Oliver Schröder

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study drug discontinuation in five patients (20.8%) receiving iron sulfate, whereas only one patient (4.5%) had to be withdrawn because of side effects due to iron sucrose.CONCLUSIONS:Although being equal in short-term efficacy and overall tolerability our results suggest a better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.

Prospective evaluation of faecal neutrophil‐derived proteins in identifying intestinal inflammation: combination of parameters does not improve diagnostic accuracy of calprotectin

Background  Differentiating symptoms of irritable bowel syndrome from those of organic intestinal disease is a common clinical problem. Several neutrophil‐derived proteins have been proposed as a marker of inflammatory bowel disease.

Dominant Expression of the CysLT2 Receptor Accounts for Calcium Signaling by Cysteinyl Leukotrienes in Human Umbilical Vein Endothelial Cells

Objective—The objective of the present study was to identify and characterize the cell-surface receptors on human umbilical vein endothelial cells (HUVECs) that transduce calcium transients elicited by cysteinyl leukotrienes (CysLTs), potent spasmogenic and proinflammatory agents with profound effects on the cardiovascular system. Methods and Results—Using quantitative reverse transcription–polymerase chain reaction, we found that HUVECs abundantly express CysLT2R mRNA in vast excess (>4000-fold) of CysLT1R mRNA. Lipopolysaccharide, tumor necrosis factor-&agr;, or interleukin-1&bgr; caused a rapid (within 30 minutes) and partially reversible suppression of CysLT2R mRNA levels. Challenge of HUVECs with BAY u9773, a specific CysLT2R agonist, triggered diagnostic Ca2+ transients. LTC4 and LTD4 are equipotent agonists, and their actions can be blocked by the dual-receptor antagonist BAY u9773, but not by the CysLT1R-selective antagonist MK571. Conclusions—HUVECs almost exclusively express the CysLT2R. Furthermore, Ca2+ fluxes elicited by CysLT in these cells emanate from perturbation of the CysLT2R, rather than the expected CysLT1R. Hence, signaling events involving CysLT2R might trigger functional responses involved in the critical components of LT-dependant vascular reactions, which in turn have implications for ischemic heart disease and myocardial infarction.

Prevalence of Anemia in Inflammatory Bowel Diseases in European Countries: A Systematic Review and Individual Patient Data Meta-analysis.

Background:The main objective is to determine the overall prevalence of anemia in inflammatory bowel diseases (IBD) in Europe. Methods:A systematic literature search in PubMed and Embase was performed for studies published between January 2007 and May 2012. Eligible studies were included if they were original full-paper publications originated from Europe and if the authors agreed to provide their data. An overall prevalence of anemia in IBD, disease specific, and age–gender stratified basis prevalences were estimated. The influence of disease entity (Crohns disease/ulcerative colitis), gender, age, disease activity (remission/active disease), and IBD-specific treatment strategies on the prevalence of anemia was analyzed by a mixed logistic regression model. Thereby, the factor country of origin was included as a random effect. Results:Data were available for 2192 patients, mainly treated in tertiary referral centers. The overall prevalence of anemia in IBD patients was 24% (95% confidence interval, 18–31). Age–gender stratified prevalences were estimated for the age strata 18 to 29, 30 to 39, 40 to 49, 50 to 64, 65 to 74, >74 years and ranged from 18% to 35%. Patients receiving IBD-specific medication (P = 0.0002, odds ratio 1.54), and patients with active disease status (P < 0.0001, odds ratio 2.72) were significantly more likely to have anemia compared with patients not receiving IBD-specific medication or being in remission. Patients with ulcerative colitis tended to have anemia less likely than patients with Crohns disease (P = 0.01, odds ratio 0.77). Conclusions:The overall prevalence of anemia in patients with Crohns disease was 27% (95% confidence interval, 19–35) and 21% (95% confidence interval, 15–27) in patients with ulcerative colitis. Thereby, 57% of the anemic patients were iron deficient.

Combining infliximab and methotrexate in fistulizing Crohn's disease resistant or intolerant to azathioprine

Background : Crohns disease is complicated by fistulas in 20–40% of patients at some time during the course of their illness. Azathioprine has been reported to heal fistulas in 30–40% of cases. Long‐lasting effects by the anti‐tumour necrosis factor‐α antibody infliximab most often require repeated infusions. Methotrexate has been shown to be an effective drug in maintaining remission in Crohns disease.

