Empirical rescue treatment of Helicobacter pylori infection in third and subsequent lines: 8-year experience in 2144 patients from the European Registry on H. pylori management (Hp-EuReg)

OBJECTIVE

To evaluate the use, effectiveness and safety of Helicobacter pylori empirical rescue therapy in third and subsequent treatment lines in Europe.

DESIGN

International, prospective, non-interventional registry of the clinical practice of European gastroenterologists. Data were collected and quality reviewed until October 2021 at Asociación Española de Gastroenterología-Research Electronic Data Capture. All cases with three or more empirical eradication attempts were assessed for effectiveness by modified intention-to-treat and per-protocol analysis.

RESULTS

Overall, 2144 treatments were included: 1519, 439, 145 and 41 cases from third, fourth, fifth and sixth treatment lines, respectively. Sixty different therapies were used; the 15 most frequently prescribed encompassed >90% of cases. Overall effectiveness remained <90% in all therapies. Optimised treatments achieved a higher eradication rate than non-optimised (78% vs 67%, p<0.0001). From 2017 to 2021, only 44% of treatments other than 10-day single-capsule therapy used high proton-pump inhibitor doses and lasted ≥14 days. Quadruple therapy containing metronidazole, tetracycline and bismuth achieved optimal eradication rates only when prescribed as third-line treatment, either as 10-day single-capsule therapy (87%) or as 14-day traditional therapy with tetracycline hydrochloride (95%). Triple amoxicillin-levofloxacin therapy achieved 90% effectiveness in Eastern Europe only or when optimised. The overall incidence of adverse events was 31%.

CONCLUSION

Empirical rescue treatment in third and subsequent lines achieved suboptimal effectiveness in most European regions. Only quadruple bismuth-metronidazole-tetracycline (10-day single-capsule or 14-day traditional scheme) and triple amoxicillin-levofloxacin therapies reached acceptable outcomes in some settings. Compliance with empirical therapy optimisation principles is still poor 5 years after clinical practice guidelines update.

TRIAL REGISTRATION NUMBER

NCT02328131.

Risk of Immunomediated Adverse Events and Loss of Response to Infliximab in Elderly Patients with Inflammatory Bowel Disease: A Cohort Study of the ENEIDA Registry

BACKGROUND AND AIMS

Immunomediated adverse events [IAEs] are the most frequently reported infliximab [IFX]-related adverse events. Combination therapy may reduce their incidence, although this strategy is not recommended in elderly patients. We aimed to compare the rates of IFX-related IAEs and loss of response [LOR] in elderly and younger patients.

METHODS

Adult patients in the ENEIDA registry who had received a first course of IFX therapy were identified and grouped into two cohorts regarding age at the beginning of treatment [over 60 years and between 18 and 50 years]. The rates of IAEs and LOR were compared.

RESULTS

In total, 939 patients [12%] who started IFX over 60 years of age and 6844 [88%] below 50 years of age were included. Elderly patients presented a higher proportion of AEs related to IFX [23.2% vs 19%; p = 0.002], infections [7.1% vs 4.3%; p < 0.001] and neoplasms [2.2% vs 0.5%; p < 0.001]. In contrast, the rates of IAEs [14.8% vs 14.8%; p = 0.999], infusion reactions [8.1% vs 8.1%; p = 0.989], late hypersensitivity [1.3% vs 1.2%; p = 0.895], paradoxical psoriasis [1% vs 1.5%; p = 0.187] and drug-induced lupus erythematosus [0.6% vs 0.7%; p = 0.947] were similar in elderly and younger patients. LOR rates were also similar between the two groups [20.5% vs 19.3%; p = 0.438]. In the logistic regression analysis, IFX monotherapy, extraintestinal manifestations and female gender were the only risk factors for IAEs, whereas IFX monotherapy, extraintestinal manifestations and Crohn's disease were risk factors for LOR.

CONCLUSIONS

Elderly patients with inflammatory bowel disease have a similar risk of developing IFX-related IAEs and LOR to that of younger patients.

