Colectomy with Permanent End Ileostomy Is More Cost-Effective than Ileal Pouch-Anal Anastomosis for Crohn's Colitis.

BACKGROUND: Much of the economic burden of Crohn's disease (CD) is related to surgery. Twenty percent of patients with CD have isolated colonic disease. While permanent end ileostomy (EI) is generally the procedure of choice for patients with refractory CD colitis, single-center experiences suggest that restorative proctocolectomy (IPAA) is durable in select patients. AIMS: We assessed the cost-effectiveness of total colectomy with permanent EI versus IPAA in medically refractory colonic CD. METHODS: We used a lifetime Markov model with 6-month cycles to simulate quality-adjusted life years (QALYs) and cost. In each of the EI and IPAA strategies, patients could transition between multiple health states. One-way and multivariable sensitivity analysis and tornado analysis were performed to identify thresholds for factors influencing cost-effectiveness. RESULTS: IPAA was more effective than EI surgery with an incremental cost-effectiveness ratio of $70,715 per QALY gained. We identified the following variables of importance in our model: (1) the cost of the EI surgery, (2) the cost of infliximab, and (3) the cost of gastroenterology ambulatory visit and labs. Threshold analysis revealed that if the costs associated with EI surgery exceeded $20,167 or if the utility of IPAA with CD remission without medical therapy exceeded 0.37, IPAA became the more cost-effective strategy. CONCLUSIONS: In patients with medically refractory CD isolated to the colon, colectomy with permanent EI is more cost-effective than IPAA unless the costs associated with the EI surgery exceed $20,167 or if the utility associated with IPAA and CD remission exceeds 0.37.

Genome-wide association study identifies new susceptibility loci for Crohn disease and implicates autophagy in disease pathogenesis.

We present a genome-wide association study of ileal Crohn disease and two independent replication studies that identify several new regions of association to Crohn disease. Specifically, in addition to the previously established CARD15 and IL23R associations, we identified strong and significantly replicated associations (combined P < 10(-10)) with an intergenic region on 10q21.1 and a coding variant in ATG16L1, the latter of which was also recently reported by another group. We also report strong associations with independent replication to variation in the genomic regions encoding PHOX2B, NCF4 and a predicted gene on 16q24.1 (FAM92B). Finally, we demonstrate that ATG16L1 is expressed in intestinal epithelial cell lines and that functional knockdown of this gene abrogates autophagy of Salmonella typhimurium. Together, these findings suggest that autophagy and host cell responses to intracellular microbes are involved in the pathogenesis of Crohn disease.

Immunosuppression impairs response to pneumococcal polysaccharide vaccination in patients with inflammatory bowel disease.

OBJECTIVES: The treatment of inflammatory bowel disease (IBD) often includes immunosuppressive medications, which may increase the risk of vaccine-preventable illnesses. We aimed to assess the impact of immunosuppression on immune responses to pneumococcal vaccination in patients with IBD. METHODS: The study design consists of a prospective controlled clinical trial. This study was carried out at a tertiary-care IBD clinic. The subjects for the study belonged to one of the following three groups: adult patients with IBD on combination TNF-blockers and immunomodulators (Group A), those without immunosuppressive therapy (Group B), and age-matched healthy controls (Group C). The treatment consisted of immunization with 23-valent pneumococcal polysaccharide vaccines (PSVs). The main outcome was immune response for five serotypes defined as a twofold or greater increase from pre-vaccination titers and > or =1 microg post-vaccination titer. RESULTS: Sixty-four subjects participated in the study: 20 in Group A, 25 in Group B, and 19 in Group C. Pre-vaccination titers were similar among the three groups. Vaccine responses were lower in Group A than in Group B (P< or =0.01 for four out of five antigens) and Group C (P<0.01 for all five antigens). Overall vaccine response was seen in 45, 80, and 85% of Groups A, B, and C (P=0.01), respectively. CONCLUSIONS: Immune response to PSV-23 is impaired in Crohn's disease (CD) patients on combination immunosuppressive therapy but is normal among non-immunosuppressed patients. Given the unpredictable likelihood for immunosuppressive therapy, newly diagnosed patients with IBD should undergo vaccination before the initiation of immunosuppressive therapy.

