Resistance to activated protein C and low levels of free protein S in Greek patients with inflammatory bowel disease

Venous Thromboembolism Among Patients With Inflammatory Bowel Diseases is Not Related to Increased Thrombophilia: A Case-Control Study

GOAL

The aim was to assess whether thrombophilia significantly contributes to the risk of venous thromboembolic events (VTEs) in patients with inflammatory bowel disease (IBD).

BACKGROUND

Patients with IBD have a high risk of VTE. The underlying mechanism has been only partially defined.

METHODS

A case-control study in adults with IBD and an episode of VTE (IBD-VTE) were matched and compared with non-IBD patients with a VTE (non-IBD-VTE). The study population was comprised of patients seen in 2 tertiary medical centers in Israel between 2000 and 2013. Characteristics of IBD and risk factors for VTE were retrieved from medical charts, and a comprehensive thrombophilia panel was completed in all patients.

RESULTS

Forty-four IBD-VTE cases (27 Crohn's disease) were matched with 127 non-IBD-VTE controls. The majority of VTE had a clear etiology and were considered provoked events. Provoked and unprovoked VTE rates were not different between the 2 groups. Likewise, thrombophilia rates were similar among patients with IBD-VTE and controls (40.9% vs. 53.5%, respectively, P=0.14). However, among patients with unprovoked VTE, thrombophilia rates were significantly lower in the IBD-VTE group compared with controls (42.1% vs. 70.7%, respectively, P=0.03). Among patients with IBD-VTE, an unprovoked event, and negative thrombophilia, 77% had active inflammation at the time of VTE.

CONCLUSION

Thrombophilia rates are similar among patients with IBD-VTE and controls but are less common among patients with unprovoked IBD-VTE. This finding suggests that either inflammation or other novel pathways drive VTE in patients with IBD.

International consensus on the prevention of venous and arterial thrombotic events in patients with inflammatory bowel disease

Patients with inflammatory bowel disease (IBD) are at increased risk of thrombotic events. Therapies for IBD have the potential to modulate this risk. The aims of this Evidence-Based Guideline were to summarize available evidence and to provide practical recommendations regarding epidemiological aspects, prevention and drug-related risks of venous and arterial thrombotic events in patients with IBD. A virtual meeting took place in May 2020 involving 14 international IBD experts and 3 thrombosis experts from 12 countries. Proposed statements were voted upon in an anonymous manner. Agreement was defined as at least 75% of participants voting as 'fully agree' or 'mostly agree' with each statement. For each statement, the level of evidence was graded according to the Scottish Intercollegiate Guidelines Network (SIGN) grading system. Consensus was reached for 19 statements. Patients with IBD harbour an increased risk of venous and arterial thrombotic events. Thromboprophylaxis is indicated during hospitalization of any cause in patients with IBD. Disease activity is a modifiable risk factor in patients with IBD, and physicians should aim to achieve deep remission to reduce the risk. Exposure to steroids should be limited. Antitumour necrosis factor agents might be associated with a reduced risk of thrombotic events.

Epidemiology and Risk Factors of Portal Venous System Thrombosis in Patients With Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Patients with inflammatory bowel disease (IBD) may be at risk of developing portal venous system thrombosis (PVST) with worse outcomes. This study aims to explore the prevalence, incidence, and risk factors of PVST among patients with IBD.

METHODS

PubMed, Embase, and Cochrane Library databases were searched. All the eligible studies were divided according to the history of colorectal surgery. Only the prevalence of PVST in patients with IBD was pooled if the history of colorectal surgery was unclear. The incidence of PVST in patients with IBD after colorectal surgery was pooled if the history of colorectal surgery was clear. Prevalence, incidence, and risk factors of PVST were pooled by only a random-effects model. Subgroup analyses were performed in patients undergoing imaging examinations. Odds ratios (ORs) with 95% CIs were calculated.

RESULTS

A total of 36 studies with 143,659 patients with IBD were included. Among the studies where the history of colorectal surgery was unclear, the prevalence of PVST was 0.99, 1.45, and 0.40% in ulcerative colitis (UC), Crohn's disease (CD), and unclassified IBD, respectively. Among the studies where all the patients underwent colorectal surgery, the incidence of PVST was 6.95, 2.55, and 3.95% in UC, CD, and unclassified IBD after colorectal surgery, respectively. Both the prevalence and incidence of PVST became higher in patients with IBD undergoing imaging examinations. Preoperative corticosteroids therapy (OR = 3.112, 95% CI: 1.017-9.525; p = 0.047) and urgent surgery (OR = 1.799, 95% CI: 1.079-2.998; p = 0.024) are significant risk factors of PVST in patients with IBD after colorectal surgery. The mortality of patients with IBD with PVST after colorectal surgery was 4.31% (34/789).

CONCLUSION

PVST is not rare, but potentially lethal in patients with IBD after colorectal surgery. More severe IBD, indicated by preoperative corticosteroids and urgent surgery, is associated with a higher risk of PVST after colorectal surgery. Therefore, screening for PVST by imaging examinations and antithrombotic prophylaxis in high-risk patients should be actively considered.

SYSTEMATIC REVIEW REGISTRATION

Registered on PROSPERO, Identifier: CRD42020159579.

Thromboelastography in Patients with Inflammatory Bowel Disease

Purpose

Patients with inflammatory bowel disease (IBD) frequently suffer from venous thromboembolic events, and the risk of thromboembolism increases along with disease activity. This study was conducted to discover novel thrombophilic markers using thromboelastography (TEG) and to evaluate the relation between the predisposing factors and the activity of disease in Chinese patients with Crohn's disease (CD) and ulcerative colitis (UC).

Methods

Thirty-four patients with CD, 29 patients with UC, and 53 healthy volunteers were enrolled into this study. Blood levels of R, K, α Angle, G, maximal amplitude (MA), and LY30 with TEG were determined.

Results

Mean values of R, K, α Angle, G, and MA were significantly different in patients with CD and UC compared with the healthy individuals. Patients with active CD had different K, α Angle, G, and MA levels compared with patients in remission (P < 0.05, P < 0.001, P < 0.001, and P < 0.001). Levels of R, α Angle, G, and MA were also significantly different in active UC patients compared with those in remission (P < 0.01, P < 0.001, P < 0.001, and P < 0.001). Except for the G level in the CD group, differences in all TEG levels between healthy individuals and IBD patients in remission were not statistically significant. No statistical differences were observed in LY30 among patients with active phase, patients in remission, and the healthy individuals.

