Natalizumab for moderate to severe Crohn's disease in clinical practice: the Mayo Clinic Rochester experience

Immunology of Inflammatory Bowel Disease: Molecular Mechanisms and Therapeutics

As a main digestive organ and an important immune organ, the intestine plays a vital role in resisting the invasion of potential pathogens into the body. Intestinal immune dysfunction remains important pathogenesis of inflammatory bowel disease (IBD). In this review, we explained the interactions among symbiotic flora, intestinal epithelial cells, and the immune system, clarified the operating mechanism of the intestinal immune system, and highlighted the immunological pathogenesis of IBD, with a focus on the development of immunotherapy for IBD. In addition, intestinal fibrosis is a significant complication in patients with long-term IBD, and we reviewed the immunological pathogenesis involved in the development of intestinal fibrogenesis and provided novel antifibrotic immunotherapies for IBD.

Biologics: how far can they go in Crohn’s disease?

Crohn’s disease is a chronic gastrointestinal inflammatory disorder, characterized by episodes of relapsing and remitting flares. As the disease mechanism becomes better elucidated, there is a significant increase in the number of available biologic therapies. This article summarizes and synthesizes current Food and Drug Administration-approved biological therapy for Crohn’s disease and examines the positioning of medical therapy as emerging biologics break onto the market.

Biologic therapy for Crohn’s disease over the last 3 decades

BACKGROUND

Despite the overload of publications on Crohn’s disease (CD), no comprehensive analysis of biologic therapy for CD has been reported.

AIM

To determine knowledge gaps and identify areas of interest of biologic therapy for CD.

METHODS

The top 100 highest-cited original articles were identified from January 1991 to December 2020 in the Clarivate Analytics Web of Science Core Collection database. We conducted a bibliometric analysis of biologic therapy for CD based on total citations, summarized the bibliographic information of the articles related to CD biologic therapy, and explored the research hotspots.

RESULTS

The top 100 highest-cited original articles were identified with total citations ranging from 307 to 2978. The 2000s (Period II, n = 66) yielded the most influential original articles and saw the most dramatic growth. Among the top 10 countries, including 8 European countries and 2 North American countries, the United States (n = 37) and Belgium (n = 20) contributed the most publications. Among the top 10 institutions, the University Hospital Gasthuisberg in Belgium (n = 23), the University of Chicago in the United States (n = 20), and the Mayo Clinic in the United States (n = 17) published the most papers. Regarding authors, Rutgeerts P in Belgium (n = 32), Sandborn WJ in the United States (n = 23), and Feagan BG in Canada (n = 18) published the highest number of studies. The cooperation relationships between the United States and Europe were most frequent. Gastroenterology (impact factor = 22.682) published the most articles on biologic therapy for CD (n = 32) with 17654 total citations. Anti-tumor necrosis factor biologics and monoclonal antibodies were the most studied topics.

CONCLUSION

The bibliometric analysis emphasized the key contributions to the development of the specialized field. These data would provide useful research insights into biologic therapy for CD for clinicians and researchers.

Anti-Integrins for the Treatment of Inflammatory Bowel Disease: Current Evidence and Perspectives

Leukocyte trafficking to the gastrointestinal tract is recognized to play a role in the pathogenesis of inflammatory bowel disease (IBD). Integrins are expressed on immune cells and interact with cell adhesion molecules (CAM) to mediate leukocyte trafficking. Blockade of the gut-tropic integrin α4β7 and its subunits has been exploited as a therapeutic target in IBD. Natalizumab (anti-α4) is approved for moderate to severe Crohn's disease (CD), but its use is limited due to potential risk of progressive multifocal leukoencephalopathy. Vedolizumab (anti-α4β7) is approved for the treatment of ulcerative colitis (UC) and CD. It is the most widely used anti-integrin therapy in IBD and has been shown to be effective in both induction and maintenance therapy, with a favorable safety profile. Several models incorporating clinical, genetic, immune, gut microbial, and vitamin D markers to predict response to vedolizumab in IBD have been developed. Etrolizumab (anti-β7) blocks leukocyte trafficking via α4β7 and cell adhesion via αEβ7 integrins. Large phase 3 clinical trials evaluating efficacy of etrolizumab in the induction and maintenance of patients with IBD are underway. Other investigational anti-integrin therapies include abrilumab (anti-α4β7 IgG2), PN-943 (orally administered and gut-restricted α4β7 antagonist peptide), AJM300 (orally active small molecule inhibitor of α4), and ontamalimab (anti-MAdCAM-1 IgG).

