Risk of malignancies in patients with inflammatory bowel disease treated with thiopurines or anti-TNF alpha antibodies.

PURPOSE: We aimed to analyse malignancy rates and predictors for the development of malignancies in a large German inflammatory bowel disease (IBD) cohort treated with thiopurines and/or anti-tumour necrosis factor (TNF) antibodies. METHODS: De novo malignancies in 666 thiopurine-treated and/or anti-TNF-treated IBD patients were analysed. Patients (n = 262) were treated with thiopurines alone and never exposed to anti-TNF antibodies (TP group). In addition, patients (n = 404) were exposed to anti-TNF antibodies (TNF+ group) with no (7.4%), discontinued (80.4%) or continued (12.1%) thiopurine therapy. RESULTS: In the TP group, 20 malignancies were observed in 18 patients compared with 8 malignancies in 7 patients in the TNF+ group (hazard ratio 4.15; 95% CI 1.82-9.44; p = 0.0007; univariate Cox regression). Moreover, 18.2% of all patients in the TP group ≥50 years of age developed a malignancy, compared with 3.8% of all patients <50 years of age (p = 0.0008). In the TNF+ group, 6.5% of all patients ≥50 years of age developed malignancies compared with 0.3% of all patients <50 years of age (p = 0.0007). In both groups combined, thiopurine treatment duration ≥4 years was associated with the risk for skin cancer (p = 0.0024) and lymphoma (p = 0.0005). CONCLUSIONS: Our data demonstrate an increased risk for the development of malignancies in IBD patients treated with thiopurines in comparison with patients treated with anti-TNF antibodies with or without thiopurines.

Safety of perioperative treatment with biologics in patients with inflammatory bowel disease undergoing bowel surgery: Experience from a large urban center.

BACKGROUND AND AIMS: Risks of peri- and postoperative complications after bowel surgery in patients with inflammatory bowel disease (IBD) receiving biologics are still discussed controversially. We therefore addressed the safety of different biologics that were applied in our IBD center before surgery. METHODS: Data of IBD patients who underwent bowel resections between 2012 and 2022 at our hospital were analyzed retrospectively. Exposure to biologics was defined by receiving biologics within 12 weeks before resective abdominal surgery. Safety considerations included minor complications, such as infections and wound healing disorders and major complications, e.g., anastomotic insufficiency or abscess formation. RESULTS: A total of 447 IBD patients (334 with Crohn's disease, 113 with ulcerative colitis), 51.9% female, were included and followed for a median follow-up of 45 months [range 0-113]. A total of 73.9% (326/447) were undergoing medical treatment at date of surgery, 61.5% (275/447) were treated with biologics within 3 months and 42.3% (189/447) within 4 weeks before surgery. Most surgeries (97.1%) were planned electively and 67.8% were performed laparoscopically. Major and minor complications occurred in 20.8% (93/447) of patients. Serious complications were rare: Six patients had acute postoperative bleeding, one CD patient developed peritonitis and two CD patients died postoperatively. After adjusting for age, disease duration, disease activity, Montreal classification, and medical treatment at date of surgery, no significant differences were observed regarding complications and exposure to biologics. CONCLUSIONS: This retrospective single center study of 447 IBD patients goes to demonstrate that perioperative use of biologics is not associated with a higher risk of complications.

Induction and maintenance of mucosal healing in Crohn's disease with ustekinumab in clinical practice across all care levels in Germany (MUCUS).