Conclusion

Thrombophilic defects are common in Chinese patients with IBD, and TEG can be considered a new direction to anticoagulant thromboprophylaxis in IBD.

Coagulopathies and inflammatory diseases: '…glimpse of a Snark'

Coagulopathies and inflammatory diseases, ostensibly, have distinct underlying molecular bases. Notwithstanding, both are host defense mechanisms to physical injury. In invertebrates, clotting can function directly in anti-pathogen defense. Molecules of the vertebrate clotting cascade have also been directly linked to the regulation of inflammation. We posit that thrombophilia may provide resistance against pathogens in vertebrates. The selective pressure of improved anti-pathogen defense may have retained mutations associated with a thrombophilic state in the human population and directly contributed to enhanced inflammation. Indeed, in some inflammatory diseases, at least a subset of patients can be identified as hypercoagulable. Therefore, anticoagulants such as warfarin or apixaban may have a therapeutic role in some inflammatory diseases.

Association between Genetic Variations of MERTK and Chronic Obstructive Pulmonary Disease in Koreans

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a debilitating lung disease. To date, a large number of clinical studies have been conducted to investigate the association between genetic variations and COPD. However, little is known regarding the genetic susceptibility of Koreans to this disease. MER receptor tyrosine kinase (MERTK) plays important roles in the inhibition of inflammation and in the clearance of apoptotic cells. Here, we investigated the association between genetic variations in MERTK and the development of COPD in Koreans.

METHODS

We conducted genetic analysis of MERTK using genomic DNA samples from 87 patients with COPD and 88 healthy controls and compared the frequency of each variation or haplotype between the patient and control groups. Subsequently, the effect of each variation was evaluated using in vitro assays.

RESULTS

Ten variations were identified in this study, four of them for the first time. In addition, we found that the frequency of each variation or haplotype was comparable between the patient and control groups. However, we observed that the frequency for the wild-type haplotype was higher in the control group, compared to that in the group of patients with COPD, in the subgroup analysis of current smokers, although the difference was not statistically significant (P = 0.080). In in vitro assays, we observed that none of the variations affected the activity of the promoter or the expression of MERTK.

CONCLUSION

Our findings indicate that the susceptibility to COPD is not related to the genetic variations or haplotypes of MERTK in Koreans.

TAM receptor tyrosine kinase function and the immunopathology of liver disease

Tyro3, Axl, MERTK (TAM) receptor tyrosine kinases are implicated in the regulation of the innate immune response through clearance of apoptotic cellular debris and control of cytokine signaling cascades. As a result they are pivotal in regulating the inflammatory response to tissue injury. Within the liver, immune regulatory signaling is employed to prevent the overactivation of innate immunity in response to continual antigenic challenge from the gastrointestinal tract. In this review we appraise current understanding of the role of TAM receptor function in the regulation of both innate and adaptive immunity, with a focus on its impact upon hepatic inflammatory pathology.

Analysis of receptor tyrosine kinase genetics identifies two novel risk loci in GAS6 and PROS1 in Behçet's disease

The TAM kinase (Tyro3, Axl, Mer) and its two ligands (Gas6 and protein S) have been shown to play an important regulatory role in the innate immune response. The present study aimed to investigate whether the tag single-nucleotide polymorphisms (tag SNPs) of these 5 protein-coding genes are associated with Behçet’s disease (BD). A two-stage association study was performed in a total of 907 BD patients and 1780 healthy controls. Altogether 32 polymorphisms were tested, using a Sequenom MassARRAY genotyping method in the first stage and a PCR-restriction fragment length polymorphism (PCR-RFLP) assay in the replication phase. Real-time PCR was performed to test the relative mRNA expression level of GAS6 and PROS1 from different SNP genotyped healthy individuals. The frequency of the C allele and CC genotype of rs9577873 in GAS6 (P_c = 4.92 × 10⁻⁵, P_c = 1.91 × 10⁻⁵, respectively) and A allele and AA genotype of rs4857037 in PROS1 (P_c = 1.85 × 10⁻⁶, P_c = 4.52 × 10⁻⁷, respectively) were significantly increased in BD. GAS6 expression in CC carriers of rs9577873 was significantly lower than that in CT/TT individuals (P = 0.001). Decreased expression of GAS6 and increased pro-inflammatory cytokines (IL-6 and IFN-γ: P = 4.23 × 10⁻⁴, P = 0.011, respectively) in individuals carrying the CC genotype suggest that the TAM-GAS6/PROS1 signal pathway may be involved in the pathogenesis of BD.

Intestinal transplantation: The anesthesia perspective

Intestinal transplantation is a complex and challenging surgery. It is very effective for treating intestinal failure, especially for those patients who cannot tolerate parenteral nutrition nor have extensive abdominal disease. Chronic parental nutrition can induce intestinal failure associated liver disease (IFALD). According to United Network for Organ Sharing (UNOS) data, children with intestinal failure affected by liver disease secondary to parenteral nutrition have the highest mortality on a waiting list when compared with all candidates for solid organ transplantation. Intestinal transplant grafts can be isolated or combined with the liver/duodenum/pancreas. Organ Procurement and Transplantation Network (OPTN) has defined intestinal donor criteria. Living donor intestinal transplant (LDIT) has the advantages of optimal timing, short ischemia time and good human leukocyte antigen matching contributing to lower postoperative complications in the recipient. Thoracic epidurals provide excellent analgesia for the donors, as well as recipients. Recipient management can be challenging. Thrombosis and obstruction of venous access maybe common due to prolonged parenteral nutrition and/or hypercoaguability. Thromboelastography (TEG) is helpful for managing intraoperative product therapy or thrombosis. Large fluid shifts and electrolyte disturbances may occur due to massive blood loss, dehydration, third spacing etc. Intestinal grafts are susceptible to warm and cold ischemia and ischemia-reperfusion injury (IRI). Post-reperfusion syndrome is common. Cardiac or pulmonary clots can be monitored with transesophageal echocardiography (TEE) and treated with recombinant tissue plasminogen activator. Vasopressors maybe used to ensure stable hemodynamics. Post-intestinal transplant patients may need anesthesia for procedures such as biopsies for surveillance of rejection, bronchoscopy, endoscopy, postoperative hemorrhage, anastomotic leaks, thrombosis of grafts etc. Asepsis, drug interactions between anesthetic and immunosuppressive agents and venous access are some of the anesthetic considerations for this group.

