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.

Adalimumab or Infliximab for the Prevention of Early Postoperative Recurrence of Crohn Disease: Results From the ENEIDA Registry.

BACKGROUND: Anti-tumor necrosis factor agents (anti-TNFs) are efficacious at preventing the postoperative recurrence (POR) of Crohn disease, as demonstrated in 2 randomized controlled trials. However, real-life data for infliximab or adalimumab in this setting are scarce. Our aim was to assess both the efficiency of anti-TNFs at preventing early POR of Crohn disease in clinical practice and the associated risk factors for POR. METHODS: Patients in whom anti-TNFs were prescribed for the prevention of POR within 3 months after ileocolonic resection and who had an endoscopic assessment within 18 months were identified from the ENEIDA registry. Clinical and endoscopic features were collected within 18 months after surgery. RESULTS: In total, 152 patients were included (55 treated with infliximab, 97 with adalimumab, and 39% with concomitant immunosuppressants). Anti-TNF treatment was started after a median time of 29 days (IQR 13-44) after surgery. Eighty-two percent of patients had at least one risk factor for POR, and 82% had been exposed to anti-TNFs before the index surgery. Overall, 34% had endoscopic POR (as defined using a Rutgeerts endoscopic score > i1); 14% had advanced endoscopic POR (>i2); and 20% had clinical POR, with no differences between infliximab and adalimumab. In the multivariate analysis, only perianal disease (odds ratio 2.73, 95% confidence interval [CI] 1.26-5.91) and rectal involvement (odds ratio 2.79, 95% CI 1.09-7.14) were independent predictors of endoscopic POR. CONCLUSIONS: In clinical practice, anti-TNFs for the prevention of POR of Crohn disease are frequently used in patients experienced with anti-TNFs and with concomitant immunosuppressants. The efficacy of infliximab and adalimumab for POR prevention is similar and in accordance with the results obtained in randomized controlled trials.

A new validation of the Spanish Work Productivity and Activity Impairment Questionnaire-Crohn's disease version.

OBJECTIVES: The Work Productivity and Activity Impairment Questionnaire (WPAI) is an instrument that measures work impairment in the setting of different diseases. One previous study validating the WPAI in Crohn's disease (CD) patients suggested that its reproducibility may be unsatisfactory. This study evaluated the validity and reproducibility of the Spain Spanish version of the WPAI questionnaire in CD patients. METHODS: In a prospective study, convergent validity was tested comparing WPAI with quality of life and CD activity indices. Known-groups validity was assessed by comparing WPAI scores in CD patients with active versus inactive disease. Reproducibility of repeated tests was evaluated by comparing two WPAI measures obtained two to four weeks apart in stable patients. RESULTS: One hundred eight patients were included in the various steps of the analysis. The WPAI showed adequate known groups validity and convergent validity. The reproducibility of the test and, specifically, that of the evaluation of presenteeism (the impairment of productivity while working) were good. CONCLUSIONS: This study confirms the validity of WPAI for measuring work impairment in CD patients. In contrast to previous studies, the test reproducibility was adequate.

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.

Development and validation of the Crohn's disease perceived work disability questionnaire.

BACKGROUND: No validated instruments have been developed to measure work disability in Crohn's disease (CD). The aim of our study was to develop and validate a CD perceived work disability questionnaire (CPWDQ). METHODS: Development phase: an initial questionnaire containing 52 items was obtained from patients' interviews plus additional sources; it was completed by 106 patients and the 16 most significant items were selected using a psychometric method in order to create the CPWDQ. Validation phase: The validation assessed the questionnaire's convergent validity, discriminant validity, test-retest reproducibility, and internal consistency in 108 patients. Spearman rank correlation, t-test, intraclass correlation, and Cronbach's alpha were used for the analysis. RESULTS: Convergent validity was confirmed by good correlations between the CPWDQ and: clinical activity (r = 0.59, P < 0.01), the Short Inflammatory Bowel Disease Questionnaire, IBDQ-9, (r = 0.76, P < 0.001), Euroqol-5D (r = 0.53, P < 0.01), and overall work impairment (WPAI_CD) r = 0.66 (P < 0.01). Discriminant validity: CPWQ scores were higher in patients expected to have more severe disability, that is, in patients with active disease (n = 38) 32.3 ± 7.3 versus inactive (n = 70) 22.6 ± 5.9 (P < 0.001), in those requiring previous sick leave 30.7 ± 7.5 (n = 45) versus no sick leave 22.6 ± 6.6 (n = 63) (P < 0.01), and in those requiring hospitalization 32.2 ± 8.6 (n = 18) versus no hospitalization 24.7 ± 7.1 (n = 90) (P < 0.01). Internal consistency was also good (Cronbach's alpha = 0.89). Reproducibility: CPWDQ measures obtained 2 weeks apart showed an excellent intraclass correlation coefficient: 0.89 (95% CI: 0.83-0.93). CONCLUSIONS: The CPWDQ seems to be a valid, reliable tool for measuring subjective work disability in CD.

Analysis of court criteria for awarding disability benefits to patients with Crohn's disease.