Real-world use of mycophenolate mofetil in inflammatory bowel disease: Results from the ENEIDA registry

BACKGROUND

Studies to evaluate the use of mycophenolate mofetil (MMF) in inflammatory bowel disease (IBD) are limited after the appearance of biological treatments.

AIMS

Our primary objective was to evaluate the effectiveness and safety of MMF in IBD.

METHODS

IBD patients who had received MMF were retrieved from the ENEIDA registry. Clinical activity as per the Harvey-Bradshaw Index (HBI), partial Mayo score (pMS), physician global assessment (PGA) and C-reactive protein (CRP) were reviewed at baseline, at 3 and 6 months, and at final follow-up. Adverse events and causes of treatment discontinuation were documented.

RESULTS

A total of 83 patients were included (66 Crohn's disease, 17 ulcerative colitis), 90% of whom had previously received other immunosuppressants. In 61% of patients systemic steroids were used at initiation of MMF, and in 27.3% biological agents were co-administered with MMF. Overall clinical effectiveness was observed in 64.7% of the population. At the end of treatment, 45.6% and 19.1% of subjects showed remission and clinical response, respectively. MMF treatment was maintained for a median of 28.9 months (IQR: 20.4-37.5).

CONCLUSION

Our study suggests, in the largest cohort to date, that MMF may be an effective alternative to thiopurines and methotrexate in IBD.

Pterostilbene modifies triglyceride metabolism in hepatic steatosis induced by high-fat high-fructose feeding: a comparison with its analog resveratrol

The use of phenolic compounds as a new therapeutic approach against NAFLD has emerged recently. In the present study, we aim to study the effect of pterostilbene in the prevention of liver steatosis developed as a consequence of high-fat (saturated) high-fructose feeding, by analysing the changes induced in metabolic pathways involved in triglyceride accumulation. Interestingly, a comparison with the anti-steatotic effect of its parent compound resveratrol will be made for the first time. Rats were distributed into 5 experimental groups and fed either a standard laboratory diet or a high-fat high-fructose diet supplemented with or without pterostilbene (15 or 30 mg per kg per d) or resveratrol (30 mg per kg per d) for 8 weeks. Serum triglyceride, cholesterol, NEFA and transaminase levels were quantified. Liver histological analysis was carried out by haematoxylin-eosin staining. Different pathways involved in liver triglyceride metabolism, including fatty acid synthesis, uptake and oxidation, triglyceride assembly and triglyceride release, were studied. Pterostilbene was shown to partially prevent high-fat high-fructose feeding induced liver steatosis in rats, demonstrating a dose-response pattern. In this dietary model, it acts mainly by reducing de novo lipogenesis and increasing triglyceride assembly and release. Improvement in mitochondrial functionality was also appreciated. At the same dose, the magnitude of pterostilbene and resveratrol induced effects, as well as the involved mechanisms of action, were similar.

Resumption of activity in gastroenterology departments. Recommendations by SEPD, AEEH, GETECCU and AEG

The set of measures proposed by SEPD, AEEH, GETECCU and AEG are aimed to help departments in their resumption of usual activity. We have prepared a number of practical recommendations regarding patient management and the stepwise resumption of healthcare activity. These recommendations are based on the sparse, changing evidence available, and will be updated in the future according to daily needs and the availability of expendable materials to suit them; in each department they will be implemented depending upon the cumulative incidence of SARS-CoV-2 infection in each region, and the burden the pandemic has represented for each hospital. The general objectives of these recommendations include: (a)To protect our patients against the risks of infection with SARS-CoV-2 and to provide them with high-quality care. (b)To protect all healthcare professionals against the risks of infection with SARS-CoV-2. (c)To resume normal functioning of our departments in a setting of ongoing risk for infection with SARS-CoV-2.

Resumption of activity in gastroenterology departments. Recommendations by SEPD, AEEH, GETECCU and AEG

The set of measures proposed by SEPD, AEEH, GETECCU and AEG are aimed to help departments in their resumption of usual activity. We have prepared a number of practical recommendations regarding patient management and the stepwise resumption of healthcare activity. These recommendations are based on the sparse, changing evidence available, and will be updated in the future according to daily needs and the availability of expendable materials to suit them; in each department they will be implemented depending upon the cumulative incidence of SARS-CoV-2 infection in each region, and the burden the pandemic has represented for each hospital. The general objectives of these recommendations include:

• To protect our patients against the risks of infection with SARS-CoV-2 and to provide them with high-quality care.

