Platelet abnormalities during colonic inflammation

Hematological, cardiovascular and oxidative DNA damage markers associated with heavy metal exposure in electronic waste (e-waste) workers of Bangladesh

Electronic waste (e-waste) contains hazardous elements such as lead (Pb), cadmium (Cd), mercury (Hg), and other toxic elements that pose significant health risks to the population directly exposed. We recruited 199 e-waste recycling workers and 104 non-exposed workers in Bangladesh and analyzed heavy metals in blood and hair, as well as hematological and cardiovascular parameters including, blood lipids and blood pressure. We fitted quantile regression models at 0.5 quantile to evaluate the impact of blood Pb, Cd, and total hair Hg (THg) on hematological and cardiovascular parameters and the role of oxidative DNA damage (8-OHdG as a biomarker) in mediatin the relationship between exposures and outcomes. Exposed workers had elevated median blood Pb (11.89 vs. 3.63 µg/dL), moderate blood Cd (1.04 vs. 0.99 µg/L), and lower level of THg (0.38 vs. 0.57 ppm) in hair than non-exposed workers. Adjusted estimates showed that Pb was positively associated with red blood cell (RBC), eosinophil count, eosinophil percentage; and negatively associated with mean platelet volume (MPV), platelet large cell ratio (P-LCR) and platelet volume distribution width (PDW) (all p≤0.05). Cd was only associated with 0.57 units increase in red blood cell distribution width (RDW) percentage (95 % CI: 0.18, 0.95). In cardiovascular outcomes, Pb was associated with 1.42 units decrease in triglyceride, 1.58 units increase in low-density lipoprotein (LDL), 0.07 units increase in LDL/HDL and 0.49 units increase in systolic blood pressure (all p≤0.05). No associations were observed between THg and hematological or cardiovascular parameters. Urinary 8-OHdG concentrations were lower, and it did not mediate exposure-outcome relationships (all p≥0.05). Our data imply that e-waste exposure impairs hematological parameters, blood lipids, and blood pressure secondary to elevated Pb levels and poses a threat to exposed individuals. As such, continuous monitoring in longitudinal studies is warranted to assess the dose-response relationship and identify effective control measures.

Effects of COVID-19 vaccines on patient-reported outcomes in patients with inflammatory bowel disease: a multicenter survey study in Korea

BACKGROUND/AIMS

The impact of vaccination on inflammatory bowel disease (IBD) patients is still unknown, and no studies have assessed the changes in patient-reported outcomes (PROs) after vaccination in patients with IBD. Therefore, in this study, we investigated the impact of vaccines on the PROs of patients with IBD.

METHODS

We conducted a questionnaire survey of patients with IBD who visited outpatient clinics at 4 specialized IBD clinics of referral university hospitals from April 2022 to June 2022. A total of 309 IBD patients were included in the study. Patient information was collected from a questionnaire and their medical records, including laboratory findings, were reviewed retrospectively. Risk factors associated with an increase in PROs after COVID-19 vaccination were analyzed using logistic regression analyses. In addition, we assessed whether there were differences in variables by vaccine order using the linear mixed model.

RESULTS

In multivariate analysis, young age ( < 40 years) and ulcerative colitis (UC) were found to be independent risk factors for aggravation of PROs in patients with IBD. In all patients, platelet count significantly increased with continued vaccination in multiple pairwise comparisons. In UC patients, PROs such as the short health scale, UC-abdominal signs and symptoms, and UC-bowel signs and symptoms were aggravated significantly with continued vaccination. There was no significant increase in the variables of patients with Crohn's disease.

CONCLUSIONS

Therefore, there may be a need to counsel patients with IBD younger than 40 years of age, and patients with UC before they receive COVID-19 vaccinations.

The Role of Platelets and von Willebrand Factor in the Procoagulant Phenotype of Inflammatory Bowel Disease

AIMS

Although the risk of thrombosis is well documented for inflammatory bowel disease [IBD] patients, the underlying pathological mechanism seems to be different from other thrombotic conditions. Determining the factors responsible for the increased risk of thrombosis in IBD would help to improve the management of this frequent complication.

METHODS

We studied the interplay between platelets, coagulation, and von Willebrand factor [VWF] in 193 IBD patients and in experimental models [acute and chronic] of colitis in wild-type and VWF-deficient mice.

RESULTS

We found a platelet-dependent increase in thrombin generation in IBD patients and in our mouse model of colitis. Agglutinated platelets were present in the blood of patients and mice. Interestingly, we observed not only a significant increase in total VWF antigen, but we were also able to detect the presence of active VWF [VWF in its platelet-binding conformation; 3.2 ± 2.7 μg/mL] in the plasma of 30% of all IBD patients. In healthy controls, active VWF levels were <0.3 μg/mL. This led us to further explore experimental colitis in VWF-deficient mice and we observed that these mice were protected against the procoagulant state triggered by the colitis. Unexpectedly, these mice also showed a significant worsening of colitis severity in both acute and chronic models.

CONCLUSION

Platelets and VWF [including its active form] appear to be central players in the procoagulant phenotype in IBD. We observed that the role of VWF in haemostasis differs from its role in colonic tissue healing, potentially opening new therapeutic avenues for a life-threatening complication in IBD patients.

Anti-oxidant and anti-inflammatory potential of different polymer-based mesalamine delayed-release granules in TNBS-induced ulcerative colitis in wistar rats

Ulcerative colitis (UC) is an inflammatory condition of colon characterized by severe damage to the innermost colon tissues. A number of studies described the use of medication delivery systems based on natural polymers like polysaccharides for the purpose of reaching the colon. In this research, polymer-based mesalamine delayed-release granules (DRGs) were tested for their antioxidant and anti-inflammatory efficacy against UC. Chitosan (C), pectin (P), and pectin-chitosan (PC) mesalamine (M) DRGs were prepared and characterized. Data revealed satisfactory compatibility, flow, packing properties, drug release pattern, and delayed drug release by DRGs. Wistar rats were treated with 2,4,6-trinitrobenzenesulfonic acid (TNBS) (100 mg/kg) via rectal administration. Mesalamine and mesalamine DRGs (50 mg/kg) were administered orally separately for 14 days. Biomarkers of oxidative stress, inflammation, hematological tests, colon profile, and histopathology were performed. The findings demonstrated the good efficacy of the polysaccharides in delivering mesalamine to colon. Mesalamine and mesalamine DRGs based on various polymers showed significant antioxidant and anti-inflammatory effects in rats with UC. Mesalamine granules significantly attenuated colon lipid peroxidation, nitrites, myeloperoxidase activity, and interleukin-1β levels, and improved anti-oxidants (GSH, SOD). Data showed upregulation of Nrf2 activity by mesalamine granules with CM-DRGs showing maximum effect. Mesalamine and different polymer-based mesalamine DRGs significantly attenuated TNBS-induced decline in body weight, ulcer severity, and colon damage. CM-DRGs showed the most pronounced ameliorative effect on colon and hematology parameters via anti-oxidant and anti-inflammatory activities. Chitosan can be used as a carrier for oral colon delivery of mesalamine in DRG formulation for enhanced therapeutic efficacy in UC.

Gut Microbiome-Generated Phenylacetylglutamine from Dietary Protein is Associated with Crohn's Disease and Exacerbates Colitis in Mouse Model Possibly via Platelet Activation

OBJECTIVES

Our aims were to better understand the interplay of diet and gut microbiota in Crohn's disease [CD], taking advantage of a new-onset treatment-naïve CD cohort. We focus on phenylacetylglutamine [PAGln], a diet-derived meta-organismal prothrombotic metabolite.

DESIGN

We collected faecal and serum samples from a CD cohort [n = 136] and healthy controls [n = 126] prior to treatment, and quantified serum PAGln using LC-MS/MS. Diet was assessed using food-frequency questionnaires. Mice [C57BL/6] were fed high/low-protein diets and administered dextran sodium sulphate [DSS] to examine plasma PAGly, thrombosis potential, and colitis severity. PAGly or saline was administered to DSS-induced colitis mice, and colitis severity and colonic tissue gene expression were examined. P-selectin and CD40L expression were determined in human platelet-rich plasma [n = 5-6] after exposure to platelet agonists following PAGln priming. Bioinformatic analysis and bacterial culturing identified the main contributor of PAGln in CD.

RESULTS

PAGln, a meta-organismal prothrombotic metabolite, is associated with CD. Administration of PAGly exacerbated colitis in a mouse model and upregulated coagulation-related biological processes. Antiplatelet medicine, dipyridamole, attenuated PAGly-enhanced colitis susceptibility. PAGln enhanced platelet activation and CD40L expression in platelet-rich plasma ex vivo. Further study revealed that high dietary protein intake and increased abundance of phenylacetic acid [PAA]-producing Proteobacteria mediated by phenylpyruvate decarboxylase act in concert to cause the elevated PAGln levels in CD patients.

