Continuous active state of coagulation system in patients with nonthrombotic inflammatory bowel disease

Antithrombin: Deficiency, Diversity, and the Future of Diagnostics

Our healthcare system provides reactive sick-care, treating patients after symptoms have appeared by prescription of generic and often suboptimal therapy. This strategy brings along high costs and high pressure which is not sustainable. Alternatively, P5 healthcare is proposed focusing on five key elements: prevention, personalization, prediction, participation, psychocognition, however, changes in current clinical care pathways are required, for which antithrombin deficiency is a prime example. Hereditary antithrombin deficiency (ATD) is a genetic disorder, for which screening is instigated after a thrombotic episode. Current diagnostic tests for ATD lack sensitivity and refinement to correctly classify patients, and generic treatments are prescribed. A molecular understanding of ATD through a molecular diagnostic test that analyzes all clinically relevant features of antithrombin is required. Here, clinically relevant molecular characteristics of antithrombin, the diversity of antithrombin (deficiency) in heath and disease, and the strengths and weaknesses of antithrombin tests are reviewed. A mass spectrometry test that molecularly characterizes a patients antithrombin proteoforms harbors the highest potential to improve the clinical pathway for ATD. Application of this MS-based test in a future enhanced clinical pathway will improve patient management and outcome through molecular characterization of antithrombin and enables the promise of P5 healthcare for ATD.

Tissue factor-dependent colitogenic CD4+ T cell thrombogenicity is regulated by activated protein C signalling

Patients with inflammatory bowel disease (IBD) have an increased risk of venous thromboembolism (VTE), but the underlying mechanistic basis remains poorly defined. Here, we find that colitogenic CD4+ T cells express tissue factor (TF) and promote rapid TF-dependent plasma thrombin generation. TF+CD3+CD4+ T cells are present in both the colons of mice with experimental colitis and blood and colonic tissue from patients with IBD. Expression of genes involved in regulating coagulation, including Protein C (PC; encoded by PROC) and its receptor (PROCR), are dysregulated in IBD patient gut biopsy tissues. Moreover, activated PC signalling reduces the procoagulant activity mediated by TF+CD4+ T cells. Our data thus identify TF-induced, colitogenic T cell-mediated thrombogenicity, and also demonstrate a new function for activated PC signalling in regulating T cell thrombo-inflammatory activity.

The Incidence and Predictive Factors of Thromboembolism During Hospitalizations for Inflammatory Bowel Disease Flare-Ups: A Retrospective Cohort Study in Taiwan

BACKGROUND/AIMS

Thromboembolism (TE) notably increase morbidity and mortality among inflammatory bowel disease (IBD) patients. Despite ECCO's 2024 guidelines advocating routine anticoagulant prophylaxis, its application in Asia remains inconsistent due to a lack of regional studies. This research investigates the incidence and predictors of TE during IBD-related hospitalizations in Taiwan, aiming to improve prevention strategies.

MATERIALS AND METHODS

Our retrospective cohort study included 282 adult IBD patients, accounting for 515 flare-up related hospitalizations at Linkou Chang Gung Memorial Hospital from January 2001 to March 2024. Patients were classified into two groups based on the occurrence of TE.

RESULTS

The incidence of TE was 1.55%. The TE group had significantly lower body weight, body mass index (BMI), hemoglobin and albumin levels but higher rate of sepsis and concurrent autoimmune diseases compared to the non-TE group. Multivariate analysis indicated that concurrent autoimmune diseases and hypoalbuminemia were independent predictors of TE. The optimal serum albumin cutoff was established at 3.01 g/dL, with sensitivities and specificities of 87.5% and 77.3%, respectively.

CONCLUSIONS

This pioneering Asian study identifies concurrent autoimmune diseases and low serum albumin as key predictors of TE in hospitalized IBD patients. We recommend targeted anticoagulant prophylaxis for IBD patients with these risk factors, especially when serum albumin falls below 3.01 g/dL.

The Role of Myeloid Cells in Thromboinflammatory Disease

Inflammation contributes to the development of thrombosis, but the mechanistic basis for this association remains poorly understood. Innate immune responses and coagulation pathways are activated in parallel following infection or injury, and represent an important host defense mechanism to limit pathogen spread in the bloodstream. However, dysregulated proinflammatory activity is implicated in the progression of venous thromboembolism and arterial thrombosis. In this review, we focus on the role of myeloid cells in propagating thromboinflammation in acute inflammatory conditions, such as sepsis and coronavirus disease 2019 (COVID-19), and chronic inflammatory conditions, such as obesity, atherosclerosis, and inflammatory bowel disease. Myeloid cells are considered key drivers of thromboinflammation via upregulated tissue factor activity, formation of neutrophil extracellular traps (NETs), contact pathway activation, and aberrant coagulation factor-mediated protease-activated receptor (PAR) signaling. We discuss how strategies to target the intersection between myeloid cell-mediated inflammation and activation of blood coagulation represent an exciting new approach to combat immunothrombosis. Specifically, repurposed anti-inflammatory drugs, immunometabolic regulators, and NETosis inhibitors present opportunities that have the potential to dampen immunothrombotic activity without interfering with hemostasis. Such therapies could have far-reaching benefits for patient care across many thromboinflammatory conditions.

The Journey Through the Pathogenesis and Treatment of Venous Thromboembolism in Inflammatory Bowel Diseases: A Narrative Review

Inflammatory bowel diseases (IBDs) are chronic inflammatory disorders of the gastrointestinal tract including Crohn's disease and ulcerative colitis, which may result in several extraintestinal complications (∼20-30% of cases), such as increased risk of venous thromboembolism (VTE). The main pathophysiological mechanism of VTE is an inflammation-induced hypercoagulable state, and recent data have shown that endothelial dysregulation due to gut and systemic inflammation may also lead to a prothrombotic state. Several prothrombotic alterations have been described, such as the activation of the coagulation system, platelet abnormalities, and dysregulation of fibrinolysis. Furthermore, the dysregulation of the gut microbiome seems to play a vital role in increasing systemic inflammation and thus inducing a procoagulant state. Our review aims to examine the main correlations between IBD and VTE, the underlying pathophysiology, and current therapeutic options.

Biological, genetic and epigenetic markers in ulcerative colitis

In this review, we have summarized the existing knowledge of ulcerative colitis (UC) markers based on current literature, specifically, the roles of potential new biomarkers, such as circulating, fecal, genetic, and epigenetic alterations, in UC onset, disease activity, and in therapy response. UC is a complex multifactorial inflammatory disease. There are many invasive and non-invasive diagnostic methods in UC, including several laboratory markers which are employed in diagnosis and disease assessment; however, colonoscopy remains the most widely used method. Common laboratory abnormalities currently used in the clinical practice include inflammation-induced alterations, serum autoantibodies, and antibodies against bacterial antigens. Other new serum and fecal biomarkers are supportive in diagnosis and monitoring disease activity and therapy response; and potential salivary markers are currently being evaluated as well. Several UC-related genetic and epigenetic alterations are implied in its pathogenesis and therapeutic response. Moreover, the use of artificial intelligence in the integration of laboratory biomarkers and big data could potentially be useful in clinical translation and precision medicine in UC management.