Natalizumab for induction of remission in Crohn's disease

BACKGROUND

This systematic review update summarizes the current evidence on the use of natalizumab for induction of remission in Crohn's disease (CD).

OBJECTIVES

To determine the efficacy and safety of natalizumab for induction of remission in CD.

SEARCH METHODS

We searched MEDLINE, Embase, CENTRAL, the Cochrane IBD Group Specialized Trials Register, and clinicaltrials.gov from inception to 10 May 2018.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) comparing natalizumab to a placebo or control therapy for induction of remission in CD.

DATA COLLECTION AND ANALYSIS

Two authors independently screened studies, extracted data and assessed methodological quality using the Cochrane risk of bias tool. The primary outcome was failure to enter clinical remission. Secondary outcomes included clinical response, mean change in Crohn's Disease Activity Index (CDAI), adverse events (AEs), withdrawal due to AEs and serious AEs. For dichotomous outcomes, we calculated the risk ratio (RR) and 95% confidence interval (95% CI). For continuous outcomes we calculated the mean difference (MD) and 95% CI. Data were pooled for meta-analysis when the interventions, patient groups and outcomes were sufficiently similar (determined by consensus). We used GRADE to assess the overall quality of the evidence.

MAIN RESULTS

A total of five RCTs (1771 participants) were included. Four studies (1692 participants) compared one, two or three infusions of natalizumab (300 mg or 3 mg/kg or 6mg/kg) to placebo. One study (79 participants) compared three infusions of natalizumab (300 mg) and infliximab (5 mg/kg) to infliximab and placebo. Four studies were rated as low risk of bias. One study was rated as unclear risk of bias for selective reporting.One, two and three infusions of natalizumab were superior to placebo for induction of remission and clinical response. Infusions were administered at weeks zero, four and eight. After one infusion, 76% (849/1117) of natalizumab participants failed to enter remission at 4 weeks compared to 83% (411/494) of placebo participants (RR 0.91, 95% CI 0.86 to 0.96, 3 studies, GRADE high quality). At 4 weeks, the RR for clinical response was 0.78 (95% CI 0.66 to 0.92, 3 studies, 1611 participants, GRADE moderate quality). After two infusions, after 8 weeks, 66% (693/1049) of natalizumab participants failed to enter remission compared to 77% (382/494) of placebo participants (RR 0.85, 95% CI 0.76 to 0.95; 3 studies, GRADE moderate quality). At 8 weeks, the RR for clinical response was 0.73 (95% CI 0.58 to 0.91, 3 studies, 1543 participants, GRADE low quality). After three infusions, at 12 weeks, 61% (596/983) of natalizumab participants failed to enter remission compared to 73% (313/431) of placebo participants (RR 0.85, 95% CI 0.78 to 0.92, 2 studies, GRADE high quality). At 12 weeks, the RR for clinical response was 0.76 (95% CI 0.67 to 0.86, 2 studies, 1414 participants, GRADE high quality). One study (507 participants) reported on change in CADI from baseline. Natalizumab participants had a larger drop in mean CDAI scores than placebo participants at 4, 8 and 12 weeks.The rates of AEs, withdrawals due to AEs and serious AEs were similar across groups at 4, 8 and 12 weeks. After one infusion, 74% (50/68) of natalizumab participants experienced an AE compared to 81% (51/63) of placebo participants (RR 0.91, 95% CI 0.75 to 1.09, GRADE moderate quality). Withdrawal due to an AE occurred in 1% (1/68) of natalizumab participants and 3% of placebo participants (RR 0.46, 95% CI 0.04 to 4.98, GRADE low quality). SAEs occurred in 10% (7/68) of natalizumab participants compared to 11% (7/63) of placebo participants (RR 0.93, 95% CI 0.34 to 2.49, GRADE low quality). After two infusions, 86% (57/66) of natalizumab participants experienced an AE compared to 81% (51/63) of placebo participants (RR 1.07, 95% CI 0.92 to 1.24, GRADE moderate quality). Withdrawal due to an AE occurred in 3% (2/66) natalizumab participants compared to 3% (2/63) placebo participants (RR 0.95, 95% CI 0.14 to 6.57, GRADE low quality). SAEs occurred in 9% (6/66) of natalizumab participants and 11% (7/63) of placebo participants (RR 0.82, 95% CI 0.29 to 2.30, GRADE low quality). After three infusions, 86% (848/984) of natalizumab participants experienced an AE compared to 83% (359/431) placebo participants (RR 1.03, 95% CI 0.98 to 1.08, GRADE high quality). Withdrawals due to AEs occurred in 8% (82/984) of natalizumab participants compared to 10% (45/431) of placebo participants (RR 0.86, 95% CI 0.59 to 1.26, GRADE moderate quality). SAEs occurred in 7% (65/983) of natalizumab participants and 8% (36/431) of placebo participants (RR 0.76. 95% CI 0.37 to 1.56, GRADE low quality). Adverse events included headache, nausea, nasopharyngitis, abdominal pain, fatigue, vomiting, and exacerbation of CD.The study comparing combination therapy with natalizumab and infliximab to infliximab and placebo demonstrated similar remission rates at 10 weeks. Sixty-four per cent (33/52) of participants assigned to natalizumab and infliximab failed to achieve remission compared to 70% (19/27) assigned to placebo and infliximab (RR 0.90, 95% CI 0.65 to 1.24, GRADE moderate quality). The rates of AEs (moderate quality evidence), withdrawals due to AEs (low quality evidence) and serious AEs (low quality evidence) were similar across groups at 10 weeks. Adverse events included headache, exacerbation of CD, nausea, and nasopharyngitis.Natalizumab is associated with the development of progressive multifocal leukoencephalopathy (PML) resulting in some patient deaths. There are currently no tests which can reliably predict those at risk of developing PML.

