Real-world NUDT15 genotyping and thiopurine treatment optimization in inflammatory bowel disease: a multicenter study

BACKGROUND

This study evaluated the effectiveness of NUDT15 codon 139 genotyping in optimizing thiopurine treatment for inflammatory bowel disease (IBD) in Japan, using real-world data, and aimed to establish genotype-based treatment strategies.

METHODS

A retrospective analysis of 4628 IBD patients who underwent NUDT15 codon 139 genotyping was conducted. This study assessed the purpose of the genotyping test and subsequent prescriptions following the obtained results. Outcomes were compared between the Genotyping group (thiopurine with genotyping test) and Non-genotyping group (thiopurine without genotyping test). Risk factors for adverse events (AEs) were analyzed by genotype and prior genotyping status.

RESULTS

Genotyping test for medical purposes showed no significant difference in thiopurine induction rates between Arg/Arg and Arg/Cys genotypes, but nine Arg/Cys patients opted out of thiopurine treatment. In the Genotyping group, Arg/Arg patients received higher initial doses than the Non-genotyping group, while Arg/Cys patients received lower ones (median 25 mg/day). Fewer AEs occurred in the Genotyping group because of their lower incidence in Arg/Cys cases. Starting with < 25 mg/day of AZA reduced AEs in Arg/Cys patients, while Arg/Arg patients had better retention rates when maintaining ≥ 75 mg AZA. Nausea and liver injury correlated with thiopurine formulation but not dosage. pH-dependent mesalamine reduced leukopenia risk in mesalamine users.

CONCLUSIONS

NUDT15 codon 139 genotyping effectively reduces thiopurine-induced AEs and improves treatment retention rates in IBD patients after genotype-based dose adjustments. This study provides data-driven treatment strategies based on genotype and identifies risk factors for specific AEs, contributing to a refined thiopurine treatment approach.

Rupture of ectopic varices of the ascending colon occurring after pancreatic cancer surgery: A case report and literature review

A 69-year-old woman, a long-term survivor of subtotal stomach-preserving pancreatoduodenectomy with the splenic vein resection for pancreatic cancer, visited our hospital with a chief complaint of bloody stools. Previously, she was diagnosed with varices in the ascending colon due to left-sided portal hypertension after pancreatoduodenectomy by computed tomography and colonoscopy. After emergency hospitalization, she went into shock, and blood tests showed acute progression of severe anemia. Computed tomography showed a mosaic-like fluid accumulation from the ascending colon to the rectum. She was diagnosed with ruptured varices in the ascending colon. Emergency colonoscopy was performed, and treatment with endoscopic injection sclerotherapy using N-butyl-2-cyanoacrylate was successful. Ectopic varices occur at any location other than the esophagus and stomach, and colonic varices are rare among them. They are mostly caused by portal hypertension due to liver cirrhosis. However, with the trend of improving the prognosis for patients with pancreatic cancer, we should occasionally pay attention to the development of ectopic varices including colonic varices in patients who have undergone pancreatoduodenectomy with superior mesenteric and splenic veins resection. Treatment methods for colonic varices varied from case to case, including conservative therapy, interventional radiology, and endoscopic procedure. In this case, endoscopic injection sclerotherapy was successfully performed without any complications. To the best of our knowledge, this is the first study to report successful treatment with endoscopic injection sclerotherapy for varices in the ascending colon caused by left-sided portal hypertension after pancreatoduodenectomy. Colonic varices should be considered in patients with obscure gastrointestinal bleeding after pancreatoduodenectomy.

Live-attenuated vaccination in patients with inflammatory bowel disease while continuing or after elective switch to vedolizumab

Background/Aims

Vedolizumab (VDZ) is a gut-selective agent with a favorable safety profile. We aimed to assess the feasibility of elective switch from other advanced therapies to VDZ and subsequent live-attenuated vaccination while continuing VDZ in patients with inflammatory bowel diseases (IBD).

Methods

We measured antibody titers specific for measles, rubella, mumps, and varicella viruses in IBD patients under immunosuppressive therapy. Those with negative titers and without vaccination history were judged unimmunized. Patients were administered vaccines while continuing VDZ or switched to VDZ if receiving other advanced therapies and then administered vaccines. Co-primary outcomes were the rate of maintaining disease severity after vaccination and the rate without vaccine-induced infection.

Results

Among 107 unimmunized patients, 37 agreed to receive live-attenuated vaccines while continuing VDZ (17 patients) or after switching to VDZ (20 patients). In the 20 patients who electively switched to VDZ, disease severity was maintained except for 1 patient who developed intestinal infection. After 54 weeks, 18 patients (90%) continued to receive VDZ, excluding 2 patients who reverted to their originally administered biologics. In all 37 patients administered live-attenuated vaccines under VDZ treatment, disease severity was maintained after vaccination. Antibody titers became positive or equivocal in 34 patients (91.9%). There were no cases of vaccine-induced infection during a median observation period of 121 weeks.

Conclusions

While live-attenuated vaccines are contraindicated under immunosuppressive therapy, they may be safely administered while receiving VDZ immunotherapy. Switching from other advanced therapies to VDZ and subsequently receiving live-attenuated vaccines may be a safe alternative in unimmunized patients.

A Phase II Clinical Trial to Study the Safety of Triamcinolone after Endoscopic Radial Incision and Cutting Dilatation for Benign Stenosis of the Lower Gastrointestinal Tract: A Study Protocol

BACKGROUND

Lower gastrointestinal tract stenosis is commonly diagnosed and is typically treated with surgery or endoscopic balloon dilation (EBD). Radial incision and cutting (RIC) is a novel treatment approach that has several benefits compared with EBD and surgery. Although RIC has demonstrated a high technical success rate and has been shown to improve subjective symptoms, previous studies revealed that restenosis after RIC remain unsolved. Herein, we report the design of a prospective, multicenter, single-arm, interventional, phase II trial to evaluate the safety of local triamcinolone acetonide (TA) administration and its feasibility in preventing restenosis after RIC for lower gastrointestinal tract stenosis.

METHODS

The major inclusion criteria are age 20-80 years and the presence of benign stenosis in the lower gastrointestinal tract accessible by colonoscope. We will perform RIC followed by local administration of TA to 20 participants. The primary outcome is the safety of local TA administration, which will be assessed by determining the frequency of adverse events of special interest. The secondary outcomes are the technical success rate of RIC, duration of procedure, improvement in subjective symptoms, and duration of hospitalization. The outcomes, improvement in subjective symptoms, and long-term results will be evaluated using descriptive statistics, Student's t-test, and Kaplan-Meier curve, respectively.

DISCUSSION

This explorative study will provide useful information regarding the safety of TA administration after RIC, which may contribute to further investigations.

Comprehensive Association Analyses of Extraintestinal Manifestations in Inflammatory Bowel Disease

BACKGROUND & AIMS

Patients with inflammatory bowel disease (IBD) frequently develop extraintestinal manifestations (EIMs) that contribute substantially to morbidity. We assembled the largest multicohort data set to date to investigate the clinical, serologic, and genetic factors associated with EIM complications in IBD.

METHODS

Data were available in 12,083 unrelated European ancestry IBD cases with presence or absence of EIMs (eg, ankylosing spondylitis [ankylosing spondylitis and sacroiliitis], primary sclerosing cholangitis [PSC], peripheral arthritis, and skin and ocular manifestations) across 4 cohorts (Cedars-Sinai Medical Center, National Institute for Diabetes and Digestive and Kidney Diseases IBD Genetics Consortium, Sinai Helmsley Alliance for Research Excellence Consortium, and Risk Stratification and Identification of Immunogenetic and Microbial Markers of Rapid Disease Progression in Children with Crohn's Disease cohort). Clinical and serologic parameters were analyzed by means of univariable and multivariable regression analyses using a mixed-effects model. Within-case logistic regression was performed to assess genetic associations.