The impact of ustekinumab (UST) on mucosal- and fistula healing and extraintestinal manifestations (EIM) in Crohn's disease (CD) were not fully elucidated in the registration trials. In this prospective, multicenter study (EudraCT number: 2017-005151-83) we evaluated the German label real-world-effectiveness of UST to achieve the primary endpoint of combined clinical and endoscopic response at week 52 and several secondary endpoints. Of 79 screened we enrolled 52 patients (female n = 28, bionaïve n = 13, biologic n = 39). At week 52 (per protocol analysis), 52% (n = 13/25) of patients achieved the primary endpoint [50% (n = 3/6) in the bionaïve, 45.5% (n = 5/11) biologic, 62.5% (n = 5/8 ) multiple biologics cohorts, respectively with age as independent predictor [OR 95% CI 0.933 (0.873, 0.998) p = 0.043], 60% (n = 15/25) achieved endoscopic response [50% (n = 3/6) in the bionaïve, 54.5% (n = 6/11) biologic, 75% (n = 6/8) multiple biologics cohorts, respectively], 36% (n = 9/25) achieved endoscopic remission [50% (n = 3/6) in the bionaïve, 27.3% (n = 3/11) biologic, 37.5% (n = 3/8) multiple biologics cohorts, respectively], 48% (n = 12/25) achieved mucosal healing [50% (n = 3/6) in the bionaïve, 36.4% (n = 4/11) biologic, 62.5% (n = 5/8) multiple biologics cohorts, respectively]. All achieved a fistula response and 33.3% (n = 1/3) in the multiple biologics group fistula remission at week 52. EIM decreased (week 0 28.2% vs. week 52 8%). CRP, FCP, PRO-2, EQ-5D-5L improved throughout. 36 patients (69.2%) experienced ≥ 1 treatment emergent adverse event, in 8 (15.4%) cases rated as severe and in 5 (9.6%) leading to UST discontinuation, but no very severe events or deaths. The effectiveness of UST was better than in the registration trials.

Iron status and analysis of efficacy and safety of ferric carboxymaltose treatment in patients with inflammatory bowel disease.

BACKGROUND AND AIMS: We analyzed iron deficiency and the therapeutic response following intravenous ferric carboxymaltose in a large single-center inflammatory bowel disease (IBD) cohort. METHODS: 250 IBD patients were retrospectively analyzed for iron deficiency and iron deficiency anemia. A subgroup was analyzed regarding efficacy and side effects of iron supplementation with ferric carboxymaltose. RESULTS: In the cohort (n = 250), 54.4% of the patients had serum iron levels ≤60 µg/dl, 81.2% had ferritin ≤100 ng/ml, and 25.6% had hemoglobin (Hb) of ≤12 g/dl (females) or ≤13 g/dl (males). In the treatment subcohort (n = 80), 83.1% of the patients had iron ≤60 µg/dl, 90.4% had ferritin ≤100 ng/ml, and 66.7% had Hb ≤12/13 g/dl before ferric carboxymaltose treatment. After a median dose of 500 mg ferric carboxymaltose, 74.7% of the patients reached iron >60 µg/dl, 61.6% had ferritin >100 ng/ml, and 90.7% reached Hb >12/13 g/dl at follow-up (p < 0.0001 for all parameters vs. pretreatment values). The most frequent adverse event was a transient increase of liver enzymes with male gender as risk factor (p = 0.008, OR 8.62, 95% CI 1.74-41.66). CONCLUSIONS: Iron deficiency and anemia are frequent in IBD patients. Treatment with ferric carboxymaltose is efficious, safe and well tolerated in iron-deficient IBD patients.

Current misunderstandings in the management of ulcerative colitis.

Past and ongoing therapeutic concepts for ulcerative colitis have only been moderately successful. A significant proportion of patients with ulcerative colitis will still have to undergo colectomy and overall half of the patients do not achieve sustained remission, leading to impairment of physical and mental health, social life, employment issues and sexual activity. Reluctance to treat patients early on with sufficiently potent drug regimens is obvious. Several popular misconceptions might have led to this situation. First, ulcerative colitis is still considered a more 'benign' disease than Crohn's disease. Furthermore, the general assumption is often that colectomy can 'cure' the disease. Mucosal healing as a therapeutic target has not been widely accepted. Finally, the use of antitumour necrosis factor antibodies in ulcerative colitis has been low because this treatment is considered to be less effective than in Crohn's disease. In the current review we try to disprove these misunderstandings by discussing relevant studies showing how harmful this disease can be and explaining why future studies targeting sustained suppression of inflammation could have an enormous impact on the natural course of the disease. Until these studies are available, we encourage physicians to intensify and maintain treatment until sustained remission and mucosal healing has been reached.

Impact of Immunotherapies on SARS-CoV-2-Infections and Other Respiratory Tract Infections during the COVID-19 Winter Season in IBD Patients.

