Severe Disease Activity May Predispose Patients to Post-colectomy Duodenitis Associated with Ulcerative Colitis.

Objective Diffuse mucosal inflammation in the duodenum, distinct from peptic ulcer disease, has been repeatedly reported in patients with ulcerative colitis (UC). The pathogenesis of this complication remains uncertain; however, colectomy for medically refractory UC appears to trigger duodenitis. Cases in which colectomy was performed for UC were analyzed to characterize UC-related duodenitis after colectomy. Methods A retrospective case-control study of UC-related duodenitis that developed after colectomy in medically refractory UC between January 2011 and June 2020 was conducted. UC-related duodenitis was diagnosed based on typical clinical, endoscopic, and histological findings, and no duodenitis was endoscopically defined by the normal duodenal mucosa. Clinical and laboratory data, disease severity, and medications used were collected and compared between the UC-related and non-duodenitis cases. Results Ten UC-related duodenitis and 35 non-duodenitis cases were identified among 45 patients with UC who underwent esophagogastroduodenoscopy after colectomy. Disease severity, defined by the C-reactive protein level and partial Mayo score prior to colectomy, was significantly higher in duodenitis patients than in non-duodenitis patients. In comparison to non-duodenitis patients, duodenitis patients more frequently received rescue therapies with calcineurin inhibitors or anti-TNF-α agents at the time of colectomy (100% vs. 65.7%). Conclusion Patients with UC with higher disease activity, especially those who require rescue therapies with calcineurin inhibitors and anti-TNF-α agents, may be prone to developing UC-related duodenitis after colectomy.

Safety Prediction of Infants Born to Mothers with Crohn's Disease Treated with Biological Agents in the Late Gestation Period.

OBJECTIVES: Knowledge gaps exist in the use of biologics for pregnant patients with Crohn's disease (CD), especially the usage of ustekinumab (UST) and infliximab (IFX) infusion during the late gestation period. In this case series, we investigated perinatal and neonatal outcomes and pharmacokinetics of these biologics in pregnant CD patients. METHODS: Pregnant CD patients under treatment with IFX or UST during January 2017 to December 2019 were monitored. Growth and development of their babies were followed up to six months. Drug concentrations were measured in maternal peripheral and cord blood at delivery and infants' blood at six months of age. RESULTS: Four cases were kept IFX treatment until late gestation (median last dose: 31.2 weeks). One case received UST until 23 weeks of gestation. All cases were in clinical remission but moderately undernourished. Babies were delivered by cesarean section at full term without any complications or congenital abnormalities. No growth or developmental defects and no susceptibility to infections were observed by six months. However, two babies whose mothers received IFX after 30 weeks of gestation were detected IFX in their blood at six months of age (0.94 and 0.24 pg/ml). Concentrations of UST in maternal and cord blood were 267.7 and 756.5 ng/ml, respectively. UST was not detected in the infant at six months of age. CONCLUSIONS: Administration of UST or IFX to pregnant patients with CD is safe, particularly IFX to be given in the late gestation period. Understanding of the pharmacokinetics of biologics in maternal-infant interactions may improve the management of pregnant CD patients.

A case of refractory chronic pouchitis successfully treated with tofacitinib.

We describe a case of refractory pouchitis successfully treated with tofacitinib. The patient was a 20-year-old woman diagnosed with ulcerative colitis at the age of 14 years. She underwent surgery at the age of 18 years for chronic active inflammation, despite an optimal medication regimen. Ten months after surgery, she was diagnosed with pouchitis. She did not respond to conventional conservative treatment; thus, the case was considered as that of refractory chronic pouchitis. Anti-tumor necrosis factor-α (TNF-α) therapy was administered, which led to some improvement; however, pouchitis recurred. Systemic steroid and vedolizumab were also administered, but the response was unsatisfactory. Therefore, surgery was considered; however, the patient refused to undergo surgery. As identical therapies are recommended for ulcerative colitis and pouchitis, they are considered to have a common etiology. Therefore, we considered tofacitinib therapy in this case. After obtaining the patient's informed consent, tofacitinib treatment was initiated. The therapy led to improvement in her symptoms as well as in the appearance of the pouch when observed on endoscopy, and surgery was avoided. Thus, tofacitinib may be considered a therapy option for refractory chronic pouchitis.

