Effects of RAD50 SNP, sodium intake, and H. pylori infection on gastric cancer survival in Korea

BACKGROUND

Double-strand break repair protein (RAD50) gene plays important roles in genomic integrity, DNA double-strand break repair, cell cycle checkpoint activation, telomere maintenance, and meiotic recombination. The risk allele of RAD50 may negatively affect cancer by reducing the DNA repair capacity. Additionally, Sodium intake and Helicobacter pylori (H. pylori) infection are major risk factors for gastric cancer (GC). Our study investigated the association between polymorphisms in RAD50 gene and the risk of GC case-fatality. We evaluated whether the association differed with sodium intake or H. pylori infection.

METHODS

We enrolled 490 patients from two hospitals between 2002 and 2006. Their survival or death was prospectively followed up until December 31, 2016, through a review of medical records and telephone surveys. The GC survival was assessed using the Cox proportional hazards regression analysis.

RESULTS

In 319 GC cases, the total person-years were 1928.3, and the median survival years was 5.4 years. A total of 137 GC deaths were recorded. Our fully adjusted model showed that the GG type of RAD50 rs17772583 polymorphism is significantly associated with an increased risk of GC case-fatality (hazard ratio [HR] = 2.20, 95% confidence interval [CI] = 1.28-3.77) compared to that associated with the homozygous AA type. In the high sodium intake group, patients with the GG type of RAD50 rs17772583 showed a significantly higher GC case-fatality (HR = 8.61, 95% CI = 2.58-26.68) than that of patients with homozygous AA type. In the positive-H. pylori infection group, patients with GG-type RAD50 rs17772583 showed a significantly higher GC case-fatality (HR = 10.11, 95% CI = 2.81-36.35) than that of with AA homozygotes.

CONCLUSIONS

Patients with GG-type RAD50 rs17772583, high sodium intake, or a positive-H. pylori infection are at a significantly increased risk of GC case-fatality compared to that associated with the absence of these risk factors.

Clinical importance of weight gain and associated factors in patients with moderate to severe ulcerative colitis: results from the MOSAIK cohort in Korea

BACKGROUND

Many patients with ulcerative colitis (UC) gain weight after treatment. However, the clinical significance of weight gain in these patients remains unclear. This study aimed to evaluate body weight changes after treatment in patients newly diagnosed with moderate-to-severe UC and their effects on patients' prognosis.

METHODS

The change in weight between diagnosis and 1 year after treatment in 212 patients enrolled in the MOSAIK cohort (mean age, 40 years; males, 60%) was analyzed. Significant weight gain was defined as a weight increase of ≥ 5% from the baseline at 1 year. Factors associated with significant weight gain and the effect of significant weight gain on the risk of major adverse outcomes (clinical relapse, hospitalization, and new use of steroids or biologics) during a follow-up period of 20 months were evaluated.

RESULTS

Mean weight gain at 1 year was 1.7 ± 4.2 kg. The proportion of overweight/obese patients increased by 9.0% from 37.9% to 46.9%. Thirty-two percent had significant weight gain; extensive colitis at diagnosis was the only factor associated with significant weight gain (odds ratio 6.5, 95% confidence interval 1.4-31.0, p = 0.006). In multivariable analysis, significant weight gain was not associated with the risk of major adverse outcomes. Weight loss symptoms at diagnosis were associated with an increased risk for new steroid use after 1 year.

CONCLUSIONS

Approximately one-third of patients with moderate-to-severe UC had significant weight gain after 1 year of treatment. However, significant weight gain was not associated with the patient's prognosis.

Association of Dietary Antioxidant Vitamin Intake and Gastric Cancer Risk According to Smoking Status and Histological Subtypes of Gastric Cancer: A Case-Control Study in Korea

Smoking is a risk factor for gastric cancer (GC) and causes oxidative stress. Antioxidant vitamins may protect against oxidative stress. This study aimed to determine the association between dietary antioxidant vitamin intake and GC risk according to smoking status and the histological subtype. This case-control study included 286 pairs of patients with GC and controls aged 20-79 years enrolled at two hospitals from 2002 to 2006, matched by age (± 2 years), sex, hospital, and participation period (± 1 years). Dietary information was collected using a quantitative food frequency questionnaire (FFQ). When stratified by smoking status, increased intake of vitamin C (OR = 0.38; 95% CI = 0.17-0.84 for highest vs. lowest; P for trend = 0.033) and folate (OR = 0.28; 95% CI = 0.12-0.64 for highest vs. lowest; P for trend = 0.003) decreased GC risk in nonsmokers. Vitamin C (P for interaction = 0.043) and folate (P for interaction =0.015) levels were significantly associated with smoking status. Similar results were observed in nonsmokers with diffuse and mixed types of GC, but not in those with intestinal type of GC. Therefore, we found an inverse association between higher intake of dietary vitamin C and folate with the risk of GC among nonsmokers. These protective associations were strong in nonsmokers with diffuse and mixed types of GC.

Association between soy products, fruits, vegetables, and dairy products and gastric cancer risk in Helicobacter pylori-infected subjects: a case-control study in Korea

BACKGROUND/OBJECTIVES

Consumption of certain protective foods may help inhibit Helicobacter pylori (H. pylori) associated gastric pathologies. However, studies conducted to assess the efficacy of protective foods in H. pylori-infected subjects are either limited or inconsistent. This study evaluated the association of individual or a combination of protective foods on the incidence of gastric cancer (GC) in H. pylori-positive subjects through a case-control study.

MATERIALS/METHODS

Subjects aged 20-79 years were selected from 2 hospitals between December 2002 and September 2006. In total, 134 patients and 212 controls tested positive for H. pylori infection. Among these, we included 82 pairs of cases and controls matched by sex, age (± 5 years), enrollment period (± 1 years), and hospital.

RESULTS

A higher intake of soy products was associated with a significantly lower risk of GC than a lower intake of soy products (odds ratio [OR] = 0.37, 95% confidence interval [CI] = 0.14-0.96). Additionally, a higher fruit intake resulted in a significantly lower risk of GC than a lower fruit intake (OR = 0.35, 95% CI = 0.13-0.94). A combination of food groups was evaluated, and a lower risk of GC was observed with a high intake of both soy products and fruits (OR = 0.20, 95% CI = 0.06-0.67), high intake of soy and dairy products (OR = 0.28, 95% CI = 0.10-0.78) and high intake of fruits and dairy products (OR = 0.28, 95% CI = 0.09-0.83).

CONCLUSIONS

A high intake of soy products or fruits was associated with a lower risk of GC. A combination of soy products or fruits with dairy products was associated with a lower risk of GC. A balanced intake of soy products, fruits, and dairy products may help reduce GC risk.

Dietary zinc intake and mortality in patients with intestinal-type gastric cancer: A prospective cohort study in Korea

Purpose

Current evidence regarding the association between zinc intake and gastric cancer (GC)-specific survival in patients with intestinal-type GC is lacking. Therefore, this cohort study investigated the association between zinc intake and GC mortality through follow-up on GC death among patients with intestinal-type GC and whether these effects differ according to the source of zinc intake.

Methods

A total of 185 patients with intestinal-type GC were enrolled from two hospitals between 2002 and 2006. Their survival or death was prospectively followed up until December 31, 2016, through a review of medical records and telephone surveys.

Results

A total of 178 patients were included and analyzed. The median follow-up period was 7.3 years. In the fully adjusted models, the highest tertile of total zinc intake showed a significantly lower GC mortality than the lowest tertile (hazard ratio, 0.22; 95% confidence interval: 0.08–0.64). In addition, the tertile of total zinc intake showed a dose-response association with GC mortality (p=0.015). Analysis of the source of zinc intake revealed that when zinc intake from staples (rice and noodles), animal, and plant food sources were combined, the results were similar to those of total zinc intake and GC mortality.

Conclusion

Zinc intake through various foods may be effective in reducing GC mortality by achieving balance with other nutrients. Our results suggest that zinc improves the survival of patients with intestinal-type GC in Korea.

Inflammatory bowel disease in Korea: epidemiology and pathophysiology

Inflammatory bowel disease (IBD) refers to a group of disorders, including Crohn's disease and ulcerative colitis, that exhibit similar but distinct manifestations. These diseases are characterized by refractory and chronic inflammation of the bowel. IBD is usually accompanied by severe symptoms. When a patient presents with suspected IBD, physicians encounter various challenges in terms of diagnosis and treatment. In addition, given such characteristics, the associated medical expenses gradually increase. Although IBD was formerly known as a disease of Western countries, the incidence and prevalence are increasing in Korea. Korean investigators have accumulated a great deal of knowledge about the regional characteristics and epidemiology of the disease, especially via well-organized, joint cohort studies. Against this background, this article describes the epidemiology of IBD in Korea compared to that in the West. In addition, an overview of the pathophysiology of the disease is provided, focusing on the latest results.

Additive effect of probiotics (Mutaflor) on 5-aminosalicylic acid therapy in patients with ulcerative colitis

BACKGROUND/AIMS

In ulcerative colitis (UC) patients, Escherichia coli Nissle 1917 (EcN) is equivalent to mesalazine for preventing disease relapse; however, evidence of the ability of EcN to increase health-related quality of life or induce remission remains scarce. We investigated the efficacy of EcN as an add-on therapy for UC.