Predicting a change in diagnosis from ulcerative colitis to Crohn's disease: a nested, case-control study.

BACKGROUND & AIMS: Some patients diagnosed with UC undergo a change in diagnosis to CD. Identification of predictors of a diagnostic change could potentially impact the management of patients with colonic inflammation. Our aim was to characterize clinical and serologic predictors of a change in diagnosis from UC to CD. METHODS: A nested, case-controlled study was performed to compare individuals with a change in diagnosis from UC to CD (cases) with age-matched UC and CD controls; primary analysis compared cases with UC controls. Subjects underwent chart review for clinical "red flags" identified by gastroenterologists with expertise in IBD. Serum collected at the time of database enrollment was tested for antibodies to oligomannan (anti-Saccharomyces cerevisiae), Pseudomonas fluorescens-related protein, Escherichia coli outer membrane porin C, CBir1 flagellin, and perinuclear antineutrophil cytoplasmic antibodies. RESULTS: Twenty-one cases, 52 UC controls, and 56 CD controls were assessed. Three red flags, but no serologic markers, differed between cases and UC controls. At initial colonoscopy, cases were more likely to have extensive colonic involvement than UC controls (P = .008). Multivariate regression identified non-bloody diarrhea at initial presentation (P = .01) and weight loss >10% at presentation (P = .007) as independent predictors of diagnostic change. Serologic markers did not add to the contribution of these 2 clinical factors in predicting a change in diagnosis from UC to CD. Diagnostic change was evident in 6 of 6 (100%) patients with both predictors, compared with 8 of 50 (16%) with neither of these factors (P < .0001). CONCLUSIONS: Patients with a diagnosis of UC with initial non-bloody diarrhea or weight loss have an increased likelihood of subsequent change in diagnosis to CD and might thus warrant further diagnostic work-up.

High-frequency haplotypes in the X chromosome locus TLR8 are associated with both CD and UC in females.

BACKGROUND: TNF-alpha and IL-1 have been associated with mucosal inflammation in both Crohn's disease (CD) and ulcerative colitis (UC). Innate immune defects have been associated with CD, specifically CARD15/NOD2. Recently, Toll-like receptor 8 (TLR8) signaling has been shown to enhance generation of both cytokines. Interestingly, TLR8 is located on the X chromosome and inflammatory bowel disease (IBD) has been associated with abnormalities of the X chromosome. The aim was to test whether TLR8 haplotypes are associated with IBD. METHODS: Subjects (735 CD, 343 UC, 245 controls) were genotyped. Single nucleotide polymorphisms (SNPs) were chosen to tag common Caucasian haplotypes. RESULTS: Both "risk (H4)" and "protective (H1)" TLR8 haplotypes were observed associated with CD in females. Eighteen percent of CD females had H4 compared with 9% of controls (P = 0.02). Fifty-nine percent of CD females had H1 compared with 72% of controls (P = 0.01). H1 was also negatively associated with UC in females (59% of UC, 72% of controls P = 0.03). Diplotype analysis of CD, UC, and all IBD in females revealed that 2 protective haplotypes (H1/H1) had a markedly diminished odds ratio, 0.4-0.5. The presence of a risk haplotype (H4 / not H1) had a significantly increased odds ratio, 2.0-2.2. Thus, the risk for IBD was 4-5 times higher in females with 1 risk haplotype than with the protective/protective diplotype. CONCLUSIONS: TLR8 is an X-linked IBD susceptibility gene with both common predisposing and protecting haplotypes. These associations further emphasize the importance of genetic variation in innate immunity as determinants, not only of CD, but of UC as well.

Ulcerative colitis-risk loci on chromosomes 1p36 and 12q15 found by genome-wide association study.

