Haemostatic system in inflammatory bowel diseases: New players in gut inflammation

Mechanistic insight: Linking cardiovascular complications of inflammatory bowel disease

Cardiovascular diseases (CVD) are the leading cause of mortality worldwide despite an aggressive reduction of traditional cardiovascular risk factors. Underlying inflammatory conditions such as inflammatory bowel disease (IBD) increase the risk of developing CVD. A broad understanding of the underlying pathophysiological processes between IBD and CVD is required to treat and prevent cardiovascular events in patients with IBD. This review highlights the commonality between IBD and CVD, including dysregulated immune response, genetics, environmental risk factors, altered gut microbiome, stress, endothelial dysfunction and abnormalities, to shed light on an essential area of modern medicine.

Inflammatory Bowel Disease Increases the Severity of Myocardial Infarction after Acute Ischemia-Reperfusion Injury in Mice

(1) Background: Increased risk of myocardial infarction (MI) has been linked to several inflammatory conditions, including inflammatory bowel disease (IBD). However, the relationship between IBD and MI remains unclear. Here, we implemented an original mouse model combining IBD and MI to determine IBD's impact on MI severity and the link between the two diseases. (2) Methods: An IBD model was established by dextran sulfate sodium (DSS) administration in drinking water, alone or with oral C. albicans (Ca) gavage. IBD severity was assessed by clinical/histological scores and intestinal/systemic inflammatory biomarker measurement. Mice were subjected to myocardial ischemia-reperfusion (IR), and MI severity was assessed by quantifying infarct size (IS) and serum cardiac troponin I (cTnI) levels. (3) Results: IBD mice exhibited elevated fecal lipocalin 2 (Lcn2) and IL-6 levels. DSS mice exhibited almost two-fold increase in IS compared to controls, with serum cTnI levels strongly correlated with IS. Ca inoculation tended to worsen DSS-induced systemic inflammation and IR injury, an observation which is not statistically significant. (4) Conclusions: This is the first proof-of-concept study demonstrating the impact of IBD on MI severity and suggesting mechanistic aspects involved in the IBD-MI connection. Our findings could pave the way for MI therapeutic approaches based on identified IBD-induced inflammatory mediators.

Gut vascular barrier in the pathogenesis and resolution of Crohn's disease: A novel link from origination to therapy

The gut vascular barrier (GVB) is the deepest layer of the gut barrier. It mainly comprised gut vascular endothelial cells, enteric glial cells, and pericytes. The GVB facilitates nutrient absorption and blocks bacterial translocation through its size-restricted permeability. Accumulating evidence suggests that dysfunction of this barrier correlates with several clinical pathologies including Crohn's disease (CD). Significant progress has been made to elucidate the mechanism of GVB dysfunction and to confirm the participation of disrupted GVB in the course of CD. However, further analyses are required to pinpoint the specific roles of GVB in CD pathogenesis. Many preclinical models and clinical trials have demonstrated that various agents are effective in protecting the GVB integrity and thus providing a potential CD treatment strategy. Through this review, we established a systemic understanding of the role of GVB in CD pathogenesis and provided novel insights for GVB-targeting strategies in CD treatment.

Serum proteome profiles in cats with chronic enteropathies

BACKGROUND

Serum protein biomarkers are used to diagnose, monitor treatment response, and to differentiate various forms of chronic enteropathies (CE) in humans. The utility of liquid biopsy proteomic approaches has not been examined in cats.

HYPOTHESIS/OBJECTIVES

To explore the serum proteome in cats to identify markers differentiating healthy cats from cats with CE.

ANIMALS

Ten cats with CE with signs of gastrointestinal disease of at least 3 weeks duration, and biopsy-confirmed diagnoses, with or without treatment and 19 healthy cats were included.

METHODS

Cross-sectional, multicenter, exploratory study with cases recruited from 3 veterinary hospitals between May 2019 and November 2020. Serum samples were analyzed and evaluated using mass spectrometry-based proteomic techniques.

RESULTS

Twenty-six proteins were significantly (P < .02, ≥5-fold change in abundance) differentially expressed between cats with CE and controls. Thrombospondin-1 (THBS1) was identified with >50-fold increase in abundance in cats with CE (P < 0.001) compared to healthy cats.

CONCLUSIONS AND CLINICAL IMPORTANCE

Damage to the gut lining released marker proteins of chronic inflammation that were detectable in serum samples of cats. This early-stage exploratory study strongly supports THBS1 as a candidate biomarker for chronic inflammatory enteropathy in cats.

Atherosclerotic Cardiovascular Disease in Inflammatory Bowel Disease: The Role of Chronic Inflammation and Platelet Aggregation

Background and Objectives: Atherosclerosis is one of inflammatory bowel disease's most significant cardiovascular manifestations. This research aimed to examine the relationship between biochemical, haemostatic, and immune parameters of atherosclerosis and ulcerative colitis patients and its relationship to platelet aggregation. Materials and Methods: A clinical, observational cross-sectional study was performed, during which the tested parameters were compared in the experimental and control groups. The patients were divided into four groups. The first group had 25 patients who had ulcerative colitis and atherosclerosis. The second group included 39 patients with ulcerative colitis without atherosclerosis. The third group comprised 31 patients suffering from atherosclerosis without ulcerative colitis, and the fourth group comprised 25 healthy subjects. Results: In our study, we registered statistically higher levels of inflammatory markers like SE, CRP, Le, fecal calprotectin, TNF-α, and IL-6, as well as the higher value of thrombocytes and thrombocyte aggregation in the group of patients with ulcerative colitis compared to the control group. Lower levels of total cholesterol and LDL were also recorded in patients with ulcerative colitis and atherosclerosis and ulcerative colitis without atherosclerosis compared to healthy control. Triglyceride and remnant cholesterol were higher in patients with ulcerative colitis and atherosclerosis when compared to patients with ulcerative colitis and healthy control but lower than in patients with atherosclerosis only. Conclusions: Several inflammatory markers and platelet aggregation could be good discrimination markers for subjects with ulcerative colitis with the highest risk of atherosclerosis.

