A high serum concentration of interleukin-6 is predictive of relapse in quiescent Crohn's disease

Safety, tolerability, and pharmacokinetics of single- and multiple-ascending doses of olamkicept: Results from randomized, placebo-controlled, first-in-human phase I trials

Olamkicept selectively inhibits the cytokine interleukin-6 (IL-6) trans-signaling pathway without blocking the classic pathway and is a promising immunoregulatory therapy for inflammatory bowel disease (IBD). These first-in-human, randomized, placebo-controlled, single- (SAD) and multiple-ascending dose (MAD) trials evaluated olamkicept safety, tolerability, pharmacokinetic, and pharmacodynamic characteristics. Doses tested in the SAD trial included seven single intravenous doses (0.75, 7.5, 75, 150, 300, 600, and 750 mg) and one subcutaneous (SC) dose (60 mg) given to healthy subjects (N = 64), and three intravenous doses (75 mg, 300 mg, and 750 mg) given to patients with Crohn's disease (CD; N = 24). Doses tested in the MAD trial included multiple intravenous doses (75, 300, and 600 mg once weekly for 4 weeks) given to healthy subjects (N = 24). No severe or serious treatment-emergent adverse events (TEAEs) were recorded. The most common TEAEs were headache, nasopharyngitis, and myalgia in the SAD trial, and diarrhea, headache, and cough in the MAD trial. Infusion-related reactions occurred in one and two subjects in the SAD and MAD trial, respectively, leading to treatment discontinuation in the MAD trial. Olamkicept showed dose-independent pharmacokinetics after single and multiple administrations, and there was no major difference in systemic exposure between healthy subjects and patients with CD. Complete target engagement (inhibition of phosphorylation of signal transducer and activator of transcription-3) was achieved in blood around or above olamkicept serum concentrations of 1-5 μg/mL. Overall, these results suggest that olamkicept is safe and well-tolerated in healthy subjects and patients with CD after single intravenous/SC and multiple intravenous administrations.

Distinct blood protein profiles associated with the risk of short-term and mid/long-term clinical relapse in patients with Crohn's disease stopping infliximab: when the remission state hides different types of residual disease activity

OBJECTIVE

Despite being in sustained and stable remission, patients with Crohn's disease (CD) stopping anti-tumour necrosis factor α (TNFα) show a high rate of relapse (~50% within 2 years). Characterising non-invasively the biological profiles of those patients is needed to better guide the decision of anti-TNFα withdrawal.

DESIGN

Ninety-two immune-related proteins were measured by proximity extension assay in serum of patients with CD (n=102) in sustained steroid-free remission and stopping anti-TNFα (infliximab). As previously shown, a stratification based on time to clinical relapse was used to characterise the distinct biological profiles of relapsers (short-term relapsers: <6 months vs mid/long-term relapsers: >6 months). Associations between protein levels and time to clinical relapse were determined by univariable Cox model.

RESULTS

The risk (HR) of mid/long-term clinical relapse was specifically associated with a high serum level of proteins mainly expressed in lymphocytes (LAG3, SH2B3, SIT1; HR: 2.2-4.5; p<0.05), a low serum level of anti-inflammatory effectors (IL-10, HSD11B1; HR: 0.2-0.3; p<0.05) and cellular junction proteins (CDSN, CNTNAP2, CXADR, ITGA11; HR: 0.4; p<0.05). The risk of short-term clinical relapse was specifically associated with a high serum level of pro-inflammatory effectors (IL-6, IL12RB1; HR: 3.5-3.6; p<0.05) and a low or high serum level of proteins mainly expressed in antigen presenting cells (CLEC4A, CLEC4C, CLEC7A, LAMP3; HR: 0.4-4.1; p<0.05).

CONCLUSION

We identified distinct blood protein profiles associated with the risk of short-term and mid/long-term clinical relapse in patients with CD stopping infliximab. These findings constitute an advance for the development of non-invasive biomarkers guiding the decision of anti-TNFα withdrawal.

Advancing the precision management of inflammatory bowel disease in the era of omics approaches and new technology

There is great heterogeneity among inflammatory bowel disease (IBD) patients in terms of pathogenesis, clinical manifestation, response to treatment, and prognosis, which requires the individualized and precision management of patients. Many studies have focused on prediction biomarkers and models for assessing IBD disease type, activity, severity, and prognosis. During the era of biologics, how to predict the response and side effects of patients to different treatments and how to quickly recognize the loss of response have also become important topics. Multiomics is a promising area for investigating the complex network of IBD pathogenesis. Integrating numerous amounts of data requires the use of artificial intelligence.