• To protect all healthcare professionals against the risks of infection with SARS-CoV-2.

• To resume normal functioning of our departments in a setting of ongoing risk for infection with SARS-CoV-2.

Resumption of activity in gastroenterology departments. Recommendations by SEPD, AEEH, GETECCU and AEG

The set of measures proposed by SEPD, AEEH, GETECCU and AEG are aimed to help departments in their resumption of usual activity. We have prepared a number of practical recommendations regarding patient management and the stepwise resumption of healthcare activity. These recommendations are based on the sparse, changing evidence available, and will be updated in the future according to daily needs and the availability of expendable materials to suit them; in each department they will be implemented depending upon the cumulative incidence of SARS-CoV-2 infection in each region, and the burden the pandemic has represented for each hospital. The general objectives of these recommendations include: • To protect our patients against the risks of infection with SARS-CoV-2 and to provide them with high-quality care. • To protect all healthcare professionals against the risks of infection with SARS-CoV-2. • To resume normal functioning of our departments in a setting of ongoing risk for infection with SARS-CoV-2.

Effectiveness and Safety of the Switch from Remicade® to CT-P13 in Patients with Inflammatory Bowel Disease

BACKGROUND AND AIMS

To evaluate the clinical outcomes in patients with IBD after switching from Remicade® to CT-P13 in comparison with patients who maintain Remicade®.

METHODS

Patients under Remicade® who were in clinical remission with standard dosage at study entry were included. The 'switch cohort' [SC] comprised patients who made the switch from Remicade® to CT-P13, and the 'non-switch' cohort [NC] patients remained under Remicade®.

RESULTS

A total of 476 patients were included: 199 [42%] in the SC and 277 [58%] in the NC. The median follow-up was 18 months in the SC and 23 months in the NC [p < 0.01]. Twenty-four out of 277 patients relapsed in the NC; the incidence of relapse was 5% per patient-year. The cumulative incidence of relapse was 2% at 6 months and 10% at 24 months in this group. Thirty-eight out of 199 patients relapsed in the SC; the incidence rate of relapse was 14% per patient-year. The cumulative incidence of relapse was 5% at 6 months and 28% at 24 months. In the multivariate analysis, the switch to CT-P13 was associated with a higher risk of relapse (HR = 3.5, 95% confidence interval [CI] = 2-6). Thirteen percent of patients had adverse events in the NC, compared with 6% in the SC [p < 0.05].

CONCLUSIONS

Switching from Remicade® to CT-P13 might be associated with a higher risk of clinical relapse, although this fact was not supported in our study by an increase in objective markers of inflammation. The nocebo effect might have influenced this result. Switching from Remicade® to CT-P13 was safe.

Prevalence and Factors Associated With Fatigue in Patients With Inflammatory Bowel Disease: A Multicentre Study

BACKGROUND AND AIMS

The aims of this study were to determine the prevalence of fatigue in patients with inflammatory bowel disease [IBD], to identify the factors associated with fatigue and its severity, to assess the impact of fatigue on quality of life [QoL], and to evaluate the relationship between fatigue and sleep disorders.

METHODS

This was a prospective multicentre study conducted at 22 Spanish centres. Consecutive patients followed at IBD Units were included. Fatigue was evaluated with the Fatigue Severity Scale [FSS] and the Fatigue Impact Scale [FIS]. Quality of life and sleep quality were assessed using the IBD Questionnaire-Short Form [IBDQ-9] and the Pittsburgh Sleep Quality Index [PSQI], respectively.