METHODS

In this multicentre, double-blind, randomised, placebo-controlled study, a total of 133 UC patients were randomly assigned to receive either EcN or placebo once daily for 8 weeks. Inflammatory bowel disease questionnaire (IBDQ) scores (primary endpoint) and clinical remission and response rates (secondary endpoints) were compared (Clinical trial registration number: NCT04969679).

RESULTS

In total, 118 patients (EcN, 58; placebo, 60) completed the study. The number of patients reaching the primary endpoint did not differ between the EcN and placebo groups (30 [51.7%] vs. 31 [51.7%]; per-protocol analysis, p = 1.0; intention-to-treat analysis, p = 0.86). However, significantly fewer patients in the EcN group exhibited a decreased IBDQ score (1 [1.7%] vs. 8 [13.3%]; per-protocol analysis, p = 0.03; intention- to-treat analysis, p = 0.02). Moreover, a significantly higher number of patients in the EcN group displayed clinical response at 4 weeks (23 [39.7%] vs. 13 [21.7%], p = 0.04) and endoscopic remission at 8 weeks (26 [46.4%] vs. 16 [27.1%], p = 0.03).

CONCLUSION

Although the number of patients reaching the primary endpoint did not differ between the EcN and placebo groups, EcN was found to be safe and effective in preventing the exacerbation of IBDQ scores and achieving clinical responses and endoscopic remission in patients with mild-to-moderate UC.

Early Infliximab Trough Levels Predict the Long-term Efficacy of Infliximab in a Randomized Controlled Trial in Patients with Active Crohn's Disease Comparing, between CT-P13 and Originator Infliximab

Background/Aims

The clinical efficacy and safety of CT-P13 are comparable to originator infliximab for Crohn's disease in CT-P13 3.4 study (NCT02096861). We performed a multivariate logistic analysis to demonstrate the association between early infliximab trough levels and treatment outcomes of CT-P13 and originator infliximab.

Methods

Early serum infliximab trough levels and anti-drug antibody (ADA) levels were compared between CT-P13 (n=100) and originator infliximab (n=98) groups. Receiver operating characteristic (ROC) analysis and multivariate logistic analysis were conducted to identify optimal cutoffs of serum infliximab trough levels and predictive factors for clinical outcomes.

Results

The median infliximab trough levels were not different between CT-P13 and originator infliximab groups at week 6, week 14, and in median ADA levels at week 14, respectively. ROC analysis found an infliximab concentration threshold of 4.5 μg/mL at week 6 and 4.0 μg/mL at week 14 as the cutoff value with the highest accuracy for the prediction of clinical outcomes. Serum infliximab trough levels at weeks 6 and 14 predicted clinical remission at weeks 30 and 54, and endoscopic remission at week 54. The combinations of clinical remission or C-reactive protein normalization with an early infliximab trough level improved the prediction of long-term clinical or endoscopic remission.

Conclusions

A threshold in serum infliximab trough level at week 6 and week 14 was highly predictive for long-term clinical outcomes. There were no statistical differences in serum infliximab trough levels and ADA levels between CT-P13 and originator infliximab.

Gastric Cancer Risk Was Associated with Dietary Factors Irritating the Stomach Wall: A Case-Control Study in Korea

The incidence of gastric cancer is high in Korea, and dietary factors are important risk factors for gastric cancer. This study examined whether gastric cancer risk was related to dietary factors that directly irritate the stomach wall. This case−control study consisted of 308 matched pairs of gastric cancer cases and controls recruited from 2002 to 2006 at two hospitals in Korea. Dietary assessments were completed using a food frequency questionnaire and a dietary habit questionnaire. Gastric cancer risk was increased for high meal frequency of >3 vs. low meal frequency of ≤3 times per day, overeating vs. not overeating, and preferred vs. not preferred spicy or salty foods. Furthermore, participants with dietary factors of high meal frequency, overeating, and preference for spicy or salty foods elevated the risk of gastric cancer compared to those with low meal frequency, not overeating, and not preferring spicy or salty foods, simultaneously. In conclusion, gastric cancer risk was significantly increased in people with dietary factors that irritate the stomach wall, such as high meal frequency, overeating, and preference for spicy or salty foods.

Perspectives of East Asian patients and physicians on complementary and alternative medicine use for inflammatory bowel disease: results of a cross-sectional, multinational study

Background/Aims

Complementary and alternative medicine (CAM) is prevalent in East Asia. However, information on CAM in East Asian patients with inflammatory bowel disease (IBD) is scarce. We aimed to profile the prevalence and pattern of CAM use among East Asian IBD patients and to identify factors associated with CAM use. We also compared physicians’ perspectives on CAM.

Methods

Patients with IBD from China, Japan, and South Korea were invited to complete questionnaires on CAM use. Patient demographic and clinical data were collected. Logistic regression analysis was applied for predictors of CAM use. Physicians from each country were asked about their opinion on CAM services or products.

Results

Overall, 905 patients with IBD participated in this study (China 232, Japan 255, and South Korea 418). Approximately 8.6% of patients with IBD used CAM services for their disease, while 29.7% of patients sought at least 1 kind of CAM product. Current active disease and Chinese or South Korean nationality over Japanese were independent predictors of CAM use. Chinese doctors were more likely to consider CAM helpful for patients with IBD than were Japanese and South Korean doctors.

Conclusions

In 8.6% and 29.7% of East Asian patients with IBD used CAM services and products, respectively, which does not differ from the prevalence in their Western counterparts. There is a significant gap regarding CAM usage among different Asian countries, not only from the patients’ perspective but also from the physicians’ point of view.

Dietary Intake of Soy Products, Vegetables, and Dairy Products and Gastric Cancer Survival according to Histological Subtype: a Long-term Prospective Cohort Study

PURPOSE

Owing to differences in the general characteristics of gastric cancer (GC) according to histological type, the association of GC risk factors, such as diet, may also differ depending on the histological type. We investigated the associations between individual and combined intake of soy products, vegetables, and dairy products and GC mortality by following up cases of death among Korean GC cases and whether these associations differ according to the histological type.

MATERIALS AND METHODS

A total of 508 GC cases were enrolled from two hospitals between 2002 and 2006. Their survival or death was prospectively followed up until December 31, 2016, through a review of medical records and telephonic surveys. Finally, 300 GC cases classified as intestinal- or diffuse-type GC cases were included. The median follow-up period was 7.1 years.

RESULTS

In the fully adjusted model, a high intake of soy products (hazard ratio [HR], 0.43; 95% confidence interval [CI], 0.19-0.96) and the combination of soy products and vegetables (HR, 0.34; 95% CI, 0.12-0.96) or soy products and dairy products (HR, 0.37; 95% CI, 0.14-0.98) decreased the mortality from intestinal-type GC. In particular, patients consuming various potentially protective foods (HR, 0.23; 95% CI, 0.06-0.83) showed a highly significant association with a lower mortality from intestinal-type GC. However, no significant association was found with diffuse-type GC.

CONCLUSIONS

High intake of potentially protective foods, including soy products, vegetables, and dairy products, may help increase survival in intestinal-type GC.

Impact of short-chain fatty acid supplementation on gut inflammation and microbiota composition in a murine colitis model

Short-chain fatty acids (SCFAs) play a pivotal role in maintaining intestinal homeostasis. We aimed to investigate the effects of SCFA supplementation on gut inflammation and microbiota composition in a murine colitis model. Mice were fed with sodium butyrate or a mixture of SCFAs in the drinking water for 2 weeks, followed by 2% dextran sulfate sodium (DSS) for 7 d. After euthanasia, mouse colons were extracted to examine histological findings. Flow cytometry of the mouse colon tissues was performed to assess T cell differentiation. Changes in gut microbiota were assessed by high-throughput sequencing of the mouse feces. There were no significant differences in weight change, colonic length, or histologic inflammation score between the DSS, butyrate, and SCFA mix groups. However, flow cytometry revealed that both the expression of CD4+Foxp3+ regulatory T cells and of IL-17-producing T cells were increased in the butyrate and SCFA mix groups. Microbial compositions of the butyrate and SCFA mix groups were significantly different from those of the control and DSS groups in principal coordinate analysis. Relative abundances of the phyla Verrucomicrobia and Proteobacteria, species Akkermansia muciniphila and Escherichia fergusonii were increased in the butyrate and SCFA mix groups. Genera Roseburia and Lactobacillus showed a negative correlation with the degree of colitis, whereas genera Escherichia and Mucispirillum showed a positive correlation. SCFA supplementation did not result in a significant reduction in colon inflammation, but it promoted both regulatory T cell and IL-17-producing T cell expression, and increased both protective and aggressive gut microbiota.