Background: COVID-19 represents one of the most significant medical problems of our time. Aims: This study is focused on the question whether patients with inflammatory bowel disease (IBD) who receive immunotherapies are more vulnerable to respiratory tract infections and SARS-CoV-2 infections in comparison to medical staff, as a cohort with an increased infection risk, and to the general population in a COVID-19 hotspot. Methods: We analysed data regarding respiratory tract infections that were collected in our IBD registry and compared them with corresponding data from medical employees in our associated Isarklinikum hospital and from the healthy general population in Munich, Germany, over the same time frame in April and June 2020. Patients were tested for SARS-CoV-2 immunoglobulins (Ig). Results: Symptoms of respiratory tract infections occurred equally frequent in IBD patients with immunotherapies as compared to those without. Older age (>49 years), TNF-inhibitor, and ustekinumab treatment showed a significantly protective role in preventing respiratory tract symptomatic COVID-19 infections that occurred in 0.45% of all our 1.091 IBD patients. Of those, 1.8% were positive for SARS-CoV-2 Ig, identically to the general population of Munich with also 1.8% positivity. Whilst more than 3% of all COVID-19 subjects of the general population died during the first wave, none of our IBD patients died or needed referral to the ICU or oxygen treatment. Conclusions: In our study, IBD patients are as susceptible to respiratory tract infections or SARS-CoV-2 as the normal population. There is no evidence of an association between IBD therapies and increased risk of COVID-19. Interestingly, a reduced rate of COVID-19 deaths in IBD patients, the majority on immunomodulator therapy, was observed, compared to the general population. Therefore, no evidence was found to suggest that IBD medication should be withheld, and adherence should be encouraged to prevent flares. In addition to older age (>49 years), TNF inhibitors and ustekinumab show a protective role in preventing respiratory tract infections. In addition, these results add to the growing evidence that supports further investigation of TNF inhibitors as a possible treatment in the early course of severe COVID-19.

Early Start of Infliximab in Crohn's Disease Increases Rates of Endoscopic Remission and Decreases Stenosis Formation: Experiences From a Single Center Cohort.

Background: Over 10 years ago, the step-up/top-down trial demonstrated favorable outcomes of Crohn's disease (CD) after early initiation of infliximab (IFX) in patients with CD. However, data on long-term effects of this treatment strategy in daily clinical practice are scarce. Methods: This retrospective study investigated effects of early (<24 months after diagnosis) versus late intervention (>24 months) of IFX in CD on endoscopic remission (ER) rates, surgery rates, and course of CD, long term. Results: Overall, 242 CD patients (94 early, 148 late intervention) were started on IFX and followed for 24 months. Sixty-one patients with early and 86 with late intervention underwent endoscopy after start of IFX. After IFX induction, 90.3% of patients with early versus 87.8% with late intervention were in clinical remission (P = .676), compared to 89.1% versus 85.8% after 24 months (P = .554). Almost half of patients with early IFX (45.9%, n = 28/61) achieved ER within 24 months compared to only one forth with late IFX intervention (25.6%, n = 22/86, P = .013). In addition, significantly less patients with early IFX intervention (9.8%, n = 6/61) developed intestinal stenosis during 24 months follow-up compared to late IFX start (29.1%, n = 25/86, P = .007). Logistic regression revealed early IFX intervention as only relevant factor achieving ER with an odds ratio of 2.386 (95% confidence interval [1.1180; 4.825], P = .016). Conclusions: Our data on early IFX therapy in CD support early IFX intervention with more patients achieving ER, and less patients developing stricturing disease behavior. Early IFX intervention could therefore change the course of CD.

Disease activity, ANCA, and IL23R genotype status determine early response to infliximab in patients with ulcerative colitis.