[Three cases of severe and fulminating ulcerative colitis with megacolon treated with continuous intravenous infusion of cyclosporine].

Dilatation of the colon in severe and fulminating ulcerative colitis is a sign of toxic megacolon and emergency surgery is usually the favored treatment option. Here we describe our experience with three cases of ulcerative colitis with megacolon in which surgery was avoided by treating the patients with a continuous intravenous infusion of cyclosporine, with full cooperation of the surgeons. We recommend that continuous intravenous infusion of cyclosporine be considered as an effective option for the conservative management of severe, fulminating ulcerative colitis with megacolon.

Efficacy and Safety of Oral Budesonide in Patients with Active Crohn's Disease in Japan: A Multicenter, Double-Blind, Randomized, Parallel-Group Phase 3 Study.

BACKGROUND: US and European guidelines recommend budesonide for the treatment of mild-to-moderate active ileocolic Crohn's disease (CD). However, budesonide has not been approved, and mesalazine is widely used as first-line treatment in Japan. The objective of this study was to evaluate the efficacy and safety of budesonide in patients with mild-to-moderate active CD in Japan. METHODS: In this phase 3 noninferiority study (NCT01514240), 112 patients with a baseline Crohn's Disease Activity Index (CDAI) score of 180-400 were randomized to budesonide or mesalazine for 8 weeks. Assessments included remission rate (CDAI score ≤150) at weeks 2, 4, and 8, change in CDAI score, health-related quality of life (measured using the Inflammatory Bowel Disease Questionnaire [IBDQ]), and tolerability. RESULTS: The remission rate at week 8 was numerically higher in the budesonide group (30.4%) than in the mesalazine group (25.0%), and the noninferiority of budesonide to mesalazine was shown. The mean total CDAI score decreased to a greater extent with budesonide than with mesalazine. Mean IBDQ scores improved from baseline to weeks 2, 4, 8, and 10 in both groups; improvements were numerically higher with budesonide than with mesalazine. No safety concerns were found. CONCLUSION: Budesonide is comparably effective to mesalazine in the treatment of Japanese patients with mild-to-moderate active CD.

Surveillance for dysplasia in patients with ulcerative colitis: Discrepancy between guidelines and practice.

BACKGROUND AND AIM: The risk of developing colorectal cancer is higher in patients with ulcerative colitis (UC) than in the general population. Guidelines recommend surveillance colonoscopy (SCS) to reduce mortality; however, few studies have assessed physicians' adherence to guidelines. This study was aimed to clarify the current status of SCS and adherence to guidelines through the characteristics of cancer/dysplasia surveillance for UC patients in Japan. METHODS: A questionnaire was mailed to 541 physicians who attended meetings on inflammatory bowel disease. RESULTS: The respondents encountered a median of 100 UC cases. Thirty percent of the respondents had never managed a UC patient with cancer. Fifty-one percent of the respondents had never diagnosed colorectal cancer with UC. Forty-seven percent of the respondents considered extensive colitis and left-sided colitis as indications for SCS, and 38% carried out SCS regardless of the disease extent. Sixty-three percent of the respondents started SCS at 7-10 years after UC onset, whereas 20% started SCS at 3 years or less. Fifty-two percent of the respondents obtained targeted biopsies only, and chromoendoscopy was used by 49% of the respondents as a special technique for surveillance. Median number of biopsies at SCS was five per patient; it was three among patients whose biopsy was carried out by physicians who obtained targeted biopsies only and seven among those carried out by physicians who obtained step biopsies and targeted biopsies (P < 0.0001). CONCLUSION: A considerable proportion of the respondents did not follow the guidelines when selecting patients for surveillance and carrying out SCS.

Caudal type homeobox 2 expression induced by leukocytapheresis might be associated with mucosal healing in ulcerative colitis.