RESULTS

A total of 544 consecutive adult IBD patients were included [50% women, mean age 44 years, 61% Crohn's disease]. The prevalence of fatigue was 41% (95% confidence interval [CI] = 37-45%). The variables associated with an increased risk of fatigue were: anxiety [OR = 2.5, 95% CI = 1.6-3.7], depression [OR = 2.4, 95% CI = 1.4-3.8], presence of extraintestinal manifestations [EIMs] [OR = 1.7, 95% CI = 1.1-2.6], and treatment with systemic steroids [OR = 2.8, 95% CI = 1.4-5.7]. The presence of EIMs [regression coefficient, RC = 8.2, 95% CI = 2.3-14.2], anxiety [RC = 25.8, 95% CI = 20.0-31.5], depression [RC = 30.6, 95% CI = 24.3-37.0], and sleep disturbances [RC = 15.0, 95% CI = 9.3-20.8] were associated with severity of fatigue. Patients with fatigue had a significantly decreased IBDQ-9 score [p < 0.001].

CONCLUSIONS

The prevalence of fatigue in IBD patients is remarkably high and has a negative impact on QoL. Therapy with systemic steroids is associated with an increased risk of fatigue. The severity of fatigue is associated with anxiety, depression, sleep disorders, and the presence of EIMs. Fatigue was not associated with anaemia, disease activity or anti-TNF therapy.

Real-world short-term effectiveness of ustekinumab in 305 patients with Crohn's disease: results from the ENEIDA registry

BACKGROUND

There are limited data of ustekinumab administered according to the doses recommended in the UNITI studies.

AIM

To assess the real-world, short-term effectiveness of ustekinumab in refractory Crohn's disease (CD) METHODS: Multicentre study of CD patients starting ustekinumab after June 2017 at the recommend dose (260, 390 or 520 mg based on weight ~6 mg/kg IV week 0 and 90 mg subcutaneously week 8). Values for Harvey-Bradshaw Index (HBI), C-reactive protein (CRP) and faecal calprotectin (FC) were recorded at baseline and at weeks 8 and 14. Demographic and clinical data, previous treatments, AEs and hospitalisations were documented. Possible predictors of clinical remission were examined.

RESULTS

Three hundred and five patients were analysed (≥2 previous anti-TNFα therapies 64% and vedolizumab 29%). At baseline, 217 (72%) had an HBI >4 points. Of these, 101 (47%) and 126 (58%) achieved clinical remission at weeks 8 and 14, respectively. FC levels returned to normal (<250 µg/g) in 46% and 54% of the patients at weeks 8 and 14 respectively. CRP returned to normal (<3 mg/L) in the 35% and 41% of the patients at week 8 and 14 respectively. AEs were recorded in 38, and 40 patients were hospitalised. Intolerance to the most recent anti-TNF agent and fewer previous anti-TNF agents were associated with clinical remission at week 14. Endoscopic severity was associated with poor response.

CONCLUSION

This is the first study to show the real-world effectiveness and safety of ustekinumab administered according to the recommended induction regimen in a cohort of highly refractory CD patients.

Efficacy and safety of endoscopic balloon dilation in inflammatory bowel disease: results of the large multicenter study of the ENEIDA registry

BACKGROUND

There is no information regarding the outcome of Crohn's disease (CD) patients treated with endoscopic balloon dilation (EBD) in non-referral hospitals, nor on the efficacy of EBD in ulcerative colitis (UC). We report herein the results of the largest series published to date.

AIM

To assess the efficacy and safety of EBD for inflammatory bowel disease (IBD) stenosis performed in 19 hospitals with different levels of complexity and to determine factors related to therapeutic success.

METHODS

We identified IBD patients undergoing EBD in the ENEIDA database. Efficacy of EBD was compared between CD and UC and between secondary and tertiary hospitals. Predictive factors of therapeutic success were assessed with multivariate analysis.

RESULTS

Four-hundred dilations (41.2% anastomotic) were performed in 187 IBD patients (13 UC/Indeterminate colitis). Technical and therapeutic success per dilation was achieved in 79.5% and 55.3%, respectively. Therapeutic success per patient was achieved in 78.1% of cases (median follow-up: 40 months) with 49.7% requiring more than one dilation. No differences related to either diagnosis or hospital complexity was found. Technical success [OR 4.12 (95%CI 2.4-7.1)] and not receiving anti-TNF at the time of dilation [OR 1.7 (95% CI 1.1-2.6)] were independently related to therapeutic success per dilation. A stricture length ≤ 2 cm [HR 2.43 (95% CI 1.11-5.31)] was a predictive factor of long-term success per patient. The rate of major complications was 1.3%.