The dietary histone deacetylase inhibitor sulforaphane induces human β-defensin-2 in intestinal epithelial cells

Antimicrobial peptides like human β‐defensin‐2 (HBD‐2) play an important role in the innate immune system protecting the intestinal mucosa against bacterial invasion. The dietary histone deacetylase (HDAC) inhibitors sulforaphane (SFN) and butyrate have received a great deal of attention because of their ability to simultaneously modulate multiple cellular targets involved in cellular protection. In this study the influence of SFN and butyrate on HBD‐2 expression as well as the molecular pathways involved in SFN‐mediated induction of HBD‐2 were scrutinized. Treatment of Caco‐2, HT‐29 and SW480 cells with SFN led to a time‐ and dose‐dependent upregulation of HBD‐2 mRNA expression as determined by semi‐quantitative reverse transcription–polymerase chain reaction. Moreover, HBD‐2 protein production increased in response to SFN, measured by enzyme‐linked immunosorbent assay. Induction of HBD‐2 was also observed in response to butyrate. Immunofluorescence analysis revealed that the protein was localized in the cytosol. Coincubation of SFN with a vitamin D receptor (VDR), or an extracellular‐regulated kinase 1/2 or a nuclear factor‐κB inhibitor all reduced HBD‐2 mRNA upregulation. In contrast, transfection of cells with a dominant‐negative peroxisome proliferator‐activated receptor γ (PPARγ) mutant vector to inhibit PPARγ wild‐type action and inhibition of p38 mitogen‐activated protein kinase (MAPK) signalling did not affect SFN‐mediated upregulation of HBD‐2 mRNA. Moreover, SFN induced the expression of VDR, PPARγ and phosphorylated ERK1/2 but did not affect p38 MAPK activation. The data clearly demonstrate for the first time that the dietary HDAC inhibitor SFN is able to induce antimicrobial peptides in colonocytes. In this process HBD‐2 expression is regulated via VDR, mitogen‐activated protein kinase kinase/extracellular‐regulated kinase and nuclear factor‐κB signalling.

Low Dose Methotrexate in Inflammatory Bowel Disease: Current Status and Future Directions

Despite many recent advances, some notable limitations exist in the medical management of patients with inflammatory bowel disease. Glucocorticoids suppress active inflammation very effectively, but their long term use is associated with high rates of relapse and unacceptable toxicity. 6-Mercaptopurine and its prodrug azathioprine are effective in inducing and maintaining remission; however, a significant number of patients are resistant or intolerant to thiopurines. Low dose methotrexate, an anti-inflammatory drug, is a well established medication for rheumatoid arthritis and psoriasis. After an initial report in 1989, several clinical trials and analyses of clinical notes have examined the role of methotrexate in patients with ulcerative colitis and Crohns disease. This review was conducted to summarize the current knowledge about the underlying basic anti-inflammatory mechanisms of methotrexate as well as the pharmacology and toxicology of this drug with particular emphasis on inflammatory bowel disease. It also critically evaluates all existing trials not only in the induction of remission but also in maintenance therapy. We conclude that low dose methotrexate is an effective and safe treatment in glucocorticoid-dependent and thiopurine intolerant patients with Crohns disease but not ulcerative colitis. It remains to be seen whether low dose methotrexate may also be useful in long term maintenance therapy in patients with inflammatory bowel disease.

PPARγ is involved in mesalazine-mediated induction of apoptosis and inhibition of cell growth in colon cancer cells