AUTHORS' CONCLUSIONS

High quality data suggest that natalizumab is effective for induction of clinical remission and response in some patients with moderately to severely active CD. However, none of the included studies had the power to detect rare but serious adverse events such as PML. Due to the association with PML, and the availability of alternative agents that are not associated with PML, natalizumab is not likely to be used in patients who fail currently available medical therapy. The use of natalizumab in select patients (e.g. patients allergic to different biologics) needs to be carefully considered against the potential risk of developing PML. Futher studies of natalizumab are not likely to be done.

Use of Anti-Tumor Necrosis Factors and Anti-Integrins in the Treatment of Crohn's Disease

In patients with Crohn's disease (CD), anti-tumor necrosis factor (TNF) therapy is efficacious for the induction and maintenance of clinical remission, mucosal healing, reducing rates of surgery and hospitalizations, and improving health-related quality of life. The decision between anti-TNFs and anti-integrins as first-line treatment in CD depends on disease severity, safety concerns, and prescription coverage. Given the existing data on long-term outcomes and safety, anti-TNFs are often preferred to anti-integrins. Additional clinical experience and preferably prospective, head-to-head studies will be important to determine whether vedolizumab should be considered more often for first-line therapy in CD.

Natalizumab in the treatment of Crohn's disease patients

INTRODUCTION

Amongst the available therapies for moderate to severe Crohn's disease (CD) patients who are refractory to conventional therapy, anti-TNF blockers are the most effective biological treatment option. However, many patients experience a primary or secondary non-response to anti-TNF therapy, creating the need for alternative biological drugs that target different mechanisms of action and inflammatory pathways. Natalizumab, the first non-anti-TNF biological drug to be approved for treatment of CD patients, is a recombinant humanized antibody that targets the α₄-subunit of both α₄β₁ and α₄β₇ integrins, thus preventing activated leukocyte homing to the intestinal mucosa. Areas covered: This article summarizes the pathophysiological background and the efficacy and safety data of natalizumab, as well as the regulatory issues surrounding it. Expert opinion: Natalizumab represents an effective therapy for refractory CD patients. However, the rare but serious event of progressive multifocal leukoencephalopathy occurrence has compromised its widespread use. The subsequent advent of more specific anti-integrin drugs (i.e. vedolizumab) that carry a more favorable safety profile further reduces the clinical indications for natalizumab. The regulatory process for natalizumab distribution and monitoring in the US may provide a forum for discussion on how to optimally manage use of drugs that offer clinical benefits to patients, while minimizing associated risks.

Neurological Complications of Gastrointestinal Disease

There is a growing interest in the extraintestinal manifestations of common pediatric gastrointestinal diseases, such as inflammatory bowel disease and celiac disease. This article specifically focuses on the neurological symptoms that manifest because of these disorders and their treatments. Many neurological symptoms have been reported in association with these diseases, including neuropathy, myopathy, ataxia, headache, and seizures, among others. It is currently believed that these neurological symptoms are largely overlooked by practitioners and could be a red flag for earlier diagnosis. However, additional research, especially in the pediatric population, is warranted to further elaborate on the causality and pathophysiology of these neurological symptoms.

