Inflammatory Bowel Disease Cohort Studies in Korea: Present and Future

CXCL10 as a shared specific marker in rheumatoid arthritis and inflammatory bowel disease and a clue involved in the mechanism of intestinal flora in rheumatoid arthritis

This study aimed to identify shared specific genes associated with rheumatoid arthritis (RA) and inflammatory bowel disease (IBD) through bioinformatic analysis and to examine the role of the gut microbiome in RA. The data were extracted from the 3 RA and 1 IBD gene expression datasets and 1 RA gut microbiome metagenomic dataset. Weighted correlation network analysis (WGCNA) and machine learnings was performed to identify candidate genes associated with RA and IBD. Differential analysis and two different machine learning algorithms were used to investigate RA's gut microbiome characteristics. Subsequently, the shared specific genes related to the gut microbiome in RA were identified, and an interaction network was constructed utilizing the gutMGene, STITCH, and STRING databases. We identified 15 candidates shared genes through a joint analysis of the WGCNA for RA and IBD. The candidate gene CXCL10 was identified as the shared hub gene by the interaction network analysis of the corresponding WGCNA module gene to each disease, and CXCL10 was further identified as the shared specific gene by two machine learning algorithms. Additionally, we identified 3 RA-associated characteristic intestinal flora (Prevotella, Ruminococcus, and Ruminococcus bromii) and built a network of interactions between the microbiomes, genes, and pathways. Finally, it was discovered that the gene CXCL10 shared between IBD and RA was associated with the three gut microbiomes mentioned above. This study demonstrates the relationship between RA and IBD and provides a reference for research into the role of the gut microbiome in RA.

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.

Plasma miRNA Profile of Crohn's Disease and Rheumatoid Arthritis Patients

Crohn's disease (CD) and rheumatoid arthritis (RA) are immune mediated inflammatory diseases. Several studies indicate a role for microRNAs (miRNAs) in the pathogenesis of a variety of autoimmune diseases, including CD and RA. Our study's goal was to investigate circulating miRNAs in CD and RA patients to identify potential new biomarkers for early detection and personalized therapeutic approaches for autoimmune diseases. For this study, subjects with CD (n = 7), RA (n = 8) and healthy controls (n = 7) were recruited, and plasma was collected for miRNA sequencing. Comparison of the expression patterns of miRNAs between CD and healthy patients identified 99 differentially expressed miRNAs. Out of these miRNAs, 4 were down regulated, while 95 were up regulated. Comparison of miRNAs between RA and healthy patients identified 57 differentially expressed miRNAs. Out of those, 12 were down regulated, while 45 were up regulated. For all the miRNAs down regulated in CD and RA patients, 420 GO terms for biological processes were similarly regulated between both groups. Therefore, the identification of new plasma miRNAs allows the emergence of new biomarkers that can assist in the diagnosis and treatment of CD and RA.

Effect of Age on the Initiation of Biologic Agent Therapy in Patients With Inflammatory Bowel Disease: Korean Common Data Model Cohort Study

BACKGROUND

The Observational Health Data Sciences and Informatics (OHDSI) network is an international collaboration established to apply open-source data analytics to a large network of health databases, including the Korean common data model (K-CDM) network.

OBJECTIVE

The aim of this study is to analyze the effect that age at diagnosis has on the prognosis of inflammatory bowel disease (IBD) in Korea using a CDM network database.

METHODS

We retrospectively analyzed the K-CDM network database from 2005 to 2015. We transformed the electronic medical record into the CDM version 5.0 used in OHDSI. A worsened IBD prognosis was defined as the initiation of therapy with biologic agents, including infliximab and adalimumab. To evaluate the effect that age at diagnosis had on the prognosis of IBD, we divided the patients into an early-onset (EO) IBD group (age at diagnosis <40 years) and a late-onset (LO) IBD group (age at diagnosis ≥40 years) with the cutoff value of age at diagnosis as 40 years, which was calculated using the Youden index method. We then used the logrank test and Cox proportional hazards model to analyze the effect that age at diagnosis (EO group vs LO group) had on the prognosis in patients with IBD.