Map of thrombogenesis in viral infections and viral-driven tumours

Viruses are pathogenic agents responsible for approximately 10% of all human cancers and significantly contribute to the global cancer burden. Until now, eight viruses have been associated with the development of a broad range of malignancies, including solid and haematological tumours. Besides triggering and promoting oncogenesis, viral infections often go hand-in-hand with haemostatic changes, representing a potential risk factor for venous thromboembolism (VTE). Conversely, VTE is a cardiovascular condition that is particularly common among oncological patients, with a detrimental impact on patient prognosis. Despite an association between viral infections and coagulopathies, it is unclear whether viral-driven tumours have a different incidence and prognosis pattern of thromboembolism compared to non-viral-induced tumours. Thus, this review aims to analyse the existing evidence concerning the association of viruses and viral tumours with the occurrence of VTE. Except for hepatitis C virus (HCV) and human immunodeficiency virus (HIV) infection, which are associated with a high risk of VTE, little evidence exists concerning the thrombogenic potential associated with oncoviruses. As for tumours that can be induced by oncoviruses, four levels of VTE risk are observed, with hepatocellular carcinoma (HCC) and gastric carcinoma (GC) associated with the highest risk and nasopharyngeal carcinoma (NPC) associated with the lowest risk. Unfortunately, the incidence of cancer-related VTE according to tumour aetiology is unknown. Given the negative impact of VTE in oncological patients, research is required to better understand the mechanisms underlying blood hypercoagulability in viral-driven tumours to improve VTE management and prognosis assessment in patients diagnosed with these tumours.

Thrombin Induced Apoptosis through Calcium-Mediated Activation of Cytosolic Phospholipase A2 in Intestinal Myofibroblasts

Thrombin is a serine protease that participates in a variety of biological signaling through protease-activated receptors. Intestinal myofibroblasts play central roles in maintaining intestinal homeostasis. In this study, we found that thrombin-induced apoptosis is mediated by the calcium-mediated activation of cytosolic phospholipase A₂ in the CCD-18Co cell. Thrombin reduced cell viability by inducing apoptosis and proteinase-activated receptor-1 antagonist attenuated thrombin-induced cell death. Endogenous ceramide did not affect the cell viability itself, but a ceramide-mediated pathway was involved in thrombin-induced cell death. Thrombin increased intracellular calcium levels and cytosolic phospholipase A₂ activity. The ceramide synthase inhibitor Fumonisin B₁, intracellular calcium chelator BAPTA-AM, and cytosolic phospholipase A₂ inhibitor AACOCF₃ inhibited thrombin-induced cell death. Thrombin stimulated arachidonic acid release and reactive oxygen species generation, which was blocked by AACOCF₃, BAPTA-AM, and the antioxidant reagent Trolox. Taken together, thrombin triggered apoptosis through calcium-mediated activation of cytosolic phospholipase A₂ in intestinal myofibroblasts.

COVID-19 Induces Cytokine Storm and Dysfunctional Hemostasis

BACKGROUND

Infection with SARS-CoV-2 leads to COVID-19 which can manifest in various ways from asymptomatic or mild disease to acute respiratory distress syndrome. The occurrence of dysregulated inflammatory responses in the form of a cytokine storm has been reported in patients with severe COVID-19. Infection can also lead to dysfunctional hemostasis reflected in elevated circulating D-dimer and fibrin degradation products. Components of hemostasis and the immune system during infection can result in a procoagulation and/or proinflammatory state. The interplay between coagulation and inflammation has been elucidated in a number of diseases.

OBJECTIVE

In this article, we discuss the occurrence of cytokine storms and dysfunctional hemostasis induced in COVID-19.

METHODS

This review was written using literature from the past two to three years investigating coagulation and inflammation in COVID-19. Additional literature, both clinical and basic research, related to pathogen infection and host responses were also considered in this review.

RESULTS/CONCLUSIONS

Infection with SARS-CoV-2 can lead to dysregulated inflammatory responses that may be detrimental to the host. The increased expression of various inflammatory factors can ultimately create an environment that promotes thrombosis.

Inflammatory Bowel Disease: An Indication to Screen for Thrombophilia?

Inflammatory bowel diseases (IBD) are systemic conditions characterized by multiple intestinal and extra-intestinal manifestations related to the associated chronic inflammatory state. Among their diverse extra-intestinal complications, venous thromboembolism (VTE) remains one of the most under recognized causes of morbidity and mortality in these patients, highlighting the need for a better understanding of the underlying mechanism of hypercoagulability, in addition to the role of acquired and inherited risk factors that further increase the risk of thrombosis with its impact on patients’ outcomes. We hereby present a review of the data regarding thrombosis in the setting of IBD, elucidating the possible role for screening in this high-risk category of patients and specifically in areas where inherited thrombophilia is expected to be highly prevalent, reporting two patients with IBD, one who developed a cerebrovascular event and another one who had recurrent VTE events; nevertheless, both of them had inherited thrombophilic mutations. The identification of specific genetic abnormalities in those patients reintroduces the controversy related to the need to screen a specific category of patients with IBD for hereditary thrombophilia, especially in regions characterized by a higher prevalence of such thrombophilic alterations.

Cardiovascular risks in patients with inflammatory bowel disease: what should be taken into account?

In recent years, there has been a steady increase in the incidence of inflammatory bowel disease (IBD) worldwide. Treatment of ulcerative colitis and Crohn’s disease has become more effective thanks to the emergence of biological therapies, increased access to specialized care and a “treat to target” approach. However, with an increase in the life expectancy of patients with IBD, there is an increase in the number of persons with comorbidity, primarily with a combination of IBD with cardiovascular pathology. Environmental factors lead to a change in the diversity and density of colonization of the intestinal microbiota, a violation of its barrier function, immune dysregulation, which in turn leads to the development of chronic inflammatory diseases and atherosclerosis. Levels of proinflammatory cytokines, C-reactive protein, and homocysteine increase in IBD, leading to endothelial dysfunction and atherosclerosis. In addition, inflammatory processes in IBD promote hypercoagulation, which occurs both in the thromboembolic complications and in the pathogenesis of the disease itself. It has been suggested that medical pathogenetic therapy for IBD is also associated with the risk of cardiovascular disease. In this review, we systematize the available data on the risks of cardiovascular diseases in patients with IBD. A literature search containing information on relevant studies was carried out in PubMed and Google Scholar systems with the keywords: inflammatory bowel disease, cardiovascular disease, inflammation, atherosclerosis.