TAM receptor signaling in immune homeostasis

The TAM receptor tyrosine kinases (RTKs)-TYRO3, AXL, and MERTK-together with their cognate agonists GAS6 and PROS1 play an essential role in the resolution of inflammation. Deficiencies in TAM signaling have been associated with chronic inflammatory and autoimmune diseases. Three processes regulated by TAM signaling may contribute, either independently or collectively, to immune homeostasis: the negative regulation of the innate immune response, the phagocytosis of apoptotic cells, and the restoration of vascular integrity. Recent studies have also revealed the function of TAMs in infectious diseases and cancer. Here, we review the important milestones in the discovery of these RTKs and their ligands and the studies that underscore the functional importance of this signaling pathway in physiological immune settings and disease.

Tyro3, Axl, and Mertk receptor signaling in inflammatory bowel disease and colitis-associated cancer

Three receptor tyrosine kinases, Tyro3, Axl, and Mertk (TAM) and their ligands Gas6 and Protein S, have emerged as potent negative regulators of innate immune responses. A number of studies using genetic ablation of TAM loci in mice have elucidated the mechanism of TAM engagement and function during the immune response and removal of apoptotic cells. Following phagocytosis of apoptotic cells or the induction of T-cell dependent adaptive immune responses, ligand-induced TAM signaling dampens proinflammatory cytokine production and thus prevents exaggerated or prolonged inflammation. It is believed that the TAM pathway may play an important role in the pathogenesis of inflammatory bowel disease. Suppression of inflammation and removal of apoptotic cells followed by tissue repair are essential processes for disease remission and the successful management of inflammatory bowel disease. In light of the key role of TAMs in controlling inflammatory responses, here, we review the recent advances on TAM research vis-à-vis the resolution of intestinal inflammation. Targeted activation of TAM receptor tyrosine kinases may represent a potent therapeutic opportunity in inflammatory bowel disease.

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.

Consensus statements on the risk, prevention, and treatment of venous thromboembolism in inflammatory bowel disease: Canadian Association of Gastroenterology

BACKGROUND & AIMS

Guidelines for the management of venous thromboembolism (VTE) from the American College of Chest Physicians do not address patients with inflammatory bowel disease (IBD), a group with a high risk of both VTE and gastrointestinal bleeding. We present recommendations for the prevention and treatment of VTE in patients with IBD.

METHODS

A systematic literature search was performed to identify studies on VTE in IBD. The quality of evidence and strength of recommendations were rated according to the Grading of Recommendation Assessment, Development, and Evaluation (GRADE) approach. Statements were developed through an iterative online platform, then finalized and voted on by a working group of adult and pediatric gastroenterologists and thrombosis specialists.

RESULTS

IBD patients have an approximately 3-fold higher risk of VTE compared with individuals without IBD, and disease flares further increase this risk. Anticoagulant thromboprophylaxis is recommended for IBD patients who are hospitalized with IBD flares without active bleeding and is suggested when bleeding is nonsevere. Anticoagulant thromboprophylaxis is suggested during moderate-severe IBD flares in outpatients with a history of VTE provoked by an IBD flare or an unprovoked VTE, but not otherwise. The recommended duration of anticoagulation after a first VTE is based on the presence of provoking factors. Specific suggestions are made for the prevention and treatment of VTE in pediatric and pregnant IBD patients.

CONCLUSIONS

Using the American College of Chest Physicians' guidelines as a foundation, we have integrated evidence from IBD studies to develop specific recommendations for the management of VTE in this high-risk population.

Protein S: A multifunctional anticoagulant vitamin K-dependent protein at the crossroads of coagulation, inflammation, angiogenesis, and cancer

Since its discovery in 1970, protein S (PS) has emerged as a key vitamin K-dependent natural anticoagulant protein at the crossroads of multiple biological processes, including coagulation, apoptosis, atherosclerosis, angiogenesis/vasculogenesis, and cancer progression. Following the binding to a unique family of protein tyrosine kinase receptors referred to as Tyro-3, Axl and Mer (TAM) receptors, PS can lead to regulation of coagulation, phagocytosis of apoptotic cells, cell survival, activation of innate immunity, vessel integrity and angiogenesis, and local invasion and metastasis. Because of these dynamics and multiple functions of PS, which are largely lost following invalidation of the mouse PROS1 gene, this molecule is currently intensively studied in biomedical research. The purpose of this review is to provide a brief chronicle of the discovery and current understanding of the mechanisms of PS signaling, and how PS and their signaling partners regulate various cellular functions, with a particular focus on TAM receptors.

T cell-derived protein S engages TAM receptor signaling in dendritic cells to control the magnitude of the immune response

Dendritic cell (DC) activation is essential for the induction of immune defense against pathogens, yet needs to be tightly controlled to avoid chronic inflammation and exaggerated immune responses. Here, we identify a mechanism of immune homeostasis by which adaptive immunity, once triggered, tempers DC activation and prevents overreactive immune responses. T cells, once activated, produced Protein S (Pros1) that signaled through TAM receptor tyrosine kinases in DCs to limit the magnitude of DC activation. Genetic ablation of Pros1 in mouse T cells led to increased expression of costimulatory molecules and cytokines in DCs and enhanced immune responses to T cell-dependent antigens, as well as increased colitis. Additionally, PROS1 was expressed in activated human T cells, and its ability to regulate DC activation was conserved. Our results identify a heretofore unrecognized, homeostatic negative feedback mechanism at the interface of adaptive and innate immunity that maintains the physiological magnitude of the immune response.

Venous and arterial disease in inflammatory bowel disease

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

Venous thrombotic events in hospitalized children and adolescents with inflammatory bowel disease

BACKGROUND

Adults with inflammatory bowel disease (IBD) have an increased risk of venous thrombotic events (TEs). We sought to evaluate the risk for TE in children and adolescents with IBD using a large population database.