BACKGROUND AND AIM: Ulcerative colitis (UC) is a chronic inflammatory disease of the colon with an intractable, recurrent course. Although the goal of UC therapy has recently been to target mucosal healing, the molecular mechanism of mucosal healing remains unknown. In this study, we aimed to elucidate the molecular dynamics related to the proliferation and differentiation of intestinal epithelial cells during cytapheresis therapy in a short duration. METHODS: Endoscopy was performed in 26 patients with UC in multicentre hospitals, and biopsy specimens were collected from the rectum before and within two weeks after leukocytapheresis (LCAP). The expression of representative proteins in intestinal epithelial cells and pathological findings was compared before and after LCAP. RESULTS: The expression of caudal type homeobox 2 (CDX2) and a hes family bHLH transcription factor 1(HES1) markedly increased after LCAP. Patients with endoscopic improvement after LCAP showed the expression of CDX2 before LCAP. Moreover, the number of goblet cells significantly increased after LCAP. Patients without endoscopic improvement after LCAP did not show the expression of CDX2 before LCAP. However, the expression of CDX2 markedly increased after LCAP. CONCLUSION: This study suggests that cytapheresis might induce CDX2 expression without affecting the cell proliferation, thus resulting in mucosal healing with goblet cell restoration.

Genetic characteristics of inflammatory bowel disease in a Japanese population.

BACKGROUND: Crohn's disease (CD) and ulcerative colitis (UC) are two major forms of inflammatory bowel disease (IBD). Meta-analyses of genome-wide association studies (GWAS) have identified 163 susceptibility loci for IBD among European populations; however, there is limited information for IBD susceptibility in a Japanese population. METHODS: We performed a GWAS using imputed genotypes of 743 IBD patients (372 with CD and 371 with UC) and 3321 controls. Using 100 tag single-nucleotide polymorphisms (SNPs) (P < 5 × 10(-5)), a replication study was conducted with an independent set of 1310 IBD patients (949 with CD and 361 with UC) and 4163 controls. In addition, 163 SNPs identified by a European IBD GWAS were genotyped, and genetic backgrounds were compared between the Japanese and European populations. RESULTS: In the IBD GWAS, two East Asia-specific IBD susceptibility loci were identified in the Japanese population: ATG16L2-FCHSD2 and SLC25A15-ELF1-WBP4. Among 163 reported SNPs in European IBD patients, significant associations were confirmed in 18 (8 CD-specific, 4 UC-specific, and 6 IBD-shared). In Japanese CD patients, genes in the Th17-IL23 pathway showed stronger genetic effects, whereas the association of genes in the autophagy pathway was limited. The association of genes in the epithelial barrier and the Th17-IL23R pathways were similar in the Japanese and European UC populations. CONCLUSIONS: We confirmed two IBD susceptibility loci as common for CD and UC, and East Asian-specific. The genetic architecture in UC appeared to be similar between Europeans and East Asians, but may have some differences in CD.

Disease susceptibility genes shared by primary biliary cirrhosis and Crohn's disease in the Japanese population.

We previously identified TNFSF15 as the most significant susceptibility gene at non-HLA loci for both primary biliary cirrhosis (PBC) and Crohn's diseases (CD) in the Japanese population. The aim of this study is to identify further disease susceptibility genes shared by PBC and CD. We selected 15 and 33 genetic variants that were significantly associated with PBC and CD, respectively, based on previously reported genome-wide association studies of the Japanese population. Next, an association study was independently performed for these genetic variants in CD (1312 CD patients and 3331 healthy controls) and PBC (1279 PBC patients and 1015 healthy controls) cohorts. Two CD susceptibility genes, ICOSLG rs2838519 and IL12B rs6556412, were also nominally associated with susceptibility to PBC (P=3.85 × 10(-2) and P=8.40 × 10(-3), respectively). Three PBC susceptibility genes, CXCR5 rs6421571, STAT4 rs7574865 and NFKB1 rs230534, were nominally associated with susceptibility to CD (P=2.82 × 10(-2), P=3.88 × 10(-2) and P=2.04 × 10(-2), respectively). The effect of ICOSLG and CXCR5 variants were concordant but the effect of STAT4, NFKB1 and IL12B variants were discordant for PBC and CD. TNFSF15 and ICOSLG-CXCR5 might constitute a shared pathogenic pathway in the development of PBC and CD in the Japanese population, whereas IL12B-STAT4-NFKB1 might constitute an opposite pathogenic pathway, reflecting the different balance between Th1 and Th17 in the two diseases.