OBJECTIVES: We analyzed the efficacy and safety of the antitumor necrosis factor-alpha antibody infliximab (IFX) for induction therapy in patients with moderate-to-severe ulcerative colitis (UC) in a large single-center cohort. METHODS: A total of 90 UC patients treated with IFX for 14 weeks were analyzed retrospectively. Colitis activity index (CAI) and markers of inflammation were measured during IFX induction therapy. Genotyping for UC-associated variants in the IL23R gene and in the IL2/IL21 region was performed. RESULTS: At week 2 (after the first IFX infusion), 64.1% of IFX-treated patients had clinical response to IFX and 52.6% were in remission. At week 14 (after three infusions), 61.0% showed clinical response and 52.5% were in remission. The mean CAI decreased significantly from 10.4 points at week 0 to 5.1 at week 2 (P<0.001), to 4.4 at week 6 (P<0.001), and to 5.0 at week 14 (P<0.001). Similarly, IFX therapy significantly decreased C-reactive protein levels and leukocyte counts (P=0.01 and P=0.001 at week 2 and week 0, respectively). Multivariate regression analysis identified high CAI before IFX therapy (P=0.01) and negative antineutrophil cytoplasmatic autoantibody (ANCA) status (P=0.01) as independent positive predictors for response to IFX. Homozygous carriers of inflammatory bowel disease (IBD) risk-increasing IL23R variants were more likely to respond to IFX than were homozygous carriers of IBD risk-decreasing IL23R variants (74.1 vs. 34.6%; P=0.001). No serious adverse IFX-related events requiring hospitalization were recorded. CONCLUSIONS: Our findings suggest that IFX therapy is safe and effective in patients with moderate-to-severe UC. A high CAI before IFX therapy, ANCA seronegativity, and the IL23R genotype were predictors of early response to IFX.

Clinical outcomes with ustekinumab as rescue treatment in therapy-refractory or therapy-intolerant ulcerative colitis.

BACKGROUND: Recently, ustekinumab a monoclonal antibody targeting interleukin-12 and -23 and successfully used in Crohn's disease also has been shown to be effective in induction and maintaining remission in patients with moderate to severe ulcerative colitis in a large phase 3 trial. However, no observational data on the use of ustekinumab in ulcerative colitis in daily clinical practice is available. AIM: The purpose of this study was to assess the clinical outcomes achieved with ustekinumab as rescue treatment in therapy-refractory or -intolerant ulcerative colitis in a real-life setting. METHODS: A retrospective data analysis was performed in 19 ulcerative colitis patients who were intolerant or refractory to all of the following drugs: steroids, purine-analogues, tumour necrosis factor antibodies and vedolizumab. To all patients ustekinumab was provided as a rescue treatment (intravenous induction with 6 mg/kg, followed by week subcutaneous injection once every eight weeks of 90 mg). The primary outcome was achievement of clinical remission at one year, defined as score of ≤ 3 points in the Lichtiger score (colitis activity index). Patients were evaluated regularly and a colonoscopy was performed before the start and at the end of the observation. Ethical approval was provided by Ethikkommission Ärztekammer Hamburg (PV 5539). RESULTS: In five patients, therapy was stopped due to refractory disease or side effects. In all remaining 14 patients the median colitis activity index dropped from 8.5 points (range 1-12) at start to 2.0 points at one year (range 0-5.5) and Mayo endoscopy scores fell from a median of two points (range 1-3, mean of 2.3) at start to a median of one point (range 1-3, mean of 1.4) at one year. Including the five drop-outs, clinical remission was achieved in 53% of the 19 patients at one year. CONCLUSIONS: In accordance with the UNIFI (A Study to Evaluate the Safety and Efficacy of Ustekinumab Induction and Maintenance Therapy in Participants With Moderately to Severely Active Ulcerative Colitis) trial our real-life data support ustekinumab as an effective and safe treatment option in therapy refractory moderate to severe ulcerative colitis with a history of biological therapies.

Early combined immunosuppression or conventional management in patients with newly diagnosed Crohn's disease: an open randomised trial.

