Hans H. Herfarth

The NLRP3 inflammasome functions as a negative regulator of tumorigenesis during colitis-associated cancer

Colitis-associated cancer (CAC) is a major complication of inflammatory bowel diseases. We show that components of the inflammasome are protective during acute and recurring colitis and CAC in the dextran sulfate sodium (DSS) and azoxymethane + DSS models. Mice lacking the inflammasome adaptor protein PYCARD (ASC) and caspase-1 demonstrate increased disease outcome, morbidity, histopathology, and polyp formation. The increased tumor burden is correlated with attenuated levels of IL-1β and IL-18 at the tumor site. To decipher the nucleotide-binding domain, leucine-rich-repeat-containing (NLR) component that is involved in colitis and CAC, we assessed Nlrp3 and Nlrc4 deficient mice. Nlrp3−/− mice showed an increase in acute and recurring colitis and CAC, although the disease outcome was less severe in Nlrp3−/− mice than in Pycard−/− or Casp1−/− animals. No significant differences were observed in disease progression or outcome in Nlrc4−/− mice compared with similarly treated wild-type animals. Bone marrow reconstitution experiments show that Nlrp3 gene expression and function in hematopoietic cells, rather than intestinal epithelial cells or stromal cells, is responsible for protection against increased tumorigenesis. These data suggest that the inflammasome functions as an attenuator of colitis and CAC.

European evidence-based Consensus on the diagnosis and management of ulcerative colitis: Definitions and diagnosis

### 1.1 Introduction Ulcerative colitis is a life long disease arising from an interaction between genetic and environmental factors, but observed predominantly in the developed countries of the world. The precise aetiology is unknown and therefore medical therapy to cure the disease is not yet available. Within Europe there is a North–South gradient, but the incidence appears to have increased in Southern and developing countries in recent years.1,2 Patients may live with a considerable symptom burden despite medical treatment (66% describe interference with work and 73% with leisure activities3) in the hope that the aetiology of ulcerative colitis will shortly be revealed and a cure emerges. Although this is conceivable in the next decade, clinicians have to advise patients on the basis of information available today. Despite randomized trials there will always be many questions that can only be answered by the exercise of judgement and opinion. This leads to differences in practice between clinicians, which may be brought into sharp relief by differences in emphasis between countries. The Consensus endeavours to address these differences. The Consensus is not meant to supersede the guidelines of different countries (such as those from the UK,4 or Germany5), which reach broadly the same conclusions since they are, after all, based on the same evidence. Rather, the aim of the Consensus is to promote a European perspective on the management of ulcerative colitis (UC) and its dilemmas. Since the development of guidelines is an expensive and time-consuming process, it may help to avoid duplication of effort in the future. A European Consensus is also considered important because an increasing number of therapeutic trials recruit from Central and Eastern European countries where practice guidelines have yet to be published. This document sets out the current European Consensus on the diagnosis and management …

The London Position Statement of the World Congress of Gastroenterology on Biological Therapy for IBD With the European Crohn's and Colitis Organization: When to Start, When to Stop, Which Drug to Choose, and How to Predict Response?

The advent of biological therapy has revolutionized inflammatory bowel disease (IBD) care. Nonetheless, not all patients require biological therapy. Selection of patients depends on clinical characteristics, previous response to other medical therapy, and comorbid conditions. Availability, reimbursement guidelines, and patient preferences guide the choice of first-line biological therapy for luminal Crohns disease (CD). Infliximab (IFX) has the most extensive clinical trial data, but other biological agents (adalimumab (ADA), certolizumab pegol (CZP), and natalizumab (NAT)) appear to have similar benefits in CD. Steroid-refractory, steroid-dependent, or complex fistulizing CD are indications for starting biological therapy, after surgical drainage of any sepsis. For fistulizing CD, the efficacy of IFX for inducing fistula closure is best documented. Unique risks of NAT account for its labeling as a second-line biological agent in some countries. Patients who respond to induction therapy benefit from systematic re-treatment. The combination of IFX with azathioprine is better than monotherapy for induction of remission and mucosal healing up to 1 year in patients who are naïve to both agents. Whether this applies to other agents remains unknown. IFX is also effective for treatment-refractory, moderate, or severely active ulcerative colitis. Patients who have a diminished or loss of response to anti-tumor necrosis factor (TNF) therapy may respond to dose adjustment of the same agent or switching to another agent. Careful consideration should be given to the reasons for loss of response. There are insufficient data to make recommendations on when to stop anti-TNF therapy. Preliminary evidence suggests that a substantial proportion of patients in clinical remission for >1 year, without signs of active inflammation can remain in remission after stopping treatment.