RESULTS

A total of 3480 patients were enrolled. There was 2017 patients with ulcerative colitis (UC) and 1463 with Crohn's disease (CD). The median follow up period was 109.5 weeks. The EO UC group was statistically significant and showed less event-free survival (ie, experiences of biologic agents) than the LO UC group (P<.001). In CD, the EO CD group showed less event-free survival (ie, experiences of biologic agents) than the LO CD group. In the Cox proportional hazard analysis, the odds ratio (OR) of the EO UC group on experiences of biologic agents compared with the LO UC group was 2.3 (95% CI 1.3-3.8, P=.002). The OR of the EO CD group on experiences of biologic agents compared with the LO CD group was 5.4 (95% CI 1.9-14.9, P=.001).

CONCLUSIONS

The EO IBD group showed a worse prognosis than the LO IBD group in Korean patients with IBD. In addition, this study successfully verified the CDM model in gastrointestinal research.

Association study between two polymorphisms of tumor necrosis factor ligand superfamily member 15 (TNFSF15) gene and ulcerative colitis in south-west of Iran

BACKGROUND AND AIMS: Ulcerative colitis (UC) is the most prevalent clinical manifestation of the inflammatory bowel disease (IBD). Several candidate genes have been suggested to be involved in the genetic susceptibility or resistance in the development of UC. Among them, tumor necrosis factor ligand superfamily member 15 (TNFSF15) have been reported in association with IBD in several studies. The aim of this study was to investigate the association of TNFSF15 gene polymorphisms located in the promoter region, including rs6478108 (G/A -9706) and rs3810936 (G/A -15524) in Iranian patients with UC. METHODS: In this way, the two single nucleotide polymorphisms were studied in 115 patients with UC and 115 healthy controls with the same ethnic group from south-west of Iran. The genomic DNA of samples was genotyped using TaqMan Real-time PCR assay. This case-control study was conducted at the Department of Immunology, Jundishapur University of Medical Sciences, Ahvaz, Iran. RESULTS AND CONCLUSION: Our results did not confirm the formerly reported association of the studied polymorphisms with UC disease in comparison with healthy controls, neither with the type of the clinical forms of Colitis in the studied Iranian population. Comparing the genotype frequency of single nucleotide polymorphism (SNP) rs6478108, wild-type homozygous and heterozygote and mutant homozygote were 33%, 55.7%, and 11.3% in cases vs. 34.8%, 50.4%, and 14.8% in the controls (P = 0.6). The genotype frequency of SNP rs3810936 were 20.9%, 40.9%, and 38.2% in the cases compared to 18.3%, 44.3%, and 37.4% in controls, which was not significant ( P = 0.8). As multiple ethnic groups reside in all around the country, further studies using different ethnicities and/or larger sample size are required to clarify the role of these polymorphisms in the genetic susceptibility of UC in Iranian populations.

Disease Phenotype, Activity and Clinical Course Prediction Based on C-Reactive Protein Levels at Diagnosis in Patients with Crohn's Disease: Results from the CONNECT Study

BACKGROUND/AIMS

C-reactive protein (CRP) is an easily measured index of disease activity, but its ability to predict clinical course is controversial. We therefore designed a study to determine whether the CRP level at Crohn's disease (CD) diagnosis is a valuable indicator of the disease phenotype, activity, and clinical course.

METHODS

We retrospectively analyzed 705 CD patients from 32 institutions. The patients were classified into two groups according to CRP level. The patients' demographic and clinical characteristics and their use of immunosuppressive or biological agents were recorded. Disease location and behavior, hospitalization, and surgery were analyzed.