Systematic bioinformatic analysis of nutrigenomic data of flavanols in cell models of cardiometabolic disease

Flavanol intake positively influences several cardiometabolic risk factors in humans. However, the specific molecular mechanisms of action of flavanols, in terms of gene regulation, in the cell types relevant to cardiometabolic disease have never been systematically addressed. On this basis, we conducted a systematic literature review and a comprehensive bioinformatic analysis of genes whose expression is affected by flavanols in cells defining cardiometabolic health: hepatocytes, adipocytes, endothelial cells, smooth muscle cells and immune cells. A systematic literature search was performed using the following pre-defined criteria: treatment with pure compounds and metabolites (no extracts) at low concentrations that are close to their plasma concentrations. Differentially expressed genes were analyzed using bioinformatics tools to identify gene ontologies, networks, cellular pathways and interactions, as well as transcriptional and post-transcriptional regulators. The systematic literature search identified 54 differentially expressed genes at the mRNA level in in vitro models of cardiometabolic disease exposed to flavanols and their metabolites. Global bioinformatic analysis revealed that these genes are predominantly involved in inflammation, leukocyte adhesion and transendothelial migration, and lipid metabolism. We observed that, although the investigated cells responded differentially to flavanol exposure, the involvement of anti-inflammatory responses is a common mechanism of flavanol action. We also identified potential transcriptional regulators of gene expression: transcriptional factors, such as GATA2, NFKB1, FOXC1 or PPARG, and post-transcriptional regulators: miRNAs, such as mir-335-5p, let-7b-5p, mir-26b-5p or mir-16-5p. In parallel, we analyzed the nutrigenomic effects of flavanols in intestinal cells and demonstrated their predominant involvement in the metabolism of circulating lipoproteins. In conclusion, the results of this systematic analysis of the nutrigenomic effects of flavanols provide a more comprehensive picture of their molecular mechanisms of action and will support the future setup of genetic studies to pave the way for individualized dietary recommendations.

Lessons learnt from COVID-19 coagulopathy

The coronavirus disease 2019 (COVID‐19) pandemic has already left an indelible mark in human lives. Despite the havoc it created, this pandemic also saw significant advances in the management of an infectious disease wherein worldwide collaborative efforts from health care professionals have been unprecedented. One of the commonest complications recognised early in the pandemic is the development of coagulopathy. In this review, the lessons learnt from COVID‐19 coagulopathy are summarised with some perspectives on future clinical and research strategies. These include how local versus systemic coagulopathy can matter, how we can put D‐dimers to effective use, exhort more input into identifying a simple platelet activation marker, rethink the role of fibrinogen, look differently at lupus anticoagulant and heparin‐induced thrombocytopenia, bring back disseminated intravascular coagulation into our differential diagnosis slate and most importantly channel more funding into haemostasis and thrombosis research.

Increased Mucosal Thrombin is Associated with Crohn's Disease and Causes Inflammatory Damage through Protease-activated Receptors Activation

BACKGROUND AND AIMS

Thrombin levels in the colon of Crohn's disease patients have recently been found to be elevated 100-fold compared with healthy controls. Our aim was to determine whether and how dysregulated thrombin activity could contribute to local tissue malfunctions associated with Crohn's disease.

METHODS

Thrombin activity was studied in tissues from Crohn's disease patients and healthy controls. Intracolonic administration of thrombin to wild-type or protease-activated receptor-deficient mice was used to assess the effects and mechanisms of local thrombin upregulation. Colitis was induced in rats and mice by the intracolonic administration of trinitrobenzene sulphonic acid.

RESULTS

Active forms of thrombin were increased in Crohn's disease patient tissues. Elevated thrombin expression and activity were associated with intestinal epithelial cells. Increased thrombin activity and expression were also a feature of experimental colitis in rats. Colonic exposure to doses of active thrombin comparable to what is found in inflammatory bowel disease tissues caused mucosal damage and tissue dysfunctions in mice, through a mechanism involving both protease-activated receptors -1 and -4. Intracolonic administration of the thrombin inhibitor dabigatran, as well as inhibition of protease-activated receptor-1, prevented trinitrobenzene sulphonic acid-induced colitis in rodent models.

CONCLUSIONS

Our data demonstrated that increased local thrombin activity, as it occurs in the colon of patients with inflammatory bowel disease, causes mucosal damage and inflammation. Colonic thrombin and protease-activated receptor-1 appear as possible mechanisms involved in mucosal damage and loss of function and therefore represent potential therapeutic targets for treating inflammatory bowel disease.

Presentation and Management of Arterial Thromboembolisms during Active Inflammatory Bowel Disease: Case Series and Literature Review

BACKGROUND

Active inflammatory bowel disease (IBD) is associated with considerable risk for thromboembolism; however, arterial thromboembolism is rare and associated with considerable morbidity and mortality. Their management requires careful coordination between multiple providers, and as a consequence, much of the published literature is limited to case reports published across specialties.

METHODS

We examined our recent institutional experience with aortoiliac, mesenteric, and peripheral arterial thromboembolisms in patients with either Crohn's disease or ulcerative colitis. To supplement our experience, a comprehensive literature review was performed using MEDLINE and EMBASE databases from 1966 to 2019. Patient demographics, flare/thromboembolism management, and outcomes were abstracted from the selected articles and our case series.

RESULTS

Fifty-two patients with IBD, who developed an arterial thromboembolism, were identified (49 from published literature and 3 from our institution). More than 82% of patients presented during an active IBD flare. Surgical intervention was attempted in 77% of patients, which included open thromboembolectomy, catheter-directed thrombolysis, or bowel resection. Thromboembolism resolution was achieved in 76% of patients with comparable outcomes with either catheter-directed thrombolysis or open thrombectomy (83.3% vs. 68.2%). Nearly one-third of patients underwent small bowel resection or colectomy. In 2 patients, thromboembolism resolution was achieved only after total abdominal colectomy for severe pancolitis. Multiple thromboembolectomies were associated with higher risk for amputation. Overall mortality was 11.5% but was greatest for occlusive aortoiliac and mesenteric thromboembolism (14.3% and 57%, respectively). All survivors of occlusive superior mesenteric artery thromboembolism suffered short gut syndrome requiring small bowel transplant.

CONCLUSIONS

Patients with IBD, who develop an arterial thromboembolism, can expect overall poor outcomes. Catheter-directed thrombolysis achieved comparable outcomes with open thromboembolectomy without undue bleeding risk. Total abdominal colectomy for moderate-to-severe pancolitis is an emerging strategy in the management of refractory arterial thromboembolism. Successful surgical management may include open thromboembolectomy, catheter-directed thrombolysis, and bowel resection when indicated.