Modulation of the Intestinal Microbiota Alters Colitis-Associated Colorectal Cancer Susceptibility

It is well established that the intestinal microbiota plays a key role in the pathogenesis of Crohns disease (CD) and ulcerative colitis (UC) collectively referred to as inflammatory bowel disease (IBD). Epidemiological studies have provided strong evidence that IBD patients bear increased risk for the development of colorectal cancer (CRC). However, the impact of the microbiota on the development of colitis-associated cancer (CAC) remains largely unknown. In this study, we established a new model of CAC using azoxymethane (AOM)-exposed, conventionalized-Il10−/− mice and have explored the contribution of the host intestinal microbiota and MyD88 signaling to the development of CAC. We show that 8/13 (62%) of AOM-Il10−/− mice developed colon tumors compared to only 3/15 (20%) of AOM- wild-type (WT) mice. Conventionalized AOM-Il10−/− mice developed spontaneous colitis and colorectal carcinomas while AOM-WT mice were colitis-free and developed only rare adenomas. Importantly, tumor multiplicity directly correlated with the presence of colitis. Il10−/− mice mono-associated with the mildly colitogenic bacterium Bacteroides vulgatus displayed significantly reduced colitis and colorectal tumor multiplicity compared to Il10−/− mice. Germ-free AOM-treated Il10−/− mice showed normal colon histology and were devoid of tumors. Il10−/−; Myd88−/− mice treated with AOM displayed reduced expression of Il12p40 and Tnfα mRNA and showed no signs of tumor development. We present the first direct demonstration that manipulation of the intestinal microbiota alters the development of CAC. The TLR/MyD88 pathway is essential for microbiota-induced development of CAC. Unlike findings obtained using the AOM/DSS model, we demonstrate that the severity of chronic colitis directly correlates to colorectal tumor development and that bacterial-induced inflammation drives progression from adenoma to invasive carcinoma.

Risk of Melanoma and Nonmelanoma Skin Cancer Among Patients With Inflammatory Bowel Disease

BACKGROUND & AIMS Patients with inflammatory bowel disease (IBD) are at risk for certain malignancies. We aimed to determine the risk of melanoma and nonmelanoma skin cancer (NMSC) in patients with IBD and how medications affect these risks. METHODS We performed retrospective cohort and nested case-control studies using administrative data from the LifeLink Health Plan Claims Database from 1997 to 2009. The cohort comprised 108,579 patients with IBD, and each was matched to 4 individuals without IBD. The risk of melanoma and NMSC was evaluated by incidence rate ratio (IRR) and by adjusted Cox proportional hazard ratio (HR) modeling. In nested case-control studies, patients with melanoma or NMSC were matched to 4 patients with IBD without melanoma or NMSC. Conditional logistic regression was used to determine associations between medications and both skin cancers. RESULTS In the cohort, IBD was associated with an increased incidence of melanoma (IRR, 1.29; 95% confidence interval [CI], 1.09-1.53). Risk was greatest among individuals with Crohns disease (IRR, 1.45; 95% CI, 1.13-1.85; adjusted HR, 1.28; 95% CI, 1.00-1.64). The incidence of NMSC also increased among patients with IBD (IRR, 1.46; 95% CI, 1.40-1.53) and was greatest among those with CD (IRR, 1.64; 95% CI, 1.54-1.74). In the nested case-control studies, therapy with biologics increased the risk of melanoma (odds ratio [OR], 1.88; 95% CI, 1.08-3.29). Patients who had been treated with thiopurines had an increased risk of NMSC (OR, 1.85; 95% CI, 1.66-2.05). CONCLUSIONS Immunosuppression increases the risk of melanoma and NMSC among patients with IBD. The risk of melanoma is increased by use of biologics, and the risk of NMSC is increased by use of thiopurines. Patients with IBD should be counseled and monitored for skin cancer.