CONCLUSION

Taken together, ppdc-carrying Proteobacteria-generated PAGln from dietary protein is associated with CD and exacerbates colitis possibly via platelet-induced coagulation and inflammation These results suggest that PAGln is a potential early diagnostic marker and therapeutic target of CD.

Sperm of more colourful males are better adapted to ovarian fluids in lake char (Salmonidae)

Fish often spawn eggs with ovarian fluids that have been hypothesized to support the sperm of some males over others (cryptic female choice). Alternatively, sperm reactions to ovarian fluids could reveal male strategies. We used wild-caught lake char (Salvelinus umbla) to experimentally test whether sperm react differently to the presence of ovarian fluid, and whether any differential sperm reaction could be predicted by male breeding coloration, male inbreeding coefficients (based of 4150 SNPs) or the kinship coefficients between males and females. Male coloration was positively linked to body size and current health (based on lymphocytosis and thrombocytosis) but was a poor predictor of inbreeding or kinship coefficients. We found that sperm of more colourful males were faster in diluted ovarian fluids than in water only, while sperm of paler males were faster in water than in ovarian fluids. We then let equal numbers of sperm compete for fertilizations in the presence or absence of ovarian fluids and genetically assigned 1464 embryos (from 70 experimental trials) to their fathers. The presence of ovarian fluids significantly increased the success of the more colourful competitors. Sperm of less inbred competitors were more successful when tested in water only than in diluted ovarian fluids. The kinship coefficients had no significant effects on sperm traits or fertilization success in the presence of ovarian fluids, although parallel stress tests on embryos had revealed that females would profit more from mating with least related males rather than most coloured ones. We conclude that sperm of more colourful males are best adapted to ovarian fluids, and that the observed reaction norms suggest male strategies rather than cryptic female choice.

Identification of novel clusters of co-expressing cytokines in a diagnostic cytokine multiplex test

Introduction

Cytokines are mediators of the immune system that are essential for the maintenance, development and resolution of immune responses. Beneficial immune responses depend on complex, interdependent networks of signaling and regulatory events in which individual cytokines influence the production and release of others. Since disruptions in these signaling networks are associated with a wide spectrum of diseases, cytokines have gained considerable interest as diagnostic, prognostic and precision therapy-relevant biomarkers. However, currently individual cytokines testing has limited value because the wider immune response context is often overlooked. The aim of this study was to identify specific cytokine signaling patterns associated with different diseases.

Methods

Unbiased clustering analyses were performed on a clinical cytokine multiplex test using a cohort of human plasma specimens drawn from individuals with known or suspected diseases for which cytokine profiling was considered clinically indicated by the attending physician.

Results and discussion

Seven clusters of co-expressing cytokines were identified, representing common patterns of immune activation. Common expression profiles of the cytokine clusters and preliminary associations of these profiles with specific diseases or disease categories were also identified. These findings increase our understanding of the immune environments underlying the clinical presentations of patients of inflammatory, autoimmune and neoplastic diseases, which could then improve diagnoses and the identification of evidence-based treatment targets.

Potential Role of Non-Steroidal Anti-Inflammatory Drugs in Colorectal Cancer Chemoprevention for Inflammatory Bowel Disease: An Umbrella Review

Inflammatory Bowel Disease (IBD) is a category of autoimmune diseases that targets the destruction of the gastrointestinal system and includes both Crohn's Disease and Ulcerative Colitis (UC). Patients with IBD are at a higher risk of developing colorectal cancer (CRC) throughout their lives due to chronically increased inflammation. Nonsteroidal anti-inflammatory drugs (NSAIDs) are potential chemopreventative agents that can inhibit the development of CRC in persons without IBD. However, the use of NSAIDs for CRC chemoprevention in IBD patients is further complicated by NSAIDs' induction of damage to the bowel mucosal layer and ulcer formation. There has been a push in new research on chemopreventative properties of certain NSAIDs for IBD. The purpose of this umbrella review is to investigate the potential of low-dose NSAID compounds as chemopreventative agents for patients with IBD. This paper will also suggest future areas of research in the prevention of CRC for patients with IBD.

Circulating Reactive Oxygen Species in Adults with Congenital Heart Disease

Oxidative stress is an important pathophysiological mechanism in the development of numerous cardiovascular disorders, but few studies have examined the levels of oxidative stress in adults with congenital heart disease (CHD). The objective of this study was to investigate oxidative stress levels in adults with CHD and the association with inflammation, exercise capacity and endothelial function. To this end, 36 adults with different types of CHD and 36 age- and gender-matched healthy controls were enrolled. Blood cell counts, hs-CRP, NT-proBNP, fasting glucose, cholesterol levels, iron saturation and folic acid concentrations were determined in venous blood samples. Levels of superoxide anion radical in whole blood were determined using electron paramagnetic resonance spectroscopy in combination with the spin probe CMH. Physical activity was assessed with the IPAQ-SF questionnaire. Vascular function assessment (EndoPAT) and cardiopulmonary exercise testing were performed in the patient group. Superoxide anion radical levels were not statistically significantly different between adults with CHD and the matched controls. Moreover, oxidative stress did not correlate with inflammation, or with endothelial function or cardiorespiratory fitness in CHD; however, a significant negative correlation with iron saturation was observed. Overall, whole blood superoxide anion radical levels in adults with CHD were not elevated, but iron levels seem to play a more important role in oxidative stress mechanisms in CHD than in healthy controls. More research will be needed to improve our understanding of the underlying pathophysiology of CHD.

Thromboembolic Events in Patients with Inflammatory Bowel Disease: A Comprehensive Overview

Inflammatory bowel disease (IBD), Crohn’s disease and ulcerative colitis are chronic inflammatory disorders of the intestines. The underlying inflammation activates the coagulation cascade leading to an increased risk of developing arterial and venous thromboembolic events such as deep vein thrombosis and pulmonary embolism. Patients with IBD are at a 2–3-fold increased risk of developing thromboembolism. This risk increases in patients with active IBD disease, flare-ups, surgery, steroid treatment, and hospitalization. These complications are associated with significant morbidity and mortality making them important in clinical practice. Clinicians should consider the increased risk of thromboembolic events in patients with IBD and manage them with appropriate prophylaxis based on the risk. In this review, we discuss the literature associated with the pathophysiology of thromboembolism in patients with IBD, summarize the studies describing the various thromboembolic events, and the management of thromboembolism in patients with IBD.

Platelets and the Cybernetic Regulation of Ischemic Inflammatory Responses through PNC Formation Regulated by Extracellular Nucleotide Metabolism and Signaling

Ischemic events are associated with severe inflammation and are here referred to as ischemic inflammatory response (IIR). Recent studies identified the formation of platelet–neutrophil complexes (PNC) as key players in IIR. We investigated the role of extracellular platelet nucleotide signaling in the context of IIR and defined a cybernetic circle, including description of feedback loops. Cybernetic circles seek to integrate different levels of information to understand how biological systems function. Our study specifies the components of the cybernetic system of platelets in IIR and describes the theoretical progression of IIR passing the cybernetic cycle with positive and negative feedback loops based on nucleotide-dependent signaling and functional regulation. The cybernetic components and feedback loops were explored by cytometry, immunohistological staining, functional blocking antibodies, and ADP/ATP measurements. Using several ex vivo and in vivo approaches we confirmed cybernetic parameters, such as controller, sensor, and effector (VASP phosphorylation, P2Y₁₂, ADORAs and GPIIb/IIIa activity), as well as set points (ADP, adenosine) and interfering control and disturbance variables (ischemia). We demonstrate the impact of the regulated platelet–neutrophil complex (PNC) formation in blood and the resulting damage to the affected inflamed tissue. Taken together, extracellular nucleotide signaling, PNC formation, and tissue damage in IIR can be integrated in a controlled cybernetic circle of platelet function, as introduced through this study.

Risk of venous thromboembolism in children and adolescents with inflammatory bowel disease: A systematic review and meta-analysis

BACKGROUND

A two- to three-fold increased risk of venous thrombotic events (VTE) has been demonstrated in patients with inflammatory bowel disease (IBD) compared to the general population, but less is known about the risk of VTE in child- and pediatric-onset IBD. In recent years, several studies have reported the rising incidence rate of VTE in juvenile patients with IBD, and the related risk factors have been explored.

AIM

To evaluate the risk of VTE in children and adolescents with IBD.

METHODS

Articles published up to April 2021 were retrieved from PubMed, Embase, Cochrane Library, Web of Science, SinoMed, CNKI, and WANFANG. Data from observational studies and clinical work were extracted. The outcome was the occurrence of VTE according to the type of IBD. The available odds ratio (OR) and the corresponding 95% confidence interval (CI) were extracted to compare the outcomes. Effect size (P), odds ratio (OR), and 95%CI were used to assess the association between VTE risk and IBD disease. Subgroup analyses stratified by subtypes of VTE and IBD were performed.

