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.

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.

The hybrid CL-SP-D molecule has the potential to regulate xenogeneic rejection by human neutrophils more efficiently than CD47.

OBJECTIVE: Innate immunity plays a vital role in xenotransplantation. A CD47 molecule, binding to the SIRPα expressed on monocyte/macrophage cells, can suppress cytotoxicity. Particularly, the SIRPα contains ITIM, which delivers a negative signal. Our previous study demonstrated that the binding between CL-P1 and surfactant protein-D hybrid (CL-SP-D) with SIRPα regulates macrophages' phagocytic activity. In this study, we examined the effects of human CD47 and CL-SP-D expression on the inhibition of xenograft rejection by neutrophils in swine endothelial cells (SECs). METHODS: We first examined SIRPα expression on HL-60 cells, a neutrophil-like cell line, and neutrophils isolated from peripheral blood. CD47-expressing SECs or CL-SP-D-expressing SECs were generated through plasmid transfection. Subsequently, these SECs were co-cultured with HL-60 cells or neutrophils. After co-culture, the degree of cytotoxicity was calculated using the WST-8 assay. The suppressive function of CL-SP-D on neutrophils was subsequently examined, and the results were compared with those of CD47 using naïve SECs as controls. Additionally, we assessed ROS production and neutrophil NETosis. RESULTS: In initial experiments, the expression of SIRPα on HL-60 and neutrophils was confirmed. Exposure to CL-SP-D significantly suppressed the cytotoxicity in HL-60 (p = 0.0038) and neutrophils (p = 0.00003). Furthermore, engagement with CD47 showed a suppressive effect on neutrophils obtained from peripheral blood (p = 0.0236) but not on HL-60 (p = 0.4244). The results of the ROS assays also indicated a significant downregulation of SEC by CD47 (p = 0.0077) or CL-SP-D (p = 0.0018). Additionally, the suppression of NETosis was confirmed (p = 0.0125) in neutrophils co-cultured with S/CL-SP-D. CONCLUSION: These results indicate that CL-SP-D is highly effective on neutrophils in xenogeneic rejection. Furthermore, CL-SP-D was more effective than CD47 at inhibiting neutrophil-mediated xenograft rejection.

Prescribing in pregnant women with inflammatory bowel disease and its relationship to congenital malformations in Japan.

BACKGROUND AND AIM: Inflammatory bowel disease (IBD) frequently affects younger patients and poses various challenges concerning pregnancy and childbirth. Maintaining good disease control throughout pregnancy is crucial, but expectant and pregnant patients may worry about the fetal impact of medications, leading to treatment discontinuation due to uncertainty about this issue. This study investigated the real-world drug-prescribing practices for pregnant patients with IBD in Japan and their potential connection to major congenital malformations (MCMs). METHODS: Overall, 277 female IBD patients who gave birth between 2010 and 2019 were selected from the JMDC claims database. The prescribing patterns of IBD medications and MCMs in the patients' offspring were analyzed. RESULTS: Among pregnant IBD patients, 74.4% received at least one medication from 90 days before pregnancy to 90 days after delivery. Trends in medication prescriptions during pregnancy in 2010-2019 revealed consistent use of oral 5-ASA, variable use of topical medications, a decrease in systemic steroids, and an increase in biologics. The prevalence of MCMs in children born to IBD-affected mothers did not differ significantly between those who did and did not receive IBD medications (8.6% vs 6.8%). Although circulatory system MCMs were slightly more common in the IBD medication group (4.9% vs 1.4%), this difference was not significant. Logistic regression analysis did not reveal an association between MCM risk and first-trimester use of IBD medications, including corticosteroids and biologics. CONCLUSIONS: This study provides insights into medication patterns in pregnant IBD patients and suggests no increased risk of MCMs associated with first-trimester IBD medication use.

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.

Remarkable improvement of diabetic nephropathy in transplanted allograft after kidney transplantation.

Although glomerular damage caused by diabetic nephropathy was thought to be irre-versible, in recent years, there have been reports on improvement in glomerular damage with strict glycemic control. However, few reports are available on the pathologic course after renal transplantation of donor-derived grafts with findings of diabetic nephropathy. A 53-year-old woman underwent an ABO blood-type compatible living-donor renal transplant. The recipient had no history of diabetes, and fasting blood glucose and hemo-globin A1c (HbA1c) levels were both normal. The donor was a 57-year-old male who had received treatment for type 2 diabetes mellitus for 10 years. Transplant renal biopsy performed 1 h after revascularization showed mesangial matrix expansion and arterial hyalinosis due to diabetic nephropathy. The blood glucose level was within the normal range after transplantation. Mesangial matrix expansion and arterial hyalinosis disap-peared in allograft biopsy samples 7 years after transplantation. We observed significant improvement in the pathological findings of donor-derived diabetic nephropathy after renal transplantation in the subsequent follow-ups.