BACKGROUND: Most patients who have active Crohn's disease are treated initially with corticosteroids. Although this approach usually controls symptoms, many patients become resistant to or dependent on corticosteroids, and long exposure is associated with an increased risk of mortality. We aimed to compare the effectiveness of early use of combined immunosuppression with conventional management in patients with active Crohn's disease who had not previously received glucocorticoids, antimetabolites, or infliximab. METHODS: We did a 2-year open-label randomised trial at 18 centres in Belgium, Holland, and Germany between May, 2001, and January, 2004. We randomly assigned 133 patients to either early combined immunosuppression or conventional treatment. The 67 patients assigned to combined immunosuppression received three infusions of infliximab (5 mg/kg of bodyweight) at weeks 0, 2, and 6, with azathioprine. We gave additional treatment with infliximab and, if necessary, corticosteroids, to control disease activity. 66 patients assigned to conventional management received corticosteroids, followed, in sequence, by azathioprine and infliximab. The primary outcome measures were remission without corticosteroids and without bowel resection at weeks 26 and 52. Analysis was by modified intention to treat. This trial was registered with ClinicalTrials.gov, number NCT00554710. FINDINGS: Four patients (two in each group) did not receive treatment as per protocol. At week 26, 39 (60.0%) of 65 patients in the combined immunosuppression group were in remission without corticosteroids and without surgical resection, compared with 23 (35.9%) of 64 controls, for an absolute difference of 24.1% (95% CI 7.3-40.8, p=0.0062). Corresponding rates at week 52 were 40/65 (61.5%) and 27/64 (42.2%) (absolute difference 19.3%, 95% CI 2.4-36.3, p=0.0278). 20 of the 65 patients (30.8%) in the early combined immunosuppression group had serious adverse events, compared with 19 of 64 (25.3%) controls (p=1.0). INTERPRETATION: Combined immunosuppression was more effective than conventional management for induction of remission and reduction of corticosteroid use in patients who had been recently diagnosed with Crohn's disease. Initiation of more intensive treatment early in the course of the disease could result in better outcomes.

Epistasis between Toll-like receptor-9 polymorphisms and variants in NOD2 and IL23R modulates susceptibility to Crohn's disease.

OBJECTIVES: Recent data suggest functional interactions between NOD2 and other receptors of the innate immune system modulating inflammatory responses. Here we analyzed the role of Toll-like receptor 9 (TLR-9) gene variants with respect to susceptibility to inflammatory bowel disease (IBD) and tested for genetic interactions with NOD2 and other susceptibility genes for Crohn's disease (CD). METHODS: The single-nucleotide polymorphisms (SNPs) -1237T/C (rs5743836) and 2848A/G (rs352140=p.Pro545Pro) in TLR9, the main CD-associated variants within the genes for NOD2, IL23R, ATG16L1, and variants in the IBD5 locus and in the DLG5 gene were assessed in 956 patients with IBD (606 CD and 350 ulcerative colitis) and in 792 healthy controls. The associations with disease susceptibility and phenotype, and epistatic gene-gene interactions, were analyzed. RESULTS: The TLR9 -1237T/C polymorphism showed significant interactions with NOD2 mutations. The frequency of -1237C was significantly higher in CD patients with at least one NOD2 mutation (P=0.004 vs. controls, odds ratio (OR) 1.60, 95% confidence interval (CI) (1.15-2.21)) and further increased in CD patients with two mutated NOD2 alleles (P=0.002 vs. controls, OR 2.37, 95% CI (1.35-4.15)). Significant gene-gene interactions were also observed for the TLR9 polymorphism -1237T/C with IL23R variants (most significantly with rs1004819, P=0.0007), with a particular high frequency of -1237C in CD patients carrying CD-protective IL23R variants. Epistatic interactions of the TLR9 -1237T/C SNP were also noted with the DLG5 113G/A variant (P=0.0007). CONCLUSIONS: Our results provide evidence for genetic interactions between polymorphisms in TLR9 and CD-associated variants in NOD2, IL23R, and DLG5, differentially modulating CD susceptibility.

Novel genetic risk markers for ulcerative colitis in the IL2/IL21 region are in epistasis with IL23R and suggest a common genetic background for ulcerative colitis and celiac disease.

OBJECTIVES: Recently, a genome-wide association study showed that single-nucleotide polymorphisms (SNPs) in the chromosome 4q27 region containing IL2 and IL21 are associated with celiac disease. Given the increased prevalence of inflammatory bowel disease (IBD) among celiac disease patients, we investigated the possible involvement of these SNPs in IBD. METHODS: Five SNPs strongly associated with celiac disease within the KIAA1109/TENR/IL2/IL21 linkage disequilibrium block on chromosome 4q27 and one coding SNP within the IL21 gene were analyzed in a large German IBD cohort. The study population comprised a total of 2,948 Caucasian individuals, including 1,461 IBD patients (ulcerative colitis (UC): n=514, Crohn's disease (CD): n=947) and 1,487 healthy unrelated controls. RESULTS: Three of the five celiac disease risk markers had a protective effect on UC susceptibility, and this effect remained significant after correcting for multiple testing: rs6840978: P=0.0082, P(corr)=0.049, odds ratio (OR) 0.77, 95% confidence interval (CI) 0.63-0.93; rs6822844: P=0.0028, P(corr)=0.017, OR 0.73, 95% CI 0.59-0.90; rs13119723: P=0.0058, P(corr)=0.035, OR 0.75, 95% CI 0.61-0.92. A haplotype consisting of the six SNPs tested was markedly associated with UC susceptibility (P=0.0025, P(corr)=0.015, OR 0.72, 95% CI 0.58-0.89). Moreover, in UC, epistasis was observed between the IL23R SNP rs1004819 and three SNPs in the KIAA1109/TENR/IL2/IL21 block (rs13151961, rs13119723, and rs6822844). CONCLUSIONS: Similar to other autoimmune diseases such as celiac disease, rheumatoid arthritis, type 1 diabetes, Graves' disease, and psoriatic arthritis, genetic variation in the chromosome 4q27 region predisposes to UC, suggesting a common genetic background for these diseases.