RESULTS

A high CRP was associated with younger age, steroid use, colonic or ileocolonic location, high CD activity index, and active inflammation at colonoscopy (p<0.001). As the disease progressed, patients with high CRP were more likely to exhibit strictures (p=0.027). There were significant differences in the use of 5-aminosalicylic acid, antibiotics, corticosteroids, azathioprine, and infliximab (p<0.001, p<0.001, p<0.001, p<0.001, and p=0.023, respectively). Hospitalization was also more frequent in patients with high CRP.

CONCLUSIONS

The CRP level at diagnosis is useful for evaluating the phenotype, activity, and clinical course of CD. Closer follow-up strategies, with early aggressive treatment, could be considered for patients with high CRP.

Impact of inflammatory bowel disease on daily life: an online survey by the Korean Association for the Study of Intestinal Diseases

BACKGROUND/AIMS

Inflammatory bowel disease (IBD) is a chronic disabling gastrointestinal disorder that diminishes the quality of life of the affected individuals. Limited data are available regarding the impact of IBD on the daily life of Koreans.

METHODS

Self-administered, computer-aided, internet-based questionnaires were distributed to members of a Korean patient organization for IBD from March to April 2013, by the Korean Association for the Study of Intestinal Diseases.

RESULTS

A total of 599 patients with IBD (387 with Crohn's disease [CD] and 212 with ulcerative colitis [UC]) were enrolled. The majority of patients (81%) expressed feelings of fatigue, weakness, and being worn out in their daily lives during times of flare; this percentage was reduced to 61% during remission. Respondents were absent from work or school for an average period of 18 days because of illness, within the first 6 months; the majority of respondents (64%) felt stressed about their absence. Forty-six percent of the respondents reported having received unfair comments at work, or having suffered discrimination. Forty-seven percent of the respondents felt that IBD had negatively affected their income and earnings. Compared with patients with UC, those with CD reported a more frequent negative impact of IBD on work, or more economic burden. More than half of the respondents (61%) reported that IBD had prevented them from making or keeping friends.

CONCLUSIONS

IBD significantly impacts daily life, including work, education, and social relationships. Treatment that addresses the full spectrum of life of a patient would be more effective.

Ophthalmologic manifestations in patients with inflammatory bowel disease

BACKGROUND/AIMS

Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), has been reported to have various ophthalmologic manifestations. The aim of this study was to evaluate the prevalence of ophthalmologic manifestations associated with IBD in Korea.

METHODS

Sixty-one patients were examined between May 2013 and October 2014. We performed complete ophthalmologic examinations.

RESULTS

Findings included 36 patients with CD and 25 with UC. The mean age of the patients was 34±16 years and disease duration was 45.3±23.9 months. Ophthalmologic manifestations were positive in 44 cases. Primary complication was diagnosed in 5 cases, as follows; iritis in 2 cases, episcleritis in one case, iritis with optic neuritis in 1 case, and serous retinal detachment in 1 case, without secondary complications. The most common coincidental complication was dry eye syndrome (DES), in 35 patients (57.4%). The prevalence of DES in the control group was 21.3%. The proportion of DES in patients with IBD was significantly higher than in the control group (P=0.002).

CONCLUSIONS

Ophthalmologic manifestations were high (72.1%) in IBD patients. Clinically significant primary ocular inflammation occurred in 8.2% of patients. The most common complication was DES. There was a higher rate of DES in patients with IBD compared to the control group. Evaluation of the eye should be a routine component in patients with IBD.

Hydrogen-rich water protects against inflammatory bowel disease in mice by inhibiting endoplasmic reticulum stress and promoting heme oxygenase-1 expression

AIM

To investigate the therapeutic effect of hydrogen-rich water (HRW) on inflammatory bowel disease (IBD) and to explore the potential mechanisms involved.