RESULTS

Twelve studies (7450272 IBD patients) were included in the meta-analysis. Child and adolescent IBD patients showed increased VTE risk (P = 0.02, 95%CI: 0.01-0.03). Subgroup analyses stratified by IBD (ulcerative colitis (UC): P = 0.05, 95%CI: 0.03-0.06; Crohn's disease (CD): P = 0.02, 95%CI: 0.00-0.04) and VTE subtypes (portal vein thrombosis: P = 0.04, 95%CI: 0.02-0.06; deep vein thrombosis: P = 0.03, 95%CI: 0.01-0.05; central venous catheter-related thrombosis: P = 0.23, 95%CI: 0.00-0.46; thromboembolic events: P = 0.02, 95%CI: 0.01-0.03) revealed a significant correlation between VTE risk and IBD. Patients with IBD were more susceptible to VTE risk than those without IBD (OR = 2.99, 95%CI: 1.45-6.18). The funnel plot was asymmetric, suggesting the presence of significant publication bias. Pediatric and adolescent IBD patients have an increased VTE risk. UC and CD patients exhibited a high risk of VTE. The risk of VTE subtypes was increased in IBD patients.

CONCLUSION

The current meta-analysis showed that the incidence and risk of VTE are significantly increased in pediatric and adolescent IBD patients. Thus, IBD might be a risk factor for VTE in children and young adults. High-quality prospective cohort studies are necessary to confirm these findings.

Serum Immune-Inflammation Index Assessment in the Patients with Ulcerative Colitis

Radiologic and endoscopic diagnostic methods are used to determine disease activity in ulcerative colitis (UC). In order for endoscopic procedures to be invasive and to prevent radiation exposure, especially in young people, studies have been carried out frequently to determine a simple, fast, and reliable activity marker with laboratory methods. Our aim in this study is to determine the usefulness of serum immune-inflammatory index as a noninvasive marker of activation in patients with ulcerative colitis. A total of 82 consecutive patients treated with a diagnosis of ulcerative colitis were included in the study. The disease activation was assessed using the Mayo endoscopic subscore. The site of involvement was grouped into two as left colitis and extensive colitis. Patients were divided into two groups as those who had active disease based on clinical and endoscopic findings and those who were in remission. C-reactive protein (CRP) levels, platelets, neutrophils, and lymphocytes were recorded in all participants. The systemic immune-inflammation index (SII) and CRP values were compared between UC patients with active disease or remission. The correlations between CRP, SII, and Mayo endoscopic subscores were analyzed. In addition, ROC curve analysis for SII was performed to determine the cut-off value, sensitivity, and specificity in determining ulcerative colitis activity. The value of SII was significantly higher in the active group than the remission group (respectively, 1497 ± 1300 and 495 ± 224, p < 0.001). In the correlation analysis, a significant correlation was found between SII and Mayo subscore. In ROC curve analysis, SII was found to be significantly effective in determining activity in ulcerative colitis patients. For 0.860 area under the curve, the sensitivity was 68.1% and the specificity was 91.2% at a cut-off value of 781.5. SII is significantly higher in patients with active ulcerative colitis than those in remission. It shows promise for use as a noninvasive marker of active ulcerative colitis.

Dichotomous roles of neutrophils in modulating pathogenic and repair processes of inflammatory bowel diseases

Neutrophils are considered as complex innate immune cells and play a critical role in maintaining intestinal mucosal homeostasis. They exert robust pro-inflammatory effects and recruit other immune cells in the acute phase of pathogen infection and intestinal inflammation, but paradoxically, they also limit exogenous microbial invasion and facilitate mucosal restoration. Hyperactivation or dysfunction of neutrophils results in abnormal immune responses, leading to multiple autoimmune and inflammatory diseases including systemic lupus erythematosus, rheumatoid arthritis, and inflammatory bowel diseases (IBD). As a refractory intestinal inflammatory disease, the pathogenesis and progression of IBD are associated with complicated immune response processes in which neutrophils are profoundly involved. However, the consensus on potential roles of neutrophils in modulating pathogenic and repair processes of IBD remains not fully understood. Accumulated infiltrating neutrophils cross the epithelial barrier and contribute to microbial dysbiosis, aggravated intestinal architectural damage, compromised resolution of intestinal inflammation and increased risk of thrombosis during IBD. Paradoxically, activated neutrophils are also associated with effective elimination of invaded microbiota, promoted angiogenesis and tissue restoration of gut mucosa in IBD. Here, we discuss the beneficial and detrimental roles of neutrophils in the onset and resolution of intestinal mucosal inflammation, hoping to provide a precise overview of neutrophil functions in the pathogenesis of IBD.

Therapeutic efficacy of rifaximin loaded tamarind gum polysaccharide nanoparticles in TNBS induced IBD model Wistar rats

Background

Rifaximin is a non-systemic antibiotic used in the treatment of inflammatory bowel disease (IBD). Antibiotics are demonstrating a significant role in the treatment of IBD by altering the dysbiotic colonic microbiota and decreases the immunogenic and inflammatory response in the patient population. Mucoadhesive colon targeted nanoparticles provide the site-specific delivery and extended stay in the colon. Since the bacteria occupy the lumen, spread over the surface of epithelial cells, and adhere to the mucosa, delivering the rifaximin as a nanoparticles with the mucoadhesive polymer enhances the therapeutic efficacy in IBD. The objective was to fabricate and characterize the rifaximin loaded tamarind gum nanoparticles and study the therapeutic efficacy in the TNBS-induced IBD model rats.

Materials and methods

The experimentation includes fabrication and characterization of drug excipient compatibility by FTIR. The fabricated nanoparticles were characterized for the hydrodynamic size and zeta potential by photon correlation spectroscopy and also analyzed by TEM. Selected best formulation was subjected to the therapeutic efficacy study in TNBS-induced IBD rats, and the macroscopic, microscopic and biochemical parameters were reported.

Results

The study demonstrated that the formulation TGN1 is best formulation in terms of nanoparticle characterization and hydrodynamic size which showed the hydrodynamic size of 171.4 nm and the zeta potential of -26.44 mV and other parameters such as TEM and drug release studies were also reported.

Conclusions

The therapeutic efficacy study revealed that TGN1 is efficiently reduced the IBD inflammatory conditions as compared to the TNBS control group and reference drug mesalamine group.

The risk of venous thromboembolic events in patients with inflammatory bowel disease: a systematic review and meta-analysis

BACKGROUND

Inflammatory bowel disease (IBD), comprising Crohn's disease (CD) and ulcerative colitis (UC), is a chronic inflammatory disorder of the gastrointestinal tract that has been associated with increased risk of extraintestinal manifestations, amongst which is venous thromboembolism (VTE). We assessed the risk for VTE in patients with IBD through systematic review and meta-analysis.

METHODS

A systematic search for English language studies was conducted in Medline, Scopus, and the Cochrane Library of publications from database inception till August 10, 2020, to identify relevant studies reporting the risk of VTE in patients with IBD. The random-effects and fixed-effect models were used to estimate relative risks (RRs) with their respective 95% confidence intervals (CIs). The quality of the included studies was assessed using the Newcastle-Ottawa scale.

RESULTS

Eleven observational studies were included in this meta-analysis, involving 3,175,012 patients with IBD and 920,144,253 controls without IBD. The overall RR for VTE in patients with IBD compared to non-IBD individuals was 2.03 (95%CI 1.72-2.39). An analysis of studies with larger population size demonstrated a lower risk for VTE (RR 1.77, 95%CI 1.48-2.13) among patients with IBD, whereas studies with a smaller population size yielded a greater risk for VTE (RR 2.67, 95%CI 1.97-2.93). After adjustment for smoking and body mass index, the RR for VTE was moderately increased (RR 2.65, 95%CI 1.51-4.65).

CONCLUSIONS

The present meta-analysis shows that IBD is linked to a 2-fold increased risk for VTE. Thus, primary prevention against VTE is of the utmost importance.

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.

Clinical significance of blood platelets and mean platelet volume in patients with ulcerative colitis

Objectives

This retrospective study aimed to investigate and analyze the clinical significance of blood platelets (PLTs) and mean platelet volume (MPV) in patients with ulcerative colitis (UC).

Methods

A total of 132 patients with UC and 208 healthy subjects were enrolled. PLTs, MPV, platelet-large cell rate (P-LCR), C-reactive protein (CRP), fibrinogen (FIB) and D-dimer were analyzed. Correlations were calculated between disease activity/extent of disease and MPV, PLT, and CRP levels in patients with UC.

Results

PLT levels were significantly higher while MPV and P-LCR were lower in patients with UC compared with controls. Disease activity was positive correlated with CRP (r = 0.564) and PLT (r = 0.307) but negatively correlated with MPV (r = −0.351). Extent of disease was positively correlated with CRP (r = 0.312) but showed no correlation with PLTs and MPV. FIB and D-dimer were higher in patients with UC, but the difference in FIB levels was not statistically significant.