METHODS

The triennial Healthcare Cost and Utilization Project Kids' Inpatient Database was used in a retrospective cohort study of hospitalized children in the United States across 1997, 2000, 2003, 2006, and 2009. Billing codes were used to identify discharges with Crohn disease, ulcerative colitis, pulmonary embolism, deep vein thrombosis, thrombophlebitis, thrombosis of intracranial venous sinus, Budd-Chiari syndrome, and portal vein thrombosis. A logistic regression model was fitted to quantify the increased risk of TE in children with IBD, while adjusting for other risk factors of thrombosis.

RESULTS

The total weighted number of pediatric discharges was 7,448,292, and 68,394 (0.92%) were identified with IBD. The incidence of any TE in a hospitalized child or adolescent with IBD was 117.9/10,000 with a relative risk (95% confidence interval) of 2.36 (2.15-2.58). The adjusted odds ratio for any TE in a patient with IBD without surgery was 1.22 (1.08-1.36). Risk factors for TE among patients with IBD include older age, central venous catheter, parenteral nutrition, and an identified hypercoagulable condition. There is an increasing trend of TE in both the IBD and non-IBD patients.

CONCLUSIONS

Hospitalized children and adolescents with IBD are at increased risk for TE. Conservative methods of TE prevention including hydration, mobilization, or pneumatic devices should be considered in hospitalized patients with IBD.

Pulmonary embolism in a patient with eosinophilic esophagitis: causal or coincidental?

Eosinophilic esophagitis is a chronic immune-mediated disease characterized by infiltration of the esophageal mucosa with eosinophils and concomitant esophageal dysfunction. Though there are well-described associations between certain chronic inflammatory conditions and venous thromboembolism, there have been no reports of venous thromboembolism occurring in eosinophilic esophagitis. We report the case of a 33-year-old man with severe eosinophilic esophagitis resulting in recurrent esophageal strictures who was unresponsive to oral viscous budesonide therapy, and who developed an isolated pulmonary embolism in the absence of risk factors for venous thromboembolism. We then discuss potential mechanisms for venous thromboembolism in eosinophilic esophagitis, such as inflammation-mediated hypercoagulability, hypereosinophilia, and immunoglobulin E-mediated platelet activation.

Peripartum consultations expand the role of the fetal/neonatal neurologist

The peripartum period entails the next prenatal interval when novel neuroprotective strategies will be designed and tested. Research development will lead to novel evaluations for maternal-fetal pairs who require inpatient treatment and possible delivery for worsening or acute neurologic problems. Future studies should critically compare serial fetal surveillance assessments with postnatal clinical findings to detect and treat more accurately fetal/neonatal brain disorders that begin or worsen during the peripartum period. Clinical management decisions require an interdisciplinary treatment approach. Protocols may begin before and during parturition, and continue through neonatal resuscitation and early postnatal periods into infancy. Appropriate choices of preventive, rescue, and repair neuroprotective interventions must consider both the timing and etiologies of encephalopathies in the context of maternal, fetal, placental, and neonatal diseases.

A Flare of Ulcerative Colitis Accompanied With Cerebral Sinus Venous Thrombosis And Bilateral Thalamic Infarctus: A Case Report

Ulcerative colitis (UC) is a chronic inflammatory and recurrent disorder that is characterized by bowel inflammation. Some patients with Inflammatory Bowel Disease (IBD) have acute, severe, and sometimes devastating intracranial complications that require immediate medical intervention. Cerebral sinus vein thrombosis is a rare but serious extraintestinal complication associated with ulcerative colitis. Herein we report a 30-year-old man with UC who presented with a flare of gastrointestinal symptoms with mental obtundation and apathy. Total colonoscopy revealed active colitis and cranial MRI showed extensive cerebral sinus venous thrombosis with thalamic infarcts. Because the patient was clinically unstable metilprednisolon with low molecular weight heparin were administered. Two days after treatment the patient was died despite all medical efforts.

Factor V Leiden and inflammatory bowel disease: a systematic review and meta-analysis

BACKGROUND

Recent studies proved that inflammatory bowel disease (IBD) patients had a higher risk of thromboembolism and a Factor V Leiden mutation that prevents the efficient inactivation of factor V, which leads to thromboembolism and thus contributes to a high potential risk of IBD. However, the relationship between Factor V Leiden mutation and IBD remains controversial.

METHODS

We conducted a systematic review with meta-analysis of studies assessing the association of Factor V Leiden mutation with the risk of IBD in humans. We extracted the number of IBD and control subjects with or without Factor V Leiden mutation from each study and conducted this analysis using a fixed-effects model.

RESULTS

Nineteen studies met the inclusion criteria and were included in the meta-analysis. No significant heterogeneity was found in results across the 19 studies (I (2) = 18.8%, P = 0.23), which showed a slight but not significant increase in the risk of IBD with Factor V Leiden mutation in the general population (summary odds ratio [OR] 1.13, 95% confidence interval [CI] 0.87-1.46). Taking into account ethnic differences, further study exhibited a slight but not significant increase in risk of IBD with Factor V Leiden mutation in Europeans (summary OR 1.20, 95% CI 0.88-1.64). However, Factor V Leiden mutation was significantly associated with a higher risk of thromboembolism in IBD patients (summary OR 5.30, 95% CI 2.25-12.48). No publication bias was found in this study.

CONCLUSIONS

This meta-analysis indicated that although Factor V Leiden mutation was not significantly associated with the risk of IBD, it was significantly associated with a higher risk of thromboembolism in IBD patients.

Factor V Leiden and thrombosis in patients with inflammatory bowel disease (IBD): a meta-analysis

BACKGROUND

Testing for genetic risks of Factor V Leiden ( FVL ) in inflammatory bowel disease (IBD) patients with thromboembolism (TE) is common, but the safety and utility of such testing need review.

AIM

The aim of the present study was to investigate whether the FVL polymorphisms would be one inherited prothrombotic risk factor that could significantly increase the risk of thrombosis in patients with IBD.

METHODS

We performed an electronic databases search to identify published studies correlating the FVL mutations with four populations including one IBD group with TE complications, one control IBD group without TE complications, one control non-IBD group with TE complications and another healthy control (HC) group. Statistical analysis was performed with Review Manager (RevMan) 5.0. Sub-analysis/sensitivity analysis was also performed.