Curcumin suppresses intestinal microvascular endothelial cells invasion and angiogenesis induced by activated platelets

The present study investigated the effects and mechanism by which curcumin suppresses intestinal microvascular endothelial cells (INMECs) invasion and angiogenesis induced by activated platelets. INMECs were obtained from healthy rats, and divided into five groups: Control, platelets, platelets +2.5 µM curcumin, platelets +5.0 µM curcumin and platelets +10.0 µM curcumin. Curcumin toxicity was determined and vascular endothelial growth factor (VEGF) concentrations of the five groups were measured using ELISA. The branch point numbers were measured using a capillary tube formation experiment, invasion cell numbers were evaluated with the Transwell assay, relative protein expression levels were measured with western blot assay and immunofluorescence staining of the nucleus. The 2.5, 5 and 10 µM curcumin concentrations were found to be suitable for INMECs. Curcumin significantly downregulated VEGF concentration, suppressed vascular lumen formation and inhibited invasion cell numbers in a dose-dependent manner. The α-smooth muscle actin, collagen I, E-cadherin, phosphorylated (p-) phosphoinositide 3-kinase (PI3K), p-protein kinase B (AKT), p-mammalian target of rapamycin (m-TOR) and hypoxia inducible factor subunit alpha (HIF-1α) protein expression levels of the curcumin-treated groups were significantly downregulated in a dose-dependent manner compared with the platelet group. HIF-1α protein expression levels in the nucleus of the curcumin-treated groups were significantly suppressed in a dose-dependent manner compared with the platelet group. In conclusion, curcumin suppressed INMEC invasion and angiogenesis induced by activated platelets via inhibiting the activation of the PI3K/AKT/mTOR pathway.

Cardiovascular Manifestations of Inflammatory Bowel Disease: Pathogenesis, Diagnosis, and Preventive Strategies

Inflammatory bowel disease (IBD) refers to a group of chronic inflammatory diseases that targets mainly the gastrointestinal tract. The clinical presentation of IBD includes both gastrointestinal manifestations and extraintestinal manifestations (EIM). The reported cardiovascular manifestations in IBD patients include pericarditis, myocarditis, venous and arterial thromboembolism, arrhythmias, atrioventricular block, heart failure, endocarditis, valvulopathies, and Takayasu arteritis. The aim of this article is to review the available literature about the possible pathogenic mechanisms and determine preventive measures capable of reducing the incidence and severity of the cardiovascular manifestations. In IBD patients, the incidence of cardiovascular manifestations is low, but higher than that in the general population. Therefore, clinicians should pay attention to any new modification that might indicate cardiovascular involvement in IBD patients, and they should consider chronic inflammatory diseases in patients with cardiac conditions without an evident cause. Considering the role of inflammation in the development of cardiovascular manifestations, the management should include prevention of flares and maintenance of remission for as long as possible. Preventive measures should also include active screening and strict control of the cardiovascular risk factors in all IBD patients.

Diagnostic Markers for Nonspecific Inflammatory Bowel Diseases

The nonspecific inflammatory bowel diseases (IBD) represent a heterogeneous group of chronic inflammatory disorders of the gastrointestinal tract, and Leśniowski-Crohn's disease (CD) and ulcerative colitis (UC) are among the two major clinical forms. Despite the great progress in understanding the pathogenesis of these diseases, their etiology remains unclear. Genetic, immune, and environmental factors are thought to play a key role. The correct diagnosis of nonspecific inflammatory bowel diseases as well as the determination of disease activity, risk stratification, and prediction of response to therapy still relies on a multidisciplinary approach based on clinical, laboratory, endoscopic, and histologic examination. However, considerable effort has been devoted to the development of an accurate panel of noninvasive biomarkers that have increased diagnostic sensitivity and specificity. Laboratory biomarkers useful in differentiating IBD with functional disorders and in evaluating disease activity, prognosis, and treatment selection for IBD are presented in this study.

Vascular Endothelial Dysfunction in Inflammatory Bowel Diseases: Pharmacological and Nonpharmacological Targets

Inflammatory bowel diseases, including Crohn's disease and ulcerative colitis, are chronic inflammatory conditions involving primarily the gastrointestinal tract. However, they may be also associated with systemic manifestations and comorbidities. The relationship between chronic inflammation and endothelial dysfunction has been extensively demonstrated. Mucosal immunity and gastrointestinal physiology are modified in inflammatory bowel diseases, and these modifications are mainly sustained by alterations of endothelial function. The key elements involved in this process are cytokines, inflammatory cells, growth factors, nitric oxide, endothelial adhesion molecules, and coagulation cascade factors. In this review, we discuss available data in literature concerning endothelial dysfunction in patients affected by inflammatory bowel disease and we focus our attention on both pharmacological and nonpharmacological therapeutic targets.

Rivaroxaban ameliorates disease course in an animal model of multiple sclerosis

Recent studies have implicated an important role for coagulation factors in neuroinflammatory disorders like multiple sclerosis (MS). Here, we investigate the role of factor X (FX) in neuroinflammation by using rivaroxaban the selective inhibitor of activated FX (FXa) in experimental autoimmune encephalomyelitis (EAE, an animal model of MS). Rivaroxaban-treated rats were less susceptible to EAE compared to the untreated control group. This finding was accompanied by reduced T-cell infiltration and microglia activation. Our study identifies FX as a possible target in neuroinflammatory diseases. As FXa inhibitors are approved for other disorders, FXa blockade could serve as a fast available medication.

Markers of inflammation and influence of nitric oxide on platelet activation in the course of ulcerative colitis

Ulcerative colitis is a non-specific inflammatory bowel disease of unknown etiology. We investigated whether severe form of ulcerative colitis may lead to increased number of platelets, changes in platelet parameters and their activation. To address our objectives, we measured concentrations of nitric oxide and markers of inflammation.

We found increased number of low-volume platelets in a group of affected patients. However, their activity was not as high as expected. In addition to that we observed eight times higher concentration of nitric oxide in patients suffering from ulcerative colitis than in healthy individuals. Besides, severe form of the disease manifested itself with increased concentrations of interleukine 6, matrix metalloproteinase-9 and neopterin.