Clinical Outcomes and Response Predictors of Vedolizumab Induction Treatment for Korean Patients With Inflammatory Bowel Diseases Who Failed Anti-TNF Therapy: A KASID Prospective Multicenter Cohort Study

BACKGROUND

We investigated the real-life effectiveness and safety of vedolizumab (VDZ) induction therapy among Korean patients with Crohn disease (CD) or ulcerative colitis (UC) for whom anti-tumor necrosis factor therapy previously failed.

METHODS

Adult patients who started VDZ induction therapy at 16 centers were prospectively enrolled in the Korean VDZ nationwide registry. The coprimary outcomes were clinical remission, defined as a Crohn's Disease Activity Index score <150 points and a partial Mayo score ≤2 points with a combined rectal bleeding and stool frequency subscore ≤1 point at week 14 and endoscopic remission defined as a Mayo endoscopic subscore ≤1 point. We also analyzed predictors of clinical remission.

RESULTS

Between August 2017 and November 2019, a total of 158 patients (80 with CD and 78 with UC) received VDZ induction therapy. Clinical remission rates among patients with CD and patients with UC were 44.1% and 44.0%, respectively. Among patients with UC, the endoscopic remission rate was 32.4%. Clinical response and remission rates showed increasing trends during induction therapy. Multivariable analysis revealed that clinical response at week 6 was the only predictor of clinical remission at week 14 for both patients with CD and patients with UC. Among patients who experienced 1 or more adverse events (n = 71; 44.9%), disease exacerbation (n = 28; 17.7%) was the most common adverse event.

CONCLUSIONS

Among Korean patients with CD or UC for whom anti-tumor necrosis factor therapy failed, VDZ induction therapy was effective and safe. The early clinical response was associated with clinical remission after VDZ induction therapy.

Meta-analysis of transanal versus laparoscopic total mesorectal excision for rectal cancer: a 'New Health Technology' assessment in South Korea

Purpose

Under the South Korea's unique health insurance structure, any new surgical technology must be evaluated first by the government in order to consider whether that particular technology can be applied to patients for further clinical trials as categorized as 'New Health Technology,' then potentially covered by the insurance sometime later. The aim of this meta-analysis was to assess the safety and efficacy of transanal total mesorectal excision (TaTME) for rectal cancer, activated by the National Evidence-based Healthcare Collaborating Agency (NECA) TaTME committee.

Methods

We systematically searched Ovid-MEDLINE, Ovid-Embase, Cochrane, and Korean databases (from their inception until August 31, 2019) for studies published that compare TaTME with laparoscopic total mesorectal excision (LaTME). End-points included perioperative and pathological outcomes.

Results

Sixteen cohort studies (7 for case-matched studies) were identified, comprising 1,923 patients (938 TaTMEs and 985 LaTMEs). Regarding perioperative outcomes, the conversion rate was significantly lower in TaTME (risk ratio, 0.19; 95% confidence interval, 0.11-0.34; P < 0.001); whereas other perioperative outcomes were similar to LaTME. There were no statistically significant differences in pathological results between the 2 procedures.

Conclusion

Our meta-analysis showed comparable results in preoperative and pathologic outcomes between TaTME and LaTME, and indicated the benefit of TaTME with low conversion. Extensive evaluations of well-designed, multicenter randomized controlled trials are required to come to unequivocal conclusions, but the results showed that TaTME is a potentially beneficial technique in some specific cases. This meta-analysis suggests that TaTME can be performed for rectal cancer patients as a 'New Health Technology' endorsed by NECA in South Korea.

Intestinal microbiota and inflammatory bowel diseases

Background: The prevalence of inflammatory bowel diseases (IBD) has been rapidly increasing over the past several decades in Korea. IBD appears to be resulted from inappropriate and chronic activation of the mucosal immune system driven by stimuli such as intestinal microbiota and various environmental factors in genetically susceptible individuals.Current Concepts: Recent advances in next-generation sequencing technology have identified alterations in the composition and function of the intestinal microbiota in individuals with IBD. Dysbiosis in patients with IBD is characterized by decreased bacterial diversity combined with an expansion of putative aggressive species and a reduction in protective species. Altered microbial composition and function in IBD correlates with increased immune stimulation, epithelial dysfunction, or enhanced mucosal permeability. Thus, dysbiosis may play an essential role in the pathogenesis of IBD.Discussion and Conclusion: Although it is currently unclear whether dysbiosis is a cause or consequence of intestinal inflammation in IBD, several microbial-based and microbial-targeted therapies have yielded promising early results.

Early course of newly diagnosed moderate-to-severe ulcerative colitis in Korea: Results from a hospital-based inception cohort study (MOSAIK)

BACKGROUND AND AIM

No inception cohort study has ever evaluated the early course of moderate-to-severe ulcerative colitis (UC) within 1 year of diagnosis in the non-Caucasian population. We aimed to investigate the early clinical course of moderate-to-severe UC patients in terms of remission, relapse, UC-related hospitalizations, colectomy, mortality, and overall use of medications.

METHODS

In the MOSAIK inception cohort, which is an ongoing multicenter, prospective, hospital-based, observational cohort, 354 patients with moderate-to-severe UC were followed up for 1 year. Main outcomes of UC and predictive factors for medication use over the course of 1 year were evaluated.

RESULT

Among 354 patients, 276 (78.0%) patients were followed up for 1 year. The rates of remission, relapse, UC-related hospitalizations, and proximal disease extension were 95.3%, 39.6%, 15.2%, and 12.3%, respectively. Systemic corticosteroids, thiopurines, and biologics were administered to 61.2%, 30.4%, and 10.5% of patients, respectively, throughout 1 year. One year after, 58.2% patients experienced remission or mild endoscopic activity. Overall disease courses did not show much difference according to moderate or severe disease activity at baseline. In addition, no colectomy and mortality were observed for 1 year. Predictive factors for medication use included disease severity, disease extent, endoscopic severity, and presence of periappendiceal inflammation at baseline for corticosteroid, disease extent and initial corticosteroid use for thiopurine, and only initial corticosteroid use for biologics.

CONCLUSION

Korean patients with moderate-to-severe UC may have more favorable early outcomes than Western patients. However, outcomes of them need to be further looked into for a longer time.

Enteroscopy in Crohn's Disease: Are There Any Changes in Role or Outcomes Over Time? A KASID Multicenter Study

Background/Aims

Although balloon-assisted enteroscopy (BAE) enables endoscopic visualization of small bowel (SB) involvement in Crohn's disease (CD), there is no data on the changes in outcomes over time. We therefore investigated the changes in BAE use on CD patients over different time periods in terms of its role and clinical outcomes.

Methods

We used a multicenter enteroscopy database to identify CD patients with SB involvement who underwent BAE (131 procedures, 116 patients). We compared BAE-related factors and outcomes between the first period (70 procedures, 60 patients) and the second period (61 procedures, 56 patients). The specific cutoff point for dividing the two periods was 2007, when BAE guidelines were introduced.

Results

Initial diagnosis of SB involvement in CD was the most common indication for BAE during each period (50.0% vs 31.1%, p=0.034). The largest change was in the number of BAE uses for stricture evaluation and/or treatment, which increased significantly in the latter period (2.9% vs 21.3%, p=0.002). The diagnostic yield in patients with suspected CD was 90.7% in the first period and 95.0% in the second (p=0.695). More endoscopic interventions were performed in the second period than in the first (5.1% vs 17.6%, p=0.041). Enteroscopic success rates were high throughout (100% in the first period vs 80.0% in the second period, p>0.999). In the first and second periods, therapeutic plans were adjusted in 62.7% and 61.4% of patients, respectively.

Conclusions

The overall clinical indications, outcomes, and effectiveness of BAE were constant over time in CD patients with SB involvement, with the exception that the frequency of enteroscopic intervention increased remarkably.

Risk Factors for Postoperative Recurrence in Korean Patients with Crohn's Disease

Background/Aims

A considerable number of patients with Crohn’s disease still need intestinal resection surgery. Postoperative recurrence is an important issue in Crohn’s disease management, including the selection of high-risk patients. Eastern Asian patients showed several differences from Caucasian patients. Therefore, we investigated the postoperative surgical recurrence outcome and identified risk factors in Korean patients.

Methods

Clinical data of 372 patients with Crohn’s disease who underwent first intestinal resection between January 2004 and August 2014 at 14 hospitals in Korea were retrospectively reviewed.

Results

Over the follow-up period, 50 patients (17.1%) showed surgical recurrence. The cumulative surgical recurrence rate was 6.5% at 1 year and 15.4% at 7 years. Age under 16 (p=0.011; hazard ratio [HR], 5.136; 95% confidence interval [CI], 1.576 to 16.731), colonic involvement (p=0.023; HR , 2.011; 95% CI, 1.102 to 3.670), and the presence of perianal disease at surgery (p=0.008; HR, 2.239; 95% CI, 1.236 to 4.059) were independent risk factors associated with surgical recurrence. Postoperative thiopurine treatment (p=0.002; HR, 0.393; 95% CI, 0.218 to 0.710) was a protective factor for surgical recurrence.

Conclusions

Among the disease characteristics at surgery, younger age, colonic location, and perianal lesions were independent risk factors for surgical recurrence. Postoperative thiopurine treatment significantly reduced the incidence of surgical recurrence.