Increased Risk for Non-Melanoma Skin Cancer in Patients With Inflammatory Bowel Disease

BACKGROUND & AIMS Patients with inflammatory bowel disease (IBD) might be at increased risk for certain malignancies. We evaluated the risk of non-melanoma skin cancer (NMSC) in patients with IBD and determined how immunosuppressive and biologic medications affect this risk. METHODS We performed retrospective cohort and nested case-control studies by using administrative data from PharMetrics Patient Centric Database. In the cohort study, 26,403 patients with Crohns disease (CD) and 26,974 patients with ulcerative colitis (UC) were each matched to 3 non-IBD controls. NMSC risk was evaluated by incidence rate ratio (IRR). In the nested case-control study, 387 CD patients and 355 UC patients with NMSC were each matched to 4 IBD patients without NMSC by using incidence density sampling. Conditional logistic regression was used to determine the association between specific IBD medication use and NMSC. RESULTS In the cohort study, the incidence of NMSC was higher among patients with IBD compared with controls (IRR, 1.64; 95% confidence interval [CI], 1.51-1.78). In the nested-case control study, recent thiopurine use (< or =90 days) was associated with NMSC (adjusted odds ratio [OR], 3.56; 95% CI, 2.81-4.50), as was recent biologic use among patients with CD (adjusted OR, 2.07; 95% CI, 1.28-3.33). Persistent thiopurine use (>365 days) was associated with NMSC (adjusted OR, 4.27; 95% CI, 3.08-5.92), as was persistent biologic use among patients with CD (adjusted OR, 2.18; 95% CI, 1.07-4.46). CONCLUSIONS Patients with IBD, especially those who receive thiopurines, are at risk for NMSC. Appropriate counseling and monitoring of such patients with IBD are recommended.

Azathioprine and 6-mercaptopurine for the prevention of postoperative recurrence in Crohn's disease: a meta-analysis

OBJECTIVES:To evaluate the efficacy and safety of purine analogs (azathioprine, 6-mercaptopurine (6-MP)) in the prevention of postoperative recurrence in Crohns disease (CD).METHODS:We searched MEDLINE, the Cochrane Library, and EMBASE. The primary end points, clinical and endoscopic recurrence at 1 and 2 years, and safety were analyzed by the methods of Peto and Der Simonian and Laird.RESULTS:Four controlled trials enrolled 433 patients and compared azathioprine (n=3) or (6-MP) (n=1) with control arms (placebo with or without antibiotic induction therapy or mesalamine). In the overall analysis, purine analogs were more effective than control arms in preventing clinical recurrence at 1 year (mean difference, 95% confidence interval (CI): 8, 1–15%, P=0.021, number needed to treat (NNT)=13) and 2 years (mean difference, 95% CI: 13%, 2–24%, P=0.018, NNT=8). In sensitivity analyses, the efficacy of purine analogs was superior to that of placebo for the prevention of clinical and endoscopic recurrence at 1 year (mean differences, 95% CI: 13, 1.8–25%, P=0.025, NNT=7, and 23%, 9–37%, P=0.0016, NNT=4, respectively). At 1 year, in the overall analysis, purine analogs were more effective than control arms were in preventing severe (i2–4) endoscopic recurrence (mean difference, CI 95%: 15, 1.8–29%, P=0.026, NNT=7), but they were not effective in the prevention of very severe (i3–4) recurrence. The rate of adverse events leading to drug withdrawal was higher in thiopurine-treated patients than in control arms (17.2 vs. 9.8%, respectively, P=0.021).CONCLUSIONS:Purine analogs are more effective than placebo in preventing both clinical and endoscopic postoperative recurrence in CD, but they are associated with a higher rate of adverse events leading to drug withdrawal.