Conclusions

PLTs and MPV are potential biomarkers for UC disease activity. These data may help clinicians to attain a more comprehensive judgment of the general condition of patients with UC.

Association of a Serum Protein Signature With Rheumatoid Arthritis Development

OBJECTIVE

The pathophysiologic events that precede the onset of rheumatoid arthritis (RA) remain incompletely understood. This study was undertaken to identify changes in the serum proteome that precede the onset of RA, with the aim of providing new insights into the pathogenic mechanisms that lead to its development.

METHODS

In a cohort of first-degree relatives of Indigenous North American RA patients, the SomaScan proteomics platform was used to determine the levels of 1,307 proteins in multiple longitudinal serum samples from 17 individuals who were followed up prospectively to the time of disease onset. Proteomic signatures from this group of individuals (designated the progressor group) were compared to those in a group of individuals who were considered at risk of developing RA, stratified as either positive (n = 63) or negative (n = 47) for anti-citrullinated protein antibodies (ACPAs) (designated the at-risk group). Machine learning was used to identify a protein signature that could accurately classify those individuals at highest risk of future RA development.

RESULTS

A preclinical proteomic signature that differentiated RA progressors from at-risk individuals, irrespective of ACPA status, was identified (area under the curve 0.913, accuracy 91.2%). Importantly, the predictive preclinical proteomic signature was present not only in serum samples obtained close to the onset of RA, but also in serum samples obtained a median of 30.9 months prior to onset. Network analysis implicated the activation of Toll-like receptor 2 and production of tumor necrosis factor and interleukin-1 as key events that precede RA progression.

CONCLUSION

Alterations in the serum proteome in the preclinical phase of RA can emerge years prior to the onset of disease. Our findings suggest that the serum proteome provides a rich source of proteins serving both to classify at-risk individuals and to identify molecular pathways involved in the development of clinically detectable RA.

Targeting AnxA1/Formyl Peptide Receptor 2 Pathway Affords Protection against Pathological Thrombo-Inflammation

Stroke is a leading cause of death and disability globally and is associated with a number of co-morbidities including sepsis and sickle cell disease (SCD). Despite thrombo-inflammation underlying these co-morbidities, its pathogenesis remains complicated and drug discovery programs aimed at reducing and resolving the detrimental effects remain a major therapeutic challenge. The objective of this study was to assess whether the anti-inflammatory pro-resolving protein Annexin A1 (AnxA1) was able to reduce inflammation-induced thrombosis and suppress platelet activation and thrombus formation in the cerebral microvasculature. Using two distinct models of pathological thrombo-inflammation (lipopolysaccharide (LPS) and sickle transgenic mice (STM)), thrombosis was induced in the murine brain using photoactivation (light/dye) coupled with intravital microscopy. The heightened inflammation-induced microvascular thrombosis present in these two distinct thrombo-inflammatory models was inhibited significantly by the administration of AnxA1 mimetic peptide AnxA1_Ac2-26 (an effect more pronounced in the SCD model vs. the endotoxin model) and mediated by the key resolution receptor, Fpr2/ALX. Furthermore, AnxA1_Ac2-26 treatment was able to hamper platelet aggregation by reducing platelet stimulation and aggregation (by moderating α_IIbβ₃ and P-selectin). These findings suggest that targeting the AnxA1/Fpr2/ALX pathway represents an attractive novel treatment strategy for resolving thrombo-inflammation, counteracting e.g., stroke in high-risk patient cohorts.

Evaluation of platelet count, erythrocyte sedimentation rate and C-reactive protein levels in paediatric patients with inflammatory and infectious disease

Inflammatory and infectious diseases are the major causes of morbidity and mortality. The identification of markers for the assessment of disease activity and response to treatment can improve long-term prognosis. The aim of this study was to evaluate platelet count, C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) among children with inflammatory and infectious disease. This cross-sectional study was conducted in the paediatric immunology and infectious units of Shahid Madani Hospital of Khorramabad. One hundred fifty children, half boys and half girls, with diagnoses of infectious and inflammatory diseases were included in the study. Platelet count, ESR and CRP were measured at the time of hospitalization and thereafter (recovery phase). A questionnaire including demographic information, diagnosis and paraclinical data was completed. At the time of hospitalization, all 150 children had abnormal ESR, 110 (73.3%) had abnormal CRP and 12 (92%) had alterations in platelet count. At the time of discharge, one patient (0.7%) had normal ESR, 132 (88%) had normal CRP and 140 patients (93.3%) had normal platelet count. At the time of discharge, we found a significant difference between the levels of CRP and platelets in girls. This study showed that CRP level is useful during treatment follow-up. Changes in platelet count are likely to be more prevalent in girls.

Diagnostic utility of the neutrophil-platelet ratio as a novel marker of activity in patients with Ulcerative Colitis

Background

Ulcerative colitis (UC) is a chronic disease characterized by periods of activity and remission. The platelet, one of the main activators of neutrophils, contains Interleukin 8 (IL-8), a potent neutrophil chemo-attractant and P-selectin that induces excretion of superoxide in the neutrophils, forming platelet-neutrophil aggregates that are increased in individuals with active UC, hence an index of both cells could produce a monitoring tool. No previous studies have evaluated this ratio in UC.

Goal

To evaluate the clinical utility of the Neutrophil-Platelet (NeuPla) ratio in patients with UC.

Study

A total of 158 patients with a diagnosis of UC. This index was based on the ratio between platelets and the neutrophil differential in blood count. The activity was classified using Mayo endoscopic sub-score, histological (Riley score) and for clinical was used the Truelove-Witts, Montreal, Mayo and Yamamoto-Furusho scores.

Results

The correlation of the NeuPla ratio with activity scales were significant (P <0.05). An optimal cut-off point to classify patients with clinical activity was 14.94 with a sensitivity 87.95% and specificity 63.5 and endoscopy activity with a cut-off 14.64 with a sensibility of 70.5% and specificity of 61.8%.

Conclusions

The NeuPla ratio showed an adequate diagnostic utility to identify UC patients with clinical and endoscopy activity without the use of invasive studies like a colonoscopy or expensive fecal biomarkers such as calprotectin and have a better diagnostic performance in comparison to other serum biomarkers (C reactive protein, erythrocyte sedimentation rate and albumin).

Whole-Genome DNA Methylation Profiling of CD14+ Monocytes Reveals Disease Status and Activity Differences in Crohn's Disease Patients

Crohn's disease (CD) is a multifactorial incurable chronic disorder. Current medical treatment seeks to induce and maintain a state of remission. During episodes of inflammation, monocytes infiltrate the inflamed mucosa whereupon they differentiate into macrophages with a pro-inflammatory phenotype. Here, we sought to characterize the circulating monocytes by profiling their DNA methylome and relate it to the level of CD activity. We gathered an all-female age-matched cohort of 16 CD patients and 7 non-CD volunteers. CD patients were further subdivided into 8 CD patients with active disease (CD-active) and 8 CD patients in remission (CD-remissive) as determined by the physician global assessment. We identified 15 and 12 differentially methylated genes (DMGs) when comparing CD with non-CD and CD-active with CD-remissive, respectively. Differential methylation was predominantly found in the promoter regions of inflammatory genes. Comparing our observations with gene expression data on classical (CD14++CD16-), non-classical (CD14+CD16++) and intermediate (CD14++CD16+) monocytes indicated that while 7 DMGs were differentially expressed across the 3 subsets, the remaining DMGs could not immediately be associated with differences in known populations. We conclude that CD activity is associated with differences in DNA methylation at the promoter region of inflammation-associated genes.

Neutrophil Extracellular Traps Induce Intestinal Damage and Thrombotic Tendency in Inflammatory Bowel Disease

BACKGROUND AND AIMS

Despite the presence of neutrophil extracellular traps [NETs] in inflamed colon having been confirmed, the role of NETs, especially the circulating NETs, in the progression and thrombotic tendency of inflammatory bowel disease [IBD] remains elusive. We extended our previous study to prove that NETs constitute a central component in the progression and prothrombotic state of IBD.

METHODS

In all 48 consecutive patients with IBD were studied. Acute colitis was induced by the treatment of C57BL/6 mice with 3.5% dextran sulphate sodium [DSS] in drinking water for 6 days. Peripheral blood neutrophils and sera were collected from IBD patients and murine colitis models. Exposed phosphatidylserine [PS] was analysed with flow cytometry and confocal microscopy. Procoagulant activity was evaluated using clotting time, purified coagulation complex, and fibrin formation assays.

RESULTS

We observed higher plasma NET levels and presence of NETs in colon tissue in patients with active IBD. More importantly, NETs were induced in mice with DSS colitis, and inhibition of NET release attenuated colitis as well as colitis-associated tumorigenesis. NET degradation through DNase administration decreased cytokine levels during DSS-induced colitis. In addition, DNase treatment also significantly attenuated the accelerated thrombus formation and platelet activation observed in DSS-induced colitis. NETs triggered PS-positive microparticle release and PS exposure on platelets and endothelial cells partially through TLR2 and TLR4, converting them to a procoagulant phenotype.