Based on the results we propose that high amounts of nitric oxide inhibit platelet activation in severe form of ulcerative colitis. Moreover, our observations regarding interleukine 6, matrix metalloproteinase-9 and neopterin suggest that they may become useful markers of active form of ulcerative colitis.

Risk of cardiovascular disease in inflammatory bowel disease

Cardiovascular disease (CVD) can arise because of chronic inflammation and inflammatory bowel disease (IBD) is one such disease where the risk for CVD and eventual heart failure is increased considerably. The incidence of IBD, which refers to both ulcerative colitis and Crohn's disease, has been on the increase in several countries and is a potential risk factor for CVD. Although IBD can potentially cause venous thromboembolism, its significance in arterial stiffening, atherosclerosis, ischemic heart disease and myocardial infarction is only being realized now and it is currently under debate. However, several studies with large groups of patients have demonstrated the association of IBD with heart disease. It has been suggested that systemic inflammation as observed in IBD patients leads to oxidative stress and elevated levels of inflammatory cytokines such as tumor necrosis factor-α (TNF-α), which lead to phenotypic changes in smooth muscle cells and sets into motion a series of events that culminate in atherosclerosis and CVD. Besides the endogenous factors and cytokines, it has been suggested that due to the compromised intestinal mucosal barrier, endotoxins and bacterial lipopolysaccharides produced by intestinal microflora can enter into circulation and activate inflammatory responses that lead to atherosclerosis. Therapeutic management of IBD-associated heart diseases cannot be achieved with simple anti-inflammatory drugs such as corticosteroids and anti-TNF-α antibodies. Treatment with existing medications for CVDs, aspirin, platelet aggregation inhibitors and statins is found to be acceptable and safe. Nevertheless, further research is needed to assess their efficacy in IBD patients suffering from heart disease.

RhoB controls endothelial barrier recovery by inhibiting Rac1 trafficking to the cell border

Endothelial barrier dysfunction underlies chronic inflammatory diseases. In searching for new proteins essential to the human endothelial inflammatory response, we have found that the endosomal GTPase RhoB is up-regulated in response to inflammatory cytokines and expressed in the endothelium of some chronically inflamed tissues. We show that although RhoB and the related RhoA and RhoC play additive and redundant roles in various aspects of endothelial barrier function, RhoB specifically inhibits barrier restoration after acute cell contraction by preventing plasma membrane extension. During barrier restoration, RhoB trafficking is induced between vesicles containing RhoB nanoclusters and plasma membrane protrusions. The Rho GTPase Rac1 controls membrane spreading and stabilizes endothelial barriers. We show that RhoB colocalizes with Rac1 in endosomes and inhibits Rac1 activity and trafficking to the cell border during barrier recovery. Inhibition of endosomal trafficking impairs barrier reformation, whereas induction of Rac1 translocation to the plasma membrane accelerates it. Therefore, RhoB-specific regulation of Rac1 trafficking controls endothelial barrier integrity during inflammation.

Endothelial dysfunction in inflammatory bowel diseases: Pathogenesis, assessment and implications

Endothelial dysfunction is considered one of the etiological factors of inflammatory bowel disease (IBD). An inflammatory process leads to functional and structural changes in the vascular endothelium. An increase of leukocyte adhesiveness and leukocyte diapedesis, as well as an increased vascular smooth muscle tone and procoagulant activity is observed. Structural changes of the vascular endothelium comprise as well capillary and venule remodeling and proliferation of endothelial cells. Hypoxia in the inflammatory area stimulates angiogenesis by up-regulation of vascular endothelial growth factor, fibroblast growth factor and tumor necrosis factor-α. Inflammatory mediators also alter the lymphatic vessel function and impair lymph flow, exacerbating tissue edema and accumulation of dead cells and bacteria. The endothelial dysfunction might be diagnosed by the use of two main methods: physical and biochemical. Physical methods are based on the assessment of large arteries vasodilatation in response to an increased flow and receptors stimulation. Flow-mediated vasodilatation (FMD) is the method that is the most widely used; however, it is less sensitive in detecting early changes of the endothelium function. Most of the studies demonstrated a decrease of FMD in IBD patients but no changes in the carotic intima-media thickness. Biochemical methods of detecting the endothelial dysfunction are based on the assessment of the synthesis of compounds produced both by the normal and damaged endothelium. The endothelial dysfunction is considered an initial step in the pathogenesis of atherosclerosis in the general population. In IBD patients, the risk of cardiovascular diseases is controversial. Large, prospective studies are needed to establish the role of particular medications or dietary elements in the endothelial dysfunction as well to determine the real risk of cardiovascular diseases.

Cardiovascular complications in inflammatory bowel disease

Over the past years, a growing number of studies have indicated that patients suffering from inflammatory bowel disease (IBD) have an increased risk of developing cardiovascular disease. Both are chronic inflammatory diseases and share certain pathophysiological mechanisms that may influence each other. High levels of cytokines, C-reactive protein (CRP), and homocysteine in IBD patients may lead to endothelial dysfunction, an early sign of atherosclerosis. IBD patients, in general, do not show the typical risk factors for cardiovascular disease but changes in lipid profiles similar to the ones seen in cardiovascular events have been reported recently. Higher levels of coagulation factors frequently occur in IBD which may predispose to arterial thromboembolic events. Finally, the gut itself may have an impact on atherogenesis during IBD through its microbiota. Microbial products are released from the inflamed mucosa into the circulation through a leaky barrier. The induced rise in proinflammatory cytokines could contribute to endothelial damage, artherosclerosis and cardiovascular events. Although large retrospective studies favor a link between IBD and cardiovascular diseases, the mechanisms behind still remain to be determined.

Cardiovascular complications in inflammatory bowel disease

Over the past years, a growing number of studies have indicated that patients suffering from inflammatory bowel disease (IBD) have an increased risk of developing cardiovascular disease. Both are chronic inflammatory diseases and share certain pathophysiological mechanisms that may influence each other. High levels of cytokines, C-reactive protein (CRP), and homocysteine in IBD patients may lead to endothelial dysfunction, an early sign of atherosclerosis. IBD patients, in general, do not show the typical risk factors for cardiovascular disease but changes in lipid profiles similar to the ones seen in cardiovascular events have been reported recently. Higher levels of coagulation factors frequently occur in IBD which may predispose to arterial thromboembolic events. Finally, the gut itself may have an impact on atherogenesis during IBD through its microbiota. Microbial products are released from the inflamed mucosa into the circulation through a leaky barrier. The induced rise in proinflammatory cytokines could contribute to endothelial damage, artherosclerosis and cardiovascular events. Although large retrospective studies favor a link between IBD and cardiovascular diseases, the mechanisms behind still remain to be determined.