PURPOSE Mesalazine has been identified as a candidate chemopreventive agent in colon cancer prophylaxis because of its pro-apoptotic and anti-proliferative effects. However, the precise mechanisms of action are not entirely understood. The aim of our study was to investigate the involvement of peroxisome proliferator-activated receptor gamma (PPARgamma) in mesalazines anticarcinogenic actions in colorectal cancer cells. EXPERIMENTAL DESIGN The effects of mesalazine on cell cycle distribution, cell count, proliferation and caspase-mediated apoptosis were examined in Caco-2, HT-29 and HCT-116 cells used as wild-type, dominant-negative PPARgamma mutant and empty vector cultures. We focused on caspase-3 activity, cleavage of poly(ADP-ribose) polymerase (PARP), caspase-8 and caspase-9, as well as on expression of survivin, X-linked inhibitor of apoptosis (Xiap), phosphatase and tensin homolog deleted from chromosome ten (PTEN) and c-Myc. Techniques employed included transfection assays, immunoblotting, flow cytometry analysis, colorimetric and fluorometric assays. RESULTS Mesalazine caused a time- and dose-dependent decrease in both cell growth and proliferation. Growth inhibition was accompanied by a G1/G0 arrest, a significant increase in PTEN, caspase-3 activity, cleavage of PARP and caspase-8, whereas the expressions of Xiap, survivin and c-Myc were decreased simultaneously. Cleavage of caspase-9 was not observed. Moreover, PPARgamma expression and activity were elevated. The growth-inhibitory effect of mesalazine was partially reduced in dominant-negative PPARgamma mutant cells, whereas the expression of c-Myc was not affected. Mesalazine-mediated increased caspase-3 activity, the expression of PTEN, cleavage of PARP and caspase-8 as well as reduced levels of survivin and Xiap were completely abolished in the PPARgamma mutant cell lines. CONCLUSION This study clearly demonstrates that mesalazine-mediated pro-apoptotic and anti-proliferative actions are regulated via PPARgamma-dependent and -independent pathways in colonocytes.

Combining infliximab with methotrexate for the induction and maintenance of remission in refractory Crohn's disease: a controlled pilot study.

Objectives Immunosuppression of chronic active Crohns disease resistant or intolerant to purine antimetabolites still remains a clinical challenge. To obtain long-lasting effects with the anti-TNF-&agr; antibody infliximab repeated infusions are often required. Methotrexate has been shown to be a moderately effective drug in maintaining remission in Crohns disease. The aim of the present pilot study was to evaluate the combination of infliximab and methotrexate as therapy for refractory Crohns disease. Methods Nineteen patients with chronic active Crohns disease resistant or intolerant to azathioprine were enrolled. Patients received either two infusions of infliximab (5 mg/kg) alone (n=8) or in combination with long-term methotrexate at a dosage of 20 mg/week (n=11) over 48 weeks. Results Two out of eight patients receiving infliximab monotherapy and four out of 11 patients treated with infliximab and concomitant methotrexate had discontinued study treatment by week 48, solely because of lack of efficacy. Clinical remission at week 48 was observed in five out of seven patients treated with infliximab and methotrexate, but only in two out of six patients receiving infliximab monotherapy. In addition, patients treated with concomitant methotrexate achieved remission earlier (median time 2 versus 18 weeks) and needed fewer steroids (median prednisolone dose 0 versus 11.8 mg). Despite an increased mean number of adverse events per patient in the methotrexate group, the proportions of patients experiencing any adverse events and serious adverse events were similar across treatment groups. Conclusions The combination of infliximab with long-term methotrexate may be a promising concept in refractory Crohns disease. Our data prompt larger trials.

PPARγ is a key target of butyrate-induced caspase-3 activation in the colorectal cancer cell line Caco-2

Background: Butyrate, a potent histone deacetylase inhibitor, belongs to a promising new class of antineoplastic agents with the capacity to induce apoptosis of cancer cells. However, the underlying mechanisms of action have yet not been elucidated. Aim: To further investigate the molecular events involved in butyrate-induced caspase-3 activation in Caco-2 wild-type, empty-vector and dominant-negative PPARγ mutant cells along the signalling pathway. In this context, the involvement and up-regulation of PPARγ was examined. Results: Stimulation of cells with butyrate resulted in increased expression of PPARγ mRNA, protein, and activity as well as phospho-p38 MAPK protein expression and caspase-3 activity. Arsenite, a direct stimulator of p38 MAPK, also led to an increased PPARγ expression, thereby mimicking the effects of butyrate. In contrast, butyrate-mediated up-regulation of PPARγ was counteracted by co-incubation with the p38 MAPK inhibitor SB203580. Treatment of cells with butyrate resulted in both increased caspase-8 and -9 activity and reduced expression of XIAP and survivin. However, butyrate-mediated effects on these apoptosis-regulatory proteins leading to caspase-3 activation were almost completely abolished in Caco-2 dominant-negative PPARγ mutant cells. Conclusions: Our data clearly unveil PPARγ as a key target in the butyrate-induced signalling cascade leading to apoptosis via caspase-3 in Caco-2 cells.