Food antigen-induced immune responses in Crohn's disease patients and experimental colitis mice.

BACKGROUND: In Crohn's disease (CD), the involvement of food antigens in immune responses remains unclear. The objective of this study was to detect immune responses against food antigens in CD patients and examine the mechanism in a mouse model of colitis. METHODS: We enrolled 98 CD patients, 50 ulcerative colitis patients, and 52 healthy controls (HCs) to compare the levels of serum immunoglobulin (Ig)Gs against 88 foods. The presence of serum IgGs against foods was also examined in interleukin (IL)-10 knockout (KO) mice in which CD4(+) T cell activation by antigenic food protein was assessed. Mice transferred with IL-10 KO cells received diets with or without food antigens, and the development of colitis was evaluated. RESULTS: The prevalence of IgGs against various foods, especially vegetables, grains, and nuts, was significantly higher in CD patients than in HCs. Similarly, the prevalence of IgGs against food proteins was higher in IL-10 KO mice than in BALB/c mice. Beta-conglycinin, identified as an antigenic food proteins in IL-10 KO mice, induced CD4(+) T cell production of interferon-γ and IL-17 through dendritic cell antigen presentation. Elimination of the food antigens ameliorated the development of colitis in mice without altering the composition of their intestinal microbiota. CONCLUSIONS: In CD colitis mice, intestinal inflammation via CD4(+) T cell hyperactivation was induced by food antigens associated with high serum IgG levels and was ameliorated by the elimination of food antigens. This disrupted immunological tolerance to food antigen, which might act as an exacerbating factor, remains to be elucidated in CD patients.

Cross-talk between RORγt+ innate lymphoid cells and intestinal macrophages induces mucosal IL-22 production in Crohn's disease.

BACKGROUND: Interleukin (IL)-22-producing RORγt innate lymphoid cells (ILCs) play a pivotal role in intestinal immunity. Recent reports demonstrated that ILCs contribute to mucosal protection and intestinal inflammation in mice. In humans, numbers of RORγt ILCs are significantly increased in the intestine of patients with Crohn's disease (CD), suggesting that ILCs may be associated with intestinal inflammation in CD. However, the mechanism by which ILCs are regulated in the intestine of patients with CD is poorly understood. This study aimed to determine the activation mechanism of intestinal ILCs in patients with CD. METHODS: CD45 lineage marker ILCs were isolated from intestinal lamina propria of patients with CD. ILCs were then subdivided into 4 distinct populations based on the expression of CD56 and CD127. Purified ILC subsets were cocultured with intestinal CD14 macrophages, and IL-22 production was evaluated. RESULTS: CD127CD56 and CD127CD56 ILC, but not CD127CD56 or CD127CD56 ILC, subsets expressed RORγt and produced IL-22. IL-22 production by these ILC subsets was enhanced when ILCs were cocultured with intestinal macrophages. IL-23 or cell-to-cell contact was required for macrophage-mediated activation of ILCs. IL-22 production by ILCs was perturbed in inflamed mucosa compared with noninflamed mucosa. IL-22 induced the expression of Reg1α and Claudin-1 in human intestinal epithelial organoids. CONCLUSIONS: RORγt ILCs might enhance mucosal barrier function through the upregulation of Reg1α through production of IL-22. Although CD14 macrophages augment intestinal inflammation in patients with CD, macrophages also promote a negative feedback pathway through the activation of IL-22 production by RORγt ILCs.

A Case of Human Leukocyte Antigen (HLA) B27-Positive Intestinal Behçet's Disease with Crohn's Disease-Like Anal Fistulas.

A 49-year-old male was admitted to our hospital with complaints of perianal pain, bloody stool, and high-grade fever due to perianal abscess. Drainage was carried out; however, the patient's complaints worsened, and biopsy findings of colonoscopy showed ulcerative colitis-like lesions. The patient was diagnosed as having Behçet's disease with intestinal involvement, did not have HLA-B51, but did have HLA-B27. We describe a case of Behcet's disease with colitis, making a differential diagnosis of inflammatory bowel disease difficult.