Non-surgical porto-mesenteric vein thrombosis is associated with worse long-term outcomes in inflammatory bowel diseases

Objective: Our aim was to assess the risk factors for non-surgery-related portal and mesenteric vein thrombosis (PMVT) and its impact on the outcomes of inflammatory bowel diseases (IBD).

Methods: All patients with a concurrent diagnosis of IBD and PMVT between January 2004 and October 2013 were identified from the electronic medical record (study group; n = 20). Patients were matched for age, sex, and IBD phenotype with control IBD patients who had no PMVT, with a ratio of 1:3 (control group; n = 60). Risk factors for PMVT and IBD-related outcomes at one year after diagnosis of PMVT were compared between the two groups.

Results: Of the 20 patients in the Study group, 6 (30%) had UC, 14 (70%) had CD and 11 (55%) were male. On multivariable analysis, inpatient status (odds ratio [OR] 6.88; 95% confidence interval [CI] 1.88–25.12) and baseline corticosteroid use (OR 4.39; 95% CI 1.27–15.19) were found to be independent risk factors for the development of PMVT. At one-year follow-up, PMVT patients were more likely to have an adverse outcome of IBD, including subsequent emergency room visit (26.3% vs. 1.7%; P = 0.003), hospitalization for medical management (60.0% vs. 20.0%; P = 0.001) or IBD-related surgery (65.0% vs. 26.7%; P = 0.003) than the non-PMVT controls. In multivariable analysis, PMVT (OR 5.19; 95% CI 1.07–25.28) and inpatient status (OR 8.92; 95% CI 1.33–59.84) were found to be independent risk factors for poor outcome, whereas baseline immunomodulator use (OR 0.07; 95% CI 0.01–0.51) was found to be a protective factor.

Conclusions: IBD patients who were inpatients or receiving corticosteroid therapy had an increased risk of the development of PMVT. The presence of PMVT was associated with poor clinical outcomes in IBD.

Antiphospholipid Antibodies and Procoagulant Profile in Tunisians With Inflammatory Bowel Diseases

The hypercoagulable state accompanying inflammatory bowel diseases (IBDs) is still poorly understood. The aim of this study was to assess antiphospholipid antibodies (APAs) and a large panel of inherited and acquired thrombotic markers simultaneously in a sample of Tunisian patients with IBD. In total, 89 consecutive patients with IBD (mean age 38 ± 15 years; 48 with Crohn disease and 41 with ulcerative colitis) and 129 controls were prospectively evaluated for immunoglobulin (Ig) G, IgM, and IgA antibodies against cardiolipin (aCL), β2glycoprotein I (aβ2GPI), and prothrombin (aPT); IgG and IgM antibodies against phosphatidic acid (aPA), phosphatidylinositol (aPI), and annexin V (aAnnV); lupus anticoagulant (LA); coagulation factors; natural inhibitors; and thrombotic genetic polymorphisms. Levels of fibrinogen, factors II, V, and VIII and von Willebrand factor, antithrombin, and protein C were significantly higher in patients with IBD than in controls (P < .05 for all comparisons). At least 1 APA subset was detected in 54 patients. The frequencies of antibodies against anionic phospholipids-aCL, aPI, and aPA-in patients with IBD were 15.9%, 21.3%, and 14.6%, respectively. The frequencies of antiphospholipid cofactor antibodies were 39.8% for aβ2GPI and 15.7% for both aAnnV and aPT. Isolated aβ2GPI IgA was detected in 22 patients, and 12 (13.5%) patients had LA. The IgA aβ2GPI antibodies were frequently detected in Tunisian patients with IBD. These results are of potential diagnostic, prognostic, and therapeutic interest.

Thrombosis in inflammatory bowel diseases: what's the link?

Inflammatory bowel disease affects more than 2 million people in Europe, with almost 20% of patients being diagnosed in pediatric age. Patients with inflammatory bowel disease are at increased risk of thromboembolic complications which may affect patients’ morbidity and mortality. The risk of the most common thromboembolic events, such as deep venous thrombosis and pulmonary embolism, are estimated to be three-fold increased compared to controls, but many other districts can be affected. Moreover, patients with ulcerative colitis and Crohn’s disease experience thromboembolic events at a younger age compared to general population. Many factors have been investigated as determinants of the pro-thrombotic tendency such as acquired risk factors or genetic and immune abnormalities, but a unique cause has not been found. Many efforts have been focused on the study of abnormalities in the coagulation cascade, its natural inhibitors and the fibrinolytic system components and both quantitative and qualitative alterations have been demonstrated. Recently the role of platelets and microvascular endothelium has been reviewed, as the possible link between the inflammatory and hemostatic process.

Increased risk of venous thromboembolic events with corticosteroid vs biologic therapy for inflammatory bowel disease

BACKGROUND & AIMS

We investigated whether treatment of active inflammatory bowel disease with biologic agents is associated with a reduced risk of venous thromboembolic events (VTEs) compared with corticosteroid therapy.

METHODS

We performed a retrospective analysis of 15,100 adults with inflammatory bowel disease who were identified from the Truven Health MarketScan databases. We analyzed data from patients who received 6 months of continuous medical and prescription coverage before and 12 months after their first diagnosis and had no VTE during the 6 months before they first received biologic or corticosteroid therapy. The outcome assessed was any VTE that occurred during the 12-month follow-up period. A multivariate logistic regression model was used to evaluate the effects of biologic, corticosteroid, and combination therapies (biologics and corticosteroids) on VTE risk.

RESULTS

Three hundred twenty-five VTEs occurred during the study period (in 2.25% of patients receiving only corticosteroids, in 0.44% of patients receiving biologics, and in 2.49% of patients receiving combination therapy). Compared with patients receiving only corticosteroids, the odds ratio for VTE in patients receiving only biologics was 0.21 (95% confidence interval, 0.05-0.87) in the multivariate model, and the odds ratio for VTE in patients on combination therapy was 1.01.

CONCLUSIONS

Compared with treatment with only a biologic agent, corticosteroid therapy is associated with a nearly 5-fold increase in risk for VTE. Combination therapy with corticosteroids and biologic agents was associated with the same risk for VTE as that of corticosteroids alone. Corticosteroids therefore appear to increase risk for VTE.