METHODS

Male mice were randomly divided into the following four groups: control group, in which the mice received equivalent volumes of normal saline (NS) intraperitoneally (ip); dextran sulfate sodium (DSS) group, in which the mice received NS ip (5 mL/kg body weight, twice per day at 8 am and 5 pm) for 7 consecutive days after IBD modeling; DSS + HRW group, in which the mice received HRW (in the same volume as the NS treatment) for 7 consecutive days after IBD modeling; and DSS + HRW + ZnPP group, in which the mice received HRW (in the same volume as the NS treatment) and ZnPP [a heme oxygenase-1 (HO-1) inhibitor, 25 mg/kg] for 7 consecutive days after IBD modeling. IBD was induced by feeding DSS to the mice, and blood and colon tissues were collected on the 7^th d after IBD modeling to determine clinical symptoms, colonic inflammation and the potential mechanisms involved.

RESULTS

The DSS + HRW group exhibited significantly attenuated weight loss and a lower extent of disease activity index compared with the DSS group on the 7^th d (P < 0.05). HRW exerted protective effects against colon shortening and colonic wall thickening in contrast to the DSS group (P < 0.05). The histological study demonstrated milder inflammation in the DSS + HRW group, which was similar to normal inflammatory levels, and the macroscopic and microcosmic damage scores were lower in this group than in the DSS group (P < 0.05). The oxidative stress parameters, including MDA and MPO in the colon, were significantly decreased in the DSS + HRW group compared with the DSS group (P < 0.05). Simultaneously, the protective indicators, superoxide dismutase and glutathione, were markedly increased with the use of HRW. Inflammatory factors were assessed, and the results showed that the DSS + HRW group exhibited significantly reduced levels of TNF-α, IL-6 and IL-1β compared with the DSS group (P < 0.05). In addition, the pivotal proteins involved in endoplasmic reticulum (ER) stress, including p-eIF2α, ATF4, XBP1s and CHOP, were dramatically reduced after HRW treatment in contrast to the control group (P < 0.05). Furthermore, HRW treatment markedly up-regulated HO-1 expression, and the use of ZnPP obviously reversed the protective role of HRW. In the DSS + HRW + ZnPP group, colon shortening and colonic wall thickening were significantly aggravated, and the macroscopic damage scores were similar to those of the DSS + HRW group (P < 0.05). The histological study also showed more serious colonic damage that was similar to the DSS group.

CONCLUSION

HRW has a significant therapeutic potential in IBD by inhibiting inflammatory factors, oxidative stress and ER stress and by up-regulating HO-1 expression.

Association of inflammatory bowel disease with ankylosing spondylitis and rheumatoid arthritis: A nationwide population-based study

OBJECTIVES

Tantalizing connections between autoimmune rheumatic diseases (ARDs) and inflammatory bowel disease (IBD) have become evident with regard to their genetic and immunologic background. However, the association between these two disease entities remains unclear. The aim of this study is to investigate the association between each ARD and IBD.

METHODS

A nationwide population-based cross-sectional study was performed using the Korean National Health Insurance Claims database. The data of patients with IBD and age- and sex-matched controls between 2009 and 2013 were collected from the database. The prevalence of ARDs, including systemic lupus erythematosus (SLE), inflammatory myositis (polymyositis and dermatomyositis), systemic sclerosis (SSc), Sjögren's syndrome (SjS), ankylosing spondylitis (AS), and rheumatoid arthritis (RA), was determined. The associations between each ARD and IBD were analyzed using multivariate logistic regression models.

RESULTS

A total of 40,843 IBD patients (28,197 patients with ulcerative colitis and 12,646 with Crohn's disease) and 122,529 controls were enrolled. The nonstratified analysis revealed that patients with IBD had significant risk of being concomitantly affected by AS (odds ratio [OR] 5.140, 95% confidence interval [95% CI] 4.069-6.492) and RA (OR: 3.474, 95% CI: 2.671-4.519) after adjusting for age and sex. No significant association was observed between IBD and other ARDs including SLE, inflammatory myositis, SSc, and SjS.

CONCLUSION

IBD is significantly associated with AS and RA in the large-scaled population-based study. This result suggests that etiopathogenesis of IBD might be shared with AS and RA.