RESULTS

We identified 112 titles and included 22 studies in this meta-analysis. The odds ratio (OR) of TE in IBD patients with FVL was higher as compared with IBD patients (OR: 4.00; 95%CI: 2.04, 7.87) and HC (OR: 3.19; 95%CI: 1.38, 7.36). There was a 1.25-fold (95%CI: 0.90-1.74) increase in incidence of FVL gene mutation in IBD patients compared with HC. The FVL mutations were not significantly different between IBD patients with thrombosis and non-IBD patients with thrombosis (OR: 0.79; 95%CI: 0.43, 1.47).

CONCLUSION

FVL plays a role in IBD-TE, but to no greater extent than it does in the general population with TE.

Thrombophilic Risk Factors in Patients With Inflammatory Bowel Disease

Background

Inflammatory bowel disease (IBD) patients have an increased risk for thromboembolism. The aim of this study was to assess the presence of thrombophilic risk factors in IBD patients and to assess the associations of these factors with disease activity.

Methods

Forty-eight patients with IBD (24 ulcerative colitis, 24 Crohn’s disease) and 40 matched healthy control individuals were enrolled. In addition to routine biochemical analysis, fasting blood samples were studied for prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, protein-C, protein-S, antithrombin III, factor VII, factor VIII, D-dimer, vitamin B₁₂, folic acid and homocysteine.

Results

Levels of erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), fibrinogen, D-dimer and the number of platelets were significantly higher in patients with IBD. When compared to control group, in patients with Crohn’s disease serum homocystein levels were significantly higher (p = 0.025) while serum folic acid levels were significantly lower (p < 0.019). Levels of fibrinogen, D-dimer, protein C, factor VIII, total homocystein and the number of platelets were found to be significantly higher in Crohn’s disease patients who were in active period of the disease.

Conclusions

Thrombophilic defects are multifactorial and might be frequently seen in IBD patients. They might contribute to thrombotic complications of this disease.

Venous thromboembolism in hospitalized inflammatory bowel disease patients: the magnitude of the problem is staggering

There is evidence that thromboembolism as a disease-specific extraintestinal manifestation of inflammatory bowel disease (IBD) is developed as the result of multiple interactions between acquired and genetic risk factors. An imbalance of procoagulant, anticoagulant, and fibrinolitic factors predisposing to thrombosis has been reported by several studies in patients with IBD. The study by Nguyen and Sam demonstrates that hospitalized IBD patients have higher prevalence of venous thromboembolism and a more than two-fold excess of mortality compared with non-IBD hospitalized patients. When the findings from this large study are combined with previous data, they suggest that thromboembolism is a significant cause of extraintestinal morbidity and mortality in IBD patients with a higher risk during hospitalization.

Thrombosis and inflammatory bowel disease-the role of genetic risk factors

Thromboembolism is a significant cause of morbidity and mortality in patients with inflammatory bowel disease (IBD). Recent data suggest thromboembolism as a disease-specific extraintestinal manifestation of IBD, which is developed as the result of multiple interactions between acquired and genetic risk factors. There is evidence indicating an imbalance of procoagulant, anticoagulant and fibrinolytic factors predisposing in thrombosis in patients with IBD. The genetic factors that have been suggested to interfere in the thrombotic manifestations of IBD include factor V Leiden, factor II (prothrombin, G20210A), methylenetetrahydrofolate reductase gene mutation (MTHFR, 6777T), plasminogen activator inhibitor type 1 (PAI-1) gene mutation and factor XIII (val34leu). In this article we review the current data and future prospects on the role of genetic risk factors in the development of thromboembolism in IBD.

Maternal ulcerative colitis and fetal brain injury: long-term neurologic outcome

Two maternal-fetal case presentations illustrate the possible association of active maternal ulcerative colitis during pregnancy and fetal brain injury resulting in long-term neurological sequelae. Thromboembolic complications may occur in the fetus based on similar mechanisms for stroke in children and adults with active inflammatory bowel disease. Identification of thrombophilia in the pregnant woman with active ulcerative colitis may better explain a pathophysiologic mechanism for long-term neurological morbidity in offspring.

Genetic risk factors in patients with inflammatory bowel disease and vascular complications: case-control study

BACKGROUND

Inherited risk factors have been suggested to play an important role in the pathogenesis of vascular complications of inflammatory bowel disease (IBD). The aim of the present study was to investigate the role of mutations associated with cardiovascular disease in IBD patients with or without vascular complications compared with thrombotic and healthy controls (HC).

METHODS

Twelve polymorphisms of thrombophilic and vasoactive genes were evaluated in a group of 30 IBD patients with vascular complications (IBD-VC) compared with 60 IBD patients without vascular complications, 30 thrombotic controls (TC), and 54 healthy controls, using a commercially available kit.

RESULTS

No significant differences between IBD-VC and TC concerning the carriage of these mutations were found. The frequencies of the factor V (FV) 506 RQ (Leiden) genotype and the 506Q allele were significantly higher in these groups than in HC (P < 0.05) but not IBD controls (P > 0.05). The allele frequency of the mutant 4G allele of the plasminogen activator inhibitor (PAI) polymorphism, similar in the IBD-VC and TC groups, was significantly higher in these groups compared with the IBD group (P = 0.03) and the HC (P = 0.001). It is noteworthy that there was a trend of association of FV R506Q polymorphism with venous thrombosis and PAI-1 gene polymorphism with arterial thrombosis.

CONCLUSIONS

Our results suggest that the investigated gene polymorphisms do not differ in patients with IBD-VC and TC. FV R506Q and PAI-1 gene polymorphisms might be associated with the increased risk of development of vascular complications in IBD.

Acute coronary syndrome after infliximab therapy in a patient with Crohn’s disease

Infliximab is a potent anti-TNF antibody, which is used with great success in Crohn’s disease patients. Since its release in clinical practice, several adverse reactions have been observed. The interest in possible consequences of its administration is still high because of the recent introduction of the drug for the long-term maintenance therapy of refractory luminal and fistulizing Crohn’s disease. We present a case of acute coronary syndrome (non-STEMI) in a patient with corticoid resistant Crohn’s disease after his first dose of infliximab. By reviewing the scant articles that exist in the literature on this topic we made an effort to delineate the possible mechanisms of this phenomenon.

