Pathogenesis of vasculopathy in systemic sclerosis and its contribution to fibrosis

Retinal Vascular Abnormalities and Clinical Parameters in Systemic Sclerosis

Background: Systemic sclerosis is a complex autoimmune disease characterized by vasculopathy, fibrosis, and immune dysregulation. Ocular manifestations in these patients are increasingly recognized, suggesting potential correlations between systemic vascular abnormalities and ocular microvascular changes. Advancements in molecular immunology and imaging technology using ocular coherence tomography (OCT) have unveiled intricate pathways underlying possible disease pathogenesis. Understanding the interplay between retinal vascular abnormalities and molecular immunology parameters could provide insights into disease mechanisms and potential biomarkers. Purpose: The aim of this study was to investigate vascular abnormalities, detected with optical coherence tomography angiography (OCT-A), in systemic sclerosis patients and to find correlations between the severity of the disease detected with molecular immunology findings and OCT-A parameters. Methods: A group of 32 systemic sclerosis patients were compared with 9 healthy controls. Ganglion cell complex thickness (GCC), retina thickness of the fovea and parafovea, nerve fiber layer thickness (RNFL) and cup/disc area ratio were investigated using OCT. Vessel density (VD) of the superficial (SCP) and deep capillary plexus (DCP) of the whole macular area and ETDRS grid, size of the foveal avascular zone (FAZ) and vessel density of the radial peripapillary capillary plexus (RPCP) were evaluated using OCT-A. Modified Rodnan skin score (mRSS), capillaroscopy and disease duration were used to stage disease severity. Results: There was a statistically significant reduction in retina thickness of the fovea and parafovea, VD of the whole DCP, VD of the SCP and DCP in ETDRS grid in the patient group compared to controls (p < 0.001). The patients presented a significant enlargement of the FAZ (p 0.005). No significant correlation between OCT and OCT-A parameters and disease severity scores was found. Conclusions: OCT-A could represent a non-invasive tool to detect retinal microvascular damage in systemic sclerosis.

Fibrosis-on-Chip: A Guide to Recapitulate the Essential Features of Fibrotic Disease

Fibrosis, which is primarily marked by excessive extracellular matrix (ECM) deposition, is a pathophysiological process associated with many disorders, which ultimately leads to organ dysfunction and poor patient outcomes