Inflammatory bowel disease and thromboembolism

Patients with inflammatory bowel disease (IBD) have an increased risk of vascular complications. Thromboembolic complications, both venous and arterial, are serious extraintestinal manifestations complicating the course of IBD and can lead to significant morbidity and mortality. Patients with IBD are more prone to thromboembolic complications and IBD per se is a risk factor for thromboembolic disease. Data suggest that thrombosis is a specific feature of IBD that can be involved in both the occurrence of thromboembolic events and the pathogenesis of the disease. The exact etiology for this special association between IBD and thromboembolism is as yet unknown, but it is thought that multiple acquired and inherited factors are interacting and producing the increased tendency for thrombosis in the local intestinal microvasculature, as well as in the systemic circulation. Clinicians' awareness of the risks, and their ability to promptly diagnose and manage tromboembolic complications are of vital importance. In this review we discuss how thromboembolic disease is related to IBD, specifically focusing on: (1) the epidemiology and clinical features of thromboembolic complications in IBD; (2) the pathophysiology of thrombosis in IBD; and (3) strategies for the prevention and management of thromboembolic complications in IBD patients.

The complement system in inflammatory bowel disease

Complement is well appreciated to be a potent innate immune defense against microbes and is important in the housekeeping act of removal of apoptotic and effete cells. It is also understood that hyperactivation of complement, or the lack of regulators, may underlie chronic inflammatory diseases. A pipeline of products to intervene in complement activation, some already in clinical use, is being studied in various chronic inflammatory diseases. To date, the role of complement in inflammatory bowel disease has not received a lot of research interest. Novel genetically modified laboratory animals and experiments using antagonists to complement effector molecules have kindled important research observations implicating the complement system in inflammatory bowel disease pathogenesis. We review the evidence base for the role and potential therapeutic manipulation of the complement cascade in inflammatory bowel disease.

Increased responsiveness to thrombin through protease-activated receptors (PAR)-1 and -4 in active Crohn's disease

BACKGROUND AND AIMS

Platelets are essential in hemostasis and inflammation, thereby linking coagulation with inflammation. Abundant thrombin generation in association with inflammation is considered a major reason for the increased risk for thromboembolic events. We therefore investigated platelet responsiveness to thrombin.

METHODS

In this case-control study 85 patients with Crohn's disease (active CD 42, remission 43) and 30 sex- and age-matched controls were enrolled. Clinical disease activity (Harvey-Bradshaw-Index) was assessed and CD-related data were determined by chart review. Platelets' response to protease activated receptor-1 and -4 (PAR-1, -4) was assessed by whole blood platelet aggregometry (MEA), levels of platelets adhering to monocytes (PMA), and platelet surface P-selectin.

RESULTS

Platelets' aggregation after activation with the specific PAR-1 agonist (SFLLRN) and PAR-4 agonist (AYPGKF) was higher in patients with active CD compared to patients in remission and controls (p=0.0068 and p=0.0023 for SFLLRN, p=0.0019 and 0.0003 for AYPGKF). Likewise, levels of PMA after activation with PAR-1 and PAR-4 receptor agonists were higher in patients with active CD compared to patients in remission and controls (p=0.0001 and p<0.0001 for SFLLRN, p=0.0329 and p=0.0125 for AYPGKF). However, P-selectin expression on human platelets showed heterogeneous results. Only PAR-1 activation of platelets resulted in significant differences between CD patients and controls (p=0.0001 and p=0.0022 for active and inactive CD versus controls, respectively).

CONCLUSIONS

Our data suggest a new mechanism of platelet activation which has the potential to increase risk for thromboembolism in patients with active CD which might be due to platelets poised for thrombin-inducible activation.

Venous thrombosis and prothrombotic factors in inflammatory bowel disease

Patients with inflammatory bowel disease (IBD) may have an increased risk of venous thrombosis (VTE). PubMed, ISI Web of Knowledge and Scopus were searched to identify studies investigating the risk of VTE and the prevalence of acquired and genetic VTE risk factors and prothrombotic abnormalities in IBD. Overall, IBD patients have a two- to fourfold increased risk of VTE compared with healthy controls, with an overall incidence rate of 1%-8%. The majority of studies did not show significant differences in the risk of VTE between Crohn’s disease and ulcerative colitis. Several acquired factors are responsible for the increased risk of VTE in IBD: inflammatory activity, hospitalisation, surgery, pregnancy, disease phenotype (e.g., fistulising disease, colonic involvement and extensive involvement) and drug therapy (mainly steroids). There is also convincing evidence from basic science and from clinical and epidemiological studies that IBD is associated with several prothrombotic abnormalities, including initiation of the coagulation system, downregulation of natural anticoagulant mechanisms, impairment of fibrinolysis, increased platelet count and reactivity and dysfunction of the endothelium. Classical genetic alterations are not generally found more often in IBD patients than in non-IBD patients, suggesting that genetics does not explain the greater risk of VTE in these patients. IBD VTE may have clinical specificities, namely an earlier first episode of VTE in life, high recurrence rate, decreased efficacy of some drugs in preventing further episodes and poor prognosis. Clinicians should be aware of these risks, and adequate prophylactic actions should be taken in patients who have disease activity, are hospitalised, are submitted to surgery or are undergoing treatment.

Multipotent role of platelets in inflammatory bowel diseases: A clinical approach

There is evidence that inflammatory bowel diseases (IBD) combine both inflammation and coagulation in their pathogenesis and clinical manifestations. Although platelets (PLT) are well known for their role in hemostasis, there are a rising number of studies supporting their considerable role as inflammatory amplifiers in chronic inflammatory conditions. IBD are associated with several alterations of PLT, including number, shape, and function, and these abnormalities are mainly attributed to the highly activated state of circulating PLT in IBD patients. When PLT activate, they increase in size, release a great variety of bio-active inflammatory and procoagulant molecules/particles, and express a variety of inflammatory receptors. These inflammatory products may represent a part of the missing link between coagulation and inflammation, and can be considered as possible IBD pathogenesis instigators. In clinical practice, thrombocytosis is associated both with disease activity and iron deficiency anemia. Controlling inflammation and iron replacement in anemic patients usually leads to a normalization of PLT count. The aim of this review is to update the role of PLT in IBD and present recent data revealing the possible therapeutic implications of anti-PLT agents in future IBD remedies.