RESULTS

Most EIMs occurred more commonly in female subjects (overall EIM: P = 9.0E-05, odds ratio [OR], 1.2; 95% CI, 1.1-1.4), with CD (especially colonic disease location; P = 9.8E-09, OR, 1.7; 95% CI, 1.4-2.0), and in subjects who required surgery (both CD and UC; P = 3.6E-19, OR, 1.7; 95% CI, 1.5-1.9). Smoking increased risk of EIMs except for PSC, where there was a "protective" effect. Multiple serologic associations were observed, including with PSC (IgG and IgA, perinuclear anti-nuclear cytoplasmic antibody; anti-Saccharomyces cerevisiae antibodies; and anti-flagellin) and any EIM (IgG and IgA, perinuclear anti-nuclear cytoplasmic antibody; anti-Saccharomyces cerevisiae antibodies; and anti-Pseudomonas fluorescens-associated sequence). We identified genome-wide significant associations within major histocompatibility complex (ankylosing spondylitis and sacroiliitis, P = 1.4E-15; OR, 2.5; 95% CI, 2.0-3.1; PSC, P = 2.7E-10; OR, 2.8; 95% CI, 2.0-3.8; ocular, P = 2E-08, OR, 3.6; 95% CI, 2.3-5.6; and overall EIM, P = 8.4E-09; OR, 2.2; 95% CI, 1.7-2.9) and CPEB4 (skin, P = 2.7E-08; OR, 1.5; 95% CI, 1.3-1.8). Genetic associations implicated tumor necrosis factor, JAK-STAT, and IL6 as potential targets for EIMs. Contrary to previous reports, only 2% of our subjects had multiple EIMs and most co-occurrences were negatively correlated.

CONCLUSIONS

We have identified demographic, clinical, and genetic associations with EIMs that revealed underlying mechanisms and implicated novel and existing drug targets-important steps toward a more personalized approach to IBD management.

Dickkopf 1 is expressed in normal fibroblasts during early stages of colorectal tumorigenesis

BACKGROUND AND PURPOSE

Colorectal cancer progression from adenoma to cancer is a time-intensive process; however, the interaction between normal fibroblasts (NFs) with early colorectal tumors, such as adenomas, remains unclear. Here, we analyzed the response of the microenvironment during early tumorigenesis using co-cultures of organoids and NFs.

MATERIALS AND METHODS

Colon normal epithelium, adenoma, cancer organoid, and NFs were established and co-cultured using Transwell inserts. Microarray analysis of NFs was performed to identify factors expressed early in tumor growth. Immunostaining of clinical specimens was performed to localize the identified factor. Functional analysis was performed using HCT116 cells. Serum DKK1 levels were measured in patients with colorectal cancer and adenoma.

RESULTS

Colorectal organoid-NF co-culture resulted in increased organoid diameter and cell viability in normal epithelial and adenomatous organoids but not in cancer organoids. Microarray analysis of NFs revealed 18 genes with increased expression when co-cultured with adenoma and cancer organoids. Immunohistochemical staining revealed DKK1 expression in the tumor stroma from early tumor growth. DKK1 stimulation reduced HCT116 cell proliferation, while DKK1 silencing by siRNA transfection increased cell proliferation. Serum DKK1 level was significantly higher in patients with advanced cancer and adenoma than in controls. Serum DKK1 level revealed area-under-the-curve values of 0.78 and 0.64 for cancer and adenoma, respectively.

CONCLUSION

These findings contribute valuable insights into the early stages of colorectal tumorigenesis and suggest DKK1 as a tumor suppressor. Additionally, serum DKK1 levels could serve as a biomarker to identify both cancer and adenoma, offering diagnostic possibilities for early-stage colon tumors. The present study has a few limitations. We considered using DKK1 as a candidate gene for gene transfer to organoids and NFs; however, it was difficult due to technical problems and the slow growth rate of NFs. Therefore, we used cancer cell lines instead. In addition, immunostaining and ELISA were based on the short-term collection at a single institution, and further accumulation of such data is desirable. As described above, most previous reports were related to advanced cancers, but in this study, new findings were obtained by conducting experiments on endoscopically curable early-stage tumors, such as adenomas.

Comparative Effectiveness of Tacrolimus and Infliximab in Hospitalized Patients With Ulcerative Colitis

INTRODUCTION

Cyclosporine or infliximab (IFX) have been used to avoid surgery in patients with severe refractory ulcerative colitis (UC). Tacrolimus (Tac) is occasionally used as an alternative to cyclosporine; however, the comparative efficacy of Tac and IFX has not been reported. We aimed to compare the effectiveness of Tac and IFX in hospitalized patients with UC.

METHODS

In a propensity score-matched cohort derived from a large nationwide database, 4-year effectiveness was compared between patients initiated on Tac and those initiated on IFX. The primary outcome was the colectomy rate during the index hospitalization. We also analyzed the cumulative medication discontinuation, UC-related rehospitalization, and colectomy rates after discharge.

RESULTS

Among 29,239 hospitalized patients, 4,565 were extracted for eligibility, of whom 2,170 were treated with Tac and the remaining 2,395 with IFX. After propensity score matching, 1,787 patients were selected for each group. During the index hospitalization, excluding patients who switched to another molecular-targeted agent, the colectomy rate was higher in the Tac group than in the IFX group (7.8% vs 4.2%, P < 0.01). Among patients discharged without colectomy, the cumulative medication discontinuation (28.4% vs 17.1%, P < 0.01) and rehospitalization (22.4% vs 15.4%, P < 0.01) rates were higher in the Tac group than in the IFX group; however, there was no difference in the cumulative colectomy rate (3.3% vs 2.7%).

DISCUSSION

Although Tac and IFX were effective for avoiding surgery in hospitalized patients with UC, IFX was more effective than Tac. IFX also had higher long-term effectiveness. Future prospective studies comparing the efficacy of Tac and IFX are warranted.

Small bowel cancer in a patient with Crohn's disease diagnosed preoperatively by double-balloon enteroscopy

A 53-year-old female patient, who had been treated for Crohn's disease for approximately 20 years, was admitted to our hospital with a chief complaint of persistent bloody stools. Colonoscopy, computed tomography, and magnetic resonance enterography revealed two stenoses of the ileum and multiple enlarged lymph nodes around the oral-side ileal stenosis. We accordingly performed transoral double-balloon enteroscopy and found ileal stenosis with an irregular mucosal surface. Based on pathological examination of the stenosis, adenocarcinoma of the small bowel was diagnosed for the oral-side stenosis. The stenosis on the anal side was benign. The two stenoses were resected simultaneously, and lymph node dissection was performed on the cancerous lesion. The diagnosis of the cancerous lesion was pStage IIIB, and immunohistochemical staining was positive for tumor protein 53. Patients with Crohn's disease are at a high risk of small bowel cancer, but no surveillance protocol has been established to date. We encountered a case of Crohn's disease in which radical surgery was possible, owing to preoperative pathological diagnosis, by using balloon-assisted enteroscopy. In this paper, we report a case that suggests the importance of performing balloon-assisted enteroscopy when small bowel stenosis is detected in patients with Crohn's disease.

HLA-DQA1*05 and upstream variants of PPARGC1B are associated with infliximab persistence in Japanese Crohn's disease patients

Recently, the HLA-DQA1*05 (rs2097432) genetic variation has been reported to be linked to early infliximab (IFX) treatment failure in the Caucasian Crohn's disease (CD) population, but that evidence is scarce in the Asian population. This study aimed to investigate the relationship between rs2097432 and the cumulative discontinuation-free time of IFX (IFX persistence) in 189 Japanese biologics-naive CD patients. We also performed a genome-wide association study (GWAS) to discover novel genetic predictors for IFX persistence. The C allele of rs2097432 significantly increased the risk of early discontinuation of IFX [Hazard ratio (HR) = 2.23 and P-value = 0.026]. In GWAS, one locus tagged by rs73277969, located upstream of PPARGC1B which attenuates macrophage-mediated inflammation, reached genome-wide significance (HR = 6.04 and P-value = 7.93E-9). Pathway analysis suggested association of signaling by PDGF and FCGR activation signaling with IFX persistence (P-value = 8.56E-5 and 5.80E-4, respectively).

Usefulness and difficulties with the thiopurine pharmacogenomic NUDT15 genotyping test: Analysis of real-world data in Japan

The usefulness of NUDT15 genotyping as a pharmacogenomic test for thiopurine has been established. The first such test developed to date, NUDT15 genotyping was approved for reimbursement in Japan in February 2019 for all indicated patients. We retrospectively examined claims data in Japan and confirmed that the proportion of patients who undergo genotyping before initiating a new thiopurine regimen has increased; furthermore, genotyping has improved the rate of treatment continuation and reduced on-treatment hospitalization. However, the genotyping rate before thiopurine induction was >50% for patients with inflammatory bowel disease and <20% for those with other immune-related diseases, indicating significant variation by disease field. Additionally, over 10% of tests were found to have been performed inappropriately, such as multiple genotyping of the same patient or testing more than 2 weeks after starting treatment. Although NUDT15 genotyping for patients requiring thiopurine treatment has been shown to improve thiopurine treatment continuation rate, measures are required to address the systematic issues identified in our analysis.

