Plasma D-dimer concentration in patients with systemic sclerosis

The Crossroads of the Coagulation System and the Immune System: Interactions and Connections

The coagulation and immune systems, two vital systems in the human body, share intimate connections that fundamentally determine patient health. These systems work together through several common regulatory pathways, including the Tissue Factor (TF) Pathway. Immune cells expressing TF and producing pro-inflammatory cytokines can influence coagulation, while coagulation factors and processes reciprocally impact immune responses by activating immune cells and controlling their functions. These shared pathways contribute to maintaining health and are also involved in various pathological conditions. Dysregulated coagulation, triggered by infection, inflammation, or tissue damage, can result in conditions such as disseminated intravascular coagulation (DIC). Concurrently, immune dysregulation may lead to coagulation disorders and thrombotic complications. This review elucidates these intricate interactions, emphasizing their roles in the pathogenesis of autoimmune diseases and cancer. Understanding the complex interplay between these systems is critical for disease management and the development of effective treatments. By exploring these common regulatory mechanisms, we can uncover innovative therapeutic strategies targeting these intricate disorders. Thus, this paper presents a comprehensive overview of the mutual interaction between the coagulation and immune systems, highlighting its significance in health maintenance and disease pathology.

An Overview of Circulating Pulmonary Arterial Hypertension Biomarkers

Pulmonary arterial hypertension (PAH), also known as Group 1 Pulmonary Hypertension (PH), is a PH subset characterized by pulmonary vascular remodeling and pulmonary arterial obstruction. PAH has an estimated incidence of 15-50 people per million in the United States and Europe, and is associated with high mortality and morbidity, with patients' survival time after diagnosis being only 2.8 years. According to current guidelines, right heart catheterization is the gold standard for diagnostic and prognostic evaluation of PAH patients. However, this technique is highly invasive, so it is not used in routine clinical practice or patient follow-up. Thereby, it is essential to find new non-invasive strategies for evaluating disease progression. Biomarkers can be an effective solution for determining PAH patient prognosis and response to therapy, and aiding in diagnostic efforts, so long as their detection is non-invasive, easy, and objective. This review aims to clarify and describe some of the potential new candidates as circulating biomarkers of PAH.

The Pathogenesis of Systemic Sclerosis: An Understanding Based on a Common Pathologic Cascade across Multiple Organs and Additional Organ-Specific Pathologies

Systemic sclerosis (SSc) is a multisystem autoimmune and vascular disease resulting in fibrosis of various organs with unknown etiology. Accumulating evidence suggests that a common pathologic cascade across multiple organs and additional organ-specific pathologies underpin SSc development. The common pathologic cascade starts with vascular injury due to autoimmune attacks and unknown environmental factors. After that, dysregulated angiogenesis and defective vasculogenesis promote vascular structural abnormalities, such as capillary loss and arteriolar stenosis, while aberrantly activated endothelial cells facilitate the infiltration of circulating immune cells into perivascular areas of various organs. Arteriolar stenosis directly causes pulmonary arterial hypertension, scleroderma renal crisis and digital ulcers. Chronic inflammation persistently activates interstitial fibroblasts, leading to the irreversible fibrosis of multiple organs. The common pathologic cascade interacts with a variety of modifying factors in each organ, such as keratinocytes and adipocytes in the skin, esophageal stratified squamous epithelia and myenteric nerve system in gastrointestinal tract, vasospasm of arterioles in the heart and kidney, and microaspiration of gastric content in the lung. To better understand SSc pathogenesis and develop new disease-modifying therapies, it is quite important to understand the complex pathogenesis of SSc from the two distinct perspectives, namely the common pathologic cascade and additional organ-specific pathologies.

Venous Thromboembolism in Systemic Sclerosis: Prevalence, Risk Factors, and Effect on Survival

OBJECTIVE

Whether systemic sclerosis (SSc) confers increased risk of venous thromboembolism (VTE) is uncertain. We evaluated the prevalence, risk factors, and effect of VTE on SSc survival.

METHODS

A cohort study was conducted of subjects with SSc who fulfilled the American College of Rheumatology/European League Against Rheumatism classification criteria between 1970 and 2017. Deep vein thrombosis was defined as thrombus on extremity ultrasound. Pulmonary embolism was defined as thrombus on thorax computed tomography angiogram. Risk factors for VTE and time to all-cause mortality were evaluated.

RESULTS

Of the 1181 subjects, 40 (3.4%) experienced VTE events. The cumulative incidence of VTE was 2.7 (95% CI 1.9-3.7) per 1000 patient-years. Pulmonary arterial hypertension (PAH; OR 3.77, 95% CI 1.83-8.17), peripheral arterial disease (OR 5.31, 95% CI 1.99-12.92), Scl-70 (OR 2.45, 95% CI 1.07-5.30), and anticardiolipin antibodies (OR 5.70, 95% CI 1.16-21.17) were predictors of VTE. There were 440 deaths. There was no difference in survival between those with and without VTE (HR 1.16, 95% CI 0.70-1.91). Interstitial lung disease (HR 1.54, 95% CI 1.27-1.88) and PAH (HR 1.35, 95% CI 1.10-1.65) were predictors of mortality.