Cardiovascular manifestations of inflammatory bowel diseases and the underlying pathogenic mechanisms

Inflammatory bowel disease (IBD), consisting of ulcerative colitis and Crohn's disease, mainly affects the gastrointestinal tract but is also known to have extraintestinal manifestations because of long-standing systemic inflammation. Several national cohort studies have found that IBD is an independent risk factor for the development of cardiovascular disorders. However, the molecular mechanisms by which IBD impairs the cardiovascular system are not fully understood. Although the gut-heart axis is attracting more attention in recent years, our knowledge of the organ-to-organ communication between the gut and the heart remains limited. In patients with IBD, upregulated inflammatory factors, altered microRNAs and lipid profiles, as well as dysbiotic gut microbiota, may induce adverse cardiac remodeling. In addition, patients with IBD have a three- to four times higher risk of developing thrombosis than people without IBD, and it is believed that the increased risk of thrombosis is largely due to increased procoagulant factors, platelet count/activity, and fibrinogen concentration, in addition to decreased anticoagulant factors. The predisposing factors for atherosclerosis are present in IBD and the possible mechanisms may involve oxidative stress system, overexpression of matrix metalloproteinases, and changes in vascular smooth muscle phenotype. This review focuses mainly on 1) the prevalence of cardiovascular diseases associated with IBD, 2) the potential pathogenic mechanisms of cardiovascular diseases in patients with IBD, and 3) adverse effects of IBD drugs on the cardiovascular system. Also, we introduce here a new paradigm for the gut-heart axis that includes exosomal microRNA and the gut microbiota as a cause for cardiac remodeling and fibrosis.

Immunothrombosis: Molecular Aspects and New Therapeutic Perspectives

Thromboinflammation or immunothrombosis is a concept that explains the existing link between coagulation and inflammatory response present in many situations, such as sepsis, venous thromboembolism, or COVID-19 associated coagulopathy. The purpose of this review is to provide an overview of the current data regarding the mechanisms involved in immunothrombosis in order to understand the new therapeutic strategies focused in reducing thrombotic risk by controlling the inflammation.

Improved comprehensive evaluation of Crohn's disease activity by intestinal computed tomography enterography combined with endoscopy and biochemical indicators

BACKGROUND AND STUDY AIMS

The treatment approach for Crohn's disease (CD) is focused on mucosal healing and resolution of transmural inflammation. The aim of this study is to evaluate the correlation between computed tomography enterography (CTE) and other treatments, in particular, endoscopy and biochemical indicators, in newly diagnosed patients with CD.

PATIENTS AND METHODS

One hundred twenty-three patients with CD who received CTE in Xiangya Hospital, Central South University, China, from April 2017 to April 2019 were included. The clinical case data and imaging results were retrospectively reviewed. The clinical activity of CD was determined by the Crohn's disease activity index (CDAI) score and biochemical indicators. The relationships between CTE and endoscopy, CDAI score, and inflammatory markers were evaluated.

RESULTS

The diagnostic rate of CTE of the 123CD patients was 68.3% (84/123). Logistic regression analysis showed that the specific CTE manifestations related to CD activity were intestinal wall stratification, comb sign, and abdominal abscesses (P < 0.05). Spearman's rank correlation analysis showed that inflammatory markers positively correlated with different CTE imaging manifestations.

CONCLUSION

Intestinal CTE combined with endoscopy and biochemical indicators is both comprehensive and effective in evaluating the condition of CD patients.

Hepatobiliary Impairments in Patients with Inflammatory Bowel Diseases: The Current Approach

Inflammatory bowel disease (IBD) refers to chronic conditions with a low mortality but high disability. The multisystemic nature of these diseases can explain the appearance of some extraintestinal manifestations, including liver damage. Abnormal liver biochemical tests can be identified in approximately one third of patients with IBD and chronic liver disease in 5% of them. Among the liver diseases associated with IBD are primary sclerosing cholangitis, cholelithiasis, fatty liver disease, hepatic amyloidosis, granulomatous hepatitis, drug-induced liver injury, venous thromboembolism, primary biliary cholangitis, IgG4-related cholangiopathy, autoimmune hepatitis, liver abscesses or the reactivation of viral hepatitis. The most common disease is primary sclerosing cholangitis, a condition diagnosed especially in patients with ulcerative colitis. The progress registered in recent years in the therapeutic management of IBD has not eliminated the risk of drug-induced liver disease. Additionally, the immunosuppression encountered in these patients increases the risk of opportunistic infections, including the reactivation of viral hepatitis. Currently, one of the concerns consists of establishing an efficiency and safety profile of the use of direct-acting antiviral agents (DAA) among patients with hepatitis C and IBD. Early diagnosis and optimal treatment of liver complications can improve the prognoses of these patients.

Dysregulated haemostasis in thrombo-inflammatory disease

Inflammatory disease is often associated with an increased incidence of venous thromboembolism in affected patients, although in most instances, the mechanistic basis for this increased thrombogenicity remains poorly understood. Acute infection, as exemplified by sepsis, malaria and most recently, COVID-19, drives 'immunothrombosis', where the immune defence response to capture and neutralise invading pathogens causes concurrent activation of deleterious prothrombotic cellular and biological responses. Moreover, dysregulated innate and adaptive immune responses in patients with chronic inflammatory conditions, such as inflammatory bowel disease, allergies, and neurodegenerative disorders, are now recognised to occur in parallel with activation of coagulation. In this review, we describe the detailed cellular and biochemical mechanisms that cause inflammation-driven haemostatic dysregulation, including aberrant contact pathway activation, increased tissue factor activity and release, innate immune cell activation and programmed cell death, and T cell-mediated changes in thrombus resolution. In addition, we consider how lifestyle changes increasingly associated with modern life, such as circadian rhythm disruption, chronic stress and old age, are increasingly implicated in unbalancing haemostasis. Finally, we describe the emergence of potential therapies with broad-ranging immunothrombotic functions, and how drug development in this area is challenged by our nascent understanding of the key molecular and cellular parameters that control the shared nodes of proinflammatory and procoagulant pathways. Despite the increasing recognition and understanding of the prothrombotic nature of inflammatory disease, significant challenges remain in effectively managing affected patients, and new therapeutic approaches to curtail the key pathogenic steps in immune response-driven thrombosis are urgently required.