CONCLUSIONS

NETs exacerbate colon tissue damage and drive thrombotic tendency during active IBD. Strategies directed against NET formation may offer a potential therapeutic approach for the treatment of IBD.

Alterations in platelet indices link polycyclic aromatic hydrocarbons toxicity to low-grade inflammation in preschool children

BACKGROUND

Environmental exposure to carcinogenic polycyclic aromatic hydrocarbons (PAHs) can disturb the immune response. However, the effect of PAHs on low-grade inflammation related to platelets in humans is unknown.

OBJECTIVES

We investigated the association of PAH exposure with low-grade inflammation and platelet parameters in healthy preschoolers.

METHODS

The present study recruited 239 participants, aged 2-7 years, from an electronic-waste (e-waste)-exposed (n = 118) and a reference (n = 121) area. We measured ten urinary PAH metabolites, four types of immune cells and cytokines, and seven platelet parameters, and compared their differences between children from the two groups. Spearman correlation analysis was performed to explore the potential risk factors for PAH exposure and the associations between urinary monohydroxylated PAHs (OH-PAHs) and biological parameters. Associations between urinary PAH metabolites and platelet indices were analyzed using quantile regression models. Mediation analysis was used to understand the relationship between urinary total hydroxynaphthalene (ΣOHNa) and interleukin (IL)-1β through seven platelet indices, as mediator variables.

RESULTS

We found higher urinary monohydroxylated PAH (OH-PAH) concentrations, especially 1-hydroxynaphthalene (1-OHNa) and 2-hydroxynaphthalene (2-OHNa), in children from the e-waste-exposed group than in the reference group. These were closely associated with child personal habits and family environment. A decreased lymphocyte ratio and increased pro-inflammatory cytokines, such as gamma interferon-inducible protein (IP)-10 and IL-1β, were found in the e-waste-exposed children. After adjustment for confounding factors, significantly negative correlations were found between levels of mean platelet volume (MPV), platelet distribution width (PDW), platelet-large cell ratio (P-LCR) and ratio of mean platelet volume to platelet count (MPVP) and OH-PAHs. In addition, ΣOHNa was positively associated with IL-1β mediated through MPV, PDW, P-LCR, and ratio of platelet count to lymphocyte count (PLR).

CONCLUSIONS

Platelet indices were significantly associated with the changes in urinary OH-PAH levels, which may can be regarded as effective biomarkers of low-grade inflammation resulting from low PAH exposure in healthy children.

Platelet-Specific Deletion of Cyclooxygenase-1 Ameliorates Dextran Sulfate Sodium-Induced Colitis in Mice

Inflammatory bowel disease (IBD) is associated with an increased risk for thromboembolism, platelet activation, and abnormalities in platelet number and size. In colitis, platelets can extravasate into the colonic interstitium. We generated a mouse with a specific deletion of cyclooxygenase (COX)-1 in megakaryocytes/platelets [(COX-1 conditional knockout (cKO)] to clarify the role of platelet activation in the development of inflammation and fibrosis in dextran sodium sulfate (DSS)-induced colitis. The disease activity index was assessed, and colonic specimens were evaluated for histologic features of epithelial barrier damage, inflammation, and fibrosis. Cocultures of platelets and myofibroblasts were performed. We found that the specific deletion of COX-1 in platelets, which recapitulated the human pharmacodynamics of low-dose aspirin, that is, suppression of platelet thromboxane (TX)A2 production associated with substantial sparing of the systemic production of prostacyclin, resulted in milder symptoms of colitis, in the acute phase, and almost complete recovery from the disease after DSS withdrawal. Reduced colonic accumulation of macrophages and myofibroblasts and collagen deposition was found. Platelet-derived TXA2 enhanced the ability of myofibroblasts to proliferate and migrate in vitro, and these effects were prevented by platelet COX-1 inhibition or antagonism of the TXA2 receptor. Our findings allow a significant advance in the knowledge of the role of platelet-derived TXA2 in the development of colitis and fibrosis in response to intestinal damage and provide the rationale to investigate the potential efficacy of the antiplatelet agent low-dose aspirin in limiting the inflammatory response and fibrosis associated with IBD. SIGNIFICANCE STATEMENT: Inflammatory bowel disease (IBD) is characterized by the development of a chronic inflammatory response, which can lead to intestinal fibrosis for which currently there is no medical treatment. Through the generation of a mouse with specific deletion of cyclooxygenase-1 in megakaryocytes/platelets, which recapitulates the human pharmacodynamics of low-dose aspirin, we demonstrate the important role of platelet-derived thromboxane A2 in the development of experimental colitis and fibrosis, thus providing the rationale to investigate the potential efficacy of low-dose aspirin in limiting the inflammation and tissue damage associated with IBD.

Platelet hyaluronidase-2 regulates the early stages of inflammatory disease in colitis

Platelets are specialized cells essential for hemostasis that also function as crucial effectors capable of mediating inflammatory and immune responses. These sentinels continually survey their environment and discriminate between homeostatic and danger signals such as modified components of the extracellular matrix. The glycosaminoglycan hyaluronan (HA) is a major extracellular matrix component that coats the vascular lumen and, under normal conditions, restricts access of inflammatory cells. In response to tissue damage, the endothelial HA matrix enhances leukocyte recruitment and regulates the early stages of the inflammatory response. We have shown that platelets can degrade HA from the surface of activated endothelial cells via the enzyme hyaluronidase-2 (HYAL2) and that HYAL2 is deficient in platelets isolated from patients with inflammatory bowel disease (IBD). Platelets are known to be involved in the pathogenesis of several chronic disease states, including IBD, but they have been largely overlooked in the context of intestinal inflammation. We therefore wanted to define the mechanism by which platelet HYAL2 regulates the inflammatory response during colitis. In this study, we provide evidence that HA catabolism is disrupted in human intestinal microvascular endothelial cells isolated from patients with IBD. Furthermore, mice deficient in HYAL2 are more susceptible to an acute model of colitis, and this increased susceptibility is abrogated by transfusion of HYAL2-competent platelets. Finally, we show that platelets, via HYAL2-dependent degradation of endothelial HA, regulate the early stages of inflammation in colitis by limiting leukocyte extravasation.

Novel Role for the AnxA1-Fpr2/ALX Signaling Axis as a Key Regulator of Platelet Function to Promote Resolution of Inflammation

Supplemental Digital Content is available in the text.

Background:

Ischemia reperfusion injury (I/RI) is a common complication of cardiovascular diseases. Resolution of detrimental I/RI-generated prothrombotic and proinflammatory responses is essential to restore homeostasis. Platelets play a crucial part in the integration of thrombosis and inflammation. Their role as participants in the resolution of thromboinflammation is underappreciated; therefore we used pharmacological and genetic approaches, coupled with murine and clinical samples, to uncover key concepts underlying this role.

Methods:

Middle cerebral artery occlusion with reperfusion was performed in wild-type or annexin A1 (AnxA1) knockout (AnxA1^−/−) mice. Fluorescence intravital microscopy was used to visualize cellular trafficking and to monitor light/dye–induced thrombosis. The mice were treated with vehicle, AnxA1 (3.3 mg/kg), WRW4 (1.8 mg/kg), or all 3, and the effect of AnxA1 was determined in vivo and in vitro.

Results:

Intravital microscopy revealed heightened platelet adherence and aggregate formation post I/RI, which were further exacerbated in AnxA1^−/− mice. AnxA1 administration regulated platelet function directly (eg, via reducing thromboxane B₂ and modulating phosphatidylserine expression) to promote cerebral protection post-I/RI and act as an effective preventative strategy for stroke by reducing platelet activation, aggregate formation, and cerebral thrombosis, a prerequisite for ischemic stroke. To translate these findings into a clinical setting, we show that AnxA1 plasma levels are reduced in human and murine stroke and that AnxA1 is able to act on human platelets, suppressing classic thrombin-induced inside-out signaling events (eg, Akt activation, intracellular calcium release, and Ras-associated protein 1 [Rap1] expression) to decrease α_IIbβ₃ activation without altering its surface expression. AnxA1 also selectively modifies cell surface determinants (eg, phosphatidylserine) to promote platelet phagocytosis by neutrophils, thereby driving active resolution. (n=5–13 mice/group or 7–10 humans/group.)

Conclusions:

AnxA1 affords protection by altering the platelet phenotype in cerebral I/RI from propathogenic to regulatory and reducing the propensity for platelets to aggregate and cause thrombosis by affecting integrin (α_IIbβ₃) activation, a previously unknown phenomenon. Thus, our data reveal a novel multifaceted role for AnxA1 to act both as a therapeutic and a prophylactic drug via its ability to promote endogenous proresolving, antithromboinflammatory circuits in cerebral I/RI. Collectively, these results further advance our knowledge and understanding in the field of platelet and resolution biology.