CONCLUSIONS

EBD can be performed with similar efficacy and safety in hospitals with differing levels of complexity and it might be a suitable treatment for UC with short stenosis. To achieve a technical success and the short length of the stenosis seem to be critical for long-term therapeutic success.

Colorectal cancer molecular classification using BRAF, KRAS, microsatellite instability and CIMP status: Prognostic implications and response to chemotherapy

Objective

The aim of this study was to validate a molecular classification of colorectal cancer (CRC) based on microsatellite instability (MSI), CpG island methylator phenotype (CIMP) status, BRAF, and KRAS and investigate each subtype’s response to chemotherapy.

Design

This retrospective observational study included a population-based cohort of 878 CRC patients. We classified tumours into five different subtypes based on BRAF and KRAS mutation, CIMP status, and MSI. Patients with advanced stage II (T4N0M0) and stage III tumours received 5-fluoruracil (5-FU)-based chemotherapy or no adjuvant treatment based on clinical criteria. The main outcome was disease-free survival (DFS).

Results

Patients with the combination of microsatellite stable (MSS) tumours, BRAF mutation and CIMP positive exhibited the worst prognosis in univariate (log rank P<0.0001) and multivariate analyses (hazard ratio 1.75, 95% CI 1.05–2.93, P = 0.03) after adjusting for age, sex, chemotherapy, and TNM stage. Treatment with 5-FU-based regimens improved prognosis in patients with the combination of MSS tumours, KRAS mutation and CIMP negative (log rank P = 0.003) as well as in patients with MSS tumours plus BRAF and KRAS wild-type and CIMP negative (log-rank P<0.001). After adjusting for age, sex, and TNM stage in the multivariate analysis, only patients with the latter molecular combination had independently improved prognosis after adjuvant chemotherapy (hazard ratio 2.06, 95% CI 1.24–3.44, P = 0.005).

Conclusion

We confirmed the prognostic value of stratifying CRC according to molecular subtypes using MSI, CIMP status, and somatic KRAS and BRAF mutation. Patients with traditional chromosomally unstable tumours obtained the best benefit from adjuvant 5-FU-based chemotherapy.

A GWAS meta-analysis from 5 population-based cohorts implicates ion channel genes in the pathogenesis of irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) shows genetic predisposition, however, large-scale, powered gene mapping studies are lacking. We sought to exploit existing genetic (genotype) and epidemiological (questionnaire) data from a series of population-based cohorts for IBS genome-wide association studies (GWAS) and their meta-analysis.

METHODS

Based on questionnaire data compatible with Rome III Criteria, we identified a total of 1335 IBS cases and 9768 asymptomatic individuals from 5 independent European genotyped cohorts. Individual GWAS were carried out with sex-adjusted logistic regression under an additive model, followed by meta-analysis using the inverse variance method. Functional annotation of significant results was obtained via a computational pipeline exploiting ontology and interaction networks, and tissue-specific and gene set enrichment analyses.

KEY RESULTS

Suggestive GWAS signals (P ≤ 5.0 × 10^-6 ) were detected for 7 genomic regions, harboring 64 gene candidates to affect IBS risk via functional or expression changes. Functional annotation of this gene set convincingly (best FDR-corrected P = 3.1 × 10^-10 ) highlighted regulation of ion channel activity as the most plausible pathway affecting IBS risk.

CONCLUSION & INFERENCES

Our results confirm the feasibility of population-based studies for gene-discovery efforts in IBS, identify risk genes and loci to be prioritized in independent follow-ups, and pinpoint ion channels as important players and potential therapeutic targets warranting further investigation.