BACKGROUND & AIMS: Chronic disability and its consequences for social life and employment are important but often neglected aspects of Crohn's disease. No specific scores have been developed to evaluate chronic disability in patients with Crohn's disease; the medical criteria used by government authorities to award disability benefits have not been analyzed. We aimed to determine the courts' criteria for awarding disability benefits to patients with Crohn's disease in Spain. METHODS: We systematically searched case law databases in Spain's regional Supreme Courts to identify sentences regarding awards of disability benefits to patients with Crohn's disease. Selected decisions were reviewed to extract variables related to the awarding of benefits. Univariate and multivariate analyses were performed to determine which variables predicted the awarding of benefits. RESULTS: Two hundred eighty sentences were reviewed. The rate of judicial decisions in favor of the claimants varied considerably between the various tribunals. Multivariate analysis showed that adequate description of the disease (odds ratio, 8.6), fecal incontinence (odds ratio, 8.9), the number of associated diseases (odds ratio, 2.3), and the presence of an ostomy (odds ratio, not estimable) were independent predictors of the awarding of Social Security benefits. CONCLUSIONS: The amount of Social Security benefits awarded to patients with Crohn's disease varied depending on the tribunal. The most important predictors of a court's disability award were the adequate description of the patient's disease, fecal incontinence, associated diseases, and presence of an ostomy.

Validation of the Spanish Work Productivity and Activity impairment questionnaire: Crohn's disease version.

BACKGROUND: The Work Productivity and Activity Impairment questionnaire has only been partially validated in Crohn's disease. OBJECTIVE: To test the Work Productivity and Activity Impairment questionnaire for use in Crohn's disease patients. METHODS: A validated Spanish translation of the test was assessed. 'Discriminant validity' was evaluated by comparing Work Productivity and Activity Impairment scores in Crohn's disease patients with active versus inactive disease, and in patients versus healthy controls. 'Convergent validity' was tested comparing Work Productivity and Activity Impairment questionnaire with quality of life, Crohn's disease activity index and a debriefing questionnaire. 'Reproducibility' of repeated tests was evaluated by comparing two Work Productivity and Activity Impairment measures obtained 2 weeks apart in stable patients. 'Responsiveness' was determined by comparing Work Productivity and Activity Impairment values in the same patients during a flare-up of Crohn's disease and during remission. The Wilcoxon test for paired data and the Mann-Whitney U test for unpaired data were used for comparisons. RESULTS: One hundred and six patients were included in the various steps of the analysis. All Work Productivity and Activity Impairment parameters showed adequate discriminant and convergent validity and responsiveness. The test's reproducibility was also adequate, except for the evaluation of presenteeism (the impairment of productivity while working). CONCLUSION: The Spanish Work Productivity and Activity Impairment questionnaire is a valid and reliable measurement of work impairment in Crohn's disease. Unexpectedly, the test did not present satisfactory reproducibility for the evaluation of presenteeism. The reliability of this last finding should be evaluated in further studies.

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.

Remission on thiopurinic immunomodulators normalizes quality of life and psychological status in patients with Crohn's disease.

BACKGROUND: Thiopurinic immunomodulators are effective for maintaining symptom remission in Crohn's disease. Little is known, however, about their effect on patients' quality of life or psychological well-being. The present study aimed to determine whether remission induced by thiopurinic immunomodulators returns levels of quality of life and psychological well-being to normal. MATERIALS AND METHODS: A case-control study was performed. Cases were 33 patients with Crohn's disease treated with azathioprine or 6-mercaptopurine and in stable remission for at least 6 months. Sixty-six healthy individuals matched 2:1 by age and sex and 14 patients with active Crohn's disease were included as control groups. Quality of life was evaluated with the Short Form (SF-36) questionnaire, and the respective Hamilton rating scales were used for anxiety and depression. ANOVA with Bonferroni's correction was used for multiple comparisons. RESULTS: SF-36 global scores were 85 in the study group, 85 in healthy controls (P = 1), and 58.6 in patients with active disease (P < 0.001 for the comparison with the other 2 groups). The differences between values were 0 (95% CI -4-4), 26.4 (95% CI 20-32), and 26.4 (95% CI 19-33), respectively. The respective anxiety and depression scores were 6.5, 5.5, and 16.2 and 3.7, 3.3, and 10.9. No significant differences were observed in any of the SF-36 domains between case and control groups, whereas in patients with active disease, all domains were significantly worse. CONCLUSIONS: Thiopurinic immunomodulator-induced remission restores normal levels of quality of life and psychological well-being in Crohn's disease patients.

[Testing a new in-office test for determination of faecal Helicobacter pylori antigen]. / Evaluación de un nuevo test rápido para la detección de Helicobacter pylori en heces.

BACKGROUND: To date, the search for an in-office reliable test for Helicobacter pylori infection has been unsuccessful. The aim of the present study was to evaluate a new immunocromatographic in-office test using monoclonal antibodies to determine the presence of Helicobacter pylori antigen in faeces (Stick H. pyl, Operon S.A. Zaragoza). We compared its reliability and reproducibility to the currently available test (HpSA, EIA, Premier Platinum HpSA, Meridian Diagnosis Inc, Cincinnati, Ohio). PATIENTS AND METHOD: 71 consecutive dyspeptic patients were enrolled. Helicobacter pylori status was determined by rapid urease test and Giemsa stain of antral biopsy. Patients with a positive result in the two tests were considered as infected and those with a negative result in both tests were regarded as not infected. Faecal Helicobacter pylori antigen was tested twice by means of HpSA. Four consecutive determinations of Stick H. pyl were also performed. We calculated sensitivity, specificity and positive and negative predictive values of each determination. Concordance between determinations was estimated by the kappa statistics. RESULTS: Forty-eight of 68 patients were infected by Helicobacter pylori. Sensitivity, specificity and positive and negative predictive values were 89-96%, 60-70% 85-88% and 74-87%, respectively, for Stick H. pyl and 70-75%, 60-85%, 85-92% and 55-80%, respectively, for HpSA. Correlation coefficients were 0.82-0.93 for Stick H. pyl and 0.57 for HpSA. CONCLUSIONS: The new Stick H. pyl test shows excellent sensitivity and reproducibility for diagnosis of H. pylori infection. Its reliability appears to be far better than that of HpSA.