MRI texture analysis parameters of contrast-enhanced T1-weighted images of Crohn's disease differ according to the presence or absence of histological markers of hypoxia and angiogenesis

Purpose

To investigate if texture analysis parameters of contrast-enhanced MRI differ according to the presence of histological markers of hypoxia and angiogenesis in Crohn’s disease (CD).

Methods

Seven CD patients (mean age 38 (19–75), 3 male)) undergoing ileal resection underwent 3T MR enterography including axial ultrafast spoiled gradient-echo T1 post IV gadolinium chelate. Regions of interest were placed in bowel destined for resection and registered to trans-mural histological sections (n = 28 across 7 bowel sections) via MRI of the resected specimen. Microvessel density (MVD) and staining for markers of hypoxia (HIF 1α) and angiogenesis (VEGF) were performed. Texture analysis features were derived utilizing an image filtration-histogram technique at spatial scaling factor (SSF) 0–6 mm, including mean, standard deviation, mean of positive pixels, entropy, kurtosis and skewness and compared according to the presence or absence of histological markers of hypoxia/angiogenesis using Mann–Whitney U/Kruskal–Wallis tests and with the log of MVD using simple linear regression.

Results

Mean, standard deviation and mean of positive pixels were significantly lower in sections expressing VEGF. For example at SSF 6 mm, median (inter-quartile range) of mean, standard deviation and mean of positive pixels in those with VEGF expression were 150.1 (134.7), 132.4 (49.2) and 184.0 (91.4) vs. 362.5 (150.2), 216.3 (100.1) and 416.6 (80.0) in those without (p = 0.001, p = 0.004 and p = 0.001), respectively. There was a significant association between skewness and MVD (ratio 1.97 (1.15–3.41)) at SSF = 2 mm.

Conclusions

Contrast-enhanced MRI texture analysis features significantly differ according to the presence or absence of histological markers of hypoxia and angiogenesis in CD.

Systematic review with meta-analysis: mucosal healing is associated with improved long-term outcomes in Crohn's disease

BACKGROUND

Clinical manifestations of Crohn's disease (CD) do not reliably correlate with endoscopic activity. While treating to achieve clinical remission (CR) has neither proven to improve CD outcomes nor alter the natural disease course, it is unclear whether targeting objective measures like mucosal healing (MH) is associated with improved long-term outcomes.

AIM

To perform a systematic review and meta-analysis comparing long-term outcomes in active CD patients who achieve MH compared to those who do not.

METHODS

We performed a systematic literature search to identify studies with prospective cohorts of active CD patients that included outcomes of patients who achieved MH at first endoscopic assessment (MH1) compared to those who did not. The primary outcome was long-term (≥50 weeks) CR. Secondary outcomes included CD-related surgery-free rate, hospitalisation-free rate and long-term MH rate. Pooled odds ratio (OR) and 95% confidence intervals (CI) were calculated.

RESULTS

Twelve studies with 673 patients met inclusion criteria. Patients achieving MH1 had a pooled OR of 2.80 (95%CI, 1.91-4.10) for achieving long-term CR, 2.22 (95%CI, 0.86-5.69) for CD-related surgery-free rate, and 14.30 (95%CI, 5.57-36.74) for long-term MH. Sensitivity analyses suggested no difference in outcomes if MH1 was achieved on biologics vs. non-biologics. No significant publication bias or heterogeneity was detected.

CONCLUSIONS

Achieving MH1 is associated with increased rates of long-term clinical remission, and maintenance of mucosal healing in active Crohn's disease and may therefore be a reasonable therapeutic target.

Anti-α4 Integrin Antibody Blocks Monocyte/Macrophage Traffic to the Heart and Decreases Cardiac Pathology in a SIV Infection Model of AIDS

Background

Cardiovascular disease (CVD), myocarditis and fibrosis are comorbidities of HIV⁺ individuals on durable antiretroviral therapy (ART). Although mechanisms for these vary, monocytes/macrophages are increasingly demonstrated to be key players.