Colorectal cancer molecular classification using BRAF, KRAS, microsatellite instability, and CIMP status: Prognostic implications and response to chemotherapy

668

Background: The aim of this study was to validate a molecular classification of colorectal cancer (CRC) based on microsatellite instability (MSI), CpG island methylator phenotype (CIMP) status, BRAF, and KRAS and investigate each subtype’s response to chemotherapy. Methods: This retrospective observational study included a population-based cohort of 878 CRC patients. We classified tumours into five different subtypes based on BRAF and KRAS mutation, CIMP status, and MSI. Patients with advanced stage II (T4N0M0) and stage III tumours received 5-fluoruracil (5-FU)-based chemotherapy or no adjuvant treatment based on clinical criteria. The main outcome was disease-free survival (DFS). Results: Patients with the combination of microsatellite stable (MSS) tumours, BRAF mutation and CIMP positive exhibited the worst prognosis in univariate (log rank P < 0.0001) and multivariate analyses (hazard ratio 1.75, 95% CI 1.05-2.93, P = 0.03) after adjusting for age, sex, chemotherapy, and TNM stage. Treatment with 5-FU-based regimens improved prognosis in patients with the combination of MSS tumours, KRAS mutation and CIMP negative (log rank P = 0.003) as well as in patients with MSS tumours plus BRAF and KRAS wild-type and CIMP negative (log-rank P < 0.001). After adjusting for age, sex, and TNM stage in the multivariate analysis, only patients with the latter molecular combination had independently improved prognosis after adjuvant chemotherapy (hazard ratio 2.06, 95% CI 1.24-3.44, P = 0.005). Conclusions: We confirmed the prognostic value of stratifying CRC according to molecular subtypes using MSI, CIMP status, and somatic KRAS and BRAF mutation. Patients with traditional chromosomally unstable tumours obtained the best benefit from adjuvant 5-FU-based chemotherapy.

Extracolonic Cancer in Inflammatory Bowel Disease: Data from the GETECCU Eneida Registry

OBJECTIVES

The objective of this study was (a) To know the prevalence and distribution of extracolonic cancer (EC) in patients with inflammatory bowel disease (IBD); (b) To estimate the incidence rate of EC; (c) To evaluate the association between EC and treatment with immunosuppressants and anti-tumor necrosis factor (TNF) agents.

METHODS

This was an observational cohort study.

INCLUSION CRITERIA

IBD and inclusion in the ENEIDA Project (a prospectively maintained registry) from GETECCU.

EXCLUSION CRITERIA

Patients with EC before the diagnosis of IBD, lack of relevant data for this study, and previous treatment with immunosuppressants other than corticosteroids, thiopurines, methotrexate, or anti-TNF agents. The Kaplan-Meier method was used to evaluate the impact of several variables on the risk of EC, and any differences between survival curves were evaluated using the log-rank test. Stepwise multivariate Cox regression analysis was used to investigate factors potentially associated with the development of EC, including drugs for the treatment of IBD, during follow-up.

RESULTS

A total of 11,011 patients met the inclusion criteria and were followed for a median of 98 months. Forty-eight percent of patients (5,303) had been exposed to immunosuppressants or anti-TNF drugs, 45.8% had been exposed to thiopurines, 4.7% to methotrexate, and 21.6% to anti-TNF drugs. The prevalence of EC was 3.6%. In the multivariate analysis, age (HR=1.05, 95% CI=1.04-1.06) and having smoked (hazards ratio (HR)=1.47, 95% confidence interval (CI)=1.10-1.80) were the only variables associated with a higher risk of EC.

CONCLUSIONS

Neither immunosuppressants nor anti-TNF drugs seem to increase the risk of EC. Older age and smoking were associated with a higher prevalence of EC.

SOX17 regulates cholangiocyte differentiation and acts as a tumor suppressor in cholangiocarcinoma

BACKGROUND & AIMS

Cholangiocarcinoma (CCA) is a biliary malignancy linked to genetic and epigenetic abnormalities, such as hypermethylation of SOX17 promoter. Here, the role of SOX17 in cholangiocyte differentiation and cholangiocarcinogenesis was studied.