Effectiveness of Antibiotics for Uncomplicated Diverticulitis: A Retrospective Investigation Using a Nationwide Database in Japan

INTRODUCTION

The efficacy of antibiotics for diverticulitis without abscess or peritonitis (uncomplicated diverticulitis) is controversial. We aimed to investigate the effectiveness of antibiotics for uncomplicated diverticulitis.

METHODS

We collected admission data for patients with acute uncomplicated diverticulitis using a nationwide database. We divided eligible admissions into two groups according to antibiotic initiation within 2 days after admission (antibiotic group vs. nonantibiotic group). We conducted propensity score matching and compared the rates of surgery (intestinal resection and stoma creation), in-hospital death, and medical costs between the groups. We also performed multivariate analysis to identify the clinical factors that affect surgery.

RESULTS

We enrolled 131,936 admissions; among these, we obtained 6,061 pairs after propensity score matching. Rates of both intestinal resection and stoma creation in the antibiotic group were lower than those in the nonantibiotic group (0.61 vs. 3.09%, p < 0.0001, and 0.08 vs. 0.26%, p = 0.027, respectively). Median costs in the antibiotic group were higher than those in the nonantibiotic group (315,820 JPY vs. 300,175 JPY, p < 0.0001, respectively). Multivariate analysis showed that non-initiation of antibiotics within 2 days after admission was a clinical factor that increased the risk of intestinal resection (odds ratio [OR] = 5.19, 95% confidence interval [CI]: 4.38-6.16, p < 0.0001) and stoma creation (OR = 2.68, 95% CI: 1.53-4.70, p = 0.0006).

CONCLUSION

Our results indicated that antibiotics for uncomplicated diverticulitis expected to have moderate to severe disease activity may reduce the risk of intestinal resection and stoma creation. Further investigations are warranted.

Sex-Dimorphic Analyses Identify Novel and Sex-Specific Genetic Associations in Inflammatory Bowel Disease

BACKGROUND

Sex is an integral variable often overlooked in complex disease genetics. Differences between sexes have been reported in natural history, disease complications, and age of onset in inflammatory bowel disease (IBD). While association studies have identified >230 IBD loci, there have been a limited number of studies investigating sex differences underlying these genetic associations.

METHODS

We report the first investigation of sex-dimorphic associations via meta-analysis of a sex-stratified association study (34 579 IBD cases, 39 125 controls). In addition, we performed chromosome (chr) X-specific analyses, considering models of X inactivation (XCI) and XCI escape. Demographic and clinical characteristics were also compared between sexes.

RESULTS

We identified significant differences between sexes for disease location and perianal complication in Crohn's disease and disease extent in ulcerative colitis. We observed genome-wide-significant sex-dimorphic associations (P < 5 × 10-8) at loci not previously reported in large-scale IBD genetic studies, including at chr9q22, CARMIL1, and UBASH3A. We identified variants in known IBD loci, including in chr2p15 and within the major histocompatibility complex on chr6, exhibiting sex-specific patterns of association (P < 5 × 10-7 in one sex only). We identified 3 chrX associations with IBD, including a novel Crohn's disease susceptibility locus at Xp22.

CONCLUSIONS

These analyses identified novel IBD loci, in addition to characterizing sex-specific patterns of associations underlying sex-dimorphic associations. By elucidating the role of sex in IBD genetics, our study will help enhance our understanding of the differences between the sexes in IBD biology and underscores a need to move beyond conventional sex-combined analyses to appreciate the genetic architecture of IBD more comprehensively.

Long-term prognosis and clinical practice for new-onset ulcerative colitis in the era of biologics: A Japanese retrospective study

Background and Aim

There is a scarcity of data on long-term outcomes in patients with new-onset ulcerative colitis (UC) in the era of biologics. We aimed to clarify the long-term prognosis of UC and the clinical practice of prescriptions for UC.

Methods

We collected 6689 new-onset UC cases using a medical claim database provided by DeSC Healthcare, Inc. We investigated the surgery-free, systemic steroid-free, and molecular targeting drug-free rates and compared their differences based on UC-onset age. We used multivariate analysis to identify clinical factors affecting long-term prognosis and investigated the transition of prescriptions for UC.

Results

The surgery-free, systemic steroid-free, and molecular targeting drug-free rates at 5 years post-UC diagnosis were 98.5%, 61.0%, and 88.7%, respectively. Pediatric patients had higher surgery-free rates compared with elderly patients and non-pediatric/non-elderly patients (P = 0.022), whereas the systemic steroid-free and molecular targeting drug-free rates were significantly lower (P< 0.0001, P < 0.0001, respectively). The retention rate of the first molecular targeting drug did not differ between drugs. The prescription rates of systemic steroid, immunomodulator, and molecular targeting drug increased from the second quarter in 2014 to the fourth quarter in 2021 (29.8%-39.1%, 6.8%-17.7%, and 7.6%-16.4%, respectively).

Conclusions

We clarified the long-term prognosis and clinical practice of new-onset UC cases. The long-term outcome after UC onset might improve because of increasing use of new therapeutic agents. Further investigations are warranted.

The Impact of Concomitant Ulcerative Colitis on the Clinical Course in Patients with Primary Sclerosing Cholangitis: An Investigation Using a Nationwide Database in Japan

Introoduction

Primary sclerosing cholangitis (PSC) is a rare disease, especially in Asian countries. PSC often develops during ulcerative colitis (UC). Little is known about the severity of PSC in patients with UC. Thus, this study aimed to investigate the impact of concomitant UC on the clinical course of patients with PSC using a nationwide database in Japan.

Methods

We collected data on patients who were admitted for PSC using a nationwide database and divided eligible admissions according to concomitant UC (PSC-UC group vs. PSC-alone group). We conducted propensity score matching and compared the rates of liver transplantation, biliary drainage, and other clinical events between the two groups. We also conducted a multivariate analysis to identify the clinical factors that affect biliary drainage, cholangiocarcinoma, and liver transplantation.

Results

We enrolled 672 patients after propensity score matching. The rate of liver transplantation in the PSC-UC group was lower than that in the PSC-alone group (2.2 vs. 5.4%, p = 0.002), whereas the rate of biliary drainage did not differ between the two groups (38.1 vs. 33.8%, p = 0.10). On multivariate analysis, concomitant UC was identified as a clinical factor that decreased the risk of liver transplantation (odds ratio = 0.40, 95% confidence interval: 0.23-0.68, p = 0.0007).

Discussion

Concomitant UC in patients with PSC may decrease the risk of liver transplantation. The milder disease activity of PSC with UC is more likely compared to that of PSC without UC.

Current Status and Future Prospects of Inflammatory Bowel Disease Genetics

BACKGROUND

The genetic background of inflammatory bowel diseases (IBDs) has been explored using genetic analysis techniques, such as genome-wide association studies for the population and whole-exome sequencing analyses of family lineages in cases of very early onset.

SUMMARY

The results of genetic analysis for IBD indicated the involvement of innate and adaptive immune system variations and epithelial abnormalities in the pathogenesis of IBD. Several associated genes were also reported, indicating that IBD occurs in a heterogeneous population with an extremely diverse background. The genetic background of IBDs is currently being studied to understand not only its onset but also its prognosis, response to treatment, and adverse effects. In the future, it will be possible to use an individual's genetic information for determining appropriate treatment. In Japan, the NUDT15 polymorphism test is performed before administering thiopurine preparations. However, because of racial differences in genetic analysis, biased analysis toward some racial groups may result in overlooking important genetic backgrounds of IBD.

KEY MESSAGE

Studies of IBDs in a more diverse range of races are expected to elucidate genetic factors through a transethnic analysis, thereby aiding the development of novel treatments and precision medicine for IBDs.