Colonoscopy quality in community hospitals and nonhospital facilities in Korea

BACKGROUND/AIMS

High-quality colonoscopy is essential to reduce colorectal cancer-related deaths. Little is known about colonoscopy quality in non-academic practice settings. We aimed to evaluate the quality of colonoscopies performed in community hospitals and nonhospital facilities.

METHODS

Colonoscopy data were collected from patients referred to six tertiary care centers after receiving colonoscopies at community hospitals and nonhospital facilities. Based on their photographs, we measured quality indicators including cecal intubation rate, withdrawal time, adequacy of bowel preparation, and number of polyps.

RESULTS

Data from a total of 1,064 colonoscopies were analyzed. The overall cecal intubation rate was 93.1%. The median withdrawal time was 8.3 minutes, but 31.3% of colonoscopies were withdrawn within 6 minutes. Community hospitals had longer withdrawal time and more polyps than nonhospital facilities (median withdrawal time: 9.9 minutes vs. 7.5 minutes, p < 0.001; mean number of polyps: 3.1 vs. 2.3, p = 0.001). Board-certified endoscopists had a higher rate of cecal intubation than non-board-certified endoscopists (93.2% vs. 85.2%, p = 0.006). A total of 819 follow-up colonoscopies were performed at referral centers with a median interval of 28 days. In total, 2,546 polyps were detected at baseline, and 1,088 were newly identified (polyp miss rate, 29.9%). Multivariable analysis revealed that older age (odds ratio [OR], 1.032; 95% confidence interval [CI], 1.020 to 1.044) and male sex (OR, 1.719; 95% CI, 1.281 to 2.308) were associated with increased risk of missed polyps.

CONCLUSION

The quality of colonoscopies performed in community hospitals and nonhospital facilities was suboptimal. Systematic reporting, auditing, and feedback are needed for quality improvement.

Role of the global gut microbial community in the development of colitis-associated cancer in a murine model

The gut microbiota has been implicated in the development of colitis-associated cancer (CAC). We investigated how the gut microbiota affects the development of CAC when the composition of the microbial community is altered by the administration of various antibiotics in a murine model. C57BL/6 mice were given intraperitoneal injection of 12.5 mg/kg azoxymethane (AOM), followed by two rounds of 2.0 % dextran sodium sulfate (DSS) exposure. Antibiotics, including ampicillin, neomycin, metronidazole, and/or vancomycin, were administered 14 days prior to AOM injection until the end of the experiment. High-throughput sequencing of mice feces was conducted to evaluate alterations of the gut microbiota. Tumorigenesis and inflammation were most markedly suppressed in the mice treated with an antibiotic cocktail therapy consisting of ampicillin, neomycin, metronidazole, and vancomycin. Individual antibiotic treatments had different effects on tumorigenesis and inflammation. Metronidazole attenuated both tumorigenesis and inflammation. Neomycin suppressed tumorigenesis but did not alleviate inflammation. Ampicillin and vancomycin did not significantly attenuate either tumorigenesis or inflammation. Antimicrobial therapy differentially altered the diversity and composition of the gut microbiota depending on antibiotic type. The phyla Proteobacteria and Tenericutes were positively correlated with tumor burden. Colon tumorigenesis was attenuated through various antibiotics in the AOM/DSS-induced CAC model. Individual antibiotics differentially altered the gut microbial composition and showed different effects on tumor suppression; however, the degree of tumor suppression was less pronounced than that relative to the antibiotic cocktail therapy, suggesting that the global gut microbial community plays an important role in the development of CAC.

Clinical Features and Outcomes of Tuberculosis in Inflammatory Bowel Disease Patients Treated with Anti-tumor Necrosis Factor Therapy

Background/Aims

Anti-tumor necrosis factor (TNF) therapy is used widely for the treatment of inflammatory bowel disease (IBD). In the present study, the characteristics and outcomes of tuberculosis (TB) in IBD patients treated with anti-TNF therapy were compared with those of non-IBD TB patients.

Methods

Twenty-five IBD patients who initially developed TB during anti-TNF therapy were enrolled in this study. Seventy-five ageand gender-matched non-IBD TB patients were selected as controls in a 1:3 ratio.

Results

The proportion of non-respiratory symptoms was higher in the IBD patients than in the non-IBD patients (12 [48.0%] in the IBD patients vs. 15 [20.0%] in the non-IBD patients; p=0.009). Eight (32.0%) IBD patients and 19 (25.3%) non-IBD patients had extra- pulmonary lesions (p=0.516). The frequency of positive smear results for acid-fast bacilli (AFB) was significantly higher in the non-IBD patients than in the IBD patients (three [12.0%] IBD patients vs. 27 [36.0%] non-IBD patients; p=0.023). Active TB was cured in 24 (96.0%) patients in the IBD group and in 70 (93.3%) patients in the non-IBD group (p=0.409). The TB-related mortality rates were 4.0% and 1.3% in the IBD patients and non-IBD patients, respectively (p=0.439).

Conclusions

The rate of extrapulmonary involvement, side effects of anti-TB medications, and clinical outcomes did not differ between the IBD patients who initially developed TB during anti-TNF therapy and non-IBD patients with TB. On the other hand, the IBD patients had a lower rate of AFB smear positivity and a higher proportion of non-respiratory symptoms.

Long-term outcomes of infliximab in a real-world multicenter cohort of patients with acute severe ulcerative colitis

BACKGROUND/AIMS

Infliximab (IFX) has proven effective as rescue therapy in steroid-refractory acute severe ulcerative colitis (ASUC), however, the long-term real-world data are scarce. Our study aimed to assess the long-term treatment outcomes of IFX in a real-life cohort.

METHODS

We established a multicenter retrospective cohort of hospitalized patients with ASUC, who met Truelove and Witt's criteria and received intravenous corticosteroid (IVCS) or IFX during index hospitalization between 2006 and 2016 in 5 university hospitals in Korea. The cohort was systematically followed up until colectomy, death or last follow-up visit.

RESULTS

A total of 296 patients were followed up for a mean of 68.9 ± 44.0 months. During index hospitalization, 49 patients were treated with IFX; as rescue therapy for IVCS failure in 37 and as first-line medical therapy for ASUC in 12. All patients treated with IFX avoided colectomy during index hospitalization. The cumulative rates of rehospitalization and colectomy were 20.4% and 6.1% at 3 months and 39.6% and 18.8% at the end of follow-up, respectively. Patients treated with IFX presented with significantly shorter colectomy-free survival than IVCS responders (P= 0.04, log-rank test). Both cytomegalovirus colitis and Clostridioides difficile infection (CDI) were the significant predictors of colectomy in the overall study cohort (hazard ratios of 6.57 and 4.61, respectively). There were no fatalities.

CONCLUSIONS

Our real-world cohort study demonstrated that IFX is an effective therapeutic option in Korean patients with ASUC, irrespective of IFX indication. Aggressive vigilance for cytomegalovirus colitis and CDI is warranted for hospitalized patients with ASUC.

Differentially Abundant Bacterial Taxa Associated with Prognostic Variables of Crohn's Disease: Results from the IMPACT Study

Limited studies have examined the intestinal microbiota composition in relation to Crohn's disease (CD) prognosis. We analyzed the differences in microbial communities and relevant metabolic pathways associated with prognostic variables in patients with CD. We applied 16S rRNA gene sequencing to analyze a cohort of 1110 CD and healthy control (HC) fecal samples. We categorized patients with CD into good (CD-G), intermediate (CD-I) and poor (CD-P) prognosis groups, according to the history of using biologics and intestinal resection. Microbiota α-diversity decreased more in CD-P than CD-G and CD-I. Microbiota ß-diversity in CD-P differed from that in CD-G and CD-I. Thirteen genera and 10 species showed differential abundance between CD-G and CD-P groups. Escherichia coli (p = 0.001) and species Producta (p = 0.01) and genera Lactobacillus (p = 0.003) and Coprococcus (p = 0.01) consistently showed differences between CD-G and CD-P groups after adjusting for confounding variables. Functional profiling suggested that the microbial catabolic pathways and pathways related to enterobacterial common antigen and lipopolysaccharide biosynthesis were better represented in the CD-P group than in the CD-G group, and E. coli were the top contributors to these pathways. CD prognosis is associated with altered microbiota composition and decreased diversity, and E. coli might be causally involved in CD progression, and may have adapted to live in inflammatory environments.