Gastrointestinal System: COVID-19 and Potential Mechanisms Associated with Coagulopathy

SARS-CoV-2 is a novel coronavirus that expanded worldwide, generating a pandemic of acute respiratory syndrome called "coronavirus disease 2019" (COVID-19), which resulted in a global health crisis. The spectrum of COVID-19 manifestations ranges from none or mild symptoms to severe respiratory failure associated with systemic manifestations, mostly gastrointestinal symptoms. Hypercoagulability is an important feature of COVID-19 disease, which can potentially influence patients' prognosis. Therefore, gastroenterologists should focus on subjects with concomitant hypercoagulable gastrointestinal disorders as they may display a higher risk of thrombotic complications during SARS-CoV-2 infection. The aim of this review is to summarize the available evidence regarding the interplay of the prothrombotic pathogenetic mechanisms of both COVID-19 and hypercoagulable digestive diseases and the possible clinical implications. We summarized the potential interplay of prothrombotic mechanisms of both COVID-19 and hypercoagulable digestive diseases in the graphical abstract.

Acute pulmonary embolism following corticosteroid administration in acute severe ulcerative colitis with gastrointestinal bleeding: A case report

Background

Ulcerative colitis often leads to gastrointestinal bleeding and venous thromboembolism (VTE). At present, there is no clear conclusion about anticoagulant therapy for these patients. Treatment for ulcerative colitis usually includes 5-aminosalicylic acid, corticosteroid, and biologics. Acute ulcerative colitis, usually caused by infection, is usually severe and can be life-threatening.

Case presentation

We report the development of VTE in a patient with severe acute ulcerative colitis who experienced gastrointestinal bleeding following hormonal therapy. The patient's indicators suggested that his blood was hypercoagulable and that his prognosis was poor.

Conclusion

Patients with ulcerative colitis are prone to form VTE. The use of corticosteroids during treatment increases the risk of thrombus. Anticoagulation strategy for patients with ulcerative colitis after gastrointestinal bleeding is a problem that needs to be discussed.

Inflammatory bowel disease and thromboembolic events: a c'lot to learn

BACKGROUND

Inflammatory bowel disease (IBD) is associated with a variety of extraintestinal manifestations including arterial and venous thromboembolism. Research evidences that IBD patients have about a 2- to 3-fold increase in the risk of venous thromboembolism when compared with the general population.

OBJECTIVES

We intended to evaluate the coagulation parameters and the prevalence of thromboembolic events (TE) in IBD patients. It was also our aim to investigate the correlation between coagulation parameters and disease phenotype and activity in this population.

METHODS

This single center prospective observational study was performed between November 2016 and April 2020. The cohort included patients with 18 years of age or older, diagnosed with IBD and followed at a gastroenterology consultation, during a follow-up period of 36 months. Patients were evaluated in terms of IBD type, extent and disease behavior, clinical scores of IBD activity, medication, smoking history, family and personal history of TE, coagulation parameters, fecal calprotectin levels, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), hospitalization due to TE, IBD-related hospitalization or surgery, pregnancy, or diagnosis of malignancy.

RESULTS

The study included 149 IBD patients (67 males and 82 females). Coagulation parameters were similar in CD and UC patients and only plasminogen was increased in CD patients [97.4 (17.0) versus 91.6 (13.3), p = 0.035], when comparing with UC patients. The determined values were in the range of the reference values described in literature for the standard population. During the follow-up period, none of the patients experienced a TE that demanded hospitalization.

CONCLUSION

In our study, acquired and inherited risk factors for TE and changes in coagulation parameters did not show to influence prothrombotic predisposition in IBD patients. As such, the clinical relevance of measuring coagulation parameters in this population is questionable.

TRIAL REGISTRY

NCT05162339 (ClinicalTrials.gov ID).

The Molecular Mechanisms of Intestinal Inflammation and Fibrosis in Crohn’s Disease

Crohn’s disease (CD) is an inflammatory bowel disease (IBD) with repeated remissions and relapses. As the disease progresses, fibrosis and narrowing of the intestine occur, leading to severe complications such as intestinal obstruction. Endoscopic balloon dilatation, surgical stricture plasty, and bowel resection have been performed to treat intestinal stenosis. The clinical issue is that some patients with CD have a recurrence of intestinal stenosis even after the medical treatments. On the other hand, there exist no established medical therapies to prevent stenosis. With the progressive intestinal inflammation, cytokines and growth factors, including transforming growth factor (TGF-β), stimulate intestinal myofibroblasts, contributing to fibrosis of the intestine, smooth muscle hypertrophy, and mesenteric fat hypertrophy. Therefore, chronically sustained inflammation has long been considered a cause of intestinal fibrosis and stenosis. Still, even after the advent of biologics and tighter control of inflammation, intestinal fibrosis’s surgical rate has not necessarily decreased. It is essential to elucidate the mechanisms involved in intestinal fibrosis in CD from a molecular biological level to overcome clinical issues. Recently, much attention has been paid to several key molecules of intestinal fibrosis: peroxisome proliferator-activating receptor gamma (PPARγ), toll-like receptor 4 (TLR4), adherent-invasive Escherichia coli (AIEC), Th17 immune response, and plasminogen activator inhibitor 1 (PAI-1). As a major problem in the treatment of CD, the pathophysiology of patients with CD is not the same and varies depending on each patient. It is necessary to integrate these key molecules for a better understanding of the mechanism of intestinal inflammation and fibrosis.

Elevated Serum D-Dimer May Reflect the Presence of Gut Inflammation in Spondyloarthritis

Background

To investigate the association of D-dimer with gut inflammation in spondyloarthritis (SpA).

Methods

Sixty-five patients with SpA and 70 healthy controls were included. Demographic, clinical, and laboratory parameters were collected. The differences of clinical and laboratory parameters were compared between patients with SpA and healthy controls, and between patients with SpA, with and without gut inflammation. The associations of D-dimer with laboratory data were analyzed. The predictive value of D-dimer was obtained by a receiver operator characteristic (ROC) curve analysis. The independent risk factors for gut inflammation in SpA were investigated by binary logistic regression analysis.

Results

Patients with SpA had higher D-dimer than healthy controls (P = 0.016). D-dimer was positively correlated with platelet (PLT), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP), and negatively correlated with hemoglobin (Hb). Besides, significant differences were observed in D-dimer between SpA patients with and without gut inflammation (P < 0.001). Furthermore, SpA patients with gut inflammation were more likely to have peripheral joint involvement than those without gut inflammation (P < 0.001). The AUC of D-dimer was 0.865 at cut-off value of 0.29 mg/L, with a sensitivity of 82.6%, and a specificity of 81%. Elevated D-dimer (OR = 15.451, 95% CI: 3.030–78.780, P = 0.001) was independently associated with gut inflammation in SpA.