The search for a common thrombophilic state during the active state of inflammatory bowel disease

The clinical course of inflammatory bowel disease (IBD) is frequently associated with thromboembolic complications. The aim of this study was to investigate common thrombophilic markers in Turkish patients with active IBD. Twenty-seven consecutive patients with IBD who were followed-up at the Hacettepe University Hospital were recruited. All the patients were in the active disease state. International normalized ratio, activated partial thromboplastin time, lupus anticoagulant, anticardiolipin IgG, IgM antibodies, protein C, protein S, antithrombin-III, factor V, and factor II mutation of all the IBD patients and of a sex-matched and age-matched control group of non-IBD patients were measured. International normalized ratio, activated partial thromboplastin time, protein C, protein S, lupus anticoagulant, anticardiolipin IgG and IgM, and Proteins C and S mutations were comparable between the 2 groups, but antithrombin-III was significantly lower in the IBD group compared with healthy control group (P<0.0001). As a conclusion, it is reasonable to assume that there may be a subpopulation of the patients with IBD, in whom thrombophilic abnormalities might be important for either disease manifestation or for thrombotic complications. Those hemostatic abnormalities could be either inherited or secondary to the ongoing disease process. Routine screening for the common markers of thrombophilia does not seem to be warranted unless simultaneous arterial and venous thrombosis, major organ thrombosis, strong family history of thrombophilia, unusual and recurrent thrombosis resistant to standard anticoagulant therapy are present. Further studies are definitely required to clarify these complicated associations.

What is the impact of resistance to activated protein C (Leiden mutation to factor V) in inflammatory bowel disease?

BACKGROUND AND AIMS

Resistance to activated protein C (APCR) caused by the Leiden mutation to factor V is the most common cause of inherited thrombosis. Patients with inflammatory bowel disease (IBD) are considered to have an increased risk of thromboembolic complications, and the role of APCR as a cause has previously been investigated. In this study, we investigated if APCR was associated with non-thrombotic morbidities in IBD.

PATIENTS/METHODS

Of 951 patients asked to participate, 389 agreed by returning a signed informed consent and filled questionnaire and took the blood test for APCR. Self-reported IBD-related surgery was used as a rough indicator for increased morbidity.

RESULTS

APCR was present in 6.6% of patients with Crohn's disease (CD; 10/152) and in 12.7% of ulcerative colitis (UC) patients (30/237). The difference of 6.1% is significant (p=0.039). Among patients with CD and APCR, 9 out of 10 had had surgery, significantly more than among those without APCR (81/142). In patients with UC and APCR, 10 out of 30 had had surgery, still significantly more than in those without APCR (36/207). For the whole group of IBD patients, APCR is associated with a significantly increased risk for thrombosis (p=0.0018), and for the UC group (8/28) p=0.0029, but not for the CD patients alone (2/9), p=0.2323. No other significant differences could be shown for parameters normally related to increased morbidity.

CONCLUSIONS

APCR in IBD was associated with an increased frequency of IBD-related surgery, which may warrant screening for APCR in therapy-resistant IBD. In patients with APCR, it may be more difficult and/or important to control inflammation.

Systemic thromboembolism in inflammatory bowel disease: mechanisms and clinical applications

Systemic thromboembolism is an extraintestinal manifestation of inflammatory bowel disease (IBD), and an important cause of patient morbidity and mortality. The underlying basis for the hypercoagulable state in IBD is complex, and involves altered activity of all three components that govern hemostasis: platelets, fibrinolysis, and the coagulation cascade. Currently, there are no distinct guidelines for treating or preventing thromboembolic (TE) events in IBD patients compared with the general population. However, the prothrombotic state in IBD stems, at least in part, from several modifiable factors, such as hyperhomocysteinemia and an active inflammatory state. In this review we summarize the mechanisms that favor thrombosis in IBD, and the principles that need to be applied for the primary and secondary prevention of TE in this selected group of patients.

Therapy insight: Vascular complications in patients with inflammatory bowel disease

Inflammatory bowel disease (IBD) is associated with an increased risk of vascular complications. The most important of these complications are arterial and venous thromboembolism, which represent a significant cause of morbidity and mortality in IBD patients. Recent data suggest that thromboembolism is a disease-specific extraintestinal manifestation of IBD. The most common thrombotic manifestations in IBD are deep vein thrombosis of the leg and pulmonary emboli. It has been suggested that disease activity and the extent of colonic localization are correlated with the risk of developing thromboembolism. The occurrence of thrombosis in patients with IBD is partially attributed to the existing hypercoagulable state in IBD. Both coagulation and fibrinolysis are activated in patients with IBD; this is especially true for those with active disease. The most common risk factors for thrombophilia in IBD patients with venous thromboembolism are Leiden mutation in the gene encoding factor V, hyperhomocysteinemia, and antiphospholipid antibodies. The main genetic defects that have been established as risk factors for venous thrombosis are rather uncommon in IBD, but when present increase the risk of thromboembolism. Screening for coagulation defects seems justified only in IBD patients with a history of thrombosis or a family history of venous thromboembolic events. Antithrombotic treatment of IBD patients with venous thromboembolism is similar to that of thrombotic non-IBD patients.

Hyperhomocysteinemia in ulcerative colitis is related to folate levels

AIM: To study the prevalence and clinical significance of hyperhomocysteinemia (hHcys), an independent factor for arterial and venous thrombosis, in a group of patients with ulcerative colitis (UC).

METHODS: Fasting homocysteine (Hcys), folate, and vitamin B12 serum levels were measured in 40 UC patients and 50 healthy controls. Clinical data regarding UC were gathered.

RESULTS: Median serum Hcys levels in UC patients were similar to those in controls (12.26 µmol/L vs 12.32 µmol/L), but the prevalence of hHcys was higher in UC patients than in controls (30% vs 10%, P = 0.028). UC significantly increased the risk of hHcys (adjusted odds ratio: 4.125; 95%CI: 1.26-13.44). Multivariate regression analysis showed that male sex, folate and vitamin B12 deficiency or lower serum values were significant independent predictors of higher Hcys levels in UC patients (r² = 0.4; P<0.001).

CONCLUSION: hHcys is common in UC patients and it is related to folate and vitamin B12 deficiency or lower serum values. It would be reasonable for patients with UC to receive folate and vitamin B complex supplements as a prophylactic measure.

Thrombosis in inflammatory bowel diseases: role of inherited thrombophilia

BACKGROUND

Inflammatory bowel diseases (IBD) are characterized by an increased risk for venous and arterial thrombosis. Although the pathogenetic mechanisms of this predisposition are unclear, a possible role of inherited risk factors for thrombosis in determining this predisposition has been suggested.