Intravenous iron sucrose versus oral iron supplementation for the treatment of iron deficiency anemia in patients with inflammatory bowel disease--a randomized, controlled, open-label, multicenter study.

OBJECTIVES:Anemia is a frequent complication in patients with inflammatory bowel disease (IBD). The optimal route for iron supplementation to replenish iron stores has not been determined so far. We therefore evaluated the efficacy and safety of intravenous iron sucrose as compared with oral iron sulfate for the treatment of iron deficiency anemia (IDA) in patients with IBD.METHODS:A randomized, prospective, open-label, multicenter study was performed in 46 patients with anemia and transferrin saturation ≤20% and/or serum ferritin concentrations ≤20 μg/L. The intravenous group received a single dose of iron sucrose of 7 mg iron/kg body weight, followed by five 200 mg infusions for the following 5 wks. The oral group received iron sulfate 100–200 mg per day for 6 wks.RESULTS:While a comparable increase in hemoglobin was observed for both administration routes (median increase 0.25 g/L in the intravenous group vs 0.21 g/L in the oral group), only iron sucrose led to a rise in serum ferritin concentrations. Intractable gastrointestinal adverse events caused permanent study drug discontinuation in five patients (20.8%) receiving iron sulfate, whereas only one patient (4.5%) had to be withdrawn because of side effects due to iron sucrose.CONCLUSIONS:Although being equal in short-term efficacy and overall tolerability our results suggest a better gastrointestinal tolerability for iron sucrose. Larger trials are mandatory to prove a possible advantage of iron sucrose in short- and long-term efficacy as well as in tolerability over iron sulfate in the management of IDA in IBD.

Prevalence and epidemiology of overweight and obesity in children with inflammatory bowel disease

Background: Obesity is a significant public health threat to children in the United States. The aims were to: 1) Determine the prevalence of obesity in a multicenter cohort of children with inflammatory bowel disease (IBD); 2) Evaluate whether overweight and obese status is associated with patient demographics or disease characteristics. Methods: We used data from the ImproveCareNow Collaborative for pediatric IBD, a multicenter registry of children with IBD, collected between April 2007 and December 2009. Children ages 2–18 years were classified into body mass index (BMI) percentiles. Bivariate analyses and multivariate logistic regression were used to compare demographic and disease characteristics by overweight (BMI >85%) and obese (BMI >95%) status. Results: The population consisted of 1598 children with IBD. The prevalence of overweight/obese status in pediatric IBD is 23.6%, (20.0% for Crohns disease [CD] and 30.1% for ulcerative colitis [UC] and indeterminate colitis [IC]). African American race (odds ratio [OR] 1.64, 95% confidence interval [CI] 1.10–2.48) and Medicaid insurance (OR 1.67, 95% CI 1.19–2.34) were positively associated with overweight/obese status. Prior IBD‐related surgery (OR 1.73, 95% CI 1.07–2.82) was also associated with overweight and obese status in children with CD. Other disease characteristics were not associated with overweight and obesity in children with IBD. Conclusions: Approximately one in five children with CD and one in three with UC are overweight or obese. Rates of obesity in UC are comparable to the general population. Obese IBD patients may have a more severe disease course, as indicated by increased need for surgery. Sociodemographic risk factors for obesity in the IBD population are similar to those in the general population. (Inflamm Bowel Dis 2010;)

Role of probiotic therapy in IBD

There is mounting evidence that probiotic therapy may alter disease expression in both animal models of IBD and in patients with IBD. The effects appear to be modest at best and may reflect the choice of probiotic organism, the variability in concentrations of organisms administered, and the variability of the diseases being treated. This review examines the data of all fully published articles currently available for the role of probiotics in the treatment of IBD.