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

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

TRIAL REGISTRY

NCT05162339 (ClinicalTrials.gov ID).

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.

Inflammatory Bowel Disease Presenting With Concurrent COVID-19 Multisystem Inflammatory Syndrome

Coronavirus disease 2019 is associated with a postinfectious multisystem inflammatory syndrome in children (MIS-C). This syndrome is marked by cytokine storm and multiorgan dysfunction, often affecting the gastrointestinal tract, the heart, and the hematopoietic system. We describe the case of a 16-year-old boy with an initial presentation of severe inflammatory bowel disease and concurrent MIS-C. He presented with abdominal pain, diarrhea, and hematochezia and met criteria for the systemic inflammatory response syndrome. Laboratory inflammatory profiling revealed markedly elevated ferritin, D-dimer, C-reactive protein, soluble interleukin 2, and interleukin 6 levels. Endoscopy and colonoscopy revealed severe active gastroduodenitis, patchy colitis, and a normal-appearing terminal ileum. The patient was treated with a combination of steroids, intravenous immunoglobulin, and infliximab, and his symptoms slowly resolved over a 3-week period. In this case, we describe coincident MIS-C with a remarkably severe and difficult-to-treat initial presentation of inflammatory bowel disease and highlight the need to investigate the effect of coronavirus disease 2019 and MIS-C on inflammatory disorders.

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

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Evidence for the important role of inflammation in xenotransplantation

There is increasing evidence of a sustained state of systemic inflammation after pig-to-nonhuman primate (NHP) xenotransplantation (that has been termed systemic inflammation in xenograft recipients [SIXR]). Increases in inflammatory markers, e.g., C-reactive protein, histones, serum amyloid A, D-dimer, cytokines, chemokines, and a decrease in free triiodothyronine, have been demonstrated in the recipient NHPs. The complex interactions between inflammation, coagulation, and the immune response are well-recognized, but the role of inflammation in xenograft recipients is not fully understood. The evidence suggests that inflammation can promote the activation of coagulation and the adaptive immune response, but the exact mechanisms remain uncertain. If prolonged xenograft survival is to be achieved, anti-inflammatory strategies (e.g., the administration of anti-inflammatory agents, and/or the generation of genetically-engineered organ-source pigs that are protected from the effect of inflammation) may be necessary to prevent, control, or negate the effect of the systemic inflammation that develops in xenograft recipients. This may allow for a reduction in the intensity of exogenous immunosuppressive therapy. If immunological tolerance to a xenograft is to be obtained, then control of inflammation may be essential.