Role of innate lymphoid cells in chronic colitis during anti-IL-17A therapy

IL-17A is an important cytokine in intestinal inflammation. However, anti-IL-17A therapy does not improve clinical outcomes in patients with Crohn's disease. We aimed to evaluate the role of RORγt+ innate lymphoid cells (ILCs) in murine colitis models in the absence of IL-17A. An acute colitis model was induced with either dextran sulfate sodium (DSS) or trinitrobenzenesulfonic acid (TNBS) and a chronic colitis model was induced by CD4+CD45RBhi T cell transfer from either wild-type C57BL/6 or Il17a-/- mice. An anti-IL-17A antibody, secukinumab, was also used to inhibit IL-17A function in the colitis model. Flow cytometry was performed to analyze the population of RORγt+ ILCs in the colonic lamina propria of mice with chronic colitis. Acute intestinal inflammation due to DSS and TNBS was attenuated in IL-17A knockout mice, whereas chronic colitis was not relieved by T cell transfer from Il17a-/- mice (% of original body weight: wild-type mice vs. Il17a-/- mice, 81.9% vs. 82.2%; P = 0.922). However, the mean proportion of Lin-RORγt+ lymphocytes was higher after T cell transfer from Il17a-/- mice than that after T cell transfer from wild-type mice (28.8% vs. 18.5%). The proportion of Lin-RORγt+ was also increased in Rag2-/- mice that received T cell transfer from wild-type mice when anti-IL-17A antibody was administered (31.7%). Additionally, Il6 and Il22 tended to be highly expressed after T cell transfer from Il17a-/- mice. In conclusion, RORγt+ ILCs may have an important role in the pathogenesis of chronic colitis in the absence of IL-17A. Blocking the function of IL-17A may upregulate Il6 and recruit RORγt+ ILCs in chronic colitis, thereby upregulating IL-22 and worsening the clinical outcomes of patients with Crohn's disease.

Novel sulfate tablet PBK-1701TC versus oral sulfate solution for colon cleansing: A randomized phase 3 trial

BACKGROUND AND AIM

PBK-1701TC is a novel sulfate tablet-based that contains 320 mg of simethicone and delivers 90% of the salt and water delivered by oral sulfate solution (OSS) preparation. This study evaluated the efficacy, safety, and tolerability of PBK-1701TC compared with OSS in bowel preparation for colonoscopy.

METHODS

This randomized, multicenter, phase 3 non-inferiority trial included adults aged 19 years or older with a body mass index of 19-30 kg/m² undergoing colonoscopy at five university hospitals in Korea. The primary efficacy endpoint was successful bowel-cleansing rate, defined as Harefield Cleansing Scale grade A or B as evaluated by blinded central readers. Secondary endpoints included the presence of residual air bubbles. Adverse events and laboratory evaluations were monitored to assess safety. Tolerability was assessed via participant interview.

RESULTS

Overall, 235 participants were randomized, and 224 were included in the per-protocol analysis (PBK, 112; OSS, 112). Successful bowel cleansing was achieved for 95.5% (107/112) in the PBK group, which was non-inferior to the OSS group (98.2%, 110/112) with a difference of -2.7% (one sided 97.5% confidence limit, -8.1%). The participants in the PBK group had fewer intraluminal bubbles (0.9% vs 81.3%, P < 0.001) and reported a lower incidence of nausea and vomiting, with better acceptance, taste, and willingness to repeat the regimen than those in the OSS group (all P < 0.05).

CONCLUSION

The novel sulfate tablet, PBK-1701TC, was non-inferior to OSS with respect to bowel-cleansing efficacy and exhibited better safety and tolerability in adults undergoing colonoscopy.

Prediagnostic Smoking and Alcohol Drinking and Gastric Cancer Survival: A Korean Prospective Cohort Study

Background/Aims

Behavioral factors, such as smoking and heavy alcohol consumption, increase the risk of gastric cancer (GC), but their effects on survival are not clear. We examined associations between prediagnostic smoking and alcohol drinking behavior and GC death by long-term follow-up.

Methods

The participants were 508 GC patients enrolled at Chungnam University Hospital and Hanyang University Guri Hospital from 2001 to 2006. Information on clinicopathologic and behavioral risk factors was collected, and patient survival was prospectively followed until 2016 by medical chart review and telephone survey.

Results

During above 10 years follow-up period, overall death was 46.2% (n=226) and GC deaths was 38.2% (n=187) among the 489 GC patients included in the analysis. No significant association was found between smoking habits and overall or GC survival. However, after stratification by histological type, the hazard ratio (HR) of GC death for current smokers tended to be higher for the diffuse type (HR 1.61, 95% CI 0.57-4.59 for current vs. never) rather than for the intestinal type (HR 0.78, 95% CI 0.28-2.19 for current vs. never). Light alcohol consumption was found to be associated with a significantly lower risk of GC death (HR 0.52, 95% CI 0.36-0.75 for <20 g/day for women or <40 g/day for men vs. never and past), and the effects of alcohol drinking habits had similar effects on GC death for the intestinal and diffuse types.

Conclusions

These results suggest smoking and alcohol drinking behaviors before a diagnosis of GC are weakly associated with GC survival. Nevertheless, the effect of smoking behavior on prognosis appears to depend on the histological type of GC.

Helicobacter pylori antibody and pepsinogen testing for predicting gastric microbiome abundance

Background

Although the high-throughput sequencing technique is useful for evaluating gastric microbiome, it is difficult to use clinically. We aimed to develop a predictive model for gastric microbiome based on serologic testing.

Methods

This study was designed to analyze sequencing data obtained from the Hanyang University Gastric Microbiome Cohort, which was established initially to investigate gastric microbial composition according to the intragastric environment. We evaluated the relationship between the relative abundance of potential gastric cancer-associated bacteria (nitrosating/nitrate-reducing bacteria or type IV secretion system [T4SS] protein gene-contributing bacteria) and serologic markers (IgG anti-Helicobacter pylori [HP] antibody or pepsinogen [PG] levels).

Results

We included 57 and 26 participants without and with HP infection, respectively. The relative abundance of nitrosating/nitrate-reducing bacteria was 4.9% and 3.6% in the HP-negative and HP-positive groups, respectively, while that of T4SS protein gene-contributing bacteria was 20.5% and 6.5% in the HP-negative and HP-positive groups, respectively. The relative abundance of both nitrosating/nitrate-reducing bacteria and T4SS protein gene-contributing bacteria increased exponentially as PG levels decreased. Advanced age (only for nitrosating/nitrate-reducing bacteria), a negative result of IgG anti-HP antibody, low PG levels, and high Charlson comorbidity index were associated with a high relative abundance of nitrosating/nitrate-reducing bacteria and T4SS protein gene-contributing bacteria. The adjusted coefficient of determination (R²) was 53.7% and 70.0% in the model for nitrosating/nitrate-reducing bacteria and T4SS protein gene-contributing bacteria, respectively.

Conclusion

Not only the negative results of IgG anti-HP antibody but also low PG levels were associated with a high abundance of nitrosating/nitrate-reducing bacteria and T4SS protein gene-contributing bacteria.

Alcohol consumption and gastric cancer risk in Korea: a case-control study

BACKGROUND/OBJECTIVES

The International Agency for Research on Cancer defined alcohol beverages and acetaldehyde derived from alcoholic beverages as a Group 1 carcinogen to humans. However, the association between alcohol consumption and gastric cancer risk has been controversial in Korean. We assessed the relationship between alcohol consumption and gastric cancer risk in Korea through a case-control study.

SUBJECTS/METHODS

From 2 hospitals, a total of 316 cases with gastric cancer (208 men, 108 women) were selected and matched to 316 controls by sex and age (± 5 years) during the same duration. The current status, frequency, and amount of alcohol consumption for a year three years ago were assessed by trained interviewers.

RESULTS

Alcohol consumption status and frequency did not show any significant association with gastric cancer risk. However, high alcohol consumption (≥ 20 g/day for women or ≥ 40 g/day for men) significantly increased the risk of gastric cancer (odds ratio (OR) 1.73; 95% confidence interval (CI) 1.05–2.85). Gastric cancer risk was strongly positively associated with alcohol consumption of ≥ 20 g/day, especially in women (OR 5.62; 95% CI 1.32–23.81).

CONCLUSION

The results from this study suggest that excessive alcohol consumption rather than the current status or frequency of alcohol consumption contributes to the increased risk of gastric cancer, especially in women.

Long-term efficacy and safety of CT-P13, a biosimilar of infliximab, in patients with inflammatory bowel disease: A retrospective multicenter study

BACKGROUND AND AIM

A biosimilar of infliximab, CT-P13 (Remsima®) has the potential to reduce treatment costs and enhance access to biological therapy for inflammatory bowel disease (IBD) patients. However, long-term clinical data on its use for IBD treatment are currently sparse. We aimed to investigate the long-term efficacy and safety of CT-P13 therapy in a large, real-life IBD cohort.

METHODS

A total of 368 IBD patients (227 with Crohn's disease [CD] and 141 with ulcerative colitis [UC]) treated with CT-P13 at 16 referral hospitals in Korea between July 2012 and December 2017 were retrospectively analyzed.

RESULTS

The cumulative retention rates at years 1, 3, and 5 were 86.1%, 68.5%, and 58.7% and 69.7%, 46.0%, and 26.7% in anti-tumor necrosis factor (TNF)-naïve CD and UC patients, respectively. The clinical response and remission rates at week 14 and at years 1, 3, and 5 were 94.3%, 92.7%, 76.8%, and 17.6% and 78.6%, 82.4%, 72.2%, and 17.6% in anti-TNF-naïve CD and 85.6%, 80.0%, 55.2%, and 6.7% and 42.6%, 59.8%, 44.2%, and 6.7% in anti-TNF-naïve UC patients, respectively. Among patients who switched from the biologic originator to CT-P13, the cumulative retention rates at years 1, 3, and 5 were 88.5%, 66.1%, and 44.8% in CD, and 73.9%, 42.5%, and 42.5% in UC patients, respectively. Significant improvements in disease activity scores were accompanied by marked reductions in inflammatory marker levels, and no unexpected adverse events including death or malignancy occurred during the study period.