Clinical Utilization of Generic Drugs and Biosimilars for Ulcerative Colitis Treatment: Insights from a Nationwide Database Study in Japan.

Introduction: Limited data exist regarding the prevalence and clinical practice involving generic drugs and biosimilars for treating ulcerative colitis (UC) in Japan. We aimed to clarify the clinical usage of these generic drugs and biosimilars for UC treatment in Japan using a nationwide database. Methods: We collected data from 30,675 UC cases, along with their prescriptions for both generic drugs or biosimilars and their original counterparts, using a medical claim database provided by DeSC Healthcare, Inc. We calculated the prescription and penetration rates of generic drugs and biosimilars and demonstrated the transition of these rates. Additionally, the cumulative retention rates between infliximab originator and biosimilar were compared using the Kaplan-Meier method. Results: The prescription rate of generic mesalazine increased from approximately 10% in 2015 to over 30% in 2021. Although the prescription rate of generic molecular targeting drugs (MTDs) also increased from approximately 0.15% in 2014 to 2.5% in 2021, the increment was lower than that of generic mesalazine. The penetration rates of generic 5-aminosalicylic acid and tacrolimus ranged from over 30% to approximately 50%. Infliximab biosimilar achieved an approximate 20% penetration rate, whereas adalimumab achieved <5%. The cumulative retention rates did not differ between infliximab originator and biosimilar. Conclusions: The penetration rates of generics and biosimilars for UC treatment are relatively low compared with those for treatment in other fields and the goal of the Ministry of Health, Labor, and Welfare. Several countermeasures are necessary for the widespread use of generics and biosimilars, ultimately contributing to cost-effective and sustainable healthcare delivery.

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.

A retroperitoneal primary undifferentiated pleomorphic sarcoma.

A 52-year-old male had pain in the right back and right hypochondrium, and an abdominal CT scan revealed a 49-mm tumor in the right upper perirenal space. Additional MRI and PET-CT suggested that the tumor may be a primary adrenal carcinoma and could invade the liver and diaphragmatic leg. The tumor was completely removed by laparotomy and histopathologically diagnosed as retroperitoneal primary undifferentiated pleomorphic sarcoma. The patient has remained recurrence-free for 1.5 years after the surgery.

Primary renal peripheral T-cell lymphoma, not otherwise specified, treated with partial nephrectomy.

Introduction: Renal involvement by non-Hodgkin's lymphoma is very rare, and the kidney as the primary site of this lymphoma is much more uncommon. We report a case of primary renal peripheral T-cell lymphoma, not otherwise specified, treated with partial nephrectomy. Case presentation: A 63-year-old man was hospitalized with coronavirus infectious disease, emerged in 2019 in the emergency department. Computed tomography examination showed a 2-cm renal mass in the right kidney. Abdominal enhanced computed tomography examination revealed that the noted mass showed good enhancement in the corticomedullary phase and washout in the nephrogenic phase. No metastatic lesions were found. He was diagnosed as having cT1aN0M0 renal cell carcinoma, and robotic-assisted partial nephrectomy was carried out. The pathological diagnosis was peripheral T-cell lymphoma, not otherwise specified. He has been followed for 20 months after robotic-assisted partial nephrectomy without additional treatment and recurrence. Conclusion: We experienced a primary renal peripheral T-cell lymphoma, not otherwise specified that was followed up without treatment after surgery.

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.

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.

Thiopurines exert harmful effects on spermatogenesis in Nudt15R138C knock-in mice.