Methods and Results

We directly blocked monocyte/macrophage traffic to the heart in an SIV model of AIDS using an anti-alpha-4 integrin antibody (natalizumab). Nineteen Rhesus macaques were SIVmac251 infected and CD8-lymphocyte depleted for the development of rapid AIDS. Ten animals received natalizumab once a week, for 3 weeks, and were sacrificed 1 week later. Six animals began treatment at the time of infection (early) and the remaining 4 began treatment 28 days post-infection (late), a time point we have previously established when significant cardiac inflammation occurs. Nine animals were untreated controls; of these, 3 were sacrificed early and 6 were sacrificed late. At necropsy, we found decreased SIV-associated cardiac pathology in late natalizumab-treated animals, compared to untreated controls. Early and late treatment resulted in significant reductions in numbers of CD163⁺ and CD68⁺ macrophages in cardiac tissues, compared to untreated controls, and a trend in decreasing numbers of newly recruited MAC387⁺ and BrdU⁺ (recruited) monocytes/macrophages. In late treated animals, decreased macrophage numbers in cardiac tissues correlated with decreased fibrosis. Early and late treatment resulted in decreased cardiomyocyte damage.

Conclusions

These data demonstrate a role for macrophages in the development of cardiac inflammation and fibrosis, and suggest that blocking monocyte/macrophage traffic to the heart can alleviate HIV- and SIV-associated myocarditis and fibrosis. They underscore the importance of targeting macrophage activation and traffic as an adjunctive therapy in HIV infection.

Downregulation of FoxC2 Increased Susceptibility to Experimental Colitis: Influence of Lymphatic Drainage Function?

BACKGROUND

Although inflammation-induced expansion of the intestinal lymphatic vasculature (lymphangiogenesis) is known to be a crucial event in limiting inflammatory processes, through clearance of interstitial fluid and immune cells, considerably less is known about the impact of an impaired lymphatic clearance function (as seen in inflammatory bowel diseases) on this cascade. We aimed to investigate whether the impaired intestinal lymphatic drainage function observed in FoxC2 mice would influence the course of disease in a model of experimental colitis.

METHODS

Acute dextran sodium sulfate colitis was induced in wild-type and haploinsufficient FoxC2 mice, and survival, disease activity, colonic histopathological injury, neutrophil, T-cell, and macrophage infiltration were evaluated. Functional and structural changes in the intestinal lymphatic vessel network were analyzed, including submucosal edema, vessel morphology, and lymphatic vessel density.

RESULTS

We found that FoxC2 downregulation in FoxC2 mice significantly increased the severity and susceptibility to experimental colitis, as displayed by lower survival rates, increased disease activity, greater histopathological injury, and elevated colonic neutrophil, T-cell, and macrophage infiltration. These findings were accompanied by structural (dilated torturous lymphatic vessels) and functional (greater submucosal edema, higher immune cell burden) changes in the intestinal lymphatic vasculature.

CONCLUSIONS

These results indicate that sufficient lymphatic clearance plays a crucial role in limiting the initiation and perpetuation of experimental colitis and those disturbances in the integrity of the intestinal lymphatic vessel network could intensify intestinal inflammation. Future therapies might be able to exploit these processes to restore and maintain adequate lymphatic clearance function in inflammatory bowel disease.

From historical perspectives to modern therapy: a review of current and future biological treatments for Crohn's disease

Crohn's disease (CD) is a debilitating, systemic inflammatory disorder with both gastrointestinal and extraintestinal manifestations. Its existence predates modern medicine, but its precise etiology remains incompletely understood. Most authorities suggest a multifactorial pathogenesis owing to a mixture of genetic disorders, immunologic dysregulation, microbiota disequilibrium and environmental influences. Of these factors, the overactive immunologic response seen in CD appears to be the most promising target of medical therapy. Biological agents comprise a relatively new class of drugs that can induce and maintain remission in moderate to severe CD, as well as in ulcerative colitis. This review will provide an overview of CD, its history, clinical features, pathophysiology, and treatment options focusing on current and future biological agents with an emphasis on drug development, dosage and administration.