rs224136 on chromosome 10q21.1 and variants in PHOX2B, NCF4, and FAM92B are not major genetic risk factors for susceptibility to Crohn's disease in the German population.

OBJECTIVES: Recently, a North American genome-wide association study identified three novel gene variants in PHOX2B, NCF4, and FAM92B as well as one single nucleotide polymorphisms (SNP; rs224136) in the intergenic region on chromosome 10q21.1 as being associated with Crohn's disease (CD). However, their influence on European CD patients as well as ulcerative colitis (UC) is unknown. Therefore we aimed to replicate these novel CD susceptibility variants in a large European cohort with inflammatory bowel disease and analyzed potential gene-gene interactions with variants in the NOD2/CARD15, IL23R, and ATG16L1 genes. METHODS: Genomic DNA from 2,833 Caucasian individuals including 854 patients with CD, 476 patients with UC, and 1,503 healthy unrelated controls was analyzed for SNPs in PHOX2B (rs16853571), NCF4 (rs4821544), and FAM92B (rs8050910), including rs224136 on chromosome 10q21.1. RESULTS: In our study population, no association of PHOX2B (P=0.563), NCF4 (P=0.506), FAM92B (P=0.401), and rs224136 (P=0.363) with CD was found. Similarly, none of these SNPs was associated with UC. In contrast, all analyzed SNPs in NOD2/CARD15, IL23R, and ATG16L1 were strongly associated with CD with P values ranging from 5.0x10(-3) to 1.6x10(-22), but there was no epistasis with polymorphisms in PHOX2B, NCF4, FAM92B, and rs224136. CONCLUSIONS: In contrast to the North American population, PHOX2B, NCF4, FAM92B, and rs224136 are not associated with CD in the European population, whereas NOD2/CARD15, IL23R, and ATG16L1 are strongly associated with CD in both the North American and European populations, confirming these three genes as major CD susceptibility genes in Caucasian populations.

Role of the novel Th17 cytokine IL-17F in inflammatory bowel disease (IBD): upregulated colonic IL-17F expression in active Crohn's disease and analysis of the IL17F p.His161Arg polymorphism in IBD.

BACKGROUND: Interleukin (IL)-17F, produced in IL-23R-expressing Th17 cells, is a novel member of the IL-17 cytokine family. Given the association of IL23R with inflammatory bowel disease (IBD), we characterized the role of IL-17F in IBD including its intestinal gene expression and the effect of the IL17F p.His161Arg polymorphism on disease susceptibility and phenotype of Crohn's disease (CD) and ulcerative colitis (UC). In addition, we analyzed the IL17F p.His161Arg polymorphism for potential epistasis with IL23R and NOD2/CARD15 variants. METHODS: Intestinal IL-17F mRNA expression was measured by quantitative polymerase chain reaction (PCR). Genomic DNA from 1682 individuals (CD: n = 499; UC: n = 216; controls: n = 967) was analyzed for the presence of the IL17F p.His161Arg polymorphism, the 3 NOD2 variants, p.Arg702Trp, p.Gly908Arg, and p.Leu1007fsX1008, and 10 CD-associated IL23R variants. RESULTS: Intestinal IL-17F mRNA expression was 4.4-fold increased in inflamed colonic lesions compared to uninflamed biopsies in CD (P = 0.016) but not in UC. However, the mean intestinal IL-17F mRNA expression was higher in UC than in CD (P < 0.0001). The IL17F p.His161Arg substitution was observed with similar frequencies in IBD patients and controls and was not associated with a certain disease phenotype, but weakly associated with a low body mass index (BMI; P = 0.009) and an earlier age of disease onset (P = 0.039) in UC. There was no evidence for epistasis between the IL17F p.His161Arg polymorphism and IBD-associated single nucleotide polymorphisms within the IL23R gene. CONCLUSIONS: Intestinal IL17F gene expression is increased in active CD. The IL17F p.His161Arg polymorphism is not associated with IBD susceptibility and has no epistatic interaction with CD-associated IL23R variants.

