. In 11 cases (11.2%), azathioprine (AZA) was switched to 6-mercaptopurine (6 MP) as 5 showed tolerance and 6 patients needed suspension due to AEs. Eight patients required hospital admission, but none of them needed intensive care unit admission. There were no fatal adverse effects. CONCLUSIONS: Thiopurines are a safe drug with few AEs, especially after the first months of treatment. These results suggest that periodic analytic follow-up may not be necessary after the initial period of treatment.

Follow-Up Study Confirms the Presence of Gastric Cancer DNA Methylation Hallmarks in High-Risk Precursor Lesions.

To adopt prevention strategies in gastric cancer, it is imperative to develop robust biomarkers with acceptable costs and feasibility in clinical practice to stratified populations according to risk scores. With this aim, we applied an unbiased genome-wide CpG methylation approach to a discovery cohort composed of gastric cancer (n = 24), and non-malignant precursor lesions (n = 64). Then, candidate-methylation approaches were performed in a validation cohort of precursor lesions obtained from an observational longitudinal study (n = 264), with a 12-year follow-up to identify repression or progression cases. H. pylori stratification and histology were considered to determine their influence on the methylation dynamics. As a result, we ascertained that intestinal metaplasia partially recapitulates patterns of aberrant methylation of intestinal type of gastric cancer, independently of the H. pylori status. Two epigenetically regulated genes in cancer, RPRM and ZNF793, consistently showed increased methylation in intestinal metaplasia with respect to earlier precursor lesions. In summary, our result supports the need to investigate the practical utilities of the quantification of DNA methylation in candidate genes as a marker for disease progression. In addition, the H. pylori-dependent methylation in intestinal metaplasia suggests that pharmacological treatments aimed at H. pylori eradication in the late stages of precursor lesions do not prevent epigenome reprogramming toward a cancer signature.

Analysis of the Association between Fatigue and the Plasma Lipidomic Profile of Inflammatory Bowel Disease Patients.

Inflammatory bowel disease (IBD) is a chronic, relapsing noninfectious inflammatory condition of the intestinal tract with two main phenotypes, ulcerative colitis (UC) and Crohn's disease (CD), and globally increasing incidence and prevalence. Nearly 80% of the IBD patients with active disease and 50% of those with inactive disease suffer fatigue with significant impairment of their quality of life. Fatigue has been associated with multiple factors in IBD patients but, in most cases, no direct cause can be identified, and risk factors in clinically quiescent IBD are contradictory. Furthermore, as the assessment of fatigue is subjective, there is an unmet clinical need for fatigue biomarkers. In this explorative study, we analyzed the plasma lipidomic profiles of 47 quiescent UC and CD patients (23 fatigued, 24 nonfatigued) using ultraperformance liquid chromatography-time-of-flight mass spectrometry (UPLC-TOFMS). The results showed changes in lipids associated with fatigue and IBD. Significantly decreased levels of phosphatidylcholines, plasmanyls, sphingomyelins, lysophosphatidylcholines, phosphatidylethanolamines, phosphatidylinositols, phosphatidylserines, and eicosanoids were observed in patients with fatigue. Network and metabolic pathway analysis indicated a dysregulation of the arachidonic acid and glycerophospholipid metabolisms and the sphingolipid pathway. The protein-metabolite interaction network showed interactions between functionally related metabolites and proteins, displaying 40 disease-associated hidden proteins including ABDH4, GLTP, and LCAT.

Droplet Digital PCR Detects Low-Density Infection in a Significant Proportion of Helicobacter Pylori-Negative Gastric Biopsies of Dyspeptic Patients.

INTRODUCTION: Helicobacter pylori-infected individuals may present low-density infection, undetectable by conventional tests such as histology, rapid urease test, or urea breath test. Droplet digital polymerase chain reaction (ddPCR) is more sensitive than other polymerase chain reaction methods. We aimed to evaluate the ability of ddPCR to detect H. pylori infection in patients diagnosed as negative by conventional tests. METHODS: Dyspeptic patients (n = 236) were tested for H. pylori by histology, urea breath test, and rapid urease test. Patients were classified as having 3 positive (n = 25, control group), 2 positive (n = 12), one positive (n = 41), or zero positive (n = 158) diagnostic tests. DNA was extracted from gastric biopsies. Triplicate ddPCR testing for each of the 16S rDNA, ureA, and vacA(s) genes was performed using a QX200 ddPCR system (Bio-Rad). A gene was considered positive when detected by at least 2 of 3 repeated ddPCRs. H. pylori positivity was defined as having 2 or more positive genes. RESULTS: All the biopsies of the control patients were positive for all 3 16S rDNA, ureA, and vacA(s) genes. H. pylori infection was detected in 57 (36%), 22 (54%), and 9 (75%) patients with zero, 1, and 2 positive diagnostic tests, respectively. The density of infection was 5, 121, 599, and 3,133 copies of H. pylori genome equivalents for patients with zero, 1, and 2 of 3 positive test results and for the control group, respectively. DISCUSSION: ddPCR detected low-density "occult" H. pylori infection in a significant proportion (36%) of patients diagnosed as negative by conventional methods. The number of conventional positive tests was related to the density of infection.