Conclusion

D-dimer may be a potential biomarker for identifying SpA patients with gut inflammation.

Thromboembolic and atherosclerotic cardiovascular events in inflammatory bowel disease: epidemiology, pathogenesis and clinical management

Inflammatory bowel disease (IBD) is associated with an increased risk of cardiovascular disease (CVD). The increased risk of CVD concerns an increased risk of venous thromboembolism (VTE), atherosclerotic cardiovascular disease (ASCVD) and heart failure (HF), at corresponding relative risks of 2.5, 1.2 and 2.0, respectively, as compared with the general population. Especially young patients under the age of 40 years run a relatively high risk of these complications when compared with the general population. Chronic systemic inflammation causes a hypercoagulable state leading to the prothrombotic tendency characteristic of VTE, and accelerates all stages involved during atherogenesis in ASCVD. Increased awareness of VTE risk is warranted in patients with extensive colonic disease in both ulcerative colitis and Crohn's disease, as well as during hospitalization, especially when patients are scheduled for surgery. Similarly, critical periods for ASCVD events are the 3 months prior to and 3 months after an IBD-related hospital admission. The increased ASCVD risk is not fully explained by an increased prevalence of traditional risk factors and includes pro-atherogenc lipid profiles with high levels of small dense low-density lipoprotein cholesterol particles and dysfunctional high-density lipoprotein cholesterol. Risk factors associated with HF are location and extent of inflammation, female sex, and age exceeding 40 years. A dose-dependent increase of overall CVD risk has been reported for corticosteroids. Immunomodulating maintenance therapy might reduce CVD risk in IBD, not only by a direct reduction of chronic systemic inflammation but possibly also by a direct effect of IBD medication on platelet aggregation, endothelial function and lipid and glucose metabolism. More data are needed to define these effects accurately. Despite accumulating evidence on the increased CVD risk in IBD, congruent recommendations to develop preventive strategies are lacking. This literature review provides an overview of current knowledge and identifies gaps in evidence regarding CVD risk in IBD, by discussing epidemiology, pathogenesis, and clinical management.

Shedding Light on Hemostasis in Patients With Inflammatory Bowel Diseases

Patients with inflammatory bowel diseases (IBD) have an increased risk of thrombosis, possibly due to changes in blood cells and molecules involved in hemostasis. They have increased platelet counts and reactivity as well as increased platelet-derived large extracellular vesicles. Coagulation is continuously activated in patients with IBD, based on measured markers of thrombin generation, and the anticoagulant functions of endothelial cells are damaged. Furthermore, fibrinogen is increased and fibrin clots are denser. However, pathogenesis of thrombosis in patients with IBD appears to differ from that of patients without IBD. Patients with IBD also take drugs that might contribute to risk of thrombosis, complicating the picture. We review the features of homeostasis that are altered in patients with IBD and possible mechanisms of this relationship.

Thrombosis in IBD in the Era of JAK Inhibition

Patients with inflammatory bowel diseases (IBD) have an increased risk of thrombosis. The interaction between inflammation and coagulation has extensively been studied. It is well-- known that some drugs can influence the haemostatic system, but several concerns on the association between therapies and increased risk of thrombosis remain open. While biologics seem to have a protective role against thrombosis via their anti-inflammatory effect, some concerns about an increased risk of thrombosis with JAK inhibitors have been raised. We conducted a literature review to assess the association between biologics/small molecules and venous/arterial thrombotic complications. An increased risk of venous and arterial thrombosis was found in patients treated with corticosteroids, whereas anti-TNFα were considered protective agents. No thromboembolic adverse event was reported with vedolizumab and ustekinumab. In addition, thromboembolic events rarely occurred in patients with ulcerative colitis (UC) after therapy with tofacitinib. The overall risk of both venous and arterial thrombosis was not increased based on the available evidence. Finally, in the era of JAK inhibitors, the treatment should be individualized by evaluating the pre-existing potential thrombotic risk balanced with the intrinsic risk of the medication used.

Experimental and Clinical Evidence of Endothelial Dysfunction in Inflammatory Bowel Disease

The endothelium has a crucial role in proper hemodynamics. Inflammatory bowel disease (IBD) is mainly a chronic inflammatory condition of the gastrointestinal tract. However, considerable evidence points to high cardiovascular risk in patients with IBD. This review positions the basic mechanisms of endothelial dysfunction in the IBD setting (both clinical and experimental). Furthermore, we review the main effects of drugs used to treat IBD in endothelial (dys)function. Moreover, we leave challenging points for enlarging the therapeutic arsenal for IBD with new or repurposed drugs that target endothelial dysfunction besides inflammation.

Inflammatory Bowel Disease and Thrombosis: A National Inpatient Sample Study

Introduction  Thrombosis is more common in inflammatory bowel disease (IBD) patients than the general population, but disease-specific correlates of thrombosis remain unclear.

Methods  We performed a retrospective analysis of discharge data from the National Inpatient Sample between 2009 and 2014, using International Disease Classification codes to identify IBD and non-IBD patients with or without thrombosis. We used NIS-provided discharge-level weights to reflect prevalence estimates. Categoric variables were analyzed by Rao-Scott Chi-square test, continuous variables by weighted simple linear regression, and covariates associated with thrombosis by weighted multivariable logistic regression.

Results  Thrombosis prevalence in IBD was significantly greater than in non-IBD, 7.52 versus 4.54%, p  < 0.0001. IBD patients with thrombosis were older and more likely to be Caucasian than IBD without thrombosis, each p  < 0.001. Thrombosis occurred most commonly in the mesenteric vein. Thrombotic risk factors in IBD include surgery, ports, malignancy, dehydration, malnutrition, and steroids at 53.7, 13.2, 13.1, 12.4, 8.9, and 8.2%, respectively. Those with thrombosis had greater severity of illness, 1.42 versus 0.96; length of stay, 7.7 versus 5.5 days; and mortality, 3.8 versus 1.5%; all p  < 0.0001. Adjusting for age and comorbidity, odds ratios for predictors of thrombosis included ports, steroids, malnutrition, and malignancy at 1.73, 1.61, 1.34, and 1.13, respectively, while Asian race, 0.61, was protective, each p  < 0.001.

Conclusion  Thrombosis prevalence is 1.7-fold greater in IBD than non-IBD patients. Adjusting for age and comorbidity, the odds ratio for thrombosis in IBD was 73% higher with ports, 61% higher with steroids, 34% with malnutrition, and 13% with malignancy. Whether long-term anticoagulation would benefit the latter is unknown.