C-reactive protein is an indicator of serum infliximab level in predicting loss of response in patients with Crohn's disease.

BACKGROUND: The ability of serum infliximab level to predict clinical outcome in infliximab therapy in Crohn's disease is unclear. Here, we aimed to clarify the correlation between the timing of loss of response (LOR) to treatment and a decrease in serum infliximab level, and, in addition, to identify an indicator of infliximab level. METHODS: The study used data from a previous clinical study of infliximab for Crohn's disease, in which infliximab was initially given at 0, 2, 6 weeks at 5 mg/kg, and then at 8-week intervals to 62 week-10 responders. Of these 62, here we analysed data from 57 in whom Crohn's disease activity index and serum infliximab level were evaluated at week 14. RESULTS: Twelve patients showed a clinical response despite an infliximab level <1 µg/mL at week 14; of these, 8 (67 %) experienced LOR by week 54. A decrease in infliximab level preceded LOR in 6 (75 %). In receiver operating characteristic curve analysis, C-reactive protein (CRP) showed better performance in detecting an infliximab level <1 µg/mL. Infliximab level was <1 µg/mL in 60-80 % of patients with CRP >0.5 mg/dL. Time to LOR (median: 22.0 weeks) was significantly longer than that to a decrease in infliximab level to <1 µg/mL (14.0 weeks, p < 0.05) or to an increase in CRP to >0.5 mg/dL (14.0 weeks, p < 0.01). CONCLUSIONS: A decrease in serum infliximab level preceded LOR, and was easily detected by an increase in CRP. The CRP may be an indicator of serum infliximab level in predicting LOR.

Characteristics of Japanese inflammatory bowel disease susceptibility loci.

BACKGROUND: There are substantial differences in inflammatory bowel disease (IBD) genetics depending on the populations examined. We aimed to identify Japanese population-specific or true culprit susceptibility genes through a meta-analysis of past genetic studies of Japanese IBD. METHODS: For this study, we reviewed 2,703 articles. The review process consisted of three screening stages: we initially searched for relevant studies and then relevant single nucleotide polymorphisms (SNPs). Finally, we adjusted them for the meta-analysis. To maximize our chances of analysis, we introduced proxy SNPs during the first stage. To minimize publication bias, no significant SNPs and solitary SNPs without pairs were combined to be reconsidered during the third stage. Additionally, two SNPs were newly genotyped. Finally, we conducted a meta-analysis of 37 published studies in 50 SNPs located at 22 loci corresponding to the total number of 4,853 Crohn's disease (CD), 5,612 ulcerative colitis (UC) patients, and 14,239 healthy controls. RESULTS: We confirmed that the NKX2-3 polymorphism is associated with common susceptibility to IBD and that HLA-DRB1*0450 alleles increase susceptibility to CD but reduce risk for UC while HLA-DRB1*1502 alleles increase susceptibility to UC but reduce CD risk. Moreover, we found individual disease risk loci: TNFSF15 and TNFα to CD and HLA-B*5201, and NFKBIL1 to UC. The genetic risk of HLA was substantially high (odds ratios ranged from 1.54 to 2.69) while that of common susceptibility loci to IBD was modest (odds ratio ranged from 1.13 to 1.24). CONCLUSIONS: Results indicate that Japanese IBD susceptibility loci identified by the meta-analysis are closely associated with the HLA regions.

Daikenchuto, a traditional Japanese herbal medicine, for the maintenance of surgically induced remission in patients with Crohn's disease: a retrospective analysis of 258 patients.