METHODS

SOX17 expression/function was evaluated along the differentiation of human induced pluripotent stem cells (iPSC) into cholangiocytes, in the dedifferentiation process of normal human cholangiocytes (NHC) in culture and in cholangiocarcinogenesis. Lentiviruses for SOX17 overexpression or knockdown were used. Gene expression and DNA methylation profiling were performed.

RESULTS

SOX17 expression is induced in the last stage of cholangiocyte differentiation from iPSC and regulates the acquisition of biliary markers. SOX17 becomes downregulated in NHC undergoing dedifferentiation; experimental SOX17 knockdown in differentiated NHC downregulated biliary markers and promoted baseline and Wnt-dependent proliferation. SOX17 expression is lower in human CCA than in healthy tissue, which correlates with worse survival after tumor resection. In CCA cells, SOX17 overexpression decreased their tumorigenic capacity in murine xenograft models, which was related to increased oxidative stress and apoptosis. In contrast, SOX17 overexpression in NHC did not affect their survival but inhibited their baseline proliferation. In CCA cells, SOX17 inhibited migration, anchorage-independent growth and Wnt/β-catenin-dependent proliferation, and restored the expression of biliary markers and primary cilium length. In human CCA, SOX17 promoter was found hypermethylated and its expression inversely correlates with the methylation grade. In NHC, Wnt3a decreased SOX17 expression in a DNMT-dependent manner, whereas in CCA, DNMT1 inhibition or silencing upregulated SOX17.

CONCLUSIONS

SOX17 regulates the differentiation and maintenance of the biliary phenotype and functions as a tumor suppressor for CCA, being a potential prognostic marker and a promising therapeutic target.

LAY SUMMARY

Understanding the molecular mechanisms involved in the pathogenesis of CCA is key in finding new valuable diagnostic and prognostic biomarkers, as well as therapeutic targets. This study provides evidence that SOX17 regulates the differentiation and maintenance of the biliary phenotype, and its downregulation promotes their tumorigenic transformation. SOX17 acts as a tumor suppressor in CCA and its genetic, molecular and/or pharmacological restoration may represent a new promising therapeutic strategy. Moreover, SOX17 expression correlates with the outcome of patients after tumor resection, being a potential prognostic biomarker.

New Advances in Polycystic Liver Diseases

Polycystic liver diseases (PLDs) include a heterogeneous group of congenital disorders inherited as dominant or recessive genetic traits; they are manifested alone or in association with polycystic kidney disease. Ductal plate malformation during embryogenesis and the loss of heterozygosity linked to second-hit mutations may promote the dilatation and/or development of a large number (> 20) of biliary cysts, which are the main cause of morbidity in these patients. Surgical procedures aimed to eliminate symptomatic cysts show short-term beneficial effects, but are not able to block the disease progression. Therefore, liver transplantation is the only curative option. Intense studies on the molecular mechanisms involved in the pathogenesis of PLDs have resulted in different clinical trials, some of them with promising outcomes. Here the authors summarize the key aspects of PLD etiology, pathogenesis, and therapy, highlighting the most recent advances and future research directions.

Mechanisms of Resistance to Chemotherapy in Gastric Cancer

Although surgical resection is the standard curative therapy for gastric cancer, these tumors are often diagnosed at an advanced stage, when surgery is not recommended. Alternative treatments such as radiotherapy and chemotherapy achieve only very modest results. There is therefore an urgent need to advance in this field of oncologic gastroenterology. The poor response of gastric cancer to chemotherapy is usually due to a combination of mechanisms of chemoresistance (MOC), which may include a reduction in drug uptake (MOC-1a), enhanced drug efflux (MOC-1b), a reduced proportion of active agents in tumor cells due to a reduction in pro-drug activation or an enhancement in drug inactivation (MOC-2), changes in the expression/function of the molecular targets of anticancer drugs (MOC-3), an enhanced ability of cancer cells to repair anticancer drug-induced DNA damage (MOC-4), and decreased expression/function of pro-apoptotic factors or up-regulation of anti-apoptotic genes (MOC-5). Two major goals of modern pharmacology aimed at overcoming this situation are the prediction of a lack of response to chemotherapy and the identification of the underlying mechanisms accounting for primary or acquired refractoriness to anticancer drugs. These are important issues if we are to select the best pharmacological regime for each patient and develop novel strategies to overcome chemoresistance. The present review reports updated information regarding the mechanisms of chemoresistance (from MOC-1 to MOC-5) in gastric cancer, the advances made in the prediction of the failure of chemotherapeutic treatment, and novel strategies based on gene therapy currently being developed to treat these tumors.