Venous thromboembolism in inflammatory bowel disease

Patients with inflammatory bowel disease (IBD) are at an increased risk for venous thromboembolism (VTE). VTE events carry significant morbidity and mortality, and have been associated with worse outcomes in patients with IBD. Studies have suggested that the hypercoagulable nature of the disease stems from a complex interplay of systems that include the coagulation cascade, natural coagulation inhibitors, fibrinolytic system, endothelium, immune system, and platelets. Additionally, clinical factors that increase the likelihood of a VTE event among IBD patients include older age (though some studies suggest younger patients have a higher relative risk of VTE, the incidence in this population is much lower as compared to the older IBD patient population), pregnancy, active disease, more extensive disease, hospitalization, the use of certain medications such as corticosteroids or tofacitinb, and IBD-related surgeries. Despite the increased risk of VTE among IBD patients and the safety of pharmacologic prophylaxis, adherence rates among hospitalized IBD patients appear to be low. Furthermore, recent data suggests that there is a population of high risk IBD patients who may benefit from post-discharge prophylaxis. This review will provide an overview of patient specific factors that affect VTE risk, elucidate reasons for lack of VTE prophylaxis among hospitalized IBD patients, and focus on recent data describing those at highest risk for recurrent VTE post-hospital discharge.

Levels of TAFI, TFPI and ADAMTS-13 in inflammatory bowel disease

BACKGROUND/AIMS

There is an increased tendency for thrombosis and thromboembolic complications in patients with inflammatory bowel disease (IBD). The aim of the present study was to determine the serum concentrations of thrombin-activatable fibrinolysis inhibitor (TAFI), tissue factor pathway inhibitor (TFPI) and a disintegrin and metalloproteinase with thrombospondin motif-13 (ADAMTS-13) in patients with IBD and to assess their possible role in the etiopathogenesis of the disease.

MATERIALS AND METHODS

Thirty-four patients with IBD (23 ulcerative colitis and 11 Crohn's disease) and 20 healthy controls were included in the present study. TAFI, TFPI, and ADAMTS-13 concentrations were determined by enzyme-linked immunosorbent assay.

RESULTS

Mean TAFI, TFPI, and ADAMTS-13 concentrations in the patient group were 17.75 ng/ml, 72.10 ng/ml, and 14.90 U/l, respectively. In the control group, these values were 117.10 ng/ml, 300 ng/ml, and 191.55 U/l, respectively. TAFI, TFPI, and ADAMTS-13 values were significantly lower in the patient group than in the control group (all p<0.01).

CONCLUSION

TAFI, TFPI, and ADAMTS-13 levels were significantly lower in the patient group. These findings indicate the presence of a clear, multifactorial imbalance in the coagulation-fibrinolytic system in the patient group. It is also possible that this imbalance in the coagulation and fibrinolytic system may play a role in the still unclear etiopathogenesis of the disease.

Coagulation factor 9-deficient mice are protected against dextran sulfate sodium-induced colitis

Patients with inflammatory bowel disease (IBD) are susceptible to thromboembolism. Interestingly, IBD occurs less frequently in patients with inherited bleeding disorders. Therefore, we analyzed whether F9-deficiency is protective against the onset of acute colitis in a genetic hemophilia B mouse model. In the 3.5% dextran sulfate sodium (DSS)-induced colitis model, F9-deficient mice were protected from body-weight loss and had a reduced disease activity score. We detected decreased colonic myeloperoxidase activity and decreased CXCL1 levels in DSS-treated F9-deficient mice compared with wild-type (WT) littermate controls, indicating decreased neutrophil infiltration. Remarkably, we identified expression of coagulation factor IX (FIX) protein in small intestinal epithelial cells (MODE-K). In epithelial cell cultures, cellular FIX protein expression was increased following stimulation with the bacterial Toll-like receptor agonists lipopolysaccharide, macrophage-activating lipopeptide-2 and Pam3CSK4. Thus, we revealed a protective role of F9-deficiency in DSS-induced colitis and identified the intestinal epithelium as a site of ectopic FIX.

This article has an associated First Person interview with the first author of the paper.

Summary: Since IBD incidence is less frequent in patients with inherited bleeding disorders, we explored and demonstrated that F9-deficiency is protective against DSS-induced acute colitis in a hemophilia B mouse model.

Impaired Coagulation Status in the Crohn's Disease Patients Complicated with Intestinal Fistula

Background:

Intestinal fistula is one of the common complications of Crohn's disease (CD) that might require surgical treatment. The clinical characteristics and outcomes of CD with intestinal fistula are much different from CD alone. This study was to investigate whether the coagulation status of CD is changed by intestinal fistula.

Methods:

Data were retrospectively analyzed for 190 patients with a definitive diagnosis of CD who were registered at the Jinling Hospital between January 2014 and September 2015. Baseline clinical characteristics and laboratory indices of initial admission and 7 days after intestinal fistula resections were collected. Student's t-test and the Wilcoxon rank-sum test were used to compare differences between the two groups.

Results:

Compared with CD patients without intestinal fistula, prothrombin time (PT) in patients with intestinal fistula was significantly longer (12.13 ± 1.27 s vs. 13.18 ± 1.51 s, P < 0.001 in overall cohort; 11.56 ± 1.21 s vs. 12.61 ± 0.73 s, P = 0.001 in females; and 12.51 ± 1.17 s vs. 13.37 ± 1.66 s, P = 0.003 in males). Platelet (PLT) count was much lower in intestinal fistula group than in nonintestinal fistula group (262.53 ± 94.36 × 10⁹/L vs. 310.36 ± 131.91 × 10⁹/L, P = 0.009). Multivariate logistic regression showed that intestinal fistula was significantly associated with a prolonged PT (odds ratio [OR] = 1.900, P < 0.001), a reduced amount of PLT (OR = 0.996, P = 0.024), and an increased operation history (OR = 5.408, P < 0.001). Among 65 CD patients receiving intestinal fistula resections, PT was obviously shorter after operation than baseline (12.28 ± 1.16 s vs. 13.02 ± 1.64 s, P = 0.006).

Conclusions:

Intestinal fistula was significantly associated with impaired coagulation status in patients complicated with CD. Coagulation status could be improved after intestinal fistula resections.