The isothiocyanate sulforaphane modulates platelet function and protects against cerebral thrombotic dysfunction

BACKGROUND AND PURPOSE

Platelet activation provides a critical link between inflammation and thrombosis. Sulforaphane (SFN), a naturally occurring isothiocyanate, has been shown to display both anti-inflammatory and anti-thrombotic actions in the systemic microvasculature. As inflammation promotes thrombosis and vice versa, in this study we investigated whether SFN is able to reduce inflammatory potentiation of thrombotic events, suppress platelet activation and thrombus formation in the cerebral microvasculature.

EXPERIMENTAL APPROACH

Thrombosis was induced in the murine brain using the light/dye-injury model, in conjunction with LPS treatment, with and without SFN treatment. In vitro and in vivo platelet assays (aggregation, flow and other functional tests) were also employed, using both human and murine platelets.

KEY RESULTS

SFN was found to reduce LPS-mediated enhancement of thrombus formation in the cerebral microcirculation. In tail-bleed experiments, LPS treatment prolonged bleeding time, and SFN treatment was found to protect against this LPS-induced derangement of platelet function. SFN inhibited collagen-mediated platelet aggregation in vitro and in vivo and the associated adhesion and impaired calcium signalling. Furthermore, glycoprotein VI was shown to be involved in the protective effects observed with SFN treatment.

CONCLUSIONS AND IMPLICATIONS

The data presented here provide evidence for the use of SFN in preventing stroke in selected high-risk patient cohorts.

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.

Platelets contribute to the initiation of colitis-associated cancer by promoting immunosuppression

Essentials Inflammation plays a key role in the development of colorectal cancer. Understanding mechanisms of cancer initiation might reveal new anticancer preventive strategy. Hyperactive platelets promote tumor formation by fostering immune evasion of cancer. Platelet inhibition by clopidogrel prevents carcinogenesis by restoring antitumor immunity.

SUMMARY

Background Clinical and experimental evidence support a role for inflammation in the development of colorectal cancer, although the mechanisms are not fully understood. Beyond thrombosis and hemostasis, platelets are key actors in inflammation; they have also been shown to be involved in cancer. However, whether platelets participate in the link between inflammation and cancer is unknown. Objective To investigate the contribution of platelets and platelet-derived proteins to inflammation-elicited colorectal tumor development. Methods We used a clinically relevant mouse model of colitis-associated cancer. Platelet secretion and platelet reactivity to thrombin were assessed at each stage of carcinogenesis. We conducted an unbiased proteomic analysis of releasates of platelets isolated at the pretumoral stage to identify soluble factors that might act on tumor development. Plasma levels of the identified proteins were measured during the course of carcinogenesis. We then treated the mice with clopidogrel to efficiently inhibit platelet release reaction. Results At the pretumoral stage, hyperactive platelets constituted a major source of circulating protumoral serum amyloid A (SAA) proteins. Clopidogrel prevented the early elevation of the plasma SAA protein level, decreased colitis severity, and delayed the formation of dysplastic lesions and adenocarcinoma. Platelet inhibition hindered the expansion and function of immunosuppressive myeloid cells, as well as their infiltration into tumors, but increased the number of tissue CD8+ T cells. Platelets and releasates of platelets from mice with cancer were both able to polarize myeloid cells towards an immunosuppressive phenotype. Conclusions Thus, platelets promote the initiation of colitis-associated cancer by enhancing myeloid cell-dependent immunosuppression. Antiplatelet agents may help to prevent inflammation-elicited carcinogenesis by restoring antitumor immunity.

A presentation of ulcerative colitis after rituximab therapy in a patient with multiple sclerosis and literature review

Multiple sclerosis (MS) is one of the most important demyelinating diseases that affects the central nervous system. Its treatment often involves a long-term disease modifying therapy. According to some studies, the prevalence of autoimmune disorders, such as autoimmune hepatitis (AIH) and ulcerative colitis (UC) is higher in MS patients than in the normal population. There are also few studies that have reported the onset of UC after rituximab therapy. The present study presents a report of a 31-years old female patient suffering from aggressive multiple sclerosis, which developed into autoimmune hepatitis during the MS therapy. Thereafter, she received rituximab for the treating both MS and AIH. One week after the third cycle of rituximab (6 doses of 1000 mg), she experienced abdominal pain, fever, and severe bloody diarrhea; finally, she was diagnosed with ulcerative colitis (UC). It seems that the administration of certain immunomodulators or immunosuppressive drugs may have a main role in the exacerbation of some autoimmune diseases.

Deviation of the Fecal Stream in Colonic Bowel Segments Results in Increased Numbers of Isolated Lymphoid Follicles in the Submucosal Compartment in a Novel Murine Model of Diversion Colitis

INTRODUCTION

Diversion colitis is a significant health problem due to its high incidence in patients with diverting enterostomy. This mucosal inflammation presents characteristic histopathological features allowing for the differentiation of this entity from other inflammatory bowel diseases. The pathophysiology of this disease remains ill-defined, in part due to the lack of appropriate animal models. The present study was performed in order to develop and characterize a murine model of diversion colitis.

METHODS

A diverting loop colostomy was performed in C57BL/6 mice either in the ascending colon or in the transverse colon. Animals were assessed for clinical and histopathological parameters during short-term and long-term survival.

RESULTS

Animals with a colostomy in the transverse colon showed a good long-term survival and developed a mild colitis in the bypassed bowel closely resembling the human pathology on a histopathological level.

CONCLUSION

This model is a promising tool to further elucidate the pathomechanism leading to impaired mucosal homeostasis in bypassed colonic segments. Moreover, the establishment of the model in the C57BL/6 background allows the combination of this colitis model with various transgenic mouse strains to investigate the effect of locally deregulated mucosal immunity on systemic immune homeostasis and to develop specific therapeutic strategies.

ADAMTS13 Deficiency Worsens Colitis and Exogenous ADAMTS13 Administration Decreases Colitis Severity in Mice

Background  Inflammatory bowel disease (IBD) affects 1.6 million people in the United States. IBD is associated with an increased risk of thrombosis, which rises with disease activity. The pathogenesis of IBD and its increased thrombotic risk is not completely understood. Ultra large von Willebrand factor (ULVWF) multimers are secreted from activated endothelium, leading to recruitment of platelets and leukocytes. A disintegrin and metalloproteinase with thrombospondin type I repeats motif 13 (ADAMTS13) cleaves highly adhesive ULVWF into smaller, less bioactive, multimers, releasing them into circulation. Mice deficient in ADAMTS13 (ADAMTS13 ^−/− ) have heightened inflammatory and thrombotic responses.

Objectives  We hypothesized that upon colitis induction, ADAMTS13 ^−/− mice would have more severe symptoms compared with wild-type (WT) mice, and rhADAMTS13 administration to mice with colitis would improve their condition.

Results  Dextran sodium sulfate–induced colitis was worse in ADAMTS13 ^−/− mice than WT. ADAMTS13 ^−/− showed increased weight loss, worse anemia, and increased clinical and histologic colitis severity, compared with WT mice. ADAMTS13 ^−/− mice had increased VWF release, with accumulation at inflamed colonic sites. Also, the majority of mice showed one or more submucosal colonic thrombi. ADAMTS13 deficiency worsened colitis and propagated intestinal inflammation, most likely through increased platelet–leukocyte recruitment by VWF. Treatment of WT mice with rhADAMTS13 decreased colitis severity without worsening anemia. Additionally, several immune-mediated chronic murine colitis models, and inflamed colon tissue specimens from IBD patients, showed increased VWF release at inflamed sites, suggesting a generalizability of our findings.

Conclusion  Measuring VWF/ADAMTS13 levels could have clinical utility. When applicable, the administration of ADAMTS13, in addition to primary treatment, may improve outcomes for IBD patients.

Serum platelet factor 4 is a reliable activity parameter in adult patients with inflammatory bowel disease: A pilot study

To investigate the diagnostic utility of serum platelet factor 4 (PF4) levels and to assess its accuracy in detecting inflammatory bowel disease activity.This study included 45 patients with ulcerative colitis (UC), 45 patients with Crohn disease (CD), and 30 control subjects at Jinling Hospital between May 2014 and July 2015. Laboratory tests measured white blood count, C-reactive protein, erythrocyte sedimentation rate, and platelet count. PF4 was examined by enzyme-linked immunosorbent assays. Patients were divided into 2 groups according to disease activity: active and inactive.Median PF4 values dramatically increased in UC and CD patients compared with the healthy group (UC: 26.64 [20.00-36.22] mg/mL vs 20.02 [14.63-26.83] mg/mL, P = 0.002; CD: 25.56 [18.57-36.36] mg/mL vs 20.02 [14.63-26.83] mg/mL, P = 0.014); however, the serum PF4 levels between UC and CD failed to show a significant difference (26.64 [20.00-36.22] mg/mL vs 25.56 [18.57-36.36] mg/mL, P = 0.521). Furthermore, serum PF4 levels were elevated in both UC and CD patients with active disease (UC: 20.19 [14.89-23.53] mg/mL vs 28.86 [22.57-37.29] mg/mL, P < 0.001; CD: 18.33 [16.72-25.77] mg/mL vs 34.38 [22.58-39.92] mg/mL, P < 0.001). Multivariate analysis revealed higher PF4 level as an independent predictor of disease activity in UC and CD patients (UC: odds ratio 30.375, P = 0.002; CD: odds ratio 54.167, P < 0.001). The cut-off level of PF4 for distinguishing active from inactive UC patients was 24.1 mg/mL. While in CD patients, the cut-off level of PF4 was 19.24 mg/mL.Serum PF4 levels could be a potential biomarker for monitoring the disease activity of inflammatory bowel disease.