Severity of acute pancreatitis in patients with inflammatory bowel disease in the era of biologics: A propensity-score-matched analysis using a nationwide database in Japan

Background and Aim

Acute pancreatitis (AP) is a rare extraintestinal manifestation of inflammatory bowel disease (IBD). Several studies from Western countries have reported that the severity of AP in patients with IBD is similar to that in the general population; however, its severity in patients from Eastern countries in the era of biologics remains unclear. This study aimed to investigate the severity of AP in patients with IBD and the effect of biologics on the severity of AP using a nationwide database.

Methods

We divided 1138 eligible AP admissions from the Diagnosis Procedure Combination database system into IBD and non-IBD groups after propensity score matching, and compared the severity of AP. We divided the IBD group into ulcerative colitis (UC) and Crohn's disease (CD) subgroups and compared each with the non-IBD group. Logistic regression analysis was conducted to identify the clinical factors affecting acute pancreatitis.

Results

IBD and UC groups had lower rate of severe AP compared to the non-IBD group (13.7% vs 28.3%, P < 0.0001 and 11.0% vs 28.3%, P < 0.0001, respectively). There were no differences in the rates of severe AP between the CD and non-IBD groups. Multivariate analysis showed that biologics did not affect the severity of AP.

Conclusion

The severity of AP in patients with IBD may be lower than that in the general population; biologics for IBD may not worsen its severity. Further prospective studies are required to clarify the severity of AP in patients with IBD.

Depression is associated with increased disease activity in patients with ulcerative colitis: A propensity score-matched analysis using a nationwide database in Japan

Background and Aim

The incidence and prevalence of psychiatric disorders are elevated in patients with inflammatory bowel disease (IBD). Whether psychiatric disorders could affect the clinical course of IBD is uncertain and controversial. We aimed to evaluate the impact of psychiatric disorders, particularly depression, on the clinical course of IBD using a nationwide database in Japan.

Methods

We collected data on admissions with IBD using the Diagnosis Procedure Combination database system introduced in Japan. We divided eligible admissions into IBD with and without depression groups using propensity score matching and compared the rates of surgery, use of molecular targeted drugs and biologics, systemic steroid administrations, and in-hospital death. We also conducted a logistic regression analysis to identify clinical factors affecting surgery, the use of molecular targeted drugs and biologics, and systemic steroid administrations.

Results

The rates of surgery, use of two or more molecular targeted drugs, systemic steroid administrations, and in-hospital deaths in the ulcerative colitis (UC) with depression group were higher than in the UC without depression group. Multivariate analysis of UC showed that depression increased the odds of systemic steroid administrations, use of two or more molecular targeted drugs, and surgery. However, analysis of Crohn's disease showed that only steroid administrations were associated with depression.

Conclusion

Our study demonstrated an association between a worse clinical course of UC and depression. Although this result indicates that depression might be associated with increased disease activity in patients with UC, the causal relationship is still unclear. Further prospective studies are warranted.

Response to COVID-19 vaccine is reduced in patients with inflammatory bowel disease, but improved with additional dose

BACKGROUND

Coronavirus disease 2019 (COVID-19) vaccination is recommended for patients with inflammatory bowel disease (IBD); however, suppressed immune responses have been reported for fully vaccinated patients under immunosuppressive therapy, mainly from Western countries. We prospectively analyzed antibody titers of IBD patients in Asia induced by two-dose and additional dose of messengerRNA COVID-19 vaccine.

METHODS

After measuring high-affinity antibody titers, factors associated with antibody titers were identified by multiple regression analyses using the following covariates: sex, age (≥60 or <60 years), disease type (Crohn's disease or ulcerative colitis), vaccine type (BNT162b2 or mRNA-1273), time from second/third vaccination, molecular-targeted agent (anti-tumor necrosis factor [TNF] agents, ustekinumab, vedolizumab, tofacitinib, or no molecular-targeted agents), thiopurine, steroid, and 5-aminosalicylic acid.

RESULTS

Among 409 patients analyzed, mean titer was 1316.7 U/mL (SD, 1799.3); 403 (98.5%) were judged to be seropositive (≥0.8 U/mL), and 389 (95.1%) had neutralizing antibodies (≥15 U/mL). After the third vaccination, mean titer raised up to 21 123.8 U/mL (SD, 23 474.5); all 179 were seropositive, and 178 (99.4%) had neutralizing antibodies. In 248 patients with genetic data, there was no difference in mean titer after two/third doses between carriers and non-carriers of HLA-A24 associated with severe disease during COVID-19 infection. A multiple regression analyses using covariates revealed that older age, vaccine type (BNT162b2), time from second/third dose, anti-TNF agent, tofacitinib, and thiopurine were independently associated with lower antibody titers.

CONCLUSIONS

Our findings further support the recommendation for COVID-19 vaccination in patients under immunosuppressive therapy, especially additional third dose for patients receiving anti-TNF agents and/or thiopurine or tofacitinib.

Validity of Diagnostic Algorithms for Inflammatory Bowel Disease in Japanese Hospital Claims Data

Inflammatory bowel disease (IBD) diagnoses are increasing in Japan. Some patients have symptoms that are difficult to control, and further research on IBD is needed. Claims databases, which have a large sample size, can be useful for IBD research. However, it is unclear whether the International Classification of Diseases, Tenth Revision (ICD-10) codes alone can correctly identify IBD. We aimed to develop algorithms to identify IBD in claims databases. We used claims data from the Department of Gastroenterology, Tohoku University Hospital from 1 January 2016 to 31 December 2020. We developed 11 algorithms by combining the ICD-10 code, prescription drug, and workup information. We had access to the database which contains all the information for Crohn’s disease and ulcerative colitis patients who visited our department, and we used it as the gold standard. We calculated sensitivity, specificity, positive predictive value (PPV), and negative predictive value for each algorithm. We enrolled 19,384 patients, and among them, 1012 IBD patients were identified in the gold standard database. Among 11 algorithms, Algorithm 4 (ICD-10 code and ≥1 prescription drugs) showed a strong performance (PPV, 94.8%; sensitivity, 75.6%). The combination of an ICD-10 code and prescription drugs may be useful for identifying IBD among claims data.

Crohn's Disease and Early Exposure to Thiopurines are Independent Risk Factors for Mosaic Chromosomal Alterations in Patients with Inflammatory Bowel Diseases

BACKGROUND AND AIMS

Mosaic chromosomal alterations [mCAs] increase the risk for haematopoietic malignancies and may be risk factors for several other diseases. Inflammatory bowel diseases [IBDs], including Crohn's disease [CD] and ulcerative colitis [UC], are associated with mCAs, and patients may be at risk for haematopoietic malignancy development and/or modification of IBD phenotypes. In the present study, we screened patients with IBD for the presence of mCAs and explored the possible pathophysiological and genetic risk factors for mCAs.

METHODS

We analysed mCAs in peripheral blood from 3339 patients with IBD and investigated the clinical and genetic risk factors for mCAs.

RESULTS

CD and exposure to thiopurines before the age of 20 years were identified as novel independent risk factors for mCAs [odds ratio = 2.15 and 5.68, p = 1.17e-2 and 1.60e-3, respectively]. In contrast, there were no significant associations of disease duration, anti-tumour necrosis factor alpha antibodies, or other clinical factors with mCAs. Gene ontology enrichment analysis revealed that genes specifically located in the mCAs in patients with CD were significantly associated with factors related to mucosal immune responses. A genome-wide association study revealed that ERBIN, CD96, and AC068672.2 were significantly associated with mCAs in patients with CD [p = 1.56e-8, 1.65e-8, and 4.92e-8, respectively].

CONCLUSIONS

The difference in mCAs between patients with CD and UC supports the higher incidence of haematopoietic malignancies in CD. Caution should be exercised when using thiopurines in young patients with IBD, particularly CD, in light of possible chromosomal alterations.

Genetic Background of Mesalamine-induced Fever and Diarrhea in Japanese Patients with Inflammatory Bowel Disease

BACKGROUND

Some patients with inflammatory bowel disease (IBD) who were under mesalamine treatment develop adverse reactions called "mesalamine allergy," which includes high fever and worsening diarrhea. Currently, there is no method to predict mesalamine allergy. Pharmacogenomic approaches may help identify these patients. Here we analyzed the genetic background of mesalamine intolerance in the first genome-wide association study of Japanese patients with IBD.