CONCLUSION

The risk of VTE in SSc is comparable to the general population. The presence of PAH, peripheral arterial disease, Scl-70, and anticardiolipin antibodies are risk factors for VTE. VTE does not independently predict SSc survival.

[Early diagnosis of connective tissue disease-related pulmonary hypertension]

It is known that prognosis of pulmonary hypertension (PH), especially connective tissue disease related PH (CTD-PH), is serious. CTD-PH is caused by not only pulmonary arterial hypertension, but also interstitial pneumonitis, hypoxia, chronic thromboembolism of pulmonary artery, or left heart diseases. Recently, prognosis of PH is improved by progress of diagnostic measures including echocardiography and development of effective vasodilators. However, early diagnosis of PH is necessary for further improvement of the prognosis. Previous reports have shown that diffusion lung capacity for carbon monoxide (DLco) is reduced in the early phase of PH, and we have shown that serum lactate dehydrogenase level is also elevated in this phase. Furthermore, we have been studying significance of stress echocardiography. Therefore, if reduced DLco or LDH elevation are recognized, follow up of laboratory data such as blood levels of KL-6, NT-proBNP, D-dimer, echocardiography, high resolution CT of the lung, in addition to clinical findings are important for prediction of PH.

Significance of microparticles in progressive systemic sclerosis with interstitial pneumonia

We measured and compared the levels of microparticles, chemokines, cell adhesion molecules and platelet activation markers with a view to developing a better understanding of their potential contributions to the pathophysiology of progressive systemic sclerosis (PSS, scleroderma). The concentrations of all the factors in PSS patients were significantly higher than those in normal subjects. PSS patients were divided to two groups by whether they have interstitial pneumonia (IP) or not. There were no differences in the levels of soluble(s) VCAM-1, sICAM-1, sE-selectin and IL-8 between the two groups. However, there were significant between-group differences in the levels of sP-selectin, sCD40L, ENA-78, RANTES (regulated on activation normally T-cell expressed and secreted), platelet-derived microparticles (PDMPs), monocyte-derived microparticle (MDMPs) and KL-6. The level of tissue factor expression on monocytes by A23187 stimulation in PSS patients was found to be similar to that in healthy controls. Although PDMP did not induce the expression of tissue factor on monocytic cell line (THP-1) directly, the recombinant sCD40 ligand-induced expression of tissue factor on THP-1 and generation of MDMP from this cell line were enhanced by the addition of PDMPs. Our findings suggested that elevated levels of PDMPs and MDMPs may be interpreted as a sign of vascular complications in PSS patients, particularly those complicated with IP, offering a new treatment strategy in these patients.

Plasma D-dimer concentration in patients with systemic sclerosis

BACKGROUND

It has been reported that increased plasma D-dimer is a reliable marker of systemic prothrombotic state in patients with cardiovascular diseases.

OBJECTIVES

To evaluate plasma D-dimer concentration in patients with systemic sclerosis (SSc) and healthy controls. We also investigated a possible relationship between the presence of a high plasma D-dimer concentration and clinical and biological parameters in patients with SSc.

METHODS

Measurements of plasma D-dimer concentration were performed in 69 consecutive patients with SSc and 69 age- and sex-matched controls. Clinical and biological findings were compared between patients with and without a high concentration of plasma D-dimer (i.e. >or=500 ng mL(-1)).

RESULTS

Median plasma D-dimer concentrations appeared significantly increased in patients with SSc compared with control subjects (506 vs. 211 ng mL(-1); P<0.001). Furthermore, a high concentration of plasma D-dimer (>or=500 ng mL(-1)) was detected more frequently in patients with SSc than in healthy controls (47.8% vs. 4.5%; P<0.0001). Among vascular manifestations related to SSc, macrovascular impairment responsible for peripheral ischaemia was more frequent in patients with SSc with high levels of D-dimer (>or=500 ng mL(-1)), compared with those without (21% vs. 6%; P=0.05).

CONCLUSIONS

The association between high levels of plasma D-dimer (>or=500 ng mL(-1)) and macrovascular involvement in patients with SSc is likely to be an innovative issue. We suggest that D-dimer levels may be a helpful additional test to identify patients with SSc at risk to develop thrombotic arterial complications (peripheral arterial disease, stroke and coronary event); such patients with high levels of plasma D-dimer (>or=500 ng mL(-1)) may require close monitoring of vascular parameters, including especially macrovascular impairment.