CONCLUSIONS

Long-term treatment with CT-P13 is effective in inducing and maintaining disease improvement and is well-tolerated in patients with IBD. CT-P13 may be a promising treatment option for IBD.

A Randomized Controlled Trial Comparing Colonoscopic Enema With Additional Oral Preparation as a Salvage for Inadequate Bowel Cleansing Before Colonoscopy

GOALS

The goal of this study was to evaluate the noninferiority of colonoscopic enema to additional oral preparation in salvage bowel cleansing for inadequate preparation for a morning colonoscopy.

BACKGROUND

Colonoscopic enema, administering additional cathartics into the right colon through the colonoscope accessory channel, is suggested to rescue poor bowel preparation for a colonoscopy but lacking comparative study.

STUDY

In this prospective, randomized, actively-controlled, parallel group, noninferiority trial, consecutive outpatients and health checkup recipients aged from 19 to 70 years with inappropriate bowel preparation during an elective colonoscopy were enrolled to receive either a colonoscopic enema of 1 L polyethylene glycol (PEG) (enema group) or additional oral intake of 2 L PEG (oral group). The primary endpoint was the proportion of adequate bowel preparation evaluated using the Boston Bowel Preparation Scale.

RESULTS

Overall, 131 participants were randomized. Adequate bowel preparation was achieved in 53% (35/66) of the enema group, which was significantly inferior to the oral group (81.5%; 53/67) with a difference of -28.5% (95% confidence interval, -44.1, -12.9; P=0.001). The largest difference in the proportion of adequate bowel preparation was observed in the right colon (57.8% in the enema group vs. 86.9% in the oral group; P<0.001), followed by the transverse colon (85.9% vs. 98.4%; P=0.017) and the left colon (90.6% vs. 96.7%; P=0.274).

CONCLUSIONS

The colonoscopic enema of 1 L PEG was inferior to the additional oral ingestion of 2 L PEG regarding efficacy as a salvage bowel preparation in adults with inadequate bowel cleansing for colonoscopy.

Impact of age on stage-specific mortality in patients with gastric cancer: A long-term prospective cohort study

Controversies exist regarding the impact of age on gastric cancer-related mortality according to cancer stage. In our prospective cohort study, we evaluated the impact of age on stage-specific mortality in patients with gastric cancer. Between 2002 and 2006, patients with newly diagnosed gastric cancer were recruited from two university-affiliated hospitals in Korea. Follow-up data were updated regularly based on medical records and telephone surveys. Patients were classified into four subgroups according to age: <50, 50-59, 60-69, and 70-79 years. A total of 448 patients were followed up for 81.6 months (interquartile range, 25.0-139.3 months). The number of patients with stage I, II, III, and IV disease was 247, 74, 88, and 39, respectively. Overall, age was an independent risk factor for gastric cancer-specific mortality (hazard ratio [HR], [95% confidence interval (CI)]: 1.53 [0.91-2.57], 1.88 [1.21-2.91], and 2.64 [1.69-4.14] in the 50-59, 60-69, and 70-79 years groups, respectively, with the <50 years group as reference). In patients with stage I and II gastric cancer, the 70-79 years group was associated with a significantly higher rate of cancer-specific mortality than the <50 years group (stage I: HR [95% CI], 9.55 [2.11-43.12]; stage II: HR [95% CI], 7.17 [2.32-22.18]). However, age was not an independently associated factor for cancer-specific mortality in patients with stage III and IV gastric cancer. Although age was an independent risk factor for gastric cancer-related mortality in patients with gastric cancer, its impact may differ depending on the stage of cancer.

Microbiota maintain colonic homeostasis by activating TLR2/MyD88/PI3K signaling in IL-10-producing regulatory B cells

Resident microbiota activate regulatory cells that modulate intestinal inflammation and promote and maintain intestinal homeostasis. IL-10 is a key mediator of immune regulatory function. Our studies described the functional importance and mechanisms by which gut microbiota and specific microbial components influenced the development of intestinal IL-10-producing B cells. We used fecal transplant to germ-free (GF) Il10+/EGFP reporter and Il10-/- mice to demonstrate that microbiota from specific pathogen-free mice primarily stimulated IL-10-producing colon-specific B cells and T regulatory-1 cells in ex-GF mice. IL-10 in turn down-regulated microbiota-activated mucosal inflammatory cytokines. TLR2/9 ligands and enteric bacterial lysates preferentially induced IL-10 production and regulatory capacity of intestinal B cells. Analysis of Il10+/EGFP mice crossed with additional gene-deficient strains and B cell co-transfer studies demonstrated that microbiota-induced IL-10-producing intestinal B cells ameliorated chronic T cell-mediated colitis in a TLR2, MyD88 and PI3K-dependent fashion. In vitro studies implicated PI3Kp110δ and AKT downstream signaling. These studies demonstrated that resident enteric bacteria activated intestinal IL-10-producing B cells through TLR2, MyD88 and PI3K pathways. These B cells reduced colonic T cell activation and maintained mucosal homeostasis in response to intestinal microbiota.

Characteristics and pathogenic role of adherent-invasive Escherichia coli in inflammatory bowel disease: Potential impact on clinical outcomes

Adherent-invasive Escherichia coli (AIEC) has been reported as associated with the pathogenesis of inflammatory bowel disease (IBD). We aimed to investigate the characteristics of mucosa-associated E. coli and the clinical significance of AIEC in Korean IBD patients. E. coli strains were isolated from the mucosal tissues of 18 Crohn’s disease (CD) patients, 24 ulcerative colitis (UC) patients, and 9 healthy controls (HC). Adhesion, invasion, and survival assays were performed to evaluate phenotypic features of E. coli isolates and to identify AIEC. The presence of virulence genes and cytokine expression were examined using PCR. In addition, data on IBD-related hospitalization were collected. A total of 59 E. coli strains were isolated (25 from CD, 27 from UC, and 7 from HC). The average levels of adhesion, invasion, and survival were higher in E. coli strains from IBD patients than those from HC (adhesion: 1.65 vs. 0.71, p = 0.046; invasion: 1.68 vs. 0.52, p = 0.039; survival: 519.55 vs. 47.55, p = 0.363). Prevalence of AIEC in HC, CD and UC patients was 22.2%, 38.9% and 37.5%, respectively. E. coli isolates from IBD patients had various virulence genes and were associated with increased expression of TNF-α and IL-17. IBD-related hospitalization within 3 years was 18.8% in patients with AIEC and 11.5% in patients without AIEC. E. coli strains from IBD patients showed high levels of adhesion, invasion, and survival. AIEC strains were identified in both CD and UC patients at a similar rate. AIEC may be associated with sustaining inflammation in the pre-existing inflammatory mucosa.

Efficacy and safety of biosimilar CT-P13 compared with originator infliximab in patients with active Crohn's disease: an international, randomised, double-blind, phase 3 non-inferiority study

BACKGROUND

The infliximab biosimilar CT-P13 was approved for use in Crohn's disease after clinical comparison with originator infliximab in ankylosing spondylitis and rheumatoid arthritis; however, concerns about such indication extrapolation have been expressed. This study investigated whether CT-P13 is non-inferior to infliximab in patients with Crohn's disease who were naive to biological therapy.

METHODS

In this randomised, multicentre, double-blind, phase 3 non-inferiority study, we enrolled patients with active Crohn's disease who had not responded to, or were intolerant to, non-biological treatments. Patients were randomly assigned (1:1:1:1) to receive CT-P13 then CT-P13, CT-P13 then infliximab, infliximab then infliximab, or infliximab then CT-P13, with switching occurring at week 30. Patients received 5 mg/kg CT-P13 or infliximab at weeks 0, 2, 6, and then every 8 weeks up to week 54. The primary endpoint was the proportion of patients with a decrease of 70 points or more in Crohn's Disease Activity Index (CDAI) from baseline to week 6. A non-inferiority margin of -20% was set (CT-P13 was non-inferior to infliximab if the lower limit of the two-sided 95% CI for the treatment difference was greater than -20). This trial is registered with ClinicalTrials.gov, number NCT02096861, and is completed.

FINDINGS

Between Aug 20, 2014, and Feb 15, 2017, 308 patients were assessed for eligibility, and 220 patients were enrolled: 111 were randomly assigned to initiate CT-P13 (56 to the CT-P13-CT-P13 group and 55 to the CT-P13-infliximab group) and 109 to initiate infliximab (54 to the infliximab-infliximab group and 55 to the infliximab-CT-P13 group). CDAI-70 response rates at week 6 were similar for CT-P13 (77 [69·4%, 95% CI 59·9 to 77·8] of 111) and infliximab (81 [74·3%, 95% CI 65·1 to 82·2] of 109; difference -4·9% [95% CI -16·9 to 7·3]), thereby establishing non-inferiority. Over the total study period, 147 (67%) patients experienced at least one treatment-emergent adverse event (36 [64%] in the CT-P13-CT-P13 group, 34 [62%] in the CT-P13-infliximab group, 37 [69%] in the infliximab-infliximab group, and 40 [73%] in the infliximab-CT-P13 group).