D-Dimer levels are correlated with disease activity in Crohn's patients

Various indices have been used to assess Crohn's disease (CD). However, the question of whether the Crohn's Disease Activity Index (CDAI) is associated with coagulation function has not been fully confirmed. In this study, we examined the association between CDAI and the coagulation and fibrinolysis parameters. In a retrospective and observational cohort study, the CDAI of 108 patients from two hospital centers was calculated, and its correlations with the prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), international normalization ratio (INR), fibrinogen (Fg) and plasma D-Dimer were investigated. Significant differences were found for PT, APTT, TT, INR, Fg and D-Dimer between the healthy controls and CD patients. However, no significant difference was found between the CDAI-High and CDAI-Low groups of CD patients. Moreover, the CDAI was positively correlated with the level of D-Dimer in CD patients of two hospitals, regardless of the detection method (hospital 1: r=0.3268, p= 0.0042; hospital 2: r=0.5553, p=0.0008). Among the blood coagulation and fibrinolysis parameters, the D-Dimer level was highly correlated with CDAI in CD patients. Thus, the level of D-Dimer expression may be a promising new marker for assessing CD disease activity.

Clinical Aspects of Idiopathic Inflammatory Bowel Disease: A Review for Pathologists

CONTEXT

-Idiopathic inflammatory bowel disease manifests with different clinical phenotypes showing varying behavior and risk for neoplasia. The clinical questions that are posed to pathologists differ depending on phase of the disease and the clinical circumstances. Understanding the clinical aspects of the dynamic disease process will enhance the role of pathology in optimizing the care of patients with inflammatory bowel disease.

OBJECTIVE

-To review clinical and surgical aspects of inflammatory bowel disease that are relevant to practicing pathologists.

DATA SOURCES

-The literature was reviewed.

CONCLUSIONS

-Diagnosis and management of inflammatory bowel disease require an integrated evaluation of clinical, endoscopic, radiologic, and pathologic features. Therefore, close interaction between clinicians and pathologists is crucial. Having this team approach improves understanding of the pertinent clinical and surgical aspects of the disease and assists in the recognition of unusual presentation of variants, as well as mimics of idiopathic inflammatory bowel disease, by pathologists.

Etiopathogenesis, Prevention, and Treatment of Thromboembolism in Inflammatory Bowel Disease

The close relationship between inflammation and thrombosis affects the progression and severity of inflammatory bowel disease (IBD). The prevalence of venous thromboembolism (VTE) varies between 1% and 7% among patients with IBD. The VTE risk in patients with IBD is at least 3 times higher than that in the normal general population. The absolute risk is very high during hospitalization, active disease, and surgery. The IBD-related VTE occurs at younger ages and recurs more frequently. The development of thrombosis in IBD is due to the interaction of many hereditary and acquired risk factors. Each patient diagnosed with IBD should be evaluated for a personal and family history of thrombosis and for prothrombotic drug use. Although procoagulant factors are increased during the natural course of inflammation, natural anticoagulants and fibrinolytic activity are decreased. Although IBD is accepted as a prothrombotic condition, there is no treatment that can remove this risk from daily practice. Patient training is required to control important factors, such as long-term immobilization and smoking. Oral contraceptives and hormone replacement therapy should be avoided. Inducing permanent disease remission must be the key approach for the prevention of thrombosis. Low-molecular-weight heparin (LMWH) is the basis of prophylactic treatment, which reduces the thrombosis risk by 50%. Prophylaxis with LMWH should be administered to all patients with IBD hospitalized due to disease attack or surgery. Long-term or even life-long anticoagulation therapy should be planned if there is insufficient disease control, recurrent VTE attacks, positive thrombophilia tests, or thrombosis in vital veins.

The Occurrence of Thrombosis in Inflammatory Bowel Disease Is Reflected in the Clot Lysis Profile

BACKGROUND

The occurrence of thromboembolic events (TE) is an important extraintestinal manifestation in patients with inflammatory bowel disease (IBD). The aim of this study was to compare fibrinolysis and clot lysis parameters between (1) patients with IBD and healthy controls and (2) patients with IBD with TE (IBD + TE) and without TE (IBD - TE).

METHODS

One hundred thirteen healthy controls and 202 patients with IBD, of which 84 patients with IBD + TE and 118 patients with IBD - TE, were included in this case-control study. Three clot lysis parameters (area under the curve, 50% clot lysis time, and amplitude) were determined using a clot lysis assay. Plasminogen activator inhibitor 1 (PAI-1) and thrombin activatable fibrinolysis inhibitor concentrations were determined by enzyme-linked immunosorbent assay.

RESULTS

PAI-1 antigen, active PAI-1, and intact thrombin activatable fibrinolysis inhibitor concentrations, as well as 50% clot lysis time and area under the curve, were significantly associated with the presence of IBD (all P < 0.05). The median time between TE and plasma collection was 5.0 (1.8-11.0) years. Comparing IBD + TE versus IBD - TE, active to total PAI-1 ratio (0.36 [0.24-0.61] versus 0.24 [0.13-0.40]), area under the curve (31 [24-49] versus 22 [13-31]), 50% clot lysis time (110 [64-132] versus 95 [70-126] minutes), and amplitude (0.295 [0.222-0.436] versus 0.241 [0.168-0.308]) were significantly higher in IBD + TE (all P <0.05) and remained higher after adjustment for age, gender, C-reactive protein, type of disease, presence of comorbidities, and disease activity.

CONCLUSIONS

Patients with IBD have an altered clot lysis profile compared with healthy controls. Clot lysis parameters differ significantly between patients with IBD with and without a history of TE and should be included in the risk assessment.

The simultaneous occurrence of both hypercoagulability and hypofibrinolysis in blood and serum during systemic inflammation, and the roles of iron and fibrin(ogen)

Although the two phenomena are usually studied separately, we summarise a considerable body of literature to the effect that a great many diseases involve (or are accompanied by) both an increased tendency for blood to clot (hypercoagulability) and the resistance of the clots so formed (hypofibrinolysis) to the typical, 'healthy' or physiological lysis. We concentrate here on the terminal stages of fibrin formation from fibrinogen, as catalysed by thrombin. Hypercoagulability goes hand in hand with inflammation, and is strongly influenced by the fibrinogen concentration (and vice versa); this can be mediated via interleukin-6. Poorly liganded iron is a significant feature of inflammatory diseases, and hypofibrinolysis may change as a result of changes in the structure and morphology of the clot, which may be mimicked in vitro, and may be caused in vivo, by the presence of unliganded iron interacting with fibrin(ogen) during clot formation. Many of these phenomena are probably caused by electrostatic changes in the iron-fibrinogen system, though hydroxyl radical (OH˙) formation can also contribute under both acute and (more especially) chronic conditions. Many substances are known to affect the nature of fibrin polymerised from fibrinogen, such that this might be seen as a kind of bellwether for human or plasma health. Overall, our analysis demonstrates the commonalities underpinning a variety of pathologies as seen in both hypercoagulability and hypofibrinolysis, and offers opportunities for both diagnostics and therapies.

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.