CCR9 antagonism: potential in the treatment of Inflammatory Bowel Disease

Inflammatory Bowel Disease (IBD), mainly comprising Crohn’s disease (CD) and ulcerative colitis (UC), is a chronic condition that primarily affects the intestine and is characterized by leukocytic infiltration. Blocking the migration of leukocytes from the circulation is therefore a reasonable therapeutic goal. Recent clinical trials using this approach have shown promise, with the monoclonal antibody to α₄β₇ integrin, vedolizumab, and previously with the monoclonal antibody to the α₄ subunit, natalizumab. Directly targeting the subset of α₄β₇ expressing cells that co-express CC chemokine receptor 9 (CCR9), using the orally administered antagonist, CCX282-B, also known as vercirnon, has also been evaluated in Phase II and III trials that have produced mixed results. Although CCX282-B showed efficacy in inducing response in active CD in early studies, this was not confirmed in a Phase III study. CCX282-B was also more effective than placebo in maintaining remission, and this result has yet to be confirmed in Phase III. The efficacy of blocking CCR9 in UC, where vedolizumab was effective, has not been tested. The prospect of targeting CCR9 in IBD remains attractive. Much of the local accumulation of inflammatory cells in the intestine arises from migration rather than local proliferation and genetic and pharmacological targeting of CCR9 or its ligand in preclinical models that mimic UC and CD ameliorate inflammation in some cases. Furthermore, binding of chemokine ligands to receptor is a critical step in activating integrin binding, so there is a potential for synergistic action between integrin and chemokine antagonists. CCR9 is expressed on a smaller proportion of circulating cells than α₄β₇ integrin, which may offer greater specificity of effect, particularly in long term use. Furthermore, while α₄β₇ is widely expressed on T and B cell subsets, CCR9 is mainly expressed on effector memory Th1 cells. Indications for the use of intestine-specific integrin and chemokine receptor targeting may also extend beyond IBD, to include, for example, postoperative ileus, and primary sclerosing cholangitis.

Translational research and efficacy of biologics in Crohn's disease: a cautionary tale

In the last several years many biologic agents for Crohn's disease have been developed. Due to their unique molecular specificity biologics are de facto indicators of the ultimate significance of the molecule targeted by the biologic itself. Here, we have reviewed many clinical studies that have used biologics for Crohn's disease. Their results show that despite potentially sound theoretical mechanisms of action and some initially promising data, most biologics - with few notable exceptions - have failed. Pharmacologic, study design or patient-related issues might explain these findings in some studies. However in many cases clinical failure of biologics might highlight the complexity of in vivo events and the potential deficiencies of current experimental settings. Hence, these observations call for new and efficient ways of predicting drug efficacy in clinical trials based on bench research. Conceivably, computer-based pathogenetic models could be used to simulate and predict clinical studies results in vivo.

Risk of infections with biological agents

An increasing proportion of patients with inflammatory bowel disease (IBD) are treated with biological medications. The risk of infectious complications remains a significant concern in patients treated with biologics. Treatment with biological agents in IBD is generally safe, but there may be an increased risk of certain opportunistic infections. Some of the infectious risks are class specific, whereas others are a common concern for all biologics. A careful screening, surveillance, and immunization program, in accordance with available guidelines, is important to minimize any risk of infectious complications.

CD84 is markedly up-regulated in Kawasaki disease arteriopathy

The major goals of Kawasaki disease (KD) therapy are to reduce inflammation and prevent thrombosis in the coronary arteries (CA), but some children do not respond to currently available non-specific therapies. New treatments have been difficult to develop because the molecular pathogenesis is unknown. In order to identify dysregulated gene expression in KD CA, we performed high-throughput RNA sequencing on KD and control CA, validated potentially dysregulated genes by real-time reverse transcription-polymerase chain reaction (RT-PCR) and localized protein expression by immunohistochemistry. Signalling lymphocyte activation molecule CD84 was up-regulated 16-fold (P < 0·01) in acute KD CA (within 2 months of onset) and 32-fold (P < 0·01) in chronic CA (5 months to years after onset). CD84 was localized to inflammatory cells in KD tissues. Genes associated with cellular proliferation, motility and survival were also up-regulated in KD CA, and immune activation molecules MX2 and SP140 were up-regulated in chronic KD. CD84, which facilitates immune responses and stabilizes platelet aggregates, is markedly up-regulated in KD CA in patients with acute and chronic arterial disease. We provide the first molecular evidence of dysregulated inflammatory responses persisting for months to years in CA significantly damaged by KD.

The integrin adhesome: from genes and proteins to human disease

The adhesive interactions of cells with their environment through the integrin family of transmembrane receptors have key roles in regulating multiple aspects of cellular physiology, including cell proliferation, viability, differentiation and migration. Consequently, failure to establish functional cell adhesions, and thus the assembly of associated cytoplasmic scaffolding and signalling networks, can have severe pathological effects. The roles of specific constituents of integrin-mediated adhesions, which are collectively known as the 'integrin adhesome', in diverse pathological states are becoming clear. Indeed, the prominence of mutations in specific adhesome molecules in various human diseases is now appreciated, and experimental as well as in silico approaches provide insights into the molecular mechanisms underlying these pathological conditions.