BACKGROUND: The association between thiopurine use and testicular reproductive functions remains unclear. In this study, we investigated whether thiopurines affect testicular functions based on the NUDT15 genotypes using Nudt15R138C knock-in mice. METHODS: The male Nudt15R138C knock-in mice (9-12 weeks) were treated with mercaptopurine (MP: 0.5 mg/kg/day) for 4 or 12 weeks. To examine reversibility, some mice were maintained for a further 12 weeks under MP-free condition. RESULTS: After MP treatment for 4 weeks, Nudt15R138C/R138C mice exhibited a significant reduction of testis weight compared to Nudt15+/+ mice and Nudt15+/R138C mice. The epithelial height and diameter of seminiferous tubules were significantly reduced in Nudt15R138C/R138C mice compared to Nudt15+/+ and Nudt15+/R138C mice. Apoptotic cells were significantly increased in Nudt15R138C/R138C mice, and most of apoptotic cells were spermatogonia. There were no significant changes in sperm counts and sperm morphology in MP-treated Nudt15R138C/R138C mice after 4-week MP treatment. On the other hand, after MP treatment for 12 weeks, the Nudt15+/R138C mice, but not Nudt15+/+ mice, exhibited a significant reduction in the testis weight and atrophic changes of seminiferous tubules, but these changes disappeared after 12-week rearing under MP-free condition. Despite a significant increase in abnormal sperm rate, there were no changes in the ability to conceive. No differences in serum levels of follicle-stimulating hormone or testosterone were observed between MP-treated Nudt15+/R138C and Nudt15+/+ mice after 12-week MP treatment. CONCLUSIONS: Thiopurines exert harmful effects on testicular reproductive function according to host NUDT15 genotypes.

A case of robot-assisted laparoscopic partial nephrectomy during pregnancy.

Introduction: Malignancy during pregnancy requires consideration of both the mother and fetus. We report a patient with renal cell carcinoma during pregnancy who was treated with robot-assisted partial nephrectomy. Case presentation: The patient was incidentally found to have a renal mass on abdominal ultrasonography. Definitive diagnosis of cT1aN0M0 RCC was made by enhanced computed tomography. Subsequently, pregnancy was discovered. RAPN was performed without complications. Pathologic examination revealed clear cell RCC. There were no postoperative complications, and the baby was born safely. Conclusion: RAPN can be safe and effective even during pregnancy. Every pregnant patient requires individualized treatment involving the timing of surgery, the procedure used, and management based on the condition of the mother and fetus, tumor stage, and the experience of the surgical team.

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.

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.

A case of abiraterone acetate withdrawal syndrome after initiation of upfront abiraterone therapy for high-risk prostate cancer.

Introduction: Transient decrease in serum prostate-specific antigen level can occur after abiraterone acetate withdrawal in male patient with metastatic castration-resistant prostate cancer. Here, we report a case of abiraterone acetate withdrawal syndrome with transient prostate-specific antigen decrease after progression to castration-resistant disease while using upfront abiraterone therapy for high-risk prostate cancer. Case presentation: A 73-year-old man with hormone-sensitive high-risk prostate cancer with multiple bone metastases (prostate-specific antigen level, 294.109 ng/mL) received upfront abiraterone/prednisolone combination and androgen deprivation therapy. One year later, prostate-specific antigen level decreased to 0.017 ng/mL (nadir) but it gradually rose by 15 months after treatment initiation. He was diagnosed as castration-resistant and new bone metastases appeared. After abiraterone was discontinued, prostate-specific antigen level decreased and stabilized at a low level for 5 months. Conclusion: Abiraterone acetate withdrawal syndrome was observed when hormone-sensitive prostate cancer with upfront abiraterone therapy progressed to castration-resistant prostate cancer.

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).

Genetics of inflammatory bowel disease in East Asia: From population to individual.

Genetic analysis of inflammatory bowel disease has identified many disease susceptibility genes in a large number of cases, mainly in Europe and North America. However, because of the ethnic differences in genetic background, analysis in various ethnic groups is needed. Although genetic analysis in East Asia began at the same time as in the West, the total number of patients analyzed has remained limited in Asia. To address these issues, meta-analyses across East Asian countries are underway, and the genetic analysis of inflammatory bowel disease in East Asians is entering a new phase. New findings on the genetic background factors associated with inflammatory bowel disease originating from East Asia have also been made, such as the association between chromosomal mosaic alteration and this disease. Genetic analysis has been conducted mainly through studies that consider patients as a group. Some of these results, such as the identified relationship between the NUDT15 gene and thiopurine-related adverse events, are beginning to be applied to the actual treatment of individuals. Meanwhile, genetic analyses of rare diseases have focused on the development of diagnostic methods and therapies by identifying causative gene mutations. Recently, genetic analysis has been moving from research on populations and pedigrees to the stage of identifying and using personal genetic information of each patient, which is important for personalized medical care. To achieve this, close collaboration between specialists in complex genetic analysis and clinicians will be critical.