Short-term effect of infliximab is reflected in the clot lysis profile of patients with inflammatory bowel disease: a prospective study

BACKGROUND

Inflammatory bowel disease (IBD) is recognized as an independent risk factor for thrombosis. First, we investigate whether the concentration of fibrinolysis inhibitors is increased in patients with IBD. Second, we investigate the effect of infliximab induction therapy on the hemostatic profile.

METHODS

This prospective study included 103 patients with IBD starting infliximab therapy and 113 healthy controls. Plasma was collected before the first infliximab infusion (wk 0) and after induction therapy (wk 14). Patients not showing a clinical response on induction were considered as primary nonresponders. Fibrinolysis inhibitors were measured by enzyme-linked immunosorbent assay. Using a clot lysis assay, the area under the curve (global marker for coagulation/fibrinolysis), 50% clot lysis time (marker for fibrinolytic capacity), and amplitude (indicator for clot formation) were determined.

RESULTS

Patients with IBD selected for infliximab treatment have higher area under the curve (median 29 [interquartile range, 20-38]) and amplitude (0.4 [0.3-0.5]) compared with healthy controls (18 [13-24] and 0.3 [0.2-0.3], respectively, P < 0.001). Primary nonresponders showed a decrease neither in inflammatory markers nor in hemostatic parameters, whereas in primary responders, a decrease in inflammatory markers was associated with a decrease in both area under the curve (29 [20-38] (wk 0) to 20 [14-28] (wk 14), P < 0.001) and amplitude (0.4 [0.3-0.5] (wk 0) to 0.3 [0.3-0.4] (wk 14), P < 0.001).

CONCLUSIONS

This is the first prospective study demonstrating that the clot lysis profile differs between patients with IBD and healthy individuals. On infliximab induction treatment, this clot lysis profile normalizes in responders suggesting that infliximab treatment is advisable for patients with IBD with an activated hemostatic profile.

The relationship between coagulation state and inflammatory bowel disease: current understanding and clinical implications

Inflammatory bowel disease (IBD) is associated with a hypercoagulable state and subsequently with an increased risk for venous thromboembolism (VTE). VTE in IBD is characterized by a high recurrence rate and is associated with the disease activity. Acquired endothelial dysfunction, abnormalities of platelets, activation of coagulation system and impaired fibrinolysis are the main changes in the coagulation state in IBD. The development of VTE in IBD has been considered to be the result of multiple interactions between acquired and inherited risk factors. The treatment of VTE in IBD patients is recommended to be similar and to follow the same protocols as for non-IBD patients. In the clinical practice, the management of IBD patients and especially the hospitalized patients should include thromboprophylaxis.

Recurrent posterior strokes in inflammatory bowel disease patients

Objective. To describe the stroke characteristics of patients with a history of inflammatory bowel disease (IBD). Background. A hypercoagulable state associated with IBD has been frequently implicated as a risk factor for ischemic stroke. Variable mechanisms and infrequent occurrence limit prospective clinical research on the association between IBD and stroke. Methods. We retrospectively reviewed consecutive patients with acute ischemic stroke presenting to our medical center from 7/2008 to 9/2013. Patients with a history of IBD were identified. Clinical variables were abstracted from our prospective stroke registry. Results. Over the period of five years we identified only three patients with a documented history of IBD. Each of these patients presented three times to our hospital with new strokes. Patients presented outside the window for intravenous tPA treatment on 8/9 admissions. Each one of our patients had posterior strokes on at least two separate occasions. Hypercoagulation panel showed elevated factor VIII with or without concomitant elevation of Von Willebrand factor (vWF) during almost every admission (8/9 admissions). Only one admission was associated with IBD flare. Conclusion. The association between IBD and posterior strokes is a novel finding. Factor VIII elevation may serve as a biomarker of a peristroke hypercoagulable state in patients with IBD.

Active PAI-1 as marker for venous thromboembolism: case-control study using a comprehensive panel of PAI-1 and TAFI assays

BACKGROUND

Both activated Thrombin Activatable Fibrinolysis Inhibitor (TAFI) and active Plasminogen Activator Inhibitor-1 (PAI-1) attenuate fibrinolysis and may therefore contribute to the pathophysiology of Venous ThromboEmbolism (VTE). Whether increased TAFI and/or PAI-1 concentrations are associated with VTE is unclear.

OBJECTIVE

To study an association of impaired fibrinolysis and VTE using a comprehensive panel of in-house developed assays measuring intact TAFI, activation peptide of TAFI (AP-TAFI), PAI-1 antigen, endogenous PAI-1:t-PA complex (PAI-1:t-PA) and active PAI-1 levels in 102 VTE patients and in 113 healthy controls (HC).

RESULTS

Active PAI-1 was significantly higher in VTE patients compared to HC (20.9 [9.6-37.8] ng/ml vs. 6.2 [3.5-9.7] ng/ml, respectively). Active PAI-1 was the best discriminator with an area under the ROC curve and 95% confidence interval (AUROC [95%CI]) of 0.84 [0.79-0.90] compared to 0.75 [0.68-0.72] for PAI-1:t-PA, 0.65 [0.58-0.73] for PAI-1 antigen, 0.62 [0.54-0.69] for AP-TAFI and 0.51 [0.44-0.59] for intact TAFI. Using ROC analysis, we defined an optimal cut-off of 12.8 ng/ml for active PAI-1, with corresponding sensitivity of 71 [61-79] % and specificity of 89 [82-94] %. A lack of association with the time between VTE event and sample collection or with the intake of anticoagulant treatment suggests that active PAI-1 levels are sustainable high in VTE patients.

CONCLUSIONS

This case-control study emphasizes the clinical importance of measuring active PAI-1 instead of PAI-1 antigen and identifies active PAI-1 as a potential marker of VTE. Prognostic studies will need to address the clinical significance of active PAI-1 as biomarker.

Construction of a scoring system for predicting the risk of severe gastrointestinal involvement in Henoch-Schönlein Purpura

Objective

To evaluate the parameters associated with significant gastrointestinal (GI) involvement in Henoch-Schönlein Purpura (HSP), and construct a scoring system for the identification of patients at high risk of gross blood in stools.

Study design

Data for HSP patients hospitalized at each of seven institutes were retrospectively analyzed. Patients were divided into four groups according to the consequent severity of GI involvement. Identification of laboratory parameters at the time of admission were then used to differentiate the groups, and a scoring system to predict gross intestinal bleeding was constructed. Prognostic efficiency, correlation with the subsequent duration of abdominal pain, and association with manifestations excluding abdominal pain were also analyzed.

Results

An analysis of variance (ANOVA) test showed significant intergroup differences in white blood cell (WBC) count, neutrophil count, serum albumin, potassium, plasma D-dimer and coagulation factor XIII activity. A scoring system consisting of these parameters showed a good prognostic value for gross intestinal bleeding in a receiver operating characteristic (ROC) analysis, and a cut-off value of 4 points showed a sensitivity of 90.0% and specificity of 80.6%. The score was also correlated with the duration of abdominal pain after admission. A significantly higher score (s) was observed in patients presenting with nephritis, although the predictive value was poor.