METHODS

Two independent pharmacogenetic IBD cohorts were analyzed: the MENDEL (n = 1523; as a discovery set) and the Tohoku (n = 788; as a replication set) cohorts. Genome-wide association studies were performed in each population, followed by a meta-analysis. In addition, we constructed a polygenic risk score model and combined genetic and clinical factors to model mesalamine intolerance.

RESULTS

In the combined cohort, mesalamine-induced fever and/or diarrhea was significantly more frequent in ulcerative colitis vs Crohn's disease. The genome-wide association studies and meta-analysis identified one significant association between rs144384547 (upstream of RGS17) and mesalamine-induced fever and diarrhea (P = 7.21e-09; odds ratio = 11.2). The estimated heritability of mesalamine allergy was 25.4%, suggesting a significant correlation with the genetic background. Furthermore, a polygenic risk score model was built to predict mesalamine allergy (P = 2.95e-2). The combined genetic/clinical prediction model yielded a higher area under the curve than did the polygenic risk score or clinical model alone (area under the curve, 0.89; sensitivity, 71.4%; specificity, 90.8%).

CONCLUSIONS

Mesalamine allergy was more common in ulcerative colitis than in Crohn's disease. We identified a novel genetic association with and developed a combined clinical/genetic model for this adverse event.

Variants in STXBP3 are Associated with Very Early Onset Inflammatory Bowel Disease, Bilateral Sensorineural Hearing Loss and Immune Dysregulation

BACKGROUND AND AIMS

Very early onset inflammatory bowel disease [VEOIBD] is characterized by intestinal inflammation affecting infants and children less than 6 years of age. To date, over 60 monogenic aetiologies of VEOIBD have been identified, many characterized by highly penetrant recessive or dominant variants in underlying immune and/or epithelial pathways. We sought to identify the genetic cause of VEOIBD in a subset of patients with a unique clinical presentation.

METHODS

Whole exome sequencing was performed on five families with ten patients who presented with a similar constellation of symptoms including medically refractory infantile-onset IBD, bilateral sensorineural hearing loss and, in the majority, recurrent infections. Genetic aetiologies of VEOIBD were assessed and Sanger sequencing was performed to confirm novel genetic findings. Western analysis on peripheral blood mononuclear cells and functional studies with epithelial cell lines were employed.

RESULTS

In each of the ten patients, we identified damaging heterozygous or biallelic variants in the Syntaxin-Binding Protein 3 gene [STXBP3], a protein known to regulate intracellular vesicular trafficking in the syntaxin-binding protein family of molecules, but not associated to date with either VEOIBD or sensorineural hearing loss. These mutations interfere with either intron splicing or protein stability and lead to reduced STXBP3 protein expression. Knock-down of STXBP3 in CaCo2 cells resulted in defects in cell polarity.

CONCLUSION

Overall, we describe a novel genetic syndrome and identify a critical role for STXBP3 in VEOIBD, sensorineural hearing loss and immune dysregulation.

Comprehensive Analysis of microRNA Profiles in Organoids Derived from Human Colorectal Adenoma and Cancer

INTRODUCTION

Exosomes are membrane-enclosed nanovesicles, which are increasingly being recognized as important cell communication components for their role in transmitting microRNAs (miRNAs). No previous study has addressed the exosomal miRNA profile in colorectal adenomas (CRAs) because the long-term culture of CRA is challenging. This study aimed to identify the miRNA signature in organoid exosomes derived from human CRA and colorectal cancer (CRC) samples.

METHODS

Organoid cultures were developed from resected colorectal tissues of patients with CRA or CRC undergoing surgery or endoscopic mucosal resection. Exosomes were prepared from the conditioned medium of the organoids. miRNAs were prepared from the exosomes and their source organoids. The miRNA expression profiles were compared using microarray analysis. The impact of alteration of miRNA expression on cell proliferation was examined using miRNA mimics or inhibitors in HT-29 human CRC cells.

RESULTS

We established 6 organoid lines from CRC and 8 organoid lines from CRA. Exosomal miRNA signatures were different between the organoids derived from CRA and CRC. Both exosomal and cellular miR-1246 expressions were upregulated in CRC-derived organoids compared to their expression in CRA-derived organoids. Alteration of miR-1246 expression by the miR-1246 mimic or inhibitor increased or decreased cell proliferation in HT-29 cells, respectively.

CONCLUSIONS

We report for the first time the miRNA profiles of exosomes in CRA- and CRC-derived organoids. The upregulation of miR-1246 might play a role in increased cell proliferation in the process of CRA-carcinoma transition.

Immunoglobulin subtype-coated bacteria are correlated with the disease activity of inflammatory bowel disease

Immune response involving various immunoglobulin (Ig) isotypes and subtypes to microbiome is involved in the pathogenesis and disease activity of inflammatory bowel diseases (IBDs). To clarify the presence of Ig-coated bacteria in the intestine and its association with disease activity in ulcerative colitis (UC) and Crohn’s disease (CD), we extracted and classified Ig-coated bacteria from fecal samples of 42 patients with IBD and 12 healthy controls (HCs) using flow cytometry and 16S ribosomal RNA sequence analysis. The percentage of bacteria coated with IgA and IgM was higher in patients with IBD than in HCs, and IgG-coated bacteria were found only in patients with IBD. Moreover, the percentages of bacteria coated with IgG1, IgG2, IgG3, and IgM in UC samples and IgG3, IgG4, and IgM in CD samples were correlated with disease activities. The proportions of Bacteroides ovatus and Streptococcus increased during the active phase of CD. Hence, the detailed analysis of Ig-coated bacteria and Ig subtypes using flow cytometry could aid in developing useful indicators of disease activity and identifying more disease-related bacteria, which could become novel treatment targets for IBDs.

Factors Associated with Fibrosis during Colorectal Endoscopic Submucosal Dissection: Does Pretreatment Biopsy Potentially Elicit Submucosal Fibrosis and Affect Endoscopic Submucosal Dissection Outcomes?

BACKGROUND

Submucosal fibrosis observed during colorectal endoscopic submucosal dissection (ESD) is an important factor related to incomplete resection. Biopsy is generally accepted as having the potential to elicit submucosal fibrosis, but few reports have presented definitive proof. This study investigated the relation between submucosal fibrosis and colorectal ESD outcomes and assessed factors related to fibrosis, including pretreatment biopsy.

METHODS

After reviewing 369 records of colorectal ESD performed between January 2011 and December 2016, we assessed the relation between fibrosis and ESD outcomes. Multiple logistic regression analysis revealed fibrosis risk factors.

RESULTS

Severe fibrosis was related significantly to ESD outcomes such as the mean procedure time (p < 0.001), en bloc resection rate (p < 0.001), and R0 resection rate (p = 0.011). Multivariate analyses indicated residual lesions (ORs 175.4, p < 0.001), pretreatment biopsy (ORs 8.30, p = 0.002), nongranular-type laterally spreading tumors (LST-NG; ORs 5.86, p = 0.025), and invasive carcinoma (ORs 5.83, p = 0.03) as independent risk factors of severe fibrosis. In each macroscopic type, LST-NG was more strongly related to fibrosis induced by pretreatment than granular-type laterally spreading tumors with adjust ORs of 50.8 and 4.69.

CONCLUSIONS

Pretreatment biopsy causes submucosal fibrosis resulting in prolonged procedure times and incomplete resection. These findings suggest important benefits of avoiding biopsy before ESD.

Liquid Biopsy for Colorectal Adenoma: Is the Exosomal miRNA Derived From Organoid a Potential Diagnostic Biomarker?

INTRODUCTION

MicroRNAs (miRNAs) can serve as tumor biomarkers; however, their role in evaluating colorectal adenoma (CRA) is unclear. Recently, the organoid culture system enabled long-term expansion of human colon epithelium. This study aimed to examine the potential of exosomal miRNAs extracted from CRA organoids as biomarkers in the clinical liquid biopsy CRA test.

METHODS

We established organoid cultures from normal colon and CRA using resected specimens. Exosomes were isolated from the conditioned medium organoids. MiRNAs were isolated from the exosomes, and their expression profiles were compared using microarray analysis. To identify miRNA candidates for liquid biopsy, we prospectively compared changes in their expression in serum and exosomes before and after endoscopic resection in 26 patients with CRA.