Genetic variation analysis in a follow-up study of gastric cancer precursor lesions confirms the association of MUC2 variants with the evolution of the lesions and identifies a significant association with NFKB1 and CD14.

Gastric carcinogenesis proceeds through a series of gastric cancer precursor lesions (GCPLs) leading to gastric cancer (GC) development. Although Helicobacter pylori infection initiates this process, genetic factors also play a role. We previously reported that genetic variability in MUC2 is associated with the evolution of GCPLs. In order to replicate previous results in an independent sample series and to explore whether genetic variability in other candidate genes plays a role in the evolution of GCPL, genomic DNA from 559 patients with GCPLs, recruited from 9 Spanish hospitals and followed for a mean of 12 years, was genotyped for 141 SNPs in 29 genes. After follow-up, 45.5% of the lesions remained stable, 37% regressed and 17.5% progressed to a more severe lesion. Genetic association with the evolution of the lesions (progression or regression) was analyzed by multinomial and binomial logistic regression. After correction for multiple comparisons, the results obtained confirmed the inverse association between MUC2 variants and the regression of the lesions. A significant association was also observed between NFKB1 and CD14 variants and the evolution of the lesions; interestingly, this association was with both progression and regression in the same direction, which could reflect the dual role of inflammation in cancer. Stratified analyses according to H. pylori virulence factors indicated some significant and differential effects but none of them passed the FDR test. These results confirm that genetic variability in MUC2, NFKB1 and CD14 may have a role in the evolution of the GCPLs along time and in gastric carcinogenesis.

Application of Individual qPCR Performance Parameters for Quality Control of Circulating MicroRNA Data.

Although circulating miRNAs are promising candidates for biomarkers, several challenges must be overcome before miRNAs can be used for diagnosis and monitoring. One is quality control for the RNA extraction and quantification process. RNA quality control techniques are unsuitable as circulating miRNAs are in the fM range. Additionally, biofluids may contain inhibitors of the reverse transcriptase and polymerase enzymes, which may survive RNA purification. Herein, we describe the protocol we have used to check the robustness of miRNA purification and measurement by the addition of spike-ins and by evaluating the quality of the qPCR data, respectively.

Plasma sample based analysis of gastric cancer progression using targeted metabolomics.

Gastric carcinogenesis is a multifactorial process described as a stepwise progression from non-active gastritis (NAG), chronic active gastritis (CAG), precursor lesions of gastric cancer (PLGC) and gastric adenocarcinoma. Gastric cancer (GC) 5-year survival rate is highly dependent upon stage of disease at diagnosis, which is based on endoscopy, biopsy and pathological examinations. Non-invasive GC biomarkers would facilitate its diagnosis at early stages leading to improved GC prognosis. We analyzed plasma samples collected from 80 patients diagnosed with NAG without H. pylori infection (NAG-), CAG with H. pylori infection (CAG+), PLGC and GC. A panel of 208 metabolites including acylcarnitines, amino acids and biogenic amines, sphingolipids, glycerophospholipids, hexoses, and tryptophan and phenylalanine metabolites were quantified using two complementary quantitative approaches: Biocrates AbsoluteIDQ®p180 kit and a LC-MS method designed for the analysis of 29 tryptophan pathway and phenylalanine metabolites. Significantly altered metabolic profiles were found in GC patients that allowing discrimination from NAG-, CAG+ and PLGC patients. Pathway analysis showed significantly altered tryptophan and nitrogen metabolic pathways (FDR P < 0.01). Three metabolites (histidine, tryprophan and phenylacetylglutamine) discriminated between non-GC and GC groups. These metabolic signatures open new possibilities to improve surveillance of PLGC patients using a minimally invasive blood analysis.