PURPOSE: Despite numerous studies, the best postoperative therapy for Crohn's disease is still undefined. We retrospectively evaluated the effects of postoperative maintenance therapy with daikenchuto, a traditional Japanese Kampo medicine, on the reoperation rate at 3 years in patients with Crohn's disease. METHODS: A total of 258 patients who underwent surgery for Crohn's disease were identified for the study. For the prevention of postoperative recurrence, patients were stratified to receive 5-aminosalicylic acid, azathioprine or daikenchuto, and their effects on preventing reoperation at 3 years were evaluated. RESULTS: Of the 258 patients, 44 required reoperation with intestinal resection within 3 years due to disease recurrence. The 3-year reoperation rate was significantly lower in the postoperative daikenchuto group than in the non-daikenchuto group (11.3 vs. 24.5 %, P = 0.01), and was similarly significantly lower in the postoperative 5-aminosalicylic acid group than in the non-5-aminosalicylic acid group (14.8 vs. 29.6 %, P = 0.0049). A multivariate Cox analysis showed that postoperative daikenchuto (P = 0.035) and postoperative 5-aminosalicylic acid (P = 0.022) were significantly and independently associated with the rate of reoperation at 3 years in patients with Crohn's disease. CONCLUSION: We propose that continuous daikenchuto therapy is a clinically useful and feasible maintenance therapy for the prevention of postoperative reoperation in patients with Crohn's disease.

Association study of 71 European Crohn's disease susceptibility loci in a Japanese population.

BACKGROUND: A large-scale meta-analysis of a series of European genome-wide association studies revealed 71 susceptibility loci for Crohn's disease (CD). However, it is not clear whether these susceptibility loci are also shared with Japanese populations. METHODS: We genotyped 71 single-nucleotide polymorphisms (SNPs) comprising 1311 CD cases and 6585 controls of Japanese descent, and their associations with CD were evaluated using the Cochran-Armitage trend test. In addition, genotype-phenotype analyses were conducted on the SNPs showing associations with Japanese CD based on the Montreal classification. RESULTS: Twenty-seven SNPs showed at least nominal association (P < 0.05) and 11 of them remained significant even after Bonferroni correction (P < 0.0007). Despite high statistical power, we could not find any association in 17 loci. Moreover, SNPs in 9 loci were rare or absent in the Japanese population. Genetic variations involved in the innate immune system (NOD2, ATG16L1, and IRGM) showed no association with CD susceptibility in the Japanese population. Genotype-phenotype analyses showed that rs3810936, a marker of TNFSF15, correlated with severe CD phenotypes. CONCLUSIONS: Our study suggests that there is a differential genetic background of CD susceptibility between Japanese and European populations.

Resection of a methicillin-resistant Staphylococcus aureus liver abscess in a patient with Crohn's disease under infliximab treatment: a case report.

INTRODUCTION: A liver abscess in Crohn's disease is a rare but important entity that is associated with a poor prognosis and high mortality when treatment is delayed. We report a case of successful liver segmentectomy for a methicillin-resistant Staphylococcus aureus liver abscess in a patient with Crohn's disease under infliximab treatment. CASE PRESENTATION: A 31-year-old Japanese man, who had been treated with infliximab infusions for Crohn's disease, was referred to our hospital presenting with an abrupt onset of high fever and an elevated white blood cell count and serum C-reactive protein level. Computed tomography revealed a liver abscess occupying segment 8. The limited effect of percutaneous transhepatic abscess drainage and antibiotics led us to perform radical resection of the abscess. The patient recovered quickly after surgery and the postoperative course was uneventful. CONCLUSION: The present case suggests that surgical removal of an abscess should be considered for patients under immunosuppression or refractory to conventional treatment.

Efficacy and tolerability of oral budesonide in Japanese patients with active Crohn's disease: a multicentre, double-blind, randomized, parallel-group Phase II study.