INTERPRETATION

This study showed non-inferiority of CT-P13 to infliximab in patients with active Crohn's disease. Biosimilar CT-P13 could be a new option for the treatment of active Crohn's disease.

FUNDING

Celltrion, Pfizer.

Adherence to Asacol once daily versus divided regimen for maintenance therapy in ulcerative colitis: a prospective, multicenter, randomized study

Background/Aims

A once-daily (OD) regimen of 5-aminosalicylic acid (5-ASA) was easier to comply with than a divided daily (DD) regimen, and that treatment efficacy for ulcerative colitis (UC) was not affected by the dosing regimen. This study evaluated treatment adherence of OD and DD dosing in the Korean UC patients.

Methods

This study was a prospective, multicenter, randomized trial. UC patients were enrolled who have been in remission for more than 3 months. Patients were randomly assigned to the OD or DD group in a 1:1 ratio. The primary endpoint was adherence rate measured by tablet counts and self-reported adherence rate at 3, 6, 9, and 12 months. The relapse rate was measured at 1 year.

Results

Data from the 180 patients who were randomized were analyzed. Both self-reported adherence rate and adherence rate measured by tablet counts were not different at every points, including 1 year. The patients’ satisfaction of the OD group was higher than that of the DD group (P<0.001). At 1 year, 91.2% and 95.5% of patients in the OD group and DD group had maintained clinical remission, respectively (P=0.37).

Conclusions

The adherence rates were not different between the OD group and DD group. The patients’ satisfaction was higher in the OD group than in the DD group. 5-ASA OD dosing might have the same effect as DD for the maintenance of UC remission.

Evaluation of gastric microbiome and metagenomic function in patients with intestinal metaplasia using 16S rRNA gene sequencing

BACKGROUND

Despite recent advances in studies on the gastric microbiome, the role of the non-Helicobacter pylori gastric microbiome in gastric carcinogenesis remains unclear. We evaluated the characteristics of the gastric microbiome and metagenomic functions in patients with IM.

METHODS

Participants were classified into six groups according to disease status (chronic superficial gastritis [CSG], intestinal metaplasia [IM], and cancer) and H. pylori- infection status (H. pylori-positive and H. pylori-negative). The gastric microbiome was analyzed in mucosal tissues at the gastric antrum by 16S rRNA gene sequencing. Moreover, we assessed the metagenome including the type IV secretion system (T4SS) gene, as T4SS proteins are essential for transferring CagA from H. pylori- into the human gastric epithelium.

RESULTS

Among the 138 included patients, 48, 9, 23, 14, 12, and 32 were classified into the H. pylori-negative CSG, H. pylori-negative IM, H. pylori-negative cancer, H. pylori-positive CSG, H. pylori-positive IM, and H. pylori-positive cancer groups, respectively. Cyanobacteria were predominant in the H. pylori-negative CSG group compared to in the H. pylori-negative IM and H. pylori-negative cancer groups (H. pylori-negative CSG vs H. pylori-negative IM vs H. pylori-negative cancer: 14.0% vs 4.2% vs 0.04%, P < 0.001). In contrast, Rhizobiales were commonly observed in the H. pylori-negative IM group (H. pylori-negative CSG vs H. pylori-negative IM vs H. pylori-negative cancer: 1.9% vs 15.4% vs 2.8%, P < 0.001). The relative abundance of Rhizobiales increased as H. pylori-infected stomachs progressed from gastritis to IM. In the H. pylori-negative IM group, genes encoding T4SS were prevalent among the metagenome. Additionally, after H. pylori- eradication therapy, the gastric microbiome was similar to the microbiome observed after spontaneous clearance of H. pylori-.

CONCLUSIONS

The relative abundance of Rhizobiales was higher in patients with H. pylori-negative IM than in those with H. pylori-negative CSG or cancer. Additionally, T4SS genes were highly observed in the metagenome of patients with IM. Highly abundant T4SS proteins in these patients may promote gastric carcinogenesis.

The Clinical Characteristics and Prognosis of Crohn's Disease in Korean Patients Showing Proximal Small Bowel Involvement: Results from the CONNECT Study

Background/Aims

We aimed to evaluate the clinical characteristics and prognosis of Crohn’s disease (CD) in patients who showed proximal small bowel involvement using a nationwide Korean CD cohort.

Methods

We reviewed the data from a cohort of patients diagnosed with CD. The clinical outcomes of patients were evaluated according to the presence of proximal small bowel involvement.

Results

Among 1,329 patients with CD for whom complete disease location data were available, 222 patients (16.7%) showed involvement of the proximal small bowel. Compared to patients without proximal small bowel involvement, those with small bowel involvement were more likely to display stricturing behavior (19.8% vs 12.7%, p=0.020). The surgery-free survival of patients who showed proximal small bowel involvement was inferior to that of patients without proximal small bowel involvement (10-year surgery-free survival: 58.4% vs 67.7%, respectively, p<0.001). Additionally, upper gastrointestinal involvement was more common in patients with proximal small bowel involvement than in those without involvement (odds ratio, 1.643; 95% confidence interval, 1.008 to 2.677).

Conclusions

Proximal small bowel involvement is a poor prognostic factor for the surgery-free survival of Korean patients with CD. Proximal small bowel involvement should be evaluated in patients with CD for predicting long-term clinical outcomes.

The effect of small or diminutive adenomas at baseline colonoscopy on the risk of developing metachronous advanced colorectal neoplasia: KASID multicenter study

BACKGROUND

The clinical significance of diminutive or small adenomas remains ill defined.

AIMS

We evaluated the clinical impact of diminutive or small adenomas at baseline on the risk of developing metachronous advanced colorectal neoplasia (CRN).

METHODS

This multicenter, retrospective cohort study included 2252 patients with 1 or more colorectal adenomas at baseline and subsequent follow-up colonoscopy. Baseline colonoscopy findings were classified into 5 groups: 1 or 2 tubular adenomas (TAs) (<10 mm); 3-10 diminutive TAs (≤5 mm); 3-10 TAs, including 1 or 2 small adenomas (6-10 mm); 3-10 TAs, including 3 or more small adenomas; and advanced adenoma.

RESULTS

In multivariate analysis, after adjusting for possible confounding variables (age at baseline, sex, body mass index, smoking habits, family history of colorectal cancer, regular use of aspirin or NSAIDs, and adenoma location), 3-10 TAs including 3 or more small adenomas (hazard ratio [HR] = 2.36, p = 0.034) and advanced adenoma (HR = 2.14, p < 0.001) were independent predictors for the risk of developing metachronous advanced CRN. However, 3-10 diminutive TAs or 3-10 TAs, including 1 or 2 small adenomas, were not associated with this outcome.

CONCLUSIONS

Multiplicity of diminutive TAs, without advanced lesions, showed no clinical significance for risk of developing metachronous advanced CRN.

Intestinal microbiota, chronic inflammation, and colorectal cancer

In addition to genetic and epigenetic factors, various environmental factors, including diet, play important roles in the development of colorectal cancer (CRC). Recently, there is increasing interest in the intestinal microbiota as an environmental risk factor for CRC, because diet also influences the composition of the intestinal microbiota. The human intestinal microbiota comprises about 100 trillion microbes. This microbiome thrives on undigested dietary residues in the intestinal lumen and produces various metabolites. It is well known that the dietary risk factors for CRC are mediated by dysbiosis of the intestinal microbiota and their metabolites. In this review, we describe the bacterial taxa associated with CRC, including Fusobacterium nucleatum, enterotoxigenic Bacteroides fragilis, Escherichia coli, and butyrate-producing bacteria. We also discuss the host-diet interaction in colorectal carcinogenesis.

Three-year colonoscopy surveillance after polypectomy in Korea: a Korean Association for the Study of Intestinal Diseases (KASID) multicenter prospective study

Background/Aims

Colonoscopic surveillance is currently recommended after polypectomy owing to the risk of newly developed colonic neoplasia. However, few studies have investigated colonoscopy surveillance in Asia. This multicenter and prospective study was undertaken to assess the incidence of advanced adenoma based on baseline adenoma findings at 3 years after colonoscopic polypectomy.

Methods

A total of 1,323 patients undergoing colonoscopic polypectomy were prospectively assigned to 3-year colonoscopy surveillance at 11 tertiary endoscopic centers. Relative risks for advanced adenoma after 3 years were calculated according to baseline adenoma characteristics.