Oxidative stress and thromboxane-dependent platelet activation in inflammatory bowel disease: effects of anti-TNF-α treatment

Patients with inflammatory bowel disease (IBD) are at higher risk of venous thromboembolism and coronary artery disease despite having a lower burden of traditional risk factors. Platelets from IBD patients release more soluble CD40 ligand (CD40L), and this has been implicated in IBD platelet hyper-activation. We here measured the urinary F2-isoprostane 8-iso-prostaglandin (PG)2α (8-iso-PGF2α), urinary 11-dehydro-thromboxane (TX) B2 (11-dehydro-TXB2) and plasma CD40L in IBD patients, and explored the in vitro action of anti-tumour necrosis factor (TNF)-α antibody infliximab on IBD differentiating megakaryocytes. Urinary and blood samples were collected from 124 IBD patients and 37 healthy subjects. Thirteen IBD patients were also evaluated before and after 6-week infliximab treatment. The in vitro effect of infliximab on patient-derived megakaryocytes was evaluated by immunoflorescence microscopy and by flow cytometry. IBD patients had significantly (p<0.0001) higher urinary 8-iso-PGF2α and 11-dehydro-TXB2 as well as plasma CD40L levels than controls, with active IBD patients displaying higher urinary and plasma values when compared to inactive patients in remission. A 6-week treatment with infliximab was associated with a significant reduction of the urinary excretion of 8-iso-PGF2α and 11-dehydro-TXB2 (p=0.008) and plasma CD40L (p=0.001). Infliximab induced significantly rescued pro-platelet formation by megakaryocytes derived from IBD patients but not from healthy controls. Our findings provide evidence for enhanced in vivo TX-dependent platelet activation and lipid peroxidation in IBD patients. Anti-TNF-α therapy with infliximab down-regulates in vivo isoprostane generation and TX biosynthesis in responder IBD patients. Further studies are needed to clarify the implication of infliximab induced-proplatelet formation from IBD megakaryocytes.

Formyl-Peptide Receptor 2/3/Lipoxin A4 Receptor Regulates Neutrophil-Platelet Aggregation and Attenuates Cerebral Inflammation: Impact for Therapy in Cardiovascular Disease

BACKGROUND

Platelet activation at sites of vascular injury is essential for hemostasis, but it is also a major pathomechanism underlying ischemic injury. Because anti-inflammatory therapies limit thrombosis and antithrombotic therapies reduce vascular inflammation, we tested the therapeutic potential of 2 proresolving endogenous mediators, annexin A1 N-terminal derived peptide (AnxA1Ac2-26) and aspirin-triggered lipoxin A4 (15-epi-lipoxin A4), on the cerebral microcirculation after ischemia/reperfusion injury. Furthermore, we tested whether the lipoxin A4 receptor formyl-peptide receptor 2/3 (Fpr2/3; ortholog to human FPR2/lipoxin A4 receptor) evoked neuroprotective functions after cerebral ischemia/reperfusion injury.

METHODS AND RESULTS

Using intravital microscopy, we found that cerebral ischemia/reperfusion injury was accompanied by neutrophil and platelet activation and neutrophil-platelet aggregate formation within cerebral microvessels. Moreover, aspirin-triggered lipoxin A4 activation of neutrophil Fpr2/3 regulated neutrophil-platelet aggregate formation in the brain and inhibited the reactivity of the cerebral microvasculature. The same results were obtained with AnxA1Ac2-26 administration. Blocking Fpr2/lipoxin A4 receptor with the antagonist Boc2 reversed this effect, and treatments were ineffective in Fpr2/3 knockout mice, which displayed an exacerbated disease severity, evidenced by increased infarct area, blood-brain barrier dysfunction, increased neurological score, and elevated levels of cytokines. Furthermore, aspirin treatment significantly reduced cerebral leukocyte recruitment and increased endogenous levels of aspirin-triggered lipoxin A4, effects again mediated by Fpr2/3.

CONCLUSION

Fpr2/lipoxin A4 receptor is a therapeutic target for initiating endogenous proresolving, anti-inflammatory pathways after cerebral ischemia/reperfusion injury.

IL-6 Mediates the Intestinal Microvascular Thrombosis Associated with Experimental Colitis

Inflammatory bowel diseases are associated with increased risk for thrombus formation both within the inflamed bowel and at distant sites. Although the increased propensity for distant organ thrombus development has been recapitulated in animal models of colitis and linked to interleukin-6 (IL-6), it remains unclear whether experimental colitis results in accelerated thrombus development within the inflamed bowel and whether IL-6 contributes to a local thrombogenic response. These issues related to thrombus formation within the inflamed bowel were addressed in mice with dextran sodium sulfate-induced colitis. Wild-type (WT) mice, IL-6 deficient (IL-6(-/-)) mice, and bone marrow chimeras (WT→WT and IL-6(-/-)→WT) were used. The effects of treatment with either an IL-6-blocking, IL-6Rα-blocking or gp130-blocking antibody were also evaluated. Disease activity index and colonic weight-to-length ratio (W/L) were used to monitor the development of colitis. Intravital videomicroscopy was used to study thrombus development (induced with the light/dye method) in mucosal vessels of the ascending colon. Thrombus development was significantly enhanced in WT colitic mice. Neither genetic deficiency nor immunoblockade of IL-6 significantly altered the disease activity index and W/L responses to dextran sodium sulfate treatment. However, colitis-induced thrombogenesis was attenuated in IL-6(-/-) mice and in WT mice treated with either the IL-6-blocking, IL-6Rα-blocking or gp130-blocking antibody. IL-6(-/-)→WT, but not WT→WT chimeras, exhibited a blunted thrombosis response to dextran sodium sulfate. These results indicate that experimental colitis is associated with accelerated thrombus development within the inflamed colon and that IL-6, derived from bone marrow-derived blood cells, is largely responsible for this response.

Phosphotidylserine exposure and neutrophil extracellular traps enhance procoagulant activity in patients with inflammatory bowel disease

Inflammatory bowel disease (IBD)-associated thromboembolic event often lacks precise aetiology. The aim of this study was to investigate the contribution of phosphatidylserine (PS) exposure and neutrophil extracellular traps (NETs) towards the hypercoagulable state in IBD. We demonstrated that the levels of PS exposed MPs and the sources of MP-origin, platelets, erythrocytes, leukocytes and cultured endothelial cells (ECs) were higher in IBD groups than in healthy controls using flow cytometry and confocal microscopy. Wright-Giemsa and immunofluorescence staining demonstrated that the elevated NETs were released by activated IBD neutrophils or by control neutrophils treated with IBD sera obtained from patients with the active disease. MPs and MP-origin cells in IBD groups, especially in active stage, markedly shortened coagulation time and had increased levels of fibrin, thrombin and FXa production as assessed by coagulation function assays. Importantly, we found that on stimulated ECs, PS rich membranes provided binding sites for FXa and FVa, promoting fibrin formation while TNF blockage or IgG depletion attenuated this effect. Treatment of control neutrophils with TNF and isolated IgG from PR3-ANCA-positive active IBD patients also resulted in the release of NETs. Blockade of PS with lactadherin prolonged coagulation time, decreased fibrin formation to control levels, and inhibited the procoagulant enzymes production in the MPs and MP-origin cells. NET cleavage by DNase I partly decreased PCA in IBD or stimulated neutrophils. Our study reveals a previously unrecognised link between hypercoagulable state and PS exposure or NETs, and may further explain the epidemiological association of thrombosis within IBD patients.