BACKGROUND AND AIMS: Current treatments for Japanese patients with active Crohn's disease have not proved optimal, and new treatment options are required. The present study therefore evaluated the efficacy and tolerability of oral budesonide in Japanese patients with mild-to-moderate active Crohn's disease. METHODS: In this multicentre, double-blind, randomized, parallel-group, Phase II study, patients (18-65 years) with baseline Crohn's Disease Activity Index (CDAI) score≥200 were randomized to once-daily (od) oral budesonide 9 mg or 15 mg, or matching placebo, for 8 weeks. Concomitant therapy with sulfasalazine or 5-aminosalicylic acid, and nutritional therapy, was allowed. The rate of remission (defined as CDAI score≤150) after 8 weeks' treatment (primary variable), health-related quality of life (assessed using the Inflammatory Bowel Disease Questionnaire [IBDQ]), and tolerability were assessed. RESULTS: 77 patients were randomized and 63 completed the study. The proportion of budesonide-treated patients with remission after 8 weeks' treatment was higher compared with placebo (23.1%, 28.0%, and 11.5% for budesonide 9 mg, 15 mg, and placebo, respectively; no significant difference). The mean change from baseline to week 8 in CDAI total score (-48.0, -58.2, and -27.2, respectively) and IBDQ total score (10.8, 23.2, and 6.5, respectively) was greater for budesonide-treated patients than placebo recipients. While budesonide 9 mg and 15 mg demonstrated similar efficacy, budesonide 9 mg caused fewer drug- and glucocorticosteroid-related adverse events and less adrenal suppression. CONCLUSIONS: Oral budesonide 9 mg od (for up to 8 weeks) may offer a new treatment option for Japanese patients with mild-to-moderate active Crohn's disease.

Incidence and characteristics of the 2009 influenza (H1N1) infections in inflammatory bowel disease patients.

BACKGROUND: In 2009, influenza A (H1N1) infections spread worldwide. Because the use of immunomodulators is associated with an increased risk of infection, inflammatory bowel disease (IBD) patients who are on immunomodulators might be concerned about H1N1 influenza infections. The aim of this study was to investigate the age distribution and risk factors associated with H1N1 influenza of IBD patients in 2009-2010. METHODS: A multicenter, prospective study was conducted, and 570 IBD patients were enrolled. Patients were followed up for 10 months to identify any new infections. The incidence and age distribution of the H1N1 influenza infections were analyzed. IBD patients with H1N1 influenza infections and 2 matched, noninfected IBD patients were selected to assess the effect of specifying the medication on the incidence of infections. RESULTS: A total of 38 patients (6.7%) developed H1N1 influenza infections. The incidence of H1N1 influenza infections in patients aged less than 20 years was significantly higher than that among patients in other age groups (p<0.01). The age distribution for H1N1 influenza infections in IBD patients was comparable to those in the general population. No patients needed hospitalization due to influenza infection. A total of 29 patients (76%) recovered from the H1N1 influenza symptoms within 7 days and 20 patients (53%) received antiviral treatment. The percentage of patients who used steroids or thiopurine was comparable between the cases of H1N1 influenza infection and the control group. CONCLUSION: Our prospective study showed that younger IBD patients were frequently infected with the influenza A (H1N1) virus as well as general population. Admission and fatal cases due to H1N1 influenza infections were not observed.

A genome-wide association study identifies 2 susceptibility Loci for Crohn's disease in a Japanese population.

BACKGROUND & AIMS: Crohn's disease is an inflammatory bowel disease induced by multiple genetic and environmental factors. Genome-wide association studies have identified genetic factors that affect the risk for Crohn's disease in European populations, but information from other ethnic groups is scarce. We therefore investigated genetic factors associated with Crohn's disease in the Japanese population. METHODS: We performed a genome-wide association study with 372 individuals with Crohn's disease (cases) and 3389 controls, all from the Japanese population. To confirm identified associations, we performed a replication study with an independent panel of 1151 Crohn's disease cases and 15,800 controls. We also performed an association analysis using genome-wide genotype imputation in the discovery cohort. RESULTS: We confirmed associations of Crohn's disease with variants in MHC (rs7765379, P = 2.11 × 10(-59)), TNFSF15 (rs6478106, P = 3.87 × 10(-45)), and STAT3 (rs9891119, P = 2.24 × 10(-14)). We identified 2 new susceptibility loci: on chromosome 4p14 (rs1487630, P = 2.40 × 10(-11); odds ratio, 1.33), and in the SLC25A15-ELF1-WBP4 region on 13q14 (rs7329174 in ELF1, P = 5.12 × 10(-9); odds ratio, 1.27). CONCLUSIONS: In a genome-wide association study, we identified 2 new susceptibility loci for Crohn's disease in a Japanese population. These findings could increase our understanding of the pathogenesis of Crohn's disease.