Ulcerative colitis is a chronic inflammatory disease of the colon that presents as diarrhea and gastrointestinal bleeding. We performed a genome-wide association study using DNA samples from 1,052 individuals with ulcerative colitis and preexisting data from 2,571 controls, all of European ancestry. In an analysis that controlled for gender and population structure, ulcerative colitis loci attaining genome-wide significance and subsequent replication in two independent populations were identified on chromosomes 1p36 (rs6426833, combined P = 5.1 x 10(-13), combined odds ratio OR = 0.73) and 12q15 (rs1558744, combined P = 2.5 x 10(-12), combined OR = 1.35). In addition, combined genome-wide significant evidence for association was found in a region spanning BTNL2 to HLA-DQB1 on chromosome 6p21 (rs2395185, combined P = 1.0 x 10(-16), combined OR = 0.66) and at the IL23R locus on chromosome 1p31 (rs11209026, combined P = 1.3 x 10(-8), combined OR = 0.56; rs10889677, combined P = 1.3 x 10(-8), combined OR = 1.29).

IL23R haplotypes provide a large population attributable risk for Crohn's disease.

BACKGROUND: The IL-23 pathway plays a pivotal role in the development of chronic mucosal inflammation seen in the inflammatory bowel diseases. Multiple studies have now established the contribution of the interleukin 23 receptor gene (IL23R) to Crohn's disease (CD) risk in general and of the IL23R R381Q variant in particular. The aim of this work was to estimate the total contribution of this gene to CD risk test using a haplotype approach. METHODS: In all, 763 CD subjects and 254 controls were genotyped for single nucleotide polymorphisms in the IL23R gene using Illumina and ABI methods. Haplotypes were assigned using PHASEv2 and tested for association with CD by chi-square and permutation. RESULTS: Haplotypes with both increased and decreased risk for CD were observed in 2 of the 4 observed blocks (Block 2 H1: 55.4% control, 64% CD, P = 0.019; H2: 64.5% control, 54.4% CD, P = 0.006; Block 3 H1: 55.8% control, 64.4% CD, P = 0.013; H2: 47.0% control, 36.6% CD, P = 0.001). The population attributable risk for these haplotypes was substantially larger than that estimated for the IL23R R381Q variant (Block 2 H1 and block 3 H1 approximately 20%, compared with approximately 4% for Block 3 H6, containing the variant). CONCLUSIONS: These observations suggest that IL23R makes a substantial contribution to CD susceptibility, larger than that estimated from the population frequency of the R381Q variant. These observations also support the expectation that finding "hits" from genomewide association studies will be but an important chapter in the story of unraveling the genetic contribution to CD, rather than the final chapter that brings clarity to all the plot twists of a complicated story.

Patients with inflammatory bowel disease are at risk for vaccine-preventable illnesses.

BACKGROUND: Patients with chronic, immune-mediated conditions such as inflammatory bowel disease (IBD) are often treated with long-term immunosuppressive therapies, potentially increasing their risk of developing an infection. Empiric data suggest that vaccines are underutilized in immunocompromised patients, despite published guidelines recommending their use. We aimed to assess exposure risk and immunization status among patients receiving care in an IBD specialty clinic. METHODS: Patients completed a self-administered, pretested, structured questionnaire during a routine visit for the management of IBD. Survey questions related to medical and immunization histories, and exposures to known risk factors for influenza, pneumococcus, viral hepatitis, and varicella. Additionally, in a subgroup of patients who agreed to donate a sample of blood, immune status to hepatitis A (HAV), hepatitis B (HBV), and varicella was determined. RESULTS: Two hundred four patients were asked to participate in the study; 169 completed surveys and comprised the study population. Mean age was 35 yr (range 13-75 yr). One hundred forty-six respondents (86%) reported current or prior use of immunosuppressive medications. Only 45% of respondents recalled tetanus immunization within the past 10 yr, 41 (28%) reported regularly receiving flu shots, and 13 (9%) reported having received pneumococcal vaccine. The most common reasons for nonimmunization with influenza included lack of awareness (49%) and concern for side effects (18%). Responses indicated that 75 (44%) patients were at risk for HBV but only 47 (28%) had been vaccinated against the infection; of patients with previous HBV vaccination, only three of nine (33%) had measurable antibodies against hepatitis B surface antigen. CONCLUSIONS: Immunization against selected vaccine-preventable illnesses was uncommon in patients with IBD, despite the presence of significant risk factors. Efforts to improve immunization status among patients with IBD and other chronic, immune-mediated conditions are needed.