Crohn's disease confined to the duodenum: A case report

Crohn’s disease (CD) can involve any part of the gastrointestinal tract from the mouth to anus. However, gastroduodenal CD is rare with a frequency reported to range between 0.5% and 4.0%. Most patients with gastroduodenal CD have concomitant lesions in the terminal ileum or colon, but isolated gastroduodenal Crohn’s disease is an extremely rare presentation of the disease accounting for less than 0.07% of all patients with CD. The symptoms of gastroduodenal CD include epigastric pain, dyspepsia, early satiety, anorexia, nausea, vomiting, and weight loss. The diagnosis of gastroduodenal CD requires a high level of clinical suspicion and can be made by comprehensive clinical evaluation. Here we report a rare case of isolated duodenal CD not confirmed by identification of granuloma on biopsy, but diagnosed by clinical evaluation.

Importance of Patients' Knowledge of Their Prescribed Medication in Improving Treatment Adherence in Inflammatory Bowel Disease

GOALS

To investigate the association between treatment nonadherence and patients' knowledge of the prescribed medication among individuals with inflammatory bowel disease (IBD), and evaluate the impact of nonadherence on relapse.

BACKGROUND

The patient's knowledge of the prescribed medication has been identified as an important predictor of treatment adherence in chronic diseases. However, this association has not been examined in IBD.

STUDY

In this prospective study, at baseline, 138 patients with IBD completed a self-reported survey on demographic data, knowledge of the prescribed medication, and candidate factors related to the degree of treatment adherence. To investigate the impact of nonadherence among patients in remission, relapse was analyzed for 18 months after enrollment.

RESULTS

Nonadherence was observed in 50 (36.2%) of the 138 subjects. In multivariate analysis, nonadherence was significantly associated with younger age (less than 30 y) at participation [odds ratio (OR), 5.88; 95% confidence interval (CI), 1.51-22.94; P=0.011], longer intervals between outpatient clinic visits (≥3 mo) (OR, 30.31; 95% CI, 3.06-300.17; P=0.004), and limited knowledge of the prescribed medication (OR, 5.61; 95% CI, 1.60-19.67; P=0.038). Nonadherent patients had a significantly greater risk of relapse of IBD than adherent patients (relative risk, 2.9; 95% CI, 2.25-3.79; P=0.045).

CONCLUSION

Younger age, longer intervals between outpatient clinic visits, and limited knowledge of the prescribed medication tended to be associated with nonadherence to treatment, which consequently also affects the risk of relapse.

Crohn's disease prognosis and early immunomodulator therapy: Results from the CONNECT study

BACKGROUND

It is unknown whether the treatment initiating time of immunomodulators such as thiopurines affects the course of Crohn's disease (CD). We evaluated the efficacy of early immunomodulator therapy (EIT) on the prognosis of patients with CD.

METHODS

We retrospectively analyzed 1157 patients with CD who were enrolled in the CrOhn's disease cliNical NEtwork and CohorT study and received immunomodulator therapy. The patients were divided into an EIT group and a conventional therapy group based on whether immunomodulators were initiated within six months after being diagnosed with CD. We compared the rates of intestinal surgery, bowel complications, and hospitalization because of CD between the groups.

RESULTS

Patient age at diagnosis and sex were not significantly different between the two groups. The mean duration of follow-up was 105.8 ± 51.5 months. A Kaplan-Meier analysis identified that the EIT group was superior to the conventional therapy group in terms of delaying surgery (P = 0.017). In multivariate analysis, EIT was an independent predicting factor associated with delaying the onset of complications (P = 0.050). Patients were divided into two groups based on the year of CD diagnosis: from 1982 to 1999 (A) and from 2000 to 2008 (B). In group A, the time from diagnosis to the start of immunomodulatory therapy was longer (P < 0.001), and the time to first intestinal surgery was shorter than group B (P = 0.002).

CONCLUSIONS

The early use of immunomodulators was associated with a good prognosis as defined by a need for surgery and the occurrence of complications in CD in our multicenter study.