RESULTS

Seven exosomal miRNAs were overexpressed in CRA organoids: miR-4323, miR-4284, miR-1268a, miR-1290, miR-6766-3p, miR-21-5p, and miR-1246. The expression levels of 4 exosomal miRNAs (miR-4323, miR-4284, miR-1290, and miR-1246) and 2 serum miRNAs (miR-1290 and miR-1246) were significantly lower in posttreatment sera. The combined expression of 4 exosomal miRNAs could identify both CRA and large-size (>12.6 cm2) CRA with respective areas under the curve of 0.698 (95% confidence interval [CI] = 0.536-0.823) and 0.834 (95% CI = 0.660-0.929). Combinations of 2-serum miRNA expression values could identify both CRA and large-size CRA with respective area under the curves of 0.691 (95% CI = 0.528-0.817) and 0.834 (95% CI = 0.628-0.938).

DISCUSSION

We found that exosomal miRNAs derived from the CRA organoid culture could be potential diagnostic biomarkers for CRA.

Localized intestinal AL amyloidosis detected as bright green using autofluorescence endoscopy

Amyloidosis is classifiable as systemic, with amyloid deposition in organs throughout the body, or localized, involving only one organ. Amyloidosis localized in the intestinal tract is rare. This report describes three cases of localized AL amyloidosis in the intestinal tract and presents their clinical characteristics, endoscopic findings, and prognoses. All three cases were asymptomatic, and were found accidentally during endoscopy for closer examination after a positive fecal occult blood test. Endoscopic findings included patchy redness and meandering dilated vessels of the lesion. Using autofluorescence (AFI) endoscopy, the lesion of amyloid deposition was enhanced as bright green. We used fluorescence microscopy to observe unstained specimens obtained from an amyloid deposition site with excitation light. Autofluorescence was detected with the broad excitation wavelength at amyloid deposition lesion sites of the specimen. Results revealed that AL amyloid has autofluorescence that engenders its detection by AFI endoscopy as bright green. In none of the three cases was systemic amyloidosis or organ failure observed. The long-term course of all the cases was favorable.

Prevalence and Effect of Genetic Risk of Thromboembolic Disease in Inflammatory Bowel Disease

BACKGROUND AND AIMS

The largest cause of mortality in patients with inflammatory bowel disease (IBD) remains thromboembolic disease (TED). Recent reports have demonstrated that both monogenic and polygenic factors contribute to TED and 10% of healthy subjects are genetically at high risk for TED. Our aim was to utilize whole-exome sequencing and genome-wide genotyping to determine the proportion of IBD patients genetically at risk for TED and investigate the effect of genetic risk of TED in IBD.

METHODS

The TED polygenic risk score was calculated from genome-wide genotyping. Thrombophilia pathogenic variants were extracted from whole-exome sequencing. In total, 792 IBD patients had both whole-exome sequencing and genotyping data. We defined patients at genetically high risk for TED if they had a high TED polygenic risk score or carried at least 1 thrombophilia pathogenic variant.

RESULTS

We identified 122 of 792 IBD patients (15.4%) as genetically high risk for TED. Among 715 of 792 subjects whose documented TED status were available, 63 of the 715 patients (8.8%) had TED events. Genetic TED risk was significantly associated with increased TED event (odds ratio, 2.5; P = .0036). In addition, we confirmed an additive effect of monogenic and polygenic risk on TED (P = .0048). Patients with high TED genetic risk more frequently had thrombosis at multiple sites (78% vs 42%, odds ratio, 3.96; P = .048).

CONCLUSIONS

Genetic risk (both poly- and monogenic) was significantly associated with TED history. Our results suggest that genetic traits identify approximately 1 in 7 patients with IBD who will experience 2.5-fold or greater risk for TED.

Altered Intestinal ACE2 Levels Are Associated With Inflammation, Severe Disease, and Response to Anti-Cytokine Therapy in Inflammatory Bowel Disease

BACKGROUND AND AIMS

The host receptor for severe acute respiratory syndrome coronavirus 2, angiotensin-converting enzyme 2 (ACE2), is highly expressed in small bowel (SB). Our aim was to identify factors influencing intestinal ACE2 expression in Crohn's disease (CD), ulcerative colitis (UC), and non-inflammatory bowel disease (IBD) controls.

METHODS

Using bulk RNA sequencing or microarray transcriptomics from tissue samples (4 SB and 2 colonic cohorts; n = 495; n = 387 UC; n = 94 non-IBD), we analyzed the relationship between ACE2 with demographics and disease activity and prognosis. We examined the outcome of anti-tumor necrosis factor and anti-interleukin-12/interleukin-23 treatment on SB and colonic ACE2 expression in 3 clinical trials. Univariate and multivariate regression models were fitted.

RESULTS

ACE2 levels were consistently reduced in SB CD and elevated in colonic UC compared with non-IBD controls. Elevated SB ACE2 was also associated with demographic features (age and elevated body mass index) associated with poor coronavirus disease 2019 outcomes. Within CD, SB ACE2 was reduced in patients subsequently developing complicated disease. Within UC, colonic ACE2 was elevated in active disease and in patients subsequently requiring anti-tumor necrosis factor rescue therapy. SB and colonic ACE2 expression in active CD and UC were restored by anti-cytokine therapy, most notably in responders.

CONCLUSIONS

Reduced SB but elevated colonic ACE2 levels in IBD are associated with inflammation and severe disease, but normalized after anti-cytokine therapy, suggesting compartmentalization of ACE2-related biology in SB and colonic inflammation. The restoration of ACE2 expression with anti-cytokine therapy might be important in the context of severe acute respiratory syndrome coronavirus 2 infection and potentially explain reports of reduced morbidity from coronavirus disease 2019 in IBD patients treated with anti-cytokines.

TL1A (TNFSF15) genotype affects the long-term therapeutic outcomes of anti-TNFα antibodies for Crohn's disease patients

Background and Aim

TL1A (TNFSF15) is a major Crohn's disease (CD) susceptibility gene, especially in the East Asian population, and is also known to be associated with some clinical phenotypes, such as stricturing and penetrating behavior. This study aims to investigate the association between TL1A genotype and the long‐term therapeutic outcomes of infliximab and adalimumab in Japanese CD patients.

Methods

We investigated 119 biologic‐naïve CD patients treated with infliximab or adalimumab. TL1A ‐358C/T (rs6478109) was genotyped as a tag single nucleotide polymorphism (SNP) for CD risk or nonrisk haplotype of TL1A (the ‐358C allele is a risk allele for CD development). We compared the long‐term therapeutic outcomes of anti‐tumor necrosis factor (TNF) antibodies between the TL1A ‐358C/C group and the C/T+T/T group.

Results

Sixty‐nine cases (58.0%) were homozygous for the risk allele (TL1A ‐358C/C group), and 50 cases (42.0%) were heterozygous for the risk allele or homozygous for the protective allele (TL1A ‐358C/T+T/T group). No significant differences were found in the cumulative retention rates and the relapse‐free survival between the TL1A genotypes. However, the surgery‐free survival was significantly lower in the TL1A ‐358C/C group than in the C/T+T/T group (log‐rank test, P < 0.05). Multivariate analysis showed that TL1A ‐358C/C was identified as an independent risk factor for surgery (hazard ratio, 4.67; 95% confidence interval, 1.39–22.1; P = 0.025).

Conclusion

An association was found between the TL1A genotype and the therapeutic outcomes of anti‐TNF therapy. Our data indicate that the design of customized therapy with anti‐TNF antibodies using TL1A genomic information could be effective in the future.

Genetic Analysis of Ulcerative Colitis in Japanese Individuals Using Population-specific SNP Array

BACKGROUND

To clarify the genetic background of ulcerative colitis (UC) in the Japanese population, we conducted a genome-wide association study (GWAS) using a population-specific single nucleotide polymorphism (SNP) array.

METHODS

We performed a GWAS and replication study including 1676 UC patients and 2381 healthy controls. The probability of colectomy was compared between genotypes of rs117506082, the top hit SNP at HLA loci, by the Kaplan-Meier method. We studied serum expression of miR-622, a newly identified candidate gene, from 32 UC patients and 8 healthy controls by quantitative reverse-transcription polymerase chain reaction.