Conclusion

A scoring system consisting of generally available parameters was of use in predicting severe GI involvement in HSP patients. Although further study is needed, initial therapy in accordance with disease activity may be taken into consideration using this scoring system.

Clinical syndromes associated with acquired antithrombin deficiency via microvascular leakage and the related risk of thrombosis

Antithrombin (AT) is a 65kDa glycoprotein belonging to a group of inhibitory factors known as serpins (serine protease inhibitors). It plays a critical role in the inhibition of coagulation and inflammation processes within the environment of the vascular endothelium. Inadequate levels of functional AT in plasma results in an increased risk of thrombotic events, both venous and arterial. AT deficiency can be inherited or acquired. Congenital AT deficiency is the most severe inherited thrombophilic condition with an odds ratio of 20 for the increased risk of venous thrombosis. Acquired AT deficiency occurs in a variety of physiologic and pathologic medical conditions with similar risks of increased thrombosis. In this article, we review clinical settings characterized by an acquired AT deficiency largely or partly subsequent to protein microvascular leakage. Other different mechanisms of AT depletion are implied in some clinical conditions together with endothelial loss, and, therefore, outlined. In addition, we provide a description of the current knowledge on the specific mechanisms underlying endothelial AT leakage and on the consequences of this protein decrease, specifically looking at thrombosis. We identify potential directions of research that might prove useful in patients with acquired AT deficiency.

Evaluation of coagulation activation after rhinovirus infection in patients with asthma and healthy control subjects: an observational study

Background

Asthma exacerbations are frequently triggered by rhinovirus infections. Both asthma and respiratory tract infection can activate haemostasis. Therefore we hypothesized that experimental rhinovirus-16 infection and asthmatic airway inflammation act in synergy on the haemostatic balance.

Methods

28 patients (14 patients with mild allergic asthma and 14 healthy non-allergic controls) were infected with low-dose rhinovirus type 16. Venous plasma and bronchoalveolar lavage fluid (BAL fluid) were obtained before and 6 days after infection to evaluate markers of coagulation activation, thrombin-antithrombin complexes, von Willebrand factor, plasmin-antiplasmin complexes, plasminogen activator inhibitor type-1, endogenous thrombin potential and tissue factor-exposing microparticles by fibrin generation test, in plasma and/or BAL fluid. Data were analysed by nonparametric tests (Wilcoxon, Mann Whitney and Spearman correlation).

Results

13 patients with mild asthma (6 females, 19-29 y) and 11 healthy controls (10 females, 19-31 y) had a documented Rhinovirus-16 infection. Rhinovirus-16 challenge resulted in a shortening of the fibrin generation test in BAL fluid of asthma patients (t = -1: 706 s vs. t = 6: 498 s; p = 0.02), but not of controls (t = -1: 693 s vs. t = 6: 636 s; p = 0.65). The fold change in tissue factor-exposing microparticles in BAL fluid inversely correlated with the fold changes in eosinophil cationic protein and myeloperoxidase in BAL fluid after virus infection (r = -0.517 and -0.528 resp., both p = 0.01).

Rhinovirus-16 challenge led to increased plasminogen activator inhibitor type-1 levels in plasma in patients with asthma (26.0 ng/mL vs. 11.5 ng/mL in healthy controls, p = 0.04). Rhinovirus-16 load in BAL showed a linear correlation with the fold change in endogenous thrombin potential, plasmin-antiplasmin complexes and plasminogen activator inhibitor type-1.

Conclusions

Experimental rhinovirus infection induces procoagulant changes in the airways of patients with asthma through increased activity of tissue factor-exposing microparticles. These microparticle-associated procoagulant changes are associated with both neutrophilic and eosinophilic inflammation. Systemic activation of haemostasis increases with Rhinoviral load.

Trial registration

This trial was registered at the Dutch trial registry (http://www.trialregister.nl): NTR1677.

Tissue factor exposing microparticles in inflammatory bowel disease

BACKGROUND

Circulating procoagulant microparticles (MPs) are thought to be involved in the pathogenesis of venous thromboembolism in patients with inflammatory bowel disease (IBD). However, the exposure of tissue factor, the primary initiator of coagulation activation, on microparticles (TF(+)MPs) and its association with hemostasis activation has not yet been studied in IBD patients.

METHODS

In this case-control study 49 IBD patients (28 Crohn's disease, 21 ulcerative colitis) and 49 sex- and age-matched, healthy controls were included. Clinical disease activity (Crohn's Disease Activity Index and Clinical Activity Index, respectively) was assessed and IBD-related data were determined by chart review. Numbers, cellular origin and procoagulant activity of TF(+)MPs in plasma were determined using flow cytometry and a chromogenic activity assay. D-dimer and high-sensitive C-reactive protein (CRP) served as markers for coagulation activation and inflammation, respectively. The primary endpoint was the number of TF(+)MPs in IBD patients compared to controls.

RESULTS

Median number (interquartile range) of TF(+)MPs was higher in IBD patients than in controls (14.0 (11.9-22.8)×10(3)/mL vs. 11.9 (11.9-19.1)×10(3)/mL plasma, P=0.029). This finding was due to generally higher plasma levels of MPs from platelets and leukocytes in IBD patients. However, the number of TF(+)MPs was neither correlated with their procoagulant activity and D-dimer nor with disease activity and CRP.

CONCLUSIONS

Increased numbers of circulating TF(+)MPs represent a new facet of hemostatic abnormalities in IBD. However, the lack of association with activation of the coagulation system and disease activity questions their pathogenetic role for venous thromboembolism in this patient group.

Genetic dissection of TAM receptor-ligand interaction in retinal pigment epithelial cell phagocytosis

Although TAM receptor tyrosine kinases play key roles in immune regulation, cancer metastasis, and viral infection, the relative importance of the two TAM ligands-Gas6 and Protein S-has yet to be resolved in any setting in vivo. We have now performed a genetic dissection of ligand function in the retina, where the TAM receptor Mer is required for the circadian phagocytosis of photoreceptor outer segments by retinal pigment epithelial cells. This process is severely attenuated in Mer mutant mice, which leads to photoreceptor death. We find that retinal deletion of either Gas6 or Protein S alone yields retinae with a normal number of photoreceptors. However, concerted deletion of both ligands fully reproduces the photoreceptor death seen in Mer mutants. These results demonstrate that Protein S and Gas6 function as independent, bona fide Mer ligands, and are, to a first approximation, interchangeable with respect to Mer-driven phagocytosis in the retina.