Macrophage migration inhibitory factor (MIF) -173G/C promoter polymorphism influences upper gastrointestinal tract involvement and disease activity in patients with Crohn's disease.

BACKGROUND: Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine with increased expression in inflammatory bowel disease. The aim of the study was to analyze the role of the MIF -173G/C single nucleotide polymorphism in Crohn's disease (CD). METHODS: Using restriction fragment length polymorphism analysis, genomic DNA of 198 patients with CD and 159 unrelated controls was analyzed for the -173G/C SNP in the MIF promoter region. Colonic MIF mRNA expression was measured by quantitative polymerase chain reaction (PCR), serum MIF levels by enzyme-linked immunosorbent assay (ELISA). RESULTS: Thirty-six of the 146 G/G wildtype carriers (24.7%) but only 3 of the 45 G/C heterozygotes (6.7%) and only 1 of the C/C homozygotes (14.3%) were diagnosed with upper gastrointestinal tract involvement (P = 0.009, odds ratio [OR] = 0.22, 95% confidence interval [CI], 0.06-0.75 for wildtype versus hetero- and homozygous carriers). This result was confirmed in a second prospective study, in which all patients diagnosed with upper gastrointestinal involvement (n = 13) were G/G wildtype carriers (P = 0.01 versus controls). All patients (n = 12; 100%) with a Crohn's disease activity index (CDAI) > 300 were G/G wildtype carriers compared to only 65.6% wildtype carriers in the group with a CDAI < 150 (P = 0.016). MIF is expressed in the colonic mucosa of CD patients and intestinal epithelial cells but its mRNA expression does not correlate with the degree of inflammation and is not upregulated by proinflammatory cytokines. In CD, MIF serum levels are not influenced by the MIF -173G/C polymorphism. CONCLUSIONS: The MIF -173G/C polymorphism appears to be a factor contributing to a particular CD phenotype characterized by protection against upper gastrointestinal tract involvement and severe disease activity.

Resistin is an inflammatory marker of inflammatory bowel disease in humans.

OBJECTIVES: Resistin, a recently discovered adipokine, has been shown to be associated with inflammatory conditions such as insulin resistance, obesity, atherosclerosis and rheumatoid arthritis. We therefore hypothesized that (i) resistin levels may be elevated in patients with inflammatory bowel disease (IBD) and (ii) resistin levels may be associated with disease activity in IBD. METHODS: We addressed these questions by testing for associations between resistin plasma levels, inflammatory parameters and clinical disease activity in a case-control study with 235 patients with Crohn's disease (CD), 112 patients with ulcerative colitis (UC) and 144 healthy controls. RESULTS: Patients with IBD showed significantly higher resistin levels compared with controls (P<0.0001). In both, patients with CD and UC, resistin concentrations were significantly associated with elevated white blood cell count (P<0.0001), C-reactive protein (CRP) (P<0.0001) and disease activity (P< or =0.0001). In multivariate logistic regression analysis, resistin levels were identified as an independent predictor of active disease (odds ratio 1.014, 95% confidence interval 1.002-1.027, P=0.02) in patients with CD after adjusting for sex, age, body mass index, white blood cell count and CRP. In UC patients, resistin was associated with active disease in multivariate regression analysis after control for sex, age, body mass index and white blood cell count (odds ratio 1.015, 95% confidence interval 1.002-1.029, P=0.02). Addition of CRP, however, abolished this association. CONCLUSION: Resistin levels are an independent predictor of disease activity in patients with CD. Resistin may represent a novel link between inflammation and IBD.