Fatigue in out-patients with inflammatory bowel disease: Prevalence and predictive factors.

BACKGROUND AND AIM: Fatigue is a common and bothersome symptom in inflammatory bowel disease (IBD) patients. The study was aimed to determine the relationship of biological and psychological factors with IBD-related fatigue. METHODS: Consecutive clinically inactive IBD outpatients receiving immunosuppressants or biological drugs were enrolled between January and December 2013. Patients completed a Fatigue score (FACIT-F), various psychological, quality of life (IBDQ-9), and IBD activity scores. Biological parameters were assessed, including levels of interleukins (IL-5, IL-8 and IL-12) and micronutrients. RESULTS: We prospectively recruited 202 patients (28% ulcerative colitis and 72% Crohn's disease) for the study. Fatigue measured by FACIT-F score was prevalent in the studied population (54%, 96/177) and higher than in the general population. In the univariate analysis no relation was found between IL levels or micronutrient deficiencies and fatigue. Fatigue was significantly related to female sex, Crohn's disease, joint disorders, body mass index (BMI), psychological tests, thiopurine use, and anti-TNF treatment. All these variables were included in the multivariate analysis. Female sex (OR: 4.8), high BMI (OR:1.2) and higher depression rates (OR:1.2) were predictors of increased fatigue. High IBDQ-9 score (OR: 0.82) was significantly related to lower degrees of fatigue. CONCLUSION: Fatigue was prevalent in quiescent IBD patients with moderate-to-severe disease. It was associated with high levels of depression, low quality of life, and female sex. No association was found with the other biological and psychological factors evaluated.

Metabolomic Analysis of Gastric Cancer Progression within the Correa's Cascade Using Ultraperformance Liquid Chromatography-Mass Spectrometry.

Gastric cancer (GC) is among the most common cancers worldwide. Gastric carcinogenesis is a multistep and multifactorial process beginning with chronic gastritis induced by Helicobacter pylori (H. pylori) infection. This process is often described via a sequence of events known as Correas's cascade, a stepwise progression from nonactive gastritis, chronic active gastritis, precursor lesions of gastric cancer (atrophy, intestinal metaplasia, and dysplasia), and finally adenocarcinoma. Our aim was to identify a plasma metabolic pattern characteristic of GC through disease progression within the Correa's cascade. This study involved the analysis of plasma samples collected from 143 patients classified in four groups: patients with nonactive gastritis and no H. pylori infection, H. pylori infected patients with chronic active gastritis, infected or noninfected patients with precursor lesions of gastric cancer, and GC. Independent partial least-squares-discriminant binary models of UPLC-ESI(+)-TOFMS metabolic profiles, implemented in a decision-directed acyclic graph, allowed the identification of tryptophan and kynurenine as discriminant metabolites that could be attributed to indoleamine-2,3-dioxygenase upregulation in cancer patients leading to tryptophan depletion and kynurenine metabolites generation. Furthermore, phenylacetylglutamine was also classified as a discriminant metabolite. Our data suggest the use of tryptophan, kynurenine, and phenylacetylglutamine as potential GC biomarkers.

Usefulness of Housekeeping Genes for the Diagnosis of Helicobacter pylori Infection, Strain Discrimination and Detection of Multiple Infection.

BACKGROUND: Helicobacter pylori infects human stomachs of over half the world's population, evades the immune response and establishes a chronic infection. Although most people remains asymptomatic, duodenal and gastric ulcers, MALT lymphoma and progression to gastric cancer could be developed. Several virulence factors such as flagella, lipopolysaccharide, adhesins and especially the vacuolating cytotoxin VacA and the oncoprotein CagA have been described for H. pylori. Despite the extensive published data on H. pylori, more research is needed to determine new virulence markers, the exact mode of transmission or the role of multiple infection. MATERIALS AND METHODS: Amplification and sequencing of six housekeeping genes (amiA, cgt, cpn60, cpn70, dnaJ, and luxS) related to H. pylori pathogenesis have been performed in order to evaluate their usefulness for the specific detection of H. pylori, the genetic discrimination at strain level and the detection of multiple infection. A total of 52 H. pylori clones, isolated from 14 gastric biopsies from 11 patients, were analyzed for this purpose. RESULTS: All genes were specifically amplified for H. pylori and all clones isolated from different patients were discriminated, with gene distances ranged from 0.9 to 7.8%. Although most clones isolated from the same patient showed identical gene sequences, an event of multiple infection was detected in all the genes and microevolution events were showed for amiA and cpn60 genes. CONCLUSIONS: These results suggested that housekeeping genes could be useful for H. pylori detection and to elucidate the mode of transmission and the relevance of the multiple infection.