AIM

To evaluate the role of factor V Leiden (G1691A) and G20210A prothrombin gene mutations in determining the occurrence of thrombosis in IBD patients.

PATIENTS AND METHODS

Forty-seven IBD patients (30 ulcerative colitis and 17 Crohn's disease) with a positive history for thrombosis (9 at arterial sites and 38 at venous sites) were enrolled in the study. For each patient, two non-IBD subjects matched for sex and age, type, and site of thrombosis were used as controls. Peripheral blood DNA specimens were amplified by PCR using appropriate primers and analyzed by restriction analysis on agarose gel electrophoresis. Statistical analysis was performed by means of Fisher's exact test.

RESULTS

The total number of subjects with one or both mutations was significantly lower in IBD patients with thrombosis than in control subjects (12.8%vs 29.8%, respectively; p= 0.035, OR = 0.34, 95% CI 0.13-0.90). The total frequency of the mutated alleles was also significantly lower in IBD than in controls (7.4%vs 16.5%, respectively; p= 0.041, OR = 0.40, 95% CI 0.17-0.96). Prothrombotic mutations were particularly unfrequent in IBD patients with active disease at the time of thrombosis compared with patients with quiescent disease (8.0%vs 36.4%, respectively; p= 0.057, OR = 0.15, 95% CI 0.02-1.01).

CONCLUSIONS

The major inherited risk factors for thrombosis are significantly less frequent in thrombotic IBD patients than in thrombotic non-IBD subjects, suggesting that acquired risk factors play the most relevant role in determining thromboembolic events observed in IBD patients, particularly during active phases of the disease.

Thrombosis and inflammatory bowel disease

Interaction between thrombosis and inflammation is increasingly recognized. With this, interest has arisen in the role of thrombosis in inflammatory conditions, including the inflammatory bowel diseases. Although the association between active inflammatory bowel disease and thromboembolic complications has long been known, there has been a resurgence in research into the role of thrombosis and the hemostatic system in the pathogenesis of both ulcerative colitis and Crohn's disease. Here we review the increased frequency of thromboembolic complications occurring in patients with inflammatory bowel disease; whether thrombosis might play a part in the initiation and maintenance of inflammation in inflammatory bowel disease; abnormalities of the coagulation system found in patients with inflammatory bowel disease; platelet dysfunction in inflammatory bowel disease; the mechanisms by which hemostatic processes might be proinflammatory in inflammatory bowel disease; and how these interactions might impact not only on the prevention of complications, but also on the treatment of the underlying inflammation in inflammatory bowel disease.

Risk factors for thromboembolic complications in inflammatory bowel disease: the role of hyperhomocysteinaemia

Inflammatory bowel disease (IBD) is associated with an increased risk for thromboembolic events. Aim of this study was to examine the relationship of hyperhomocysteinemia and thrombosis in IBD patients and to assess the role of this factor in addition to other known prothrombotic abnormalities. IBD patients with a history of thrombosis (n = 22) and sex-, age-, and diagnosis-matched IBD controls (n = 23) were studied. Homocysteine (tHcy) was assessed before and after methionine loading. Plasma levels of protein C, protein S, antithrombin III, and fibrinogen and the presence of anticardiolipin and antiphospholipid antibodies were determined and genetic testing for factor V Leiden and the prothrombin gene mutation was performed. Results showed that fasting homocysteine levels in IBD patients with a history of arterial or venous thrombosis tended to be higher than in IBD controls, although not significantly. The increase in homocysteine levels after methionine loading was significantly higher in IBD patients in the arterial thrombosis group than in IBD controls (40.9 +/- 17.7 vs. 27.2 +/- 9.9 microM; P < 0.05). Among the other prothrombotic factors, only factor V Leiden was significantly associated with a history of venous thrombosis (20 vs. 0%). At least one risk factor was found in 64% of the IBD patients with previous thromboembolic complications. We conclude that there is an association between hyperhomocysteinemia and a history of arterial thrombosis in IBD patients. We confirm the high prevalence of factor V Leiden in IBD patients with a history of venous thrombosis. In the majority of IBD patients with previous thromboembolic complications, at least one prothrombotic risk factor is detected.

Anesthetic management for small bowel transplantation

Small bowel transplantation is quickly becoming the therapy of choice for short-gut syndrome. Improvements in surgical techniques, immunosuppressants, and anesthetic management of patients have allowed this procedure to become the standard of care for patients with irreversible intestinal failure who are unable to continue total parenteral nutrition therapy. This article discusses the evaluation process for candidate selection, including work-up for vascular access and hypercoagulability, intraoperative management of patients (including appropriate monitoring, hemodynamic changes, fluid management, surgical techniques, and effects of immunosuppressants), and patient survival and outcome.

Effects of dermatan sulfate derivatives on platelet surface P-selectin expression and protein C activity in blood of inflammatory bowel disease patients

AIM: To investigate the effect of dermatan sulfate (DS) derivatives on platelet surface P-selectin expression and blood activated protein C (APC) activity in patients with inflammatory bowel disease (IBD), and to clarity the anti-inflammatory mechanism of DS derivatives.

METHODS: Dermatan sulfate (DS) was sulfated with chlorosulfonic acid to prepare polysulfated dermatan sulfate (PSDS). The major disaccharides of DS and PSDS were determined by ¹H nuclear magnetic resonance spectroscopy (¹H-NMR) and ¹³C-NMR. Both DS and PSDS were depolymerized with hydrogen peroxide. The fragments were separated by gel filtration chromatography. The effects of DS derivatives on P-selectin expression were assayed by ELISA method, and blood APC activity was assayed by the synthetic chromogenic substrate method.