RESULTS

In the GWAS, only the HLA loci showed genome-wide significant associations with UC (rs117506082, P = 6.69E-28). Seven nominally significant regions included 2 known loci, IL23R (rs76418789, P = 6.29E-7) and IRF8 (rs16940202, P = 1.03E-6), and 5 novel loci: MIR622 (rs9560575, P = 8.23E-7), 14q31 (rs117618617, P = 1.53E-6), KAT6B (rs12260609, P = 1.81E-6), PAX3-CCDC140-SGPP2 (rs7589797, P = 2.87E-6), and KCNA2 (rs118020656, P = 4.01E-6). Combined analysis revealed that IL23R p.G149R (rs76418789, P = 9.03E-11; odds ratio [OR], 0.51) had genome-wide significant association with UC. Patients with GG genotype of rs117506082 had a significantly lower probability of total colectomy than those with the GA+AA genotype (P = 1.72E-2). Serum expression of miR-622 in patients with inactive UC tended to be higher than in healthy controls and patients with active UC (inactive UC vs healthy controls, P = 3.03E-02; inactive UC vs active UC, P = 6.44E-02).

CONCLUSIONS

IL23R p.G149R is a susceptibility locus for UC in Japanese individuals. The GG genotype of rs117506082 at HLA loci may predict a better clinical course.

Reduced expression of COVID-19 host receptor, ACE2 is associated with small bowel inflammation, more severe disease, and response to anti-TNF therapy in Crohn's disease

Angiotensin-Converting Enzyme 2 ( ACE2 ) has been identified as the host receptor for SARS-coronavirus 2 (SARS-CoV-2) which has infected millions world-wide and likely caused hundreds of thousands of deaths. Utilizing transcriptomic data from four cohorts taken from Crohn's disease (CD) and non-inflammatory bowel disease (IBD) subjects, we observed evidence of increased ACE2 mRNA in ileum with demographic features that have been associated with poor outcomes in COVID-19 including age and raised BMI. ACE2 was downregulated in CD compared to controls in independent cohorts. Within CD, ACE2 expression was reduced in inflamed ileal tissue and also remarkably, from uninvolved tissue in patients with a worse prognosis in both adult and pediatric cohorts. In active CD, small bowel ACE2 expression was restored by anti-TNF therapy particularly in anti-TNF responders. Collectively our data suggest that ACE2 downregulation is associated with inflammation and worse outcomes in CD.

Repertoire analysis of memory T-cell receptors in Japanese patients with inflammatory bowel disease

Background and Aim

The T‐cell receptor (TCR) repertoire was assessed in response to various antigens and was considered to be associated with the pathogenesis of inflammatory bowel disease (IBD). Thus, we performed TCR repertoire analysis to examine the pathology of IBD from changes in the TCR repertoire of memory T cells in the intestinal lamina propria mononuclear cells (LPMCs) and peripheral blood mononuclear cells (PBMCs) of patients with IBD.

Methods

LPMCs in the surgical specimens and PBMCs were isolated from 12 patients with IBD (5 patients with ulcerative colitis [UC] and 7 patients with Crohn's disease [CD]). PBMCs were collected from 10 healthy individuals as controls. Comprehensive TCR sequence analyses of adaptor‐ligation polymerase chain reaction (PCR) products were performed using MiSeq.

Results

The diversity of TCR‐α and TCR‐β in PBMCs was significantly lower in patients with IBD than that in controls (P = 0.00084 and 0.0013, respectively). Comparisons of TCR diversity in LPMCs and PBMCs between CD and UC showed that the diversity in LPMC was not affected by diseases, whereas that in PBMCs was significantly lower in CD than in UC (P = 0.045 and 0.049, respectively). Some TCR clones may have shown a specific increase or decrease in CD and UC, and many clones were common to both LPMCs and PBMCs in the same patients.

Conclusion

The diversity of TCR clones in LPMCs and PBMCs in patients with IBD was significantly lower than that of PBMCs in controls. TCR diversity in PBMCs was particularly low in patients with CD.

Correction to: High-resolution melt analysis enables simple genotyping of complicated polymorphisms of codon 18 rendering the NUDT15 diplotype

The correct name of the last author should be.

High-resolution melt analysis enables simple genotyping of complicated polymorphisms of codon 18 rendering the NUDT15 diplotype

BACKGROUND

The genetic variants of NUDT15 have been verified to induce adverse events (AEs) of thiopurines. Codon 139 variants are frequently observed in Asians, while multiple variants are seen in codon 18 which also cause AEs including the European ancestry. The purpose of this study is to establish a technique capable of the simple genotyping of NUDT15 codon 18 and to evaluate its efficacy.

METHODS

A high-resolution melt (HRM) technique is performed to simply determine genotypes. The accuracy of HRM analysis was evaluated with DNAs from 1245 Japanese patients with inflammatory bowel diseases. Subsequently, another group of 572 patients was analyzed to verify the method. The diplotypes and the frequency of their AEs were estimated on the basis of codon 18 and 139 genotypes.

RESULTS

The HRM analysis enabled the correct identification of the three main genotypes, ref/ref, ref/ins, and ref/V18I, in 1236 of 1241 cases. All rare genotypes including ref/del were identified as the impossible-to-determine group, the proper diagnosis rate was 99.6%. In the verification test using other samples, the diagnosis rate was 99.7%. By estimating diplotypes using both codon 18 and 139 genotypes, 2.74% and 2.13% of Japanese patients with Arg/Arg and Arg/Cys of codon 139 have a lower enzymatic activity of NUDT15 and a higher risk for adverse responses than those estimated by codon 139 genotypes alone.

CONCLUSIONS

Our study showed that HRM method enables simple genotyping of complicated codon 18 variants essential to haplotype estimation of the NUDT15.

Modulation of methotrexate-induced intestinal mucosal injury by dietary factors

Methotrexate (MTX)-induced intestinal mucosal injury in animals has been studied to understand how MTX can cause gastrointestinal disorders, but the pathogenesis of gastrointestinal disorders is still uncertain. We have attempted to reveal how dietary factors influence intestinal toxicity due to MTX. Mice were fed normal chow (NC) or a high-fat high-sucrose diet (HFHSD) before oral administration of MTX. While MTX significantly decreased the survival rates of mice fed HFHSD, the intestinal epithelial injury was detected. MTX excretion in the feces of mice fed HFHSD was reduced. Change of diets between NC and HFHSD influences the survival. The survival rates of the mice fed a high-sucrose diet or control diet were higher than those fed HFHSD. Higher survival rates were observed in mice fed a high-fat high-sucrose diet modified (HFHSD-M) in which casein was replaced by soybean-derived proteins. The survival rates of mice treated with vancomycin were lower than those administered neomycin. Microbiome and metabolome analyses on feces suggest a similarity of the intestinal environments of mice fed NC and HFHSD-M. HFHSD may modify MTX-induced toxicity in intestinal epithelia on account of an altered MTX distribution as a result of change in the intestinal environment.

P4678The hemodynamic improvement with balloon pulmonary angioplasty in chronic thromboembolic pulmonary hypertension depends on the lesion location

Background

Pulmonary endarterectomy (PEA) is a treatment of choice for patients with chronic thromboembolic pulmonary hypertension (CTEPH). Patients with proximal pulmonary artery disease are considered to be good candidates for PEA because of their generally excellent outcomes. However, not all patients can be operated because of patients' advanced age, comorbidities and poor general condition. Balloon pulmonary angioplasty (BPA) has become an alternative treatment for CTEPH patients especially whose lesions locate in the distal site. The effectiveness of BPA in patients who have lesions in the proximal pulmonary arteries but cannot be a candidate for PEA remains unclear.

Purpose

The aim of this study was to investigate the outcome of BPA in CTEPH patients whose lesions appears operable but ineligible for PEA.

Methods

A total of 370 patients who underwent BPA in our institute from November 2004 to January 2018 were enrolled. All the patients were divided into operable group and inoperable group according to the difference of lesion location based on the findings of perfusion scintigraphy, computed tomography and pulmonary angiography. Hemodynamic effects of BPA in both groups were investigated. We also conducted survival analyses using the Kaplan-Meier method with the log-rank test.