Good diagnostic accuracy of a chemiluminescent immunoassay in stool samples for diagnosis of Helicobacter pylori infection in patients with dyspepsia.

Laboratory-based chemiluminescence immunoassays (CLIA) are widely used in clinical laboratories. Some years ago, a CLIA test was developed for the detection of Helicobacter pylori in stool samples, known as LIAISON H. pylori SA, but little information on its use has been reported. To evaluate the accuracy of the LIAISON H. pylori SA assay for diagnosing H. pylori infection prior to eradication treatment. Diagnostic reliability was evaluated in 252 untreated consecutive patients with dyspepsia. The gold standard for diagnosing H. pylori infection was defined as the concordance of the rapid urease test (RUT), histopathology and urea breath test (UBT). The CLIA assay was performed according to the manufacturer's instructions. Sensitivity, specificity, positive and negative predictive values, and 95% CIs were calculated. According to the gold standard selected, 121 patients were positive for H. pylori infection and 131 negative. LIAISON H. pylori SA had a sensitivity of 90.1% and a specificity of 92.4%, with positive and negative predictive values of 91.6% and 90.1%, respectively. The accuracy of the LIAISON H. pylori SA chemiluminescent diagnostic assay seems comparable to that of ELISA or the best-performing LFIAs. Its sensitivity and specificity, however, seem slightly lower than those of histology, RUT or UBT. The advantages of the assay are that it is cheap, automated, and minimally labor-intensive.

Diagnostic accuracy of three monoclonal stool tests in a large series of untreated Helicobacter pylori infected patients.

OBJECTIVES: Immunochromatographic tests need to be improved in order to enhance their reliability. Recently, several new kits have appeared on the market. The objective was to evaluate the diagnostic accuracy of three monoclonal rapid stool tests - the new Uni-Gold™ H.pylori Antigen (Trinity Biotech, Ireland), the RAPID Hp StAR (Oxoid Ltd., UK) and the ImmunoCard STAT! HpSA (Meridian Diagnostics, USA) - for detecting H. pylori infection prior to eradication treatment. DESIGN AND METHODS: Diagnostic accuracy (sensitivity and specificity) and reliability (concordance between observers) were evaluated in 250 untreated consecutive dyspeptic patients. The gold standard for diagnosing H. pylori infection was defined as the concordance of two or more of rapid urease test (RUT), histopathology and urease breath test (UBT) or positive culture in isolation. Readings of immunochromatographic tests were performed by two 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 three tests showed a good correlation, with Kappa values>0.9. RAPID Hp StAR had a sensitivity of 91%-92% and a specificity ranging from 77% to 85%. Its sensitivity was higher than that of Uni-Gold™ H.pylori Antigen and ImmunoCard STAT! HpSA (p<0.01). Uni-Gold™ H.pylori Antigen kit showed a sensitivity of 83%, similar to ImmunoCard STAT! HpSA. Specificity of Uni-Gold™ H.pylori Antigen approached 90% (87-89%) and was superior to that of RAPID Hp StAR (p<0.01). CONCLUSIONS: Uni-Gold™ H.pylori Antigen and ImmunoCard STAT! HpSA present similar levels of diagnostic accuracy. RAPID Hp StAR was the most sensitive but less reliable of the three immunochromatographic stool tests. None are as accurate and reliable as UBT, RUT and histology.

Data on individual PCR efficiency values as quality control for circulating miRNAs.

This data article contains data related to the research article entitled "Variability in microRNA recovery from plasma: Comparison of five commercial kits, doi:10.1016/j.ab.2015.07.018" Brunet-Vega (2015) [1]. PCR efficiency, along with RNA and cDNA quality, are the most important factors affecting the quality of qPCR results. Constant amplification efficiency in all compared samples is indispensable when relative quantification is used to measure changes in gene expression. An easy way to measure PCR efficiency, without the need of a standard curve, is LinRegPCR software. Individual PCR efficiency can be determined as a part of qPCR quality control. This is especially important when the initial RNA quantity is so low that cannot be accurately quantified, such as in circulating RNA extractions. This data article reports the Cqs and PCR efficiencies of 5 miRNAs quantified in RNA isolated from 4 patients with colorectal cancer (CRC) and 4 healthy donors using five commercially available kits.