Standardization of the homogeneous mobility shift assay protocol for evaluation of anti-infliximab antibodies. Application of the method to Crohn's disease patients treated with infliximab

BACKGROUND

The availability of a quantitative method to measure anti-infliximab (IFX) antibodies (ATI) would facilitate the implementation of therapeutic drug monitoring in clinical decision-making. Our aim was to standardize the homogeneous mobility shift assay (HMSA) used in the measure of ATI levels.

METHODS

In this prospective longitudinal multicenter study, 50 IFX-treated Crohn's disease (CD) patients were followed up for 54weeks. During this period 360 human serum samples were analysed. Monomeric ATI levels were measured by a quantitative HMSA-method using an anti-IFX calibrator. IFX trough levels measured by ELISA were correlated with ATI levels.

RESULTS

Using HMSA and a pure anti-idiotypic monoclonal antibody specific for IFX (anti-IFX calibrator), we measured the levels of monomeric ATI generated in Crohn's disease patients treated with IFX. Anti-IFX calibrator allowed to quantify monomeric antibodies against IFX with a low limit of quantification (3nM). The threshold level of ATI in order to classify the immunogenicity of the patients was 10nM. We observed that 24% (12/50) of IFX-treated patients developed ATI (>10nM) during the observation period (54weeks). Serum concentration of ATI higher than 10nM dramatically increased the probability (OR=51.1; 95% CI: 20.4-128.0; p<0.0001) of presenting low levels of IFX (⩽1.5nM) in serum, as observed in some CD patients treated with standard doses of the drug.

CONCLUSIONS

The HMSA-method described here allows an accurate quantification of ATI concentration in international units (IU) and therefore it could be useful in the study of the relationship between ATI concentration, infliximab level and the clinical response to the drug.

Peptic Ulcer Bleeding Risk. The Role of Helicobacter Pylori Infection in NSAID/Low-Dose Aspirin Users

OBJECTIVES

Helicobacter pylori (H. pylori) infection and NSAID/low-dose aspirin (ASA) use are associated with peptic ulcer disease. The risk of peptic ulcer bleeding (PUB) associated with the interaction of these factors remains unclear. The objective of this study was to determine the risk of PUB associated with the interaction between H. pylori infection and current nonsteroidal anti-inflammatory drugs (NSAIDs) or low-dose ASA use.

METHODS

This was a case-control study of consecutive patients hospitalized because of PUB. Controls were matched by age, sex, and month of admission. H. pylori infection status was determined in all cases and controls by serology. Drug use was determined by structured questionnaire. Adjusted relative risk (RR) associated with different factors, and the interaction between NSAID/ASA and H. pylori infection was estimated by logistic regression analysis.

RESULTS

The study included 666 cases of PUB and 666 controls; 74.3% cases and 54.8% controls (RR: 2.6; 95% confidence interval (CI): 2.0-3.3) tested positive for H. pylori infection; 34.5% of cases had current NSAID use compared with 13.4% of controls (RR: 4.0; 95% CI: 3.0-5.4). Respective proportions for low-dose ASA use were 15.8 and 12%, respectively (RR: 1.9; 95% CI: 1.3-2.7). The RR of PUB for concomitant NSAID use and H. pylori infection suggested an additive effect (RR: 8.0; 95% CI: 5.0-12.8), whereas no interaction was observed with ASA use (RR: 3.5; 95% CI: 2.0-6.1).

CONCLUSIONS

NSAID, low-dose ASA use, and H. pylori infection are three independent risk factors for the development of PUB, but there were differences in the interaction effect between low-dose ASA (no interaction) or NSAID (addition) use and H. pylori infection, which may have implications for clinical practice in prevention strategies.