MyD88 mediates the protective effects of probiotics against the arteriolar thrombosis and leukocyte recruitment associated with experimental colitis

Several studies in patients with IBD and in animal models of IBD have revealed a protective effect of probiotics in reducing clinical symptoms of disease and in blunting the gut inflammation that accompanies this condition. However, the mechanism underlying the therapeutic effect of probiotics is currently unknown. Furthermore, the ability of probiotics to influence the enhanced thrombus development that accompanies IBD has not been studied. This study addresses whether the enhanced extraintestinal thrombosis (induced by light/dye injury) associated with experimental colitis is altered by oral treatment with the probiotic preparation VSL#3 or by the absence of microbiota. Colitis was induced by DSS 3% in Swiss Webster mice, germ-free mice, C57BL/6 WT, or Myd88 mice. In some experiments, mice received VSL#3 for 8 days before and during DSS feeding. Swiss Webster mice were also subjected to a chronic model of DSS colitis, and the effect of VSL#3 was evaluated. VSL#3 treatment significantly attenuated the accelerated thrombus formation observed in both acute and chronic models of colitis. VSL#3-treated mice also exhibited attenuated inflammatory response and injury in the colon. The protective effects of VSL#3 on colitis-associated thrombogenesis and inflammation were not evident in MyD88-deficient mice. Our results suggest that improved control of the enteric microflora in IBD may afford protection against the hypercoagulable prothrombotic state that follows this condition.

Are Platelets Cells? And if Yes, are They Immune Cells?

Small fragments circulating in the blood were formally identified by the end of the nineteenth century, and it was suggested that they assisted coagulation via interactions with vessel endothelia. Wright, at the beginning of the twentieth century, identified their bone-marrow origin. For long, platelets have been considered sticky assistants of hemostasis and pollutants of blood or tissue samples; they were just cell fragments. As such, however, they were acknowledged as immunizing (to specific HPA and HLA markers): the platelet’s dark face. The enlightened face showed that besides hemostasis, platelets contained factors involved in healing. As early as 1930s, platelets entered the arsenal of medicines were transfused, and were soon manipulated to become a kind of glue to repair damaged tissues. Some gladly categorized platelets as cells but they were certainly not fully licensed as such for cell physiologists. Actually, platelets possess almost every characteristic of cells, apart from being capable of organizing their genes: they have neither a nucleus nor genes. This view prevailed until it became evident that platelets play a role in homeostasis and interact with cells other than with vascular endothelial cells; then began the era of physiological and also pathological inflammation. Platelets have now entered the field of immunity as inflammatory cells. Does assistance to immune cells itself suffice to license a cell as an “immune cell”? Platelets prove capable of sensing different types of signals and organizing an appropriate response. Many cells can do that. However, platelets can use a complete signalosome (apart from the last transcription step, though it is likely that this step can be circumvented by retrotranscribing RNA messages). The question has also arisen as to whether platelets can present antigen via their abundantly expressed MHC class I molecules. In combination, these properties argue in favor of allowing platelets the title of immune cells.

The impact of primary and persistent cytomegalovirus infection on the progression of acute colitis in a murine model

Cytomegalovirus (CMV) infects 60-100% of the population worldwide. CMV has been implicated in many diseases through the induction of inflammation. Inflammatory bowel disease (IBD) affects over 1 million Americans annually. IBD, in particular ulcerative colitis, has been associated with CMV infection. Here we use a murine model to test if both primary and persistent CMV infections exacerbate colitis. C57Bl/6J mice were injected with Mock inoculum or murine CMV (mCMV) 4d (primary infection) or 6wks (persistent infection) before inducing colitis. Colitis was induced by administering 3% DSS (dextran sodium sulfate) in the drinking water for 6 days. Distilled water was given to controls. Disease activity index (DAI), derived from scores for stool consistency, body weight loss, occult blood, and rectal bleeding, was recorded daily. DAI increased early with DSS treatment in Mocks when compared with water-treated controls. This was accelerated by both primary and persistent mCMV and appeared to be primarily due to the earlier appearance of gross bleeding vs. their Mock controls. Mocks reached similar DAI values by day 6. Myeloperoxidase was modestly elevated in the mCMV 4d-DSS over the Mock 4d-DSS, however there was no such synergism in the 6wk groups. Histology was comparable in Mock and mCMV groups. Taken together our findings show that mCMV accelerated the development of acute colitis although a milder model of colitis may be needed to better delineate the impact of the virus on disease progression. Further work focusing on disruption of barrier function and bleeding may help determine the underlying mechanisms.

Long-term risk of mesenteric ischemia in patients with inflammatory bowel disease: a 13-year nationwide cohort study in an Asian population

BACKGROUND

It is unclear whether patients with inflammatory bowel disease (IBD) have higher risks of developing mesenteric ischemia.

METHODS

We enrolled 9,363 patients who had been hospitalized because of IBD between January 1998 and December 2010, along with 37,452 control patients who were matched at a 1:4 proportion for age, sex, and index year. We accounted the cumulative incidences and hazard ratios (HRs) of developing mesenteric ischemia during the 13-year study period.

RESULTS

Patients with IBD had a considerably higher incidence rate of subsequent mesenteric ischemia compared with the controls (22.7 vs 3.09 per 10,000 person-years), with adjusted HR of 6.33 (95% confidence interval: 4.75 to 8.43). A multivariate stratified analysis showed that the mesenteric ischemia risk after adjustment for comorbidities is significantly higher in patients of all age groups, particularly in patients younger than 44 years (adjusted HR: 48.0; 95% confidence interval: 11.3 to 203.9). Moreover, patients with IBD were at highest risk of developing mesenteric ischemia within the first year of follow-up.

CONCLUSIONS

Careful follow-up and effective therapy are necessary to reduce the excessive risk in these patients.

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.

Thrombosis in inflammatory bowel disease: are we tailoring prophylaxis to those most at risk?

Inflammatory bowel disease (IBD) is a disease-specific risk factor for incident and recurrent venous thromboembolism (VTE). The reasons are acquired, multifactorial, and related to prothrombotic aberrations during active disease, although the mechanisms remain incompletely elucidated. VTE represents a potentially life-threatening extraintestinal manifestation of IBD, but the associated morbidity and mortality can be reduced by appropriate use of thromboprophylaxis. Nevertheless, despite international guidelines advocating thromboprophylaxis in hospitalised patients with IBD, practice is highly variable, since 65% of gastroenterologists may not use pharmacological VTE prophylaxis in hospitalised patients with acute severe colitis. Furthermore, there is no guidance on appropriate prophylaxis for ambulatory outpatients with active disease who are at an appreciable risk of VTE. Thus the question: are we tailoring thromboprophylaxis to those patients with IBD who are most at risk?

Platelet activation and platelet-leukocyte aggregation elicited in experimental colitis are mediated by interleukin-6

There is growing evidence for an interdependence of inflammation, coagulation, and thrombosis in acute and chronic inflammatory diseases. Inflammatory bowel diseases (IBD) are associated with a hypercoagulable state and an increased risk of thromboembolism. Although the IBD-associated prothrombogenic state has been linked to the inflammatory response, the mediators that link these 2 conditions remain unclear. Recent evidence suggests that interleukin-6 (IL-6) may be important in this regard. The objective of this study was to more fully define the contribution of IL-6 to the altered platelet function that occurs during experimental colitis. The number of immature and mature platelets, activated platelets, and platelet-leukocyte aggregates were measured in wild-type and IL-6 mice with dextran sodium sulfate (DSS)-induced colonic inflammation. DSS treatment of WT mice was associated with significant increases in the number of both immature and mature platelets, activated platelets, and platelet-leukocyte aggregates. These platelet responses to DSS were not observed in IL-6 mice. Chronic IL-6 infusion (through an Alzet pump) in WT mice reproduced all of the platelet abnormalities observed in DSS-colitic mice. IL-6-infused mice also exhibited an acceleration of thrombus formation in arterioles, similar to DSS. These findings implicate IL-6 in the platelet activation and enhanced platelet-leukocyte aggregate formation associated with experimental colitis, and support a role for this cytokine as a mediator of the enhanced thrombogenesis in IBD.

Interleukin-6 mediates the platelet abnormalities and thrombogenesis associated with experimental colitis

Clinical studies and animal experimentation have shown that colonic inflammation is associated with an increased number and reactivity of platelets, coagulation abnormalities, and enhanced thrombus formation. The objective of this study was to define the contribution of IL-6 to the thrombocytosis, exaggerated agonist-induced platelet aggregation, and enhanced extra-intestinal thrombosis that occur during experimental colitis. The number of mature and immature platelets, platelet life span, thrombin-induced platelet aggregation response, and light/dye-induced thrombus formation in cremaster muscle arterioles were measured in wild-type (WT) and IL-6-deficient (IL-6(-/-)) mice with dextran sodium sulfate (DSS)-induced colitis. DSS colitis in WT mice was associated with thrombocytosis with an elevated number of both mature and immature platelets and no change in platelet life span. The thrombocytosis response was absent in IL-6(-/-) mice. DSS treatment also enhanced the platelet aggregation response to thrombin and accelerated thrombus development in WT mice, but not in IL-6(-/-) mice. Exogenous IL-6 administered to WT mice elicited a dose-dependent enhancement of thrombus formation. These findings indicate that IL-6 mediates the thrombocytosis, platelet hyperreactivity, and accelerated thrombus development associated with experimental colitis. The IL-6-dependent colitis-induced thrombocytosis appears to result from an enhancement of thrombopoiesis because platelet life span is unchanged.