RESULTS: The major disaccharides of DS and PSDS were IdoA-1→3-GalNAc-4-SO₃ and IdoA-2SO₃-1→3-GalNAc4, 6-diSO₃, respectively. Compared with the adenosine diphosphate stimulated group and IBD control group, DS and its derivatives all had significant inhibitory effects on P-selectin expression (P < 0.01), but there was no difference between DS-derived oligosaccharides (DSOSs) and PSDS-derived oligosaccharides (PSDSOSs). The experiments on APC activity showed that DS and its derivatives all enhanced APC activity. The most active DSOS was the one with a relative molecular weight (M_r) of 4825, which enhanced the APC activity from 106.5% ± 11.5% to 181.8% ± 22.3% (P < 0.01). With the decrease of M_r, the activity of DSOSs decreased gradually. The effect of PSDS on APC activity enhancement was more significant than that of DS, and the APC activity was raised to 205.2% ± 22.1% (P < 0.01). All the PSDSOSs were more active than DSOSs on the basis of comparable M_r. With the decrease of M_r, the activity of PSDSOSs increased gradually, and the most active PSDSOS was PSDSOS₃ with M_r of 2749, which enhanced the APC activity to 331.2% ± 27.8% (P < 0.01), then the activity of PSDSOSs decreased gradually.

CONCLUSION: DS and its derivatives can significantly inhibit P-selectin expression on platelet surface, but the effect has no correlation with DS molecular mass and sulfation. The effect of DS or its derivatives on APC activity at molecular level involves complex mechanisms that depend on the molecular mass, the degree of sulfation, and the heterogeneous composition of DS. On the same molecular size, the higher the degree of DS sulfation, the more significant the effect on enhancing APC activity.

Inhibitory effect of heparin-derived oligosaccharides on secretion of interleukin-4 and interleukin-5 from human peripheral blood T lymphocytes

AIM: To investigate the inhibitory effect of heparin-derived oligosaccharides (Oligs) on secretion of interleukin-4 (IL-4) and interleukin-5 (IL-5) from human peripheral blood T lymphocytes (PBTLs).

METHODS: Oligs were prepared by three different heparin depolymerization methods and separated by gel filtration chromatography. PBTLs from ten adult patients with allergic eosinophilic gastroenteritis were treated with phytahematoagglutinin (PHA) and Oligs. The supernatants from the cell culture of PBTLs were harvested and subjected to the determination of IL-4 and IL-5 contents by ELISA method.

RESULTS: At the concentration of 5 μg/mL, Oligs with different M_r had different effects on the secretion of IL-4 and IL-5. The tetrasaccharide with M_r of 1142, produced by depolymerizing heparin with hydrogen peroxide, had the strongest inhibitory effect on the secretion of IL-4. It decreased the IL-4 content from 375.6 ± 39.2 ng/L (PHA group) to 12.5 ± 5.7 ng/L (P < 0.01). The hexasaccharide with M_r of 1806, produced by depolymerizing heparin with β -elimination method, had the strongest inhibitory effect on the secretion of IL-5. It decreased the IL-5 content from 289.2 ± 33.4 ng/L (PHA group) to 22.0 ± 5.2 ng/L (P < 0.01).

CONCLUSION: The inhibitory activity of Oligs on the secretion of IL-4 and IL-5 from human PBTLs closely depends on their molecular structure, and there may be an essential structure to act as an inhibitor. The most effective inhibitors of IL-4 and IL-5 secretion are tetrasaccharides and hexasaccharides, respectively.

Aortic mural thrombi in patients with inflammatory bowel disease: report of two cases and review of the literature

Thromboembolic events are a known complication in inflammatory bowel disease (IBD). We report on 2 young women with IBD and aortic mural thrombi as a source of arterioarterial embolization to the lower limbs resulting in significant morbidity. The first case was a 36-year-old woman with severe ulcerative colitis who presented with signs of microembolism into two toes of her right foot. A thrombus in the otherwise normal infrarenal aorta with occlusion of the inferior mesenteric artery was revealed by computed tomography (CT) and intrarterial angiography. The digital ischemia resolved without sequelae. The second case was a 41-year-old woman with Crohn's disease complicated by fistulas. She developed acute ischemia of her right leg. Arteriography and CT revealed infrapopliteal embolic occlusions and a thrombus in the distal otherwise normal abdominal aorta and the left iliac artery. A primarily successful thrombectomy had to be repeated 5 times because of reocclusion. Eventually the leg was exarticulated at the knee. In both patients no further thromboembolic event occurred during follow-up of 4 1/2 years and 5 1/2 years, respectively, and aortic thrombi had resolved at follow-up CT scans. Extensive work up for hypercoagulability was negative in both patients. We consider IBD as the most likely trigger for arterioarterial embolization in the absence of thrombophilia in both patients. Finally we give an overview of the literature of similar cases with aortic mural thrombi in IBD patients.

High prevalence of combined thrombophilic abnormalities in patients with inflammatory bowel disease

INTRODUCTION

A hypercoagulable state has been recognized in patients with inflammatory bowel disease.

OBJECTIVE

The aim of this study was to determine the frequency of single and combined thrombophilic abnormalities in patients from northern Portugal with Crohn's disease or ulcerative colitis, without a history of thrombosis. METHODS A cross-sectional study involving 116 patients (42 with ulcerative colitis, 74 with Crohn's disease), and 141 randomly chosen asymptomatic blood donors was carried out. Prothrombotic variables and genetic abnormalities were assessed.

RESULTS

The prevalence of single prothrombotic abnormalities (only one alteration) in inflammatory bowel disease patients was higher than in the reference population (26% and 18%, respectively; P < 0.02). The allelic frequency of genetic polymorphisms was higher in Crohn's disease and ulcerative colitis for MTHFR C677T, ACE Del and PAI-1 4G (P < 0.001) than in the reference population. The prevalence of combined thrombophilic abnormalities (at least two alterations) in both Crohn's disease and ulcerative colitis was also higher (22% and 21%, respectively) than in the reference population (9%; P < 0.01). These differences were not related to age or gender; however, in Crohn's disease the frequency of two or more abnormalities was related to disease activity (odds ratio 3.0 [1.3-6.7]).

CONCLUSION

Higher prevalences of single and combined thrombophilic defects were found in inflammatory bowel disease patients, factors that could be involved in the disease pathogenesis.

Review article: inherited thrombophilia in inflammatory bowel disease

Individuals with inflammatory bowel disease frequently experience increased systemic thromboembolic complications, which represent an important cause of morbidity and mortality. Risk factors for thrombosis can be inherited or acquired. The most common inherited risk factors for thromboembolism are factor V Leiden mutation, G20210A mutation in the prothrombin gene, and homozygous C677T mutation in the methylenetetrahydrofolate reductase gene. In the last few years, a great amount of literature has focused on the prevalence of such genetic mutations and their role in determining thrombosis in IBD patients. In this review, we summarize the results of these studies.