Inflammatory bowel disease: epidemiology, pathology and risk factors for hypercoagulability

Hypercoagulability observed in patients with inflammatory bowel diseases (IBD) may lead to thromboembolic events (TE), which affect the venous and arterial systems alike and are an important factor in patients' morbidity and mortality. The risk of TE in IBD patients has been demonstrated to be approximately three-fold higher as compared to the general population. The pathogenesis of thrombosis in IBD patients is multifactorial and not fully explained. The most commonly listed factors include genetic and immune abnormalities, disequilibrium between procoagulant and anticoagulant factors, although recently, the role of endothelial damage as an IBD-triggering factor is underlined. Several studies report that the levels of some coagulation enzymes, including fibrinogen, factors V, VII, VIII, active factor XI, tissue factor, prothrombin fragment 1 + 2 and the thrombin-antithrombin complex, are altered in IBD patients. It has been demonstrated that there is a significant decrease of tissue plasminogen activator level, a marked increase of plasminogen activator inhibitor type 1 and thrombin-activable fibrinolysis inhibitor, a significantly lower level of antithrombin III and tissue factor pathway inhibitor. IBD patients have been also observed to produce an increased amount of various anticoagulant antibodies. Hyperhomocysteinemia, which is a potential risk factor for TE was also observed in some IBD patients. Further studies are necessary to assess the role of coagulation abnormalities in IBD etiology and to determine indications for thromboprophylactic treatment in patients at high risk of developing TE.

Orbital and optic nerve complications of inflammatory bowel disease

BACKGROUND AND AIMS

Extraintestinal manifestations of inflammatory bowel disease (IBD) can involve the orbit and the optic nerve. Although these manifestations are rare, they can be particularly serious as they can lead to permanent loss of vision. The aim of the review is to present the existing literature on IBD-related optic nerve and orbital complications.

METHODS

A literature search identified the publications reporting on incidence, clinical features and management of IBD patients with optic nerve and orbital manifestations.

RESULTS

Posterior scleritis and orbital inflammatory disease (orbital pseudotumor) are the most commonly encountered entities affecting the structures of the orbit. On the other hand, the optic nerve of IBD patients can be affected by conditions such as optic (demyelinating) neuritis ("retrobulbar" neuritis), or ischaemic optic neuropathy. Other neuro-ophthalmic manifestations that can be encountered in patients with IBD are related to increased intracranial pressure or toxicity secondary to anti tumour necrosis factor (anti-TNF) agents.

CONCLUSIONS

IBD-related optic nerve and orbital complications are rare but potentially vision-threatening. Heightened awareness and close cooperation between gastroenterologists and ophthalmologists are warranted.

Venous and arterial disease in inflammatory bowel disease

Awareness is increasing that risk of venous thromboembolism and development of atherosclerosis is elevated in patients with some chronic inflammatory diseases. This review aimed to examine the risk of vascular disease in patients with inflammatory bowel disease (IBD) and to identify potential pathogenic mechanisms and therapeutic approaches. An extensive literature search was conducted using MEDLINE database, Cochrane Library and international conference abstracts for studies pertaining to venous and arterial thromboembolism in adult IBD patients. There is a 1.1-3.6 fold risk of venothromboembolism in IBD, affecting 0.55-6.15% of patients. Risks are increased during a flare or with chronically active inflammation. Evidence is building that there may be a modestly increased risk of arterial disease overall, despite evidence that traditional risk factors may be reduced. Multiple pathogenic factors have been identified including endothelial dysfunction, inflammation-mediated calcium deposition in the media of arteries, hyperhomocysteinemia, platelet activation, and altered coagulation and fibrinolysis. The key to active and preventive therapy is to effectively treat inflammation. Recommendations for prophylaxis of venothromboembolism have followed guidelines where they exist and have been extrapolated from studies of other at-risk conditions, as have those for arterial disease, where screening for risk factors and actively treating abnormalities is encouraged. In conclusion, patients with IBD are at considerably increased risk of venothromboembolism and probably of arterial disease, in particular mesenteric ischemia and ischemic heart disease. Increased penetration of gaps between this knowledge and clinical therapeutic action to prevent thromboembolic events into IBD clinical practice is needed.

Evaluation of early atherosclerosis in patients with inflammatory bowel disease

BACKGROUND

Data regarding early atherosclerosis and inflammatory bowel disease are limited and conflicting results are present.

AIMS

The purpose of this study was to evaluate serological and sonographical evidence of subclinical vascular involvement in patients with inflammatory bowel disease.

METHODS

Thirty-nine patients with inflammatory bowel disease (20 Crohn's disease, and 19 ulcerative colitis patients) and 31 healthy controls were consecutively enrolled in the study. Flow mediated dilatation of the brachial artery and intima media thickness assessments of the common carotid artery were measured sonographically. Soluble CD40 ligand levels were evaluated. Crohn's disease activity index and modified Truelove-Witt's criteria were also noted.

RESULTS

Age, sex distribution, serum lipids, smoking status, and intima media thickness of the common carotid artery were similar between the inflammatory bowel disease patients and controls (p > 0.05). However, both endothelium dependent and independent flow mediated dilatation values were significantly impaired in the inflammatory bowel disease group compared with healthy controls (p < 0.05). Erythrocyte sedimentation rate, C-reactive protein and soluble CD40 ligand values were significantly increased in inflammatory bowel disease patients compared with controls (p < 0.05), and soluble CD40 ligand was negatively correlated with flow mediated dilatation (r = -0.3, p < 0.05). Flow mediated dilatation was significantly predicted from the concentrations of C-reactive protein and soluble CD40 ligand.

CONCLUSION

Functional atherosclerosis is present in inflammatory bowel disease before early structural changes occur in vasculature. Higher sCD40L may indicate worse vascular outcome for IBD.

What’s hot in inflammatory bowel disease in 2011?

Ulcerative colitis and Crohn’s disease (CD) are the two major forms of inflammatory bowel disease (IBD). In this highlight topic series of articles, the most recent advances in the IBD field are reviewed, especially the newly described cytokines, including the therapeutic implications for their manipulation. In addition, the interplay between the intestinal microbiota and the host is reviewed, including the role of defensins and dysbiosis in CD pathogenesis. Finally, the importance of the non immune systems such as endothelial cells and the hemostatic system are highlighted as new players in IBD pathogenesis.