Predictive value of the CARD15 variant 1007fs for the diagnosis of intestinal stenoses and the need for surgery in Crohn's disease in clinical practice: results of a prospective study.

BACKGROUND AND AIM: The diagnostic and therapeutic relevance of CARD15 genotyping in Crohn's disease (CD) for daily clinical practice has not been investigated so far. We therefore analyzed whether CARD15 variants are independent predictive factors for small bowel stenosis in CD evaluated by magnetic resonance enteroclysis (MRE). On the basis of these findings, the potential implications for patient management were investigated. METHODS: Eighty CD patients with clinical symptoms suggestive of small bowel stenosis were included. All patients were genotyped for the CARD15 variants c.2104C > T (p.R702W), c.2722G > C (p.G908R), and c.3019_3020insC (p.Leu1007fsX1008) and examined by MRE of the small bowel. RESULTS: CARD15 variants were found in 40 (50%) patients. MRE identified 31 (38%) patients with small bowel stenoses. Twenty-five of the 40 (62%) patients with at least one CARD15 variant were diagnosed of intestinal stenosis by MRE (odds ratio [OR] = 9.44; confidence interval [CI] 3.21-27.77; P = 0.00028, Bonferroni corrected). Particularly, the presence of the 1007fs variant was associated with an increased risk of an intestinal stenosis (OR = 12.00, CI 3.47-41.54, P = 0.00042, Bonferroni corrected). Twenty-one of 31 (68%) patients with stenoses required surgical intervention, with 13 of these 21 (62%) patients carrying the 1007fs variant. CONCLUSION: In the largest prospective study analyzing the diagnostic value of CARD15 variants in CD patients performed so far, we identified the 1007fs variant as strong predictor for intestinal stenoses with need for surgery in CD patients. Genotyping could therefore be an important diagnostic tool in clinical practice for identifying high-risk patients with specific diagnostic and therapeutic needs. Moreover, MRE is an excellent technique for diagnosing small bowel stenoses.

Role of the NFKB1 -94ins/delATTG promoter polymorphism in IBD and potential interactions with polymorphisms in the CARD15/NOD2, IKBL, and IL-1RN genes.

BACKGROUND: Recently, an association of the NFKB1 polymorphism -94ins/delATTG with ulcerative colitis (UC) has been reported. This 4-bp insertion/deletion polymorphism is localized in the promoter region of the NFKB1 gene and appears to be functionally relevant. The aim of the present study was to confirm the association of the -94ins/delATTG (W/D) NFKB1 promoter polymorphism with UC in a population of German origin and to test for a potential association with Crohn's disease (CD). Furthermore, potential interactions of the -94ins/delATTG polymorphism with the IKBL and the IL-1RN genes should be determined. MATERIALS AND METHODS: The study population comprised 630 patients with CD, 365 patients with UC, and 974 healthy controls. Genotyping was performed using polymerase chain reaction and restriction fragment length polymorphism analysis. For statistical evaluation, the chi-square test and the Fisher exact test were used. RESULTS: No significant association of the W/D NFKB1 polymorphism with CD or UC was detected. In addition, no significant interactions between the -94ins/delATTG NFKB1 polymorphism and polymorphisms within the IKBL and the IL-1RN genes, respectively, were found in CD or UC. Also, no significant interactions of the NFKB1 polymorphism with mutations of the CARD15/NOD2 gene and with clinical phenotypes were detected in CD. Moreover, no associations of the NFKB1 polymorphism were found in UC depending on disease localization. CONCLUSIONS: The present study could not confirm the reported association of the -94ins/delATTG NFKB1 polymorphism with UC and also found no evidence for a role of this polymorphism in CD. The results do not give evidence for a role of this NFKB1 polymorphism in the pathogenesis of UC and CD.

Reaching out for the causative agent in inflammatory bowel disease: is there evidence for Chlamydia pneumoniae as a pathogenic factor?

In this issue of the Journal, Muller and colleagues attempt to define the role of specific bacterial pathogens, particularly Chlamydia pneumoniae, as causative agents in inflammatory bowel disease. Even if a major role for C. pneumoniae in the pathogenesis of inflammatory bowel disease could be ruled out, our current understanding of inflammatory pathways in Crohn's disease and ulcerative colitis implies that the search for other microorganisms as causative agents should continue.