Results

Among 1,323 patients enrolled, 387 patients (29.3%) were followed up, and the mean follow-up interval was 31.0±9.8 months. The percentage of patients with advanced adenoma on baseline colonoscopy was higher in the surveillance group compared to the non-surveillance group (34.4% vs. 25.7%). Advanced adenoma recurrence was observed in 17 patients (4.4%) at follow-up. The risk of advanced adenoma recurrence was 2 times greater in patients with baseline advanced adenoma than in those with baseline non-advanced adenoma, though the difference was not statistically significant (6.8% [9/133] vs. 3.1% [8/254], P=0.09). Advanced adenoma recurrence was observed only in males and in subjects aged ≥50 years. In contrast, adenoma recurrence was observed in 187 patients (48.3%) at follow-up. Male sex, older age (≥50 years), and multiple adenomas (≥3) at baseline were independent risk factors for adenoma recurrence.

Conclusions

A colonoscopy surveillance interval of 3 years in patients with baseline advanced adenoma can be considered appropriate.

Risk of Clostridium difficile Infection with the Use of a Proton Pump Inhibitor for Stress Ulcer Prophylaxis in Critically Ill Patients

Background/Aims

Proton pump inhibitors (PPIs) and histamine-2 receptor antagonists (H2RAs) are commonly prescribed for stress ulcer prophylaxis (SUP) in critically ill patients. Several studies have suggested that the use of PPIs is a potential risk factor for Clostridium difficile infection (CDI). We compared the incidences of CDI in the PPI group and H2RA group for SUP in critically ill patients.

Methods

From August 2005 to July 2012, the incidences of CDI were retrospectively analyzed in patients who were admitted directly to intensive care units and stayed for more than 3 days. SUP-related CDI was defined as a CDI diagnosed during the SUP period. Patient clinical data were analyzed to identify potential risk factors for SUP-related CDI.

Results

Of the 1,005 patients enrolled (444 patients received PPI and 561 received H2RA), 38 (3.8%) were diagnosed with SUP-related CDI. The incidence of SUP-related CDI was considerably higher in patients who received PPI than in those who received H2RA (6.7% vs 1.8%). PPI use for SUP (odds ratio [OR], 3.3; confidence interval [CI], 1.5 to 7.1; p=0.003) and diabetes mellitus (OR, 2.3; CI, 1.2 to 4.7; p=0.019) were independent risk factors for SUP-related CDI.

Conclusions

PPI therapy is associated with a higher risk of SUP-related CDI than H2RA therapy in critically ill patients.

Risk factors of nonadherence to colonoscopy surveillance after polypectomy and its impact on clinical outcomes: a KASID multicenter study

BACKGROUND

An optimal surveillance program is important to prevent advanced colorectal neoplasm. In this context, we have evaluated the cumulative risk of high-risk adenoma (HRA) or colorectal cancer (CRC) according to surveillance interval time after polypectomy. In addition, we assessed risk factors for late surveillance to determine whether late surveillance can impact the risk of subsequent advanced colorectal neoplasm.

METHODS

This was a multicenter retrospective cohort study involving 3562 subjects who had undergone removal of at least one adenoma at the index colonoscopy and who subsequently underwent a surveillance colonoscopy. The subjects were classified into an early, appropriate or late group depending on the timing of the surveillance colonoscopy, performed using modified U.S.

RESULTS

With 3% of the study population with LRA and HRA at the index colonoscopy going on to develop HRA or CRC, the estimated surveillance intervals calculated would be 6.3 [95% confidence interval (CI) 5.42-7.10] years and 3.1 (95% CI 2.61-4.45) years, respectively. The predictors of late surveillance were female gender [odd ratio (OR) 1.21; 95% CI 1.04-1.40], having undergone the procedure in small-to-medium-sized cities (OR 1.92; 95% CI 1.36-2.72) and HRA at index colonoscopy (OR 1.37; 95% CI 1.19-1.59). The risk factors for subsequent HRA or CRC were late surveillance (OR 1.34; 95% CI 1.03-1.74), male gender (OR 2.13; 95% CI 1.54-2.95), having undergone the procedure in small-to-medium-sized cities (OR 1.63; 95% CI 1.11-2.40) and HRA at index colonoscopy (OR 2.60; 95% CI 2.04-3.33).

CONCLUSIONS

Women, having undergone the procedure in small-to-medium-sized cities and the presence of an HRA at the index colonoscopy were found to be independent risk factors for late surveillance colonoscopy. Late surveillance is significantly predictive of subsequent HRA or CRC.

Factors Contributing to the Preference of Korean Patients with Crohn's Disease When Selecting an Anti-Tumor Necrosis Factor Agent (CHOICE Study)

Background/Aims

Two comparable anti-tumor necrosis factor (TNF) agents with different routes of administration (intravenous [iv] infliximab [IFX] vs subcutaneous [sc] adalimumab [ADA]) are available for patients with Crohn’s disease (CD) in Korea. This study aimed to identify the preferences of Korean CD patients for a specific anti-TNF agent and the factors contributing to the decision.

Methods

A prospective survey was performed among anti-TNF-naive CD patients in 10 tertiary referral hospitals. A 16-item questionnaire addressed patient preferences and the factors contributing to the decision in favor of a particular anti-TNF agent. A logistic regression was conducted to assess predictive factors for ADA preference.

Results

Overall, 189 patients (139 males; mean age, 32.47±11.71 years) completed the questionnaire. IFX and ADA were preferred by 63.5% (120/189) and 36.5% (69/189) of patients, respectively. The most influential reason for choosing IFX was ‘doctor’s presence’ (68.3%, 82/120), and ADA was “easy to use” (34.8%, 24/69). Amid various clinicodemographic data, having a >60-minute travel time to the hospital was a significant independent predictive factor for ADA preference.

Conclusions

A large number of anti-TNF-naive Korean patients with CD preferred anti-TNFs with an iv route of administration. The reassuring effect of a doctor’s presence might be the main contributing factor for this decision.

Do surveillance intervals in patients with more than five adenomas at index colonoscopy be shorter than those in patients with three to four adenomas? A Korean Association for the Study of Intestinal Disease study

BACKGROUND AND AIM

There is controversy about the surveillance interval after colonoscopy when 5-10 adenomas have been found on index colonoscopy. This study aimed to investigate the risk of colorectal neoplasm (CRN) according to the number of adenomas at index colonoscopy.

METHODS

A retrospective, multicenter study was conducted at 10 university hospitals in Korea. We included 1394 patients with ≥ 3 adenomas at index colonoscopy. The risk of advanced CRN was compared according to the number of adenomas (intermediate risk group, 3-4 small adenomas or at least one ≥ 10 mm, and high risk group, ≥ 5 small adenomas or ≥ 3 at least one ≥ 10 mm).

RESULTS

Overall, 164 (11.8%) developed an advanced CRN after a mean of 4.0 years from baseline colonoscopy. The 3-year and 5-year risk of advanced CRN was 2.1% (95% CI 2.09-2.11) and 14.4% (95% CI 14.36-14.44) in intermediate risk group and 3.2% (95% CI 3.19-3.21) and 23.3% (95% CI 19.15-19.25) in high risk group (P = 0.01). Having ≥ 5 adenomas (OR = 1.57, 95% CI 1.11-2.23, P = 0.01) detected at index colonoscopy was a significant risk factor for developing advanced CRN.

CONCLUSIONS

Although risk of advanced CRN in patients with 5-10 adenomas was significantly higher than that in patients with 3-4 adenomas, the cumulative risk at 3 years was low at 3.2%. Thus, we suggest that a 3-year surveillance interval might be appropriate for the patients with 5-10 adenomas, and further prospective studies are needed to investigate whether more intensive surveillance is needed in this group.

Metformin use and the risk of colorectal adenoma: A systematic review and meta-analysis

BACKGROUND AND AIM

Although it is known that metformin can reduce risk of colorectal cancer, it is unclear whether it protects against colorectal adenoma.

METHODS

This study conducted a systematic literature search on MEDLINE, EMBASE, and the Cochrane Library using the primary keywords "colorectal," "colon," "rectal," "rectum," "adenoma," "polyp," "neoplasia," "neoplasm," "metformin," and "diabetes." Studies were included if they evaluated the association between metformin use and colorectal adenoma and reported odds ratios (ORs) or provided data from which these could be estimated.

RESULTS

Ten studies and a total of 8726 patients were evaluated. Across all studies, a median of 32.1% (range: 15.2-53.0%) of patients taking metformin also had adenoma; a median of 43.5% (range: 20.5-59.6%) of those not taking metformin had adenoma. In our meta-analysis, metformin use reduced the risk of adenoma (pooled OR = 0.76, 95% confidence interval [CI] = 0.63-0.92, I²  = 60%). Upon subgroup analyses, metformin use tended to reduce risk of adenoma in a high-risk population consisting of patients with a history of colorectal neoplasia (CRN) (pooled OR = 0.61, 95% CI = 0.34-1.10, I²  = 79%). In addition, metformin reduced the risk of adenoma in a high-risk population consisting of patients with diabetes mellitus (pooled OR = 0.75, 95% CI = 0.62-0.91, I²  = 57%).

CONCLUSION

Metformin use seemed to be associated with a reduced risk of colorectal adenoma, especially in high-risk populations consisting of patients with diabetes mellitus or a history of CRN, although statistical power was not achieved in patients with a history of CRN.