Chronic inflammatory diseases: do immunological patterns drive the choice of biotechnology drugs? A critical review

Chronic inflammatory diseases represent a heterogeneous group of conditions that can affect practically any organ or system. An increasing number of biologic agents have been developed to selectively target the cell populations and signaling pathways involved in chronic inflammation, including cytokines, monoclonal antibodies and engineered receptors. This approach has been remarkably successful in alleviating some of the signs and symptoms of refractory autoimmune diseases. The use of this therapeutic strategy is likely to increase with the introduction of biosimilar agents. The different nature of these biological products makes the comparison of their pharmaceutical and clinical characteristics difficult, including safety and potency and these issues may be particularly relevant in the case of biosimilars. In addition, the heterogeneity of autoimmune diseases and of autoimmune patients, further adds to the complexity of choosing the right drug for each patient and predicting efficacy and safety of the treatment. In this review, we summarize actual knowledge about current biological agents and their use in autoimmune diseases, with a special emphasis for rheumatoid arthritis, inflammatory bowel diseases and psoriasis. The purpose of this analysis is to address the most critical issues raised by the rapid advancements in this field over recent years, and to acknowledge the potentially valuable gains brought about by the increasing availability of these new biologic agents.

Immunosuppressive therapies for inflammatory bowel disease

Inflammatory bowel disease (IBD) is comprised of Crohn’s disease and ulcerative colitis, both chronic inflammatory intestinal disorders of unknown etiology characterized by a waxing and waning clinical course. For many years, the drug therapy was limited to sulfasalazine and related aminosalicylates, corticosteroids and antibiotics. Studies suggesting that the pathophysiology of these disorders relates to a disregulated, over-active immune response to indigenous bacteria have led to the increasing importance of immunosuppressive drugs for the therapy of IBD. This review details the mechanisms of action, clinical efficacy, and adverse effects of these agents.

The safety and efficacy of adalimumab in patients with Crohn's disease: the experience of a single Canadian tertiary care centre

BACKGROUND. Adalimumab (ADA), an antitumor necrosis factor (anti-TNF) monoclonal antibody, is effective in treating moderate-to-severely active Crohn's disease (CD). ADA has been associated with a variety of adverse events (AE). The purpose of this study is to determine the safety and efficacy of ADA in CD patients in clinical practice. METHODS. A retrospective analysis was performed on CD patients treated with ADA. Data extracted and analyzed included patient and CD demographics, remission and response rates with ADA, and safety and tolerability of ADA. RESULTS. A total of 149 ADA-treated CD patients were included. The mean duration of therapy with ADA was 20 months with 32% of patients discontinuing treatment. Anti-TNF-naïve and anti-TNF-exposed patients on ADA achieved clinical remission in 45% and 32%, had a clinical response in 23% and 23%, and had no clinical response in 32% and 45%, respectively. Anti-TNF-naïve and anti-TNF-exposed patients maintained remission in 82% and 67%, respectively. Fistulas healed in 19% and improved in 19%. AE occurred in 38% of patients with infection being the most common (20%). Serious infections lead to death in one (<1%). Logistic regression of AE did not identify statistically significant predictors except for colonic disease location (odds ratio [OR] = 0.31, 95% CI = 0.12-0.82, p = 0.018) and the rate of ADA discontinuation (OR = 3.24, 95% CI = 1.58-6.64, p = 0.0013). CONCLUSION. ADA is an effective treatment for CD. AE can occur commonly leading to discontinuation of medication and may be influenced by disease location. Although serious complications are rare, close monitoring of all patients on ADA is needed.

Inflammatory bowel disease: An increased risk factor for neurologic complications

Only a very few systematic studies have investigated the frequency of neurologic disorders in patients with Crohn’s disease (CD) and ulcerative colitis (UC), which are the two main types of inflammatory bowel disease (IBD). Results have been inconsistent and variable, owing to differences in case-finding methods and evaluated outcomes in different studies. The most frequent neurologic manifestations reported in CD and UC populations are cerebrovascular disease (with either arterial or venous events), demyelinating central nervous system disease, and peripheral neuropathy (whether axonal or demyelinating); however, the literature describes numerous nervous system disorders as being associated with IBD. The pathogenesis of nervous system tissue involvement in IBD has yet to be elucidated, although it seems to be related to immune mechanisms or prothrombotic states. The recently-introduced tumor necrosis factor (TNF) inhibitors have proven successful in controlling moderate to severe IBD activity. However, severe neurologic disorders associated with TNF inhibitors have been reported, which therefore raises concerns regarding the effect of anti-TNF-α antibodies on the nervous system. Although neurological involvement associated with IBD is rarely reported, gastroenterologists should be aware of the neurologic manifestations of IBD in order to provide early treatment, which is crucial for preventing major neurologic morbidity.