Relationships of circulating CD4+ T cell subsets and cytokines with the risk of relapse in patients with Crohn’s disease

Background and aims

We aimed to analyze circulating CD4+ T cell subsets and cytokines during the course of Crohn’s disease (CD).

Methods and results

CD4+ T cell subsets, ultrasensitive C-reactive protein (usCRP), and various serum cytokines (IL-6, IL-8, IL-10, IL-13, IL-17A, IL-23, TNFα, IFNγ, and TGFβ) were prospectively monitored every 3 months for 1 year, using multicolor flow cytometry and an ultrasensitive Erenna method in CD patients in remission at inclusion. Relapse occurred in 35 out of the 113 consecutive patients (31%). For patients in remission within 4 months prior to relapse and at the time of relapse, there was no significant difference in Th1, Th17, Treg, and double-positive CD4+ T cell subsets co-expressing either IFNγ and FOXP3, IL-17A and FOXP3, or IFNγ and IL-17A. On the contrary, in patients who remained in remission, the mean frequency and number of double-positive IL-17A+FOXP3+ CD4+ T cells and the level of usCRP were significantly higher (p ≤ 0.01) 1 to 4 months prior to relapse. At the time of relapse, only the IL-6 and usCRP levels were significantly higher (p ≤ 0.001) compared with those patients in remission. On multivariate analysis, a high number of double-positive IL-17A+FOXP3+ CD4+ T cells (≥1.4 cells/mm3) and elevated serum usCRP (≥3.44 mg/L) were two independent factors associated with risk of relapse.

Conclusions

Detection of circulating double-positive FOXP3+IL-17A+ CD4+ T cell subsets supports that T cell plasticity may reflect the inflammatory context of Crohn’s disease. Whether this subset contributes to the pathogenesis of CD relapse needs further studies.

Estrogen-related receptor alpha (ERRα) is a key regulator of intestinal homeostasis and protects against colitis

The estrogen-related receptor alpha (ERRα) is a primary regulator of mitochondrial energy metabolism, function and dynamics, and has been implicated in autophagy and immune regulation. ERRα is abundantly expressed in the intestine and in cells of the immune system. However, its role in inflammatory bowel disease (IBD) remains unknown. Here, we report a protective role of ERRα in the intestine. We found that mice deficient in ERRα were susceptible to experimental colitis, exhibiting increased colon inflammation and tissue damage. This phenotype was mediated by impaired compensatory proliferation of intestinal epithelial cells (IEC) following injury, enhanced IEC apoptosis and necrosis and reduced mucus-producing goblet cell counts. Longitudinal analysis of the microbiota demonstrated that loss of ERRα lead to a reduction in microbiome α-diversity and depletion of healthy gut bacterial constituents. Mechanistically, ERRα mediated its protective effects by acting within the radio-resistant compartment of the intestine. It promoted disease tolerance through transcriptional control of key genes involved in intestinal tissue homeostasis and repair. These findings provide new insights on the role of ERRα in the gut and extends our current knowledge of nuclear receptors implicated in IBD.

Association of serum interleukin-6 and soluble interleukin-2-receptor levels with disease activity status in patients with inflammatory bowel disease: A prospective observational study

Crohn’s disease (CD) and ulcerative colitis (UC) are characterized by overexpression of proinflammatory cytokines. We determined the association of serum levels of interleukin (IL)-6, soluble-IL-2-receptor (sIL-2R) and CRP as well as of faecal calprotectin (FC) values with disease activity in CD and UC patients. This prospective study included 145 CD and 84 UC patients. Serum proinflammatory biomarkers and FC levels were measured and demographic, clinical and endoscopic characteristics were collected. Uni- and multivariate statistical analyses were performed. Serum IL-6 and CRP levels as well as FC values of CD patients were associated with clinical and endoscopic remission. In multivariate analysis serum IL-6 levels remained significantly associated with clinical and endoscopic remission. FC levels were also associated with endoscopic remission in CD patients. CD patients under the threshold levels of 8.5 pg/mL and 5.5 pg/mL for serum IL-6 were in 70% and 66% in clinical and endoscopic remission, respectively. Serum sIL-2R, CRP levels and FC values of UC patients were associated in univariate analysis with clinical and endoscopic remission. In multivariate analysis CRP and FC values were associated with clinical remission and serum sIL-2R as well as FC levels with endoscopic remission. UC patients under the threshold levels of 759 IU/mL and 646 IU/mL for serum sIL-2R were in 76% and 76% in clinical and endoscopic remission, respectively. Beside CRP and FC, serum IL-6 levels in CD patients and sIL-2R levels in UC patients can be a further useful non-invasive biomarker to identify the disease activity status.

Serum Biomarkers for Inflammatory Bowel Disease

Background: Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, is a chronic, inflammatory disorder of the gastrointestinal tract. As the novel therapeutic goal and biologicals are widely recognized, accurate assessment of disease and prediction of therapeutic response have become a crucial challenge in clinical practice. Also, because of the continuously rising incidence, convenient and economical methods of diagnosis and clinical assessment are urgently needed. Recently, serum biomarkers have made a great progress and become a focus in IBD study because they are non-invasive, convenient, and relatively inexpensive than are markers in biopsy tissue, stool, breath, and other body fluids.

Aims: To review the available data on serological biomarkers for IBD.

Methods: We searched PubMed using predefined key words on relevant literatures of serum biomarkers regarding diagnosis, evaluation of therapeutic efficacy, surveillance of disease activity, and assessment of prognosis for IBD.

Results: We reviewed serological biomarkers that are well-established and widely used (e.g., C-reactive protein), newly discovered biomarkers (e.g., cytokines, antibodies, and non-coding RNAs), and also recently advancements in serological biomarkers (e.g., metabolomics and proteomics) that are used in different aspects of IBD management.

Conclusions: With such a wealth of researches, to date, there are still no ideal serum biomarkers for IBD. Serum profiling and non-coding RNAs are just starting to blossom but reveal great promise for future clinical practice. Combining different biomarkers can be valuable in improving performance of disease evaluation.

Exploring inflammatory and apoptotic signatures in distinct Crohn's disease phenotypes: Way towards molecular stratification of patients and targeted therapy

BACKGROUND

Crohn's disease (CD) is chronic inflammatory bowel disease with different phenotypic characteristics influencing disease prognosis and therapeutic strategies. The aim of this pilot study was to analyze selected inflammatory and apoptotic markers in non-inflamed and inflamed samples of ileal mucosa of non-stricturing/non-penetrating (NS/NP) and stricturing (S) CD mucosal phenotypes in order to characterize their distinct profiles.

METHODS

From twenty CD patients (9 NS/NP, 11 S) paired non-inflamed and inflamed ileal biopsies were collected and used for analysis of cytokine (TNF and IL6) and apoptotic (Bcl2, Bax, Fas and FasL) genes' expression levels by real-time PCR, while NFκB transcriptional potency was assessed by electromobility gel shift assay.

RESULTS

Our results demonstrated significant upregulation of TNF and IL6 in inflamed area of both NS/NP (p = 0.03, p = 0.01) and S phenotypes (p = 0.04, p = 0.04), respectively. However, TNF increase was more prominent in NS/NP compared to S inflamed mucosa (p = 0.02). Also, level of proapoptotic Bax was significantly higher in NS/NP compared to S inflamed mucosa (p = 0.01). Opposing transcription potency of NFκB has been detected between two phenotypes: being decreased in NS/NP (p = 0.07) and increased in S (p = 0.1) inflamed compared to non-inflamed mucosa, demonstrating trend towards statistical significance.

CONCLUSIONS

We found that two distinct CD phenotypes have specific molecular signatures. Obtained results could direct improvement of current and development of new therapeutic strategies based on more specific molecular stratification of CD patients.

Microbiome-skin-brain axis: A novel paradigm for cutaneous wounds

Chronic wounds cause a significant burden on society financially, medically, and psychologically. Unfortunately, patients with nonhealing wounds often suffer from comorbidities that further compound their disability. Given the high rate of depressive symptoms experienced by patients with chronic wounds, further studies are needed to investigate the potentially linked pathophysiological changes in wounds and depression in order to improve patient care. The English literature on wound healing, inflammatory and microbial changes in chronic wounds and depression, and antiinflammatory and probiotic therapy was reviewed on PubMed. Chronic wound conditions and depression were demonstrated to share common pathologic features of dysregulated inflammation and altered microbiome, indicating a possible relationship. Furthermore, alternative treatment strategies such as immune-targeted and probiotic therapy showed promising potential by addressing both pathophysiological pathways. However, many existing studies are limited to a small study population, a cross-sectional design that does not establish temporality, or a wide range of confounding variables in the context of a highly complex and multifactorial disease process. Therefore, additional preclinical studies in suitable wound models, as well as larger clinical cohort studies and trials are necessary to elucidate the relationship between wound microbiome, healing, and depression, and ultimately guide the most effective therapeutic and management plan for chronic wound patients.

Systematic Review: Components of a Comprehensive Geriatric Assessment in Inflammatory Bowel Disease-A Potentially Promising but Often Neglected Risk Stratification

BACKGROUND

The population of older patients with inflammatory bowel disease [IBD] is increasing. Patient age does not fully account for poor outcomes and its clinical utility for risk stratification is limited. Comprehensive geriatric assessment [CGA], comprising a somatic, functional, mental, and social assessment or frailty, could be a predictor tool.

AIMS

To systematically review literature on the kind of components of a CGA being used in adult IBD patients and the association of these components with adverse health outcomes.

METHODS

An electronic literature search was performed on January 16, 2018, using PubMed, Embase, Web of Science, the Cochrane Library, CENTRAL, Emcare, and PsycINFO. Longitudinal studies relating somatic, functional, mental, and social assessment or frailty to adverse health outcomes during follow-up in IBD patients were included. The Newcastle-Ottawa scale was used to assess individual study quality.

RESULTS

Of 4080 identified citations, 27 studies were included, reporting 169 associations. Median sample size was 108 patients (interquartile range [IQR] 60-704). No studies performed subgroup analyses on older patients, and the highest mean age reported was 52.7 years. Somatic and functional assessments were used in three studies, mental in 24, and social in five. No study assessed cognitive status, functional performance, or frailty. In 62 associations [36.7%], components of a CGA were significantly associated with adverse health outcome measurements.

CONCLUSIONS

Components of a CGA were associated with adverse health outcomes in IBD patients, but older patients were under-represented. More studies among older patients with IBD are warranted to further establish the clinical impact of a CGA.

Fermented Portulaca oleracea L. Juice: A Novel Functional Beverage with Potential Ameliorating Effects on the Intestinal Inflammation and Epithelial Injury

P. oleracea L. contains high level of nutrients and biologically active compounds. Recently, lactic fermentation has been proposed as a biotechnological option to enrich the profile of biogenic compounds of Portulaca oleracea L. puree. This study investigated the capability of fermentation by selected lactic acid bacteria to enhance the restoring features of Portulaca oleracea juice towards intestinal inflammation and epithelial injury. Lactic acid fermentation markedly increased the total antioxidant capacity of P. oleracea juice, preserved the inherent levels of vitamins C, A, and E, and increased the bioavailability of the level of vitamin B₂ and that of phenolics. The effects of fermented P. oleracea juice on a Caco-2 cell line were investigated using an in vitro model closest to the in vivo conditions. Fermented P. oleracea juice strongly decreased the levels of pro-inflammatory mediators and reactive oxygen species. It also counteracted the disruption of the Caco-2 cell monolayers treated with the inflammatory stimulus. We used a diversified spectrum of lactic acid bacteria species, and some effects appeared to be strains- or species-specific. Fermentation with Lactobacillus kunkeei B7 ensured the best combination for the content of bioactive compounds and the ability to counteract the intestinal inflammation and epithelial injury.

Pien Tze Huang ameliorates DSS‑induced colonic inflammation in a mouse colitis model through inhibition of the IL‑6/STAT3 pathway

Interleukin‑6 (IL‑6)/signal transducer and activator of transcription 3 (STAT3) pathway plays essential roles in the development of inflammatory diseases including ulcerative colitis (UC). Therefore, suppression of IL‑6/STAT3 signaling provides a promising therapeutic strategy in UC. Pien Tze Huang (PZH), a well‑known traditional Chinese formula, has been used in China and Southeast Asia for centuries as a folk remedy for various inflammatory diseases. However, the molecular mechanisms of its anti‑inflammatory effects remain to be elucidated. In the present study, we generated a mouse colitis model by using dextran sulfate sodium (DSS) and evaluated the therapeutic efficacy of PZH against UC by observing the clinical manifestations. We found that PZH obviously alleviated DSS‑induced colitis symptoms, including body weight loss, rectal bleeding and stool consistency. In addition, administration of PZH profoundly prevented DSS‑induced colon shortening, and ameliorated colonic histopathological changes such as mucosal ulceration, infiltration of inflammatory cells, crypt distortion and hyperplastic epithelium. Moreover, PZH markedly inhibited the serum level of the inflammatory biomarker serum amylase A (SAA) in UC mice. Furthermore, PZH treatment significantly inhibited DSS‑induced expression of IL‑6 in colon tissues. Finally, the increased phosphorylation level of STAT3, induced either by DSS in experimental mice or by IL‑6 in the differentiated human colorectal carcinoma cells, was significantly suppressed by PZH. These results suggest that the inhibition of IL‑6/STAT3 signaling is a potential mechanism by which PZH is used in the treatment of UC.

Immunotherapy in inflammatory bowel disease: Novel and emerging treatments

Inflammatory bowel disease (IBD) is a chronic disabling inflammatory process that affects young individuals, with growing incidence. The etiopathogenesis of IBD remains poorly understood. A combination of genetic and environmental factors triggers an inadequate immune response against the commensal intestinal flora in IBD patients. Thus, a better understanding of the immunological mechanisms involved in IBD pathogenesis is central to the development of new therapeutic options.

Current pharmacological treatments used in clinical practice like thiopurines or anti-TNF are effective but can produce significant side effects and their efficacy may diminish over time. In fact, up to one third of the patients do not have a satisfactory response to these therapies. Consequently, the search for new therapeutic strategies targeting alternative immunological pathways has intensified. Several new oral and parenteral substances are in the pipeline for IBD.

In this review we discuss novel therapies targeting alternative pro-inflammatory pathways like IL-12/23 axis, IL-6 pathway or Janus Kinase inhibitors; as well as others modulating anti-inflammatory signalling pathways like transforming growth factor-β1 (TGF-β1). We also highlight new emerging therapies targeting the adhesion and migration of leukocytes into the inflamed intestinal mucosa by blocking selectively different subunits of α₄β₇ integrins or binding alternative adhesion molecules like MAdCAM-1. Drugs reducing the circulating lymphocytes by sequestering them in secondary lymphoid organs (sphingosine-1-phosphate (S1P) receptor modulators) are also discussed. Finally, the latest advances in cell therapies using mesenchymal stem cells or engineered T regs are reviewed. In addition, we provide an update on the current status in clinical trials of these new immune-regulating therapies that open a new era in the treatment of IBD.

6-Formylindolo(3,2-b)carbazole induced aryl hydrocarbon receptor activation prevents intestinal barrier dysfunction through regulation of claudin-2 expression

6-Formylindolo(3,2-b)carbazole (FICZ), a high-affinity aryl hydrocarbon receptor (AhR) ligand, plays a protective role in inflammatory bowel disease (IBD) through activation of AhR. Interleukin-6 (IL-6) induced intestinal epithelial barrier dysfunction is involved in the pathological process of IBD. In this study, we investigated the protective effects of FICZ on IL-6 induced intestinal epithelial barrier injury. Our data show that AhR activation by FICZ ameliorated colonic inflammation, decreased IL-6 and claudin-2 expression, and maintained intestinal barrier function in a mouse model of dextran sulphate sodium (DSS)-induced colitis. In Caco-2 and T84 intestinal epithelial cells, FICZ also prevented the increase of intestinal epithelial permeability and claudin-2 expression induced by IL-6. Depletion of AhR expression by small interfering (si)RNA reversed FICZ induced decrease of claudin-2. Furthermore, IL-6 induced upregulation of claudin-2 was required for increased caudal-related homeobox 2 (CDX-2) and hepatocyte-nuclear factor (HNF)-1α. However, FICZ repressed the increase of CDX-2 and HNF-1α expression induced by IL-6. These results reveal the protective effects of FICZ on IL-6 induced disruption of intestinal epithelial barrier function through suppressing the expression of claudin-2. In addition, CDX-2 and HNF-1α are involved in the regulation of claudin-2 after IL-6 and FICZ treatment. Therefore compounds related to AhR ligands may be potential pharmaceutical agents to treat IBD.

Evaluation of interleukin-6 and its soluble receptor components sIL-6R and sgp130 as markers of inflammation in inflammatory bowel diseases

PURPOSE

Interleukin-6 (IL-6) production and signalling are increased in the inflamed mucosa in inflammatory bowel diseases (IBD). As published serum levels of IL-6 and its soluble receptors sIL-6R and sgp130 in IBD are from small cohorts and partly contradictory, we systematically evaluated IL-6, sIL-6R and sgp130 levels as markers of disease activity in Crohn's disease (CD) and ulcerative colitis (UC).

METHODS

Consecutive adult outpatients with confirmed CD or UC were included, and their disease activity and medication were monitored. Serum from 212 CD patients (815 measurements) and 166 UC patients (514 measurements) was analysed, and 100 age-matched healthy blood donors were used as controls.

RESULTS

IL-6 serum levels were significantly elevated in active versus inactive CD and UC, also compared with healthy controls. However, only a fraction of IBD patients showed increased serum IL-6. IL-6 levels ranged up to 32.7 ng/mL in active CD (> 5000-fold higher than in controls), but also up to 6.9 ng/mL in inactive CD. Increases in active UC (up to 195 pg/mL) and inactive UC (up to 27 pg/mL) were less pronounced. Associations between IL-6 serum levels and C-reactive protein concentrations as well as leukocyte and thrombocyte counts were observed. Median sIL-6R and sgp130 levels were only increased by up to 15%, which was considered of no diagnostic significance.

CONCLUSIONS

Only a minority of IBD patients shows elevated IL-6 serum levels. However, in these patients, IL-6 is strongly associated with disease activity. Its soluble receptors sIL-6R and sgp130 do not appear useful as biomarkers in IBD.

Portulaca oleracea extracts and their active compounds ameliorate inflammatory bowel diseases in vitro and in vivo by modulating TNF-α, IL-6 and IL-1β signalling

Portulaca oleracea L. (P. oleracea) is an herb that is widely used in traditional medicine to treat various diseases. However, its effects on inflammatory diseases, such as inflammatory bowel disease (IBD), are not yet well characterized. Here, we investigated the impact of the ethyl acetate (EtOAc) and ethanol (EtOH) extracts of P. oleracea on lipopolysaccharide (LPS)-induced inflammatory responses and phosphorylation of ERK, JNK, and p38 expression in RAW264.7 macrophages. In addition, the inhibitory effects of these extracts and fractions on 3% dextran sulphate sodium (DSS)-induced ulcerative colitis were examined using an ICR mouse model. DSS-induced colitis, including body weight loss, reduced colon length, and histological colon injury, was significantly ameliorated in mice fed the P. oleracea extracts (200 and 500mg/kg). In particular, P. oleracea extracts also inhibited pro-inflammatory cytokine (TNF-α, IL-6, and 1L-1β) production in mice with DSS-induced colitis; the P. oleracea extracts displayed higher and/or similar inhibitory activity to sulfasalazine at high concentrations. Furthermore, the chemical structures of active compounds separated from the EtOAc extract of P. oleracea were elucidated using nuclear magnetic resonance (NMR) spectroscopy (see Figure in supplementary materials), resulting in the identification of three known compounds. Among these active compounds, cis-N-feruloyl-3'-methoxytyramine (2) exhibited the strongest effects on preventing DSS-induced IBD in animal models. Thus, extract of P. oleracea and their active compounds represents a new therapeutic approach for patients with inflammatory bowel diseases.

Activity of inflammatory bowel disease influences the expression of cytokines in gingival tissue

This study assessed the cytokine expression in gingival and intestinal tissues from periodontitis patients with inflammatory bowel disease (IBD) and evaluated if IBD activity is a covariate to the amount of gingival cytokines. Paired gingival and intestinal tissues were collected from 21 patients and homogenised using a cell disruptor. Cytokine expression (IL-1β, IL-4, IL-6, IL-10, IL-21, IL-22, IL-23, IL-25, IL-31, IL-33, IL-17A, IL-17F, IFN-γ, sCD40L, and TNF-α) was evaluated using bead-based multiplex technology. An inflammation score was developed using the intestinal cytokines that showed good accuracy to discriminate IBD active patients from those in remission and then a similar score was applied to gingival tissue. IL-4, IL-10 and IL-21 expressions were significantly increased in gingival tissue from patients with an active disease as compared to those with a disease in remission. The inflammation score (mean value of IL-1β, IL-6, IL-21, and sCD40L) was significantly higher in gingival tissue from patients with IBD activity. There was a significant correlation between gingival and intestinal inflammation scores (rho=0.548; P=0.01). Significantly higher IL-23 and IFN-γ levels and lower IL-31 and TNF-α levels were observed in gingival tissues than in intestinal ones. Activity of inflammatory bowel disease influenced the cytokine expression in gingival tissue.

Immune-to-Brain Communication Pathways in Inflammation-Associated Sickness and Depression

A growing body of evidence now highlights a key role for inflammation in mediating sickness behaviors and depression. Systemic inflammatory diseases such as rheumatoid arthritis, inflammatory bowel disease, and chronic liver disease have high comorbidity with depression. How the periphery communicates with the brain to mediate changes in neurotransmission and thereby behavior is not completely understood. Traditional routes of communication between the periphery and the brain involve neural and humoral pathways with TNFα, IL-1β, and IL-6 being the three main cytokines that have primarily been implicated in mediating signaling via these pathways. However, in recent years communication via peripheral immune-cell-to-brain and the gut-microbiota-to-brain routes have received increasing attention for their ability to modulate brain function. In this chapter we discuss periphery-to-brain communication pathways and their potential role in mediating inflammation-associated sickness behaviors and depression.

Utility of surrogate markers for the prediction of relapses in inflammatory bowel diseases

Patients with diagnosed inflammatory bowel disease (IBD) will commonly experience a clinical relapse in spite of a prolonged therapy-induced period of clinical remission. The current methods of assessing subclinical levels of low-grade inflammation which predispose patients to relapse are not optimal when considering both cost and patient comfort. Over the past few decades, much investigation has discovered that proteins such as calprotectin that are released from inflammatory cells are capable of indicating disease activity. Along with C-reactive protein and erythrocyte sedimentation rate, calprotectin has now become part of the current methodology for assessing IBD activity. More recently, research has identified that other fecal and serum biomarkers such as lactoferrin, S100A12, GM-CSF autoantibodies, α1-antitrypsin, eosinophil-derived proteins, and cytokine concentrations have variable degrees of utility in monitoring gastrointestinal tract inflammation. In order to provide direction toward novel methods of predicting relapse in IBD, we provide an up-to-date review of these biomarkers and their potential utility in the prediction of clinical relapse, given their observed activities during various stages of clinical remission.

Clinical Utility of Biomarkers in IBD

There is no gold standard for the diagnosis and monitoring of inflammatory bowel diseases (IBD). Biomarkers are useful tools for the management of patients suffering from IBD. However, they should be used only when their additional information is useful for clinical decision-making. In principal, four situations during the management of an individual IBD patient can be discriminated from a clinical standpoint in which biomarkers provide useful information. First, biomarkers may be helpful when the diagnosis of IBD is established and aid in the discrimination between ulcerative colitis (UC) and Crohn's disease (CD) is necessary. Second, biomarkers may be helpful in the prognostic evaluation of IBD severity or disease behavior and for early decisions on the best treatment. The third situation in which biomarkers are useful is the evaluation of disease activity during the disease course, for monitoring and for guidance of ongoing treatment. Finally, the fourth typical situation when biomarkers are of value is after surgery to predict or diagnose a relapse of the disease. From a clinical point of view, it may be more useful to discuss specific biomarkers and their individual value and impact in these four prototypic situations than to sum up advantages and disadvantages for each biomarker isolated from the clinical situation. Therefore, this overview is structured in chapters reflecting those four typical situations during the disease course of IBD patents to critically evaluate the potential and value of each of the biomarkers in the specific situation.

Comparison of energy metabolism and nutritional status of hospitalized patients with Crohn's disease and those with ulcerative colitis

This study aimed to compare the nutritional status and energy expenditure of hospitalized patients with Crohn’s disease (CD) and those with ulcerative colitis (UC). Twenty-two hospitalized patients with CD and 18 patients with UC were enrolled in this study. We analyzed nutritional status upon admission by using nutritional screening tools including subjective global assessment, malnutrition universal screening tool, and laboratory tests. We measured resting energy expenditure (mREE) of the patients with indirect calorimetry and predicted resting energy expenditure (pREE) was calculated by using the Harris-Benedict equation. Results presented here indicate no significant difference in nutritional parameters and energy metabolism between CD and UC patients. In UC patients, a significant correlation was observed between mREE/body weight and disease activity detected by the Lichtiger and Seo indices. However, there was no correlation between mREE/body weight and Crohn’s disease activity index in CD patients. Inflammatory cytokine interleukin-6 levels correlated with mREE/pREE in CD and UC patients while tumor necrosis factor-α was not. In conclusion, energy expenditure significantly correlated with disease activity in UC patients but not in CD patients. These results indicate that establishing daily energy requirements based on disease activity of UC is imperative for improving the nutritional status of patients.

From physiology to disease and targeted therapy: interleukin-6 in inflammation and inflammation-associated carcinogenesis

Since its discovery in 1986, originally as B cell stimulating factor 2, the knowledge on IL-6 for immune homeostasis and its pathophysiological implications has rapidly increased. It is now clear that IL-6, alone or in combination with other cytokines, is an architect for shaping and generating immune responses which exerts profound activities on the induction of acute-phase reactions, the differentiation of B lymphocytes, the modulation of T cell apoptosis, the activation of T helper cells and the balance between regulatory T cells and Th17 cells. In parallel to the identification of these physiologic functions, IL-6 has emerged as a critical mediator for perpetuating chronic inflammation and autoimmunity and is increasingly recognized as a key cytokine for linking chronic inflammation to cancer development. In this review, we begin by briefly summarizing the molecular events of IL-6 regulation and signaling and then describe the role of IL-6 in orchestrating innate and adaptive immune responses and its immunopathological relevance for chronic inflammatory diseases. We further outline how IL-6 links chronic inflammation and cancer development and finally provide an outlook on novel therapeutic strategies targeting IL-6 signaling for the treatment of chronic inflammatory diseases and cancer.

Intestinal permeability regulation by tight junction: implication on inflammatory bowel diseases

Epithelial tight junctions (TJs) are the key structures regulating paracellular trafficking of macromolecules. The TJ is multi-protein complex that forms a selective permeable seal between adjacent epithelial cells and demarcates the boundary between apical and basolateral membrane domains. Disruption of the intestinal TJ barrier, followed by permeation of luminal noxious molecules, induces a perturbation of the mucosal immune system and inflammation, which can act as a trigger for the development of intestinal and systemic diseases. Inflammatory bowel disease (IBD) patients demonstrate increased intestinal paracellular permeability. Although it remains unclear whether barrier dysfunction precedes disease or results from active inflammation, increased intestinal TJ disruption is observed in IBD patients suggest that dysregulation of TJ barrier integrity may predispose or enhance IBD progression. Therefore, therapeutic target to restore the TJ barrier integrity may provide effective therapeutic and preventive approaches against IBD. This review discusses the molecular structure and regulation of intestinal TJs and the involvement of intestinal TJs in IBD pathogenesis.

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.

Targeting interleukins for the treatment of inflammatory bowel disease-what lies beyond anti-TNF therapy?

: Inflammatory bowel disease accounts for significant patient morbidity in the Western world. Several immunosuppressive therapies are available but are associated with potential significant adverse effects. In addition, there remains a cohort of patients with refractory or relapsing disease. Therefore, the search for novel therapeutic agents continues. In this review, we evaluate the role of a number of designated cytokines that are candidates in the pathogenesis of inflammatory bowel disease and discuss how their manipulation has been explored as a therapeutic strategy for this disease. The interleukins (ILs) chosen for discussion reflect those that currently show most promise as future therapeutic targets, as well as discussing the role of some of the most recently identified ILs, such as IL-27, IL-33, IL-35, and IL-22, in this context.

Liver-brain interactions in inflammatory liver diseases: implications for fatigue and mood disorders

Chronic inflammatory liver diseases are often accompanied by behavior alterations including fatigue, mood disorders, cognitive dysfunction and sleep disturbances. These altered behaviors can adversely affect patient quality of life. The communication pathways between the inflamed liver and the brain that mediate changes in central neural activity leading to behavior alterations during liver inflammation are poorly understood. Neural and humoral communication pathways have been most commonly implicated as driving peripheral inflammation to brain signaling. Classically, the cytokines TNFα, IL-1β and IL-6 have received the greatest scientific attention as potential mediators of this communication pathway. In mice with liver inflammation we have identified a novel immune-mediated liver-to-brain communication pathway whereby CCR2(+) monocytes found within the peripheral circulation transmigrate into the brain parenchyma in response to MCP-1/CCL2 expressing activated microglia. Inhibition of cerebral monocyte infiltration in these mice significantly improved liver inflammation associated sickness behaviors. Importantly, in recent work we have found that at an earlier time point, when cerebral monocyte infiltration is not evident in mice with liver inflammation, increased monocyte:cerebral endothelial cell adhesive interactions are observed using intravital microscopy of the brain. These monocyte:cerebral endothelial cell adhesive interactions are P-selectin mediated, and inhibition of these interactions attenuated microglial activation and sickness behavior development. Delineating the pathways that the periphery uses to communicate with the brain during inflammatory liver diseases, and the central neurotransmitter systems that are altered through these communication pathways (e.g., serotonin, corticotrophin releasing hormone) to give rise to liver inflammation-associated sickness behaviors, will allow for the identification of novel therapeutic targets to decrease the burden of debilitating symptoms in these patients.