Variability in microRNA recovery from plasma: Comparison of five commercial kits.

Numerous studies have indicated that microRNAs (miRNAs) are present and stable in multiple biological fluids, suggesting a great potential as biomarkers for molecular diagnostics and prognostics. Variations in the amount of starting material and isolation method to obtain miRNA may introduce bias and contribute to quantification errors. Given these concerns, we compared five commercially available kits for serum/plasma miRNA isolation to determine whether the plasma miRNA profile varies with the isolation method. We isolated miRNAs in blood plasma from colorectal cancer patients and healthy donors with five commercially available kits: Exiqon, Norgen, Macherey-Nagel, Qiagen, and Zymo Research. First, we assessed the robustness of the RNA isolation process and the quality of isolated miRNAs with the miRCURY microRNA QC PCR Panel (Exiqon), which contains six RNA spike-ins for quality control of RNA isolation (UniSp2, -4, and -5), complementary DNA (cDNA) synthesis (UniSp6 and cel-miR-39-3p), and polymerase chain reaction (PCR) amplification (UniSp3). This panel also includes circulating human miR-103, miR-191, miR-23a, and miR-451. Second, to evaluate the variability in miRNA profiling in relation to the extraction method, we analyzed plasma levels of candidate miRNA biomarkers for colorectal cancer (miR-18a, miR-21, and miR-29a). To determine PCR efficiencies per amplicon and per sample, we used LinRegPCR software. We found that all isolation methods were suitable for extracting miRNA from plasma samples and that all had similar Cq values in the three steps analyzed: RNA isolation, cDNA synthesis, and quantitative reverse transcription (qRT)-PCR. However, although the PCR replicates were excellent, the intersample variability of the spike-ins was unsatisfactorily high and all kits yielded suboptimal PCR efficiencies for some amplicons. Overall, our results underline the great difficulties involved in measuring miRNAs in plasma. The use of spike-ins is critical to control technical factors that affect final miRNA levels. We recommend that researchers investigating circulating miRNAs verify the PCR efficiency for each amplicon because quantification may be influenced by sample and PCR components.

Diagnosis and epidemiology of Helicobacter pylori infection.

A limited amount of new information was published in the field of diagnosis and epidemiology of Helicobacter pylori this last year. Besides some improvement in current tests, it is interesting to note the attempts to identify severe disease, for example gastric cancer, by breath analysis using nanomaterial-based sensors. In contrast, the predictive value for gastric cancer and atrophy of pepsinogen determinations was found inadequate. Prevalence studies of H. pylori infection have been carried out in adults and children around the world in the general population but also in specific communities. The usual risk factors were found. In addition, a Japanese study highlighted the role of grandmothers in the familial transmission of H. pylori. A study showed that the infection may not always readily establish itself in children, given the number of transient infections observed. It was also noted that after eradication, a first-year relapse is likely to be a recurrence of the previous infection, while later on it is probably a reinfection with a new strain.

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.

Accuracy of monoclonal stool tests for determining cure of Helicobacter pylori infection after treatment.

BACKGROUND: Studies comparing new monoclonal fecal tests for evaluating cure of Helicobacter pylori infection after treatment are scarce. The objective was to compare the diagnostic accuracy of three monoclonal stool tests: two rapid in-office tools -RAPID Hp StAR and ImmunoCard STAT! HpSA - and an EIA test - Amplified IDEIA Hp StAR. MATERIALS AND METHODS: Diagnostic reliability of the three tests was evaluated in 88 patients at least 8 weeks after H. pylori treatment. Readings of immunochromatographic tests were performed by two different observers. Sensitivity, specificity, positive and negative predictive values and 95% confidence intervals were calculated. RESULTS: All tests presented similar performance for post-eradication testing. Sensitivity for detecting persistent infection was 100% for both Amplified IDEIA and RAPID Hp StAR and 90% for ImmunoCard STAT! HpSA. Respective specificities were 94.9%, 92.3-93.6% and 94.9%. Negative predictive values were very high (100%, 100% and 98.7% respectively). But positive predictive values were lower, ranging from 62.5 to 71.4%. CONCLUSION: All monoclonal fecal tests in this series presented similar performance in the post-treatment setting. A negative test after treatment adequately predicted cure of the infection. However, nearly a third of tests were false positive, showing a poor predictive yield for persistent 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.

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.