Advances in therapeutic interventions targeting the vascular and lymphatic endothelium in inflammatory bowel disease

PURPOSE OF REVIEW

The review summarizes the current knowledge of the roles played by the vascular and lymphatic endothelium throughout the gut in the pathogenesis of inflammatory bowel disease (IBD) and gives an update on emerging strategies targeting both vasculatures.

RECENT FINDINGS

Enormous efforts have been made to understand the mechanisms underlining the origin, development and maintenance of intestinal chronic inflammation. In particular, new studies focused their attention on the role played by the microvascular and lymphatic endothelium in the pathogenesis of IBD. During inflammation, whereas the microvasculature is responsible for the entry and distribution of immune cells in the mucosa, the lymphatic system controls leukocyte exit, bacterial clearance and edema absorption. The study of these events, which are aberrant during chronic inflammation, has resulted in the identification and validation of several targets for the treatment of experimental colitis, some of which have translated into effective treatments for patients with IBD.

SUMMARY

Although much attention has been paid to the microvascular endothelium and to antiangiogenic therapies, specific studies on the lymphatic vasculature and its functions in IBD are still at the initial stage, and other molecular mechanisms, genes, molecules and new pathways must definitely be explored.

Mucosal healing is associated with improved long-term outcome of maintenance therapy with natalizumab in Crohn's disease

BACKGROUND

Natalizumab is an efficacious agent for induction and maintenance of remission in patients with Crohn's disease (CD) who have failed anti-tumor necrosis factor agents. We aimed to assess the impact of endoscopic severity and mucosal healing on the long-term outcome of natalizumab treatment in CD.

METHODS

We retrospectively assessed endoscopic severity according to the Simple Endoscopic Score for Crohn's Disease in patients with CD who received natalizumab therapy. The degree of endoscopic severity before natalizumab treatment and mucosal healing after treatment and their correlation with long-term outcome were studied.

RESULTS

Thirty-two patients with CD (15 male, median age 32.5 years) receiving natalizumab underwent at least 1 colonoscopy before or during natalizumab treatment. All patients had previously failed immunomodulator(s), and 31 failed anti-tumor necrosis factor agent(s). Mean duration of natalizumab treatment was 14.1 months. Baseline Simple Endoscopic Score for CD was categorized into quartiles, and those with a greater score were less likely to respond to treatment as assessed by Kaplan-Meier survival analysis (n = 32, log-rank test, P = 0.0055). Mucosal healing (decrease of Simple Endoscopic Score for CD of >70%) was achieved in 11 of 26 patients (42.3%), and this was correlated with an improved long-term outcome (log-rank test, P = 0.0063).

CONCLUSIONS

The degree of endoscopic inflammation correlates to response to natalizumab and maintenance of remission. These findings provide prognostic information for patient management decisions.

Efficacy and safety of natalizumab in Crohn's disease patients treated at 6 Boston academic hospitals

BACKGROUND

Despite trials demonstrating its efficacy, many physicians harbor concerns regarding the use of natalizumab in the treatment of patients with refractory Crohn's disease (CD). The purpose of this study was to perform a descriptive analysis of a series of CD patients not currently enrolled in a clinical trial.

METHODS

A retrospective case review of patients treated with natalizumab at 6 sites in Massachusetts: Boston Medical Center, Beth Israel Deaconess Medical Center, Brigham & Women's Hospital, Lahey Clinic, Massachusetts General Hospital, and UMass Medical Center.

RESULTS

Data on 69 CD patients on natalizumab were collected. At the start of treatment, patients' disease duration was 12 years. A high proportion of patients were women (68%), presented with perianal disease (65%) and upper gastrointestinal tract involvement (14%). Prior nonbiologic therapies were steroids (96%), thiopurines (94%), antibiotics (74%), methotrexate (58%), and at least two anti-tumor necrosis factor agent failures (81%). Sixty-nine percent (44 of 64 patients) with available medical evaluation had a partial or complete clinical response. Loss of response was 13% after an average of 1 year of treatment. Adverse events were infusion reactions, headaches, fever, and infections. No case of progressive multifocal leukoencephalopathy was observed.

CONCLUSIONS

In our clinical experience outside the context of a clinical trial, natalizumab is largely reserved for CD patients with extensive ileocolonic disease who have failed conventional immunosuppressants and of at least 2 anti-tumor necrosis factor agents. This drug is, however, well tolerated and offers significant clinical improvement for more than a year in one-third of these difficult-to-treat CD patients.