Results

Among 370 patients, 90 patients deemed operable. The main reasons why not operated in the PEA operable group were patient's refusal (44%), advanced age (14%), and comorbidities (27%). There were no baseline characteristic differences between two groups except for the history of acute pulmonary embolism. Mean pulmonary artery pressure (mPAP) and pulmonary vascular resistance (PVR) equally improved after BPA in both groups (operable: 38.2±10.8 mmHg to 21.5±4.7mmHg, inoperable: 42.4±11.3 mmHg to 21.8±4.8 mmHg, p<0.001, operable: 8.0±4.2 wood unit to 3.5±1.5 wood unit, inoperable: 9.1±4.6 wood unit to 3.4±1.3 wood unit, p<0.001). Furthermore, five-year cumulative survival rates were not different between two groups (inoperable vs. operable: 93% vs. 88%, p=0.23, median follow-up period was 23.0 months (range: 5–136 months)). Meanwhile, the absolute change of mPAP and PVR in inoperable group were greater than those in operable group (inoperable: 20.7±11.2 mmHg, operable: 16.6±11.0 mmHg, p=0.010, inoperable: 5.6±4.4 wood unit, operable: 4.5±3.9 wood unit, p=0.015).

Conclusions

Although the outcome of BPA for CTEPH patients with operable lesions appears acceptable, absolute change in hemodynamics was lower than that of the patients with inoperable lesions. CTEPH with proximal lesions should be treated with PEA rather than BPA.

P4675The utility of additional balloon pulmonary angioplasty for residual hypoxemia in normohemodynamic chronic thromboembolic pulmonary hypertension patients after invasive treatments

Background

Balloon pulmonary angioplasty (BPA) improves hemodynamics, symptoms and exercise capacity in patients with chronic thromboembolic pulmonary hypertension (CTEPH) who are ineligible for pulmonary endarterectomy (PEA). However, certain patients still have hypoxemia after BPA or PEA despite normalization of hemodynamics. In CTEPH, hypoxemia is related increased dead space ventilation caused by vascular obstruction.

Purpose

This study was aimed to clarify whether additional BPA can improve hypoxemia of CTEPH patients after normalization of hemodynamics.

Methods

A total of 335 patients who underwent initial series of BPA in our institute were followed up. Sixty-four patients with mean pulmonary artery pressure (mPAP) <30mmHg and percutaneous oxygen saturation (SpO2) <95% without oxygen inhalation at more than 6 months after the initial series of BPA and of patients who could reevaluate hemodynamics and oxygenation after additional BPA were enrolled. These patients were divided into two groups with or without additional BPA procedures. Change of hemodynamics and SpO2 were retrospectively investigated.

Results

Thirty-three of 64 patients underwent additional BPA procedures. Patients' age was older in BPA group than those in non-BPA group (71.3±10.4 vs. 66.5±9.4 years old, p=0.02). mPAP and pulmonary vascular resistance (PVR) was significantly higher in BPA group (mPAP: 23.9±3.2 vs. 20.7±3.8 mmHg, p=0.001, PVR: 4.2±1.2 vs. 3.5±1.4 wood unit, p=0.03, respectively). Among the 1.8±1.4 BPA procedures per person, total 6.6±3.8 segmental pulmonary arteries per person were treated. While no obvious improvements were observed in non-BPA group, PVR and SpO2 in BPA group were significantly improved (4.2±1.2 to 3.7±1.3 wood unit, p=0.002, 90.7±3.1% to 94.1±3.6%, p<0.001, respectively). In the multivariate logistic regression analysis, additional BPA procedures were associated with further improvement of SpO2 (hazard ratio, 3.7; 95% confidence interval, 1.2–11.5; P=0.02).

Conclusions

Additional BPA procedure was associated with improvement of hypoxemia in CTEPH patients after normalization of hemodynamics. Treating as many lesions as possible in BPA might relieve the patients' residual dyspnea.

A Genome-wide Association Study Identifying RAP1A as a Novel Susceptibility Gene for Crohn's Disease in Japanese Individuals

BACKGROUND AND AIMS

Genome-wide association studies [GWASs] of European populations have identified numerous susceptibility loci for Crohn's disease [CD]. Susceptibility genes differ by ethnicity, however, so GWASs specific for Asian populations are required. This study aimed to clarify the Japanese-specific genetic background for CD by a GWAS using the Japonica array [JPA] and subsequent imputation with the 1KJPN reference panel.

METHODS

Two independent Japanese case/control sets (Tohoku region [379 CD patients, 1621 controls] and Kyushu region [334 CD patients, 462 controls]) were included. GWASs were performed separately for each population, followed by a meta-analysis. Two additional replication sets [254 + 516 CD patients and 287 + 565 controls] were analysed for top hit single nucleotide polymorphisms [SNPs] from novel genomic regions.

RESULTS

Genotype data of 4 335 144 SNPs from 713 Japanese CD patients and 2083 controls were analysed. SNPs located in TNFSF15 (rs78898421, Pmeta = 2.59 × 10-26, odds ratio [OR] = 2.10), HLA-DQB1 [rs184950714, pmeta = 3.56 × 10-19, OR = 2.05], ZNF365, and 4p14 loci were significantly associated with CD in Japanese individuals. Replication analyses were performed for four novel candidate loci [p <1 × 10-6], and rs488200 located upstream of RAP1A was significantly associated with CD [pcombined = 4.36 × 10-8, OR = 1.31]. Transcriptome analysis of CD4+ effector memory T cells from lamina propria mononuclear cells of CD patients revealed a significant association of rs488200 with RAP1A expression.

CONCLUSIONS

RAP1A is a novel susceptibility locus for CD in the Japanese population.

Long-term prognosis of Japanese patients with biologic-naïve Crohn's disease treated with anti-tumor necrosis factor-α antibodies

Background/Aims

Few reports have described the long-term treatment outcomes of the anti-tumor necrosis factor-α antibody for Japanese Crohn’s disease (CD) patients. The aim of this study was to evaluate them and clarify the clinical factors that affect the long-term prognosis of the anti-tumor necrosis factor-α treatments.

Methods

This was a retrospective, observational, single-center cohort study. Japanese CD patients treated with either infliximab or adalimumab as a first-line therapy were analyzed. The cumulative retention rates of the biologics, relapse-free survival, and surgery-free survival were analyzed using Kaplan-Meier methods. The clinical factors associated with the long-term outcomes were estimated by both the log-rank test and Cox proportional hazard model.

Results

The cumulative retention rate was significantly higher in the group with a concomitant elemental diet of ≥900 kcal/day, baseline C-reactive protein (CRP) levels <2.6 mg/dL, and baseline serum albumin levels ≥3.5 g/dL, respectively. The baseline serum albumin levels were also associated with both relapse-free and surgery-free survival. The lack of concomitant use of an elemental diet ≥900 kcal/day was identified as the only independent risk factor for the withdrawal of the biologics.

Conclusions

Baseline CRP levels and serum albumin levels could affect the long-term outcomes in CD patients. Concomitant elemental diet of ≥900 kcal/day could have a positive influence on clinical treatment course.

Clinical and genetic risk factors for decreased bone mineral density in Japanese patients with inflammatory bowel disease

BACKGROUND AND AIM

Patients with inflammatory bowel disease (IBD) are at a high risk of low bone mineral density (BMD). Reportedly, clinical and genetic factors cause low BMD in Caucasians; however, studies in non-Caucasian populations remain scarce.

METHODS

Clinical risk factors for low BMD were investigated in 266 Japanese patients with IBD, and a genome-wide association analysis (GWAS) was performed using linear regression with associated clinical factors as covariates. Genotyping was performed using a population-optimized genotyping array (Japonica array^® ). After quality control, the genotype data of 4 384 682 single-nucleotide polymorphisms (SNPs) from 254 patients with IBD were used for GWAS.

RESULTS

Body mass index, age, and disease duration were independently associated with the BMD of the femoral neck (P = 1.41E - 13, 1.04E - 5, and 1.58E - 3, respectively), and body mass index and sex were associated with the BMD of the lumbar spine (P = 6.90E - 10 and 6.84E - 3, respectively). In GWAS, 118 and 42 candidate SNPs of the femoral neck and lumbar spine, respectively, were identified. Among 118, 111 candidate SNPs of the femoral neck were located within the SLC22A23 gene, which is a known IBD susceptibility gene (minimum P = 1.42E - 07). Among 42, 18 candidate SNPs of the lumbar spine were located within the MECOM gene, which is associated with osteopenia (minimum P = 5.86E - 07). Interestingly, none of the known loci showed a significant association with BMD.

CONCLUSIONS

Although clinical risk factors for low BMD in IBD were similar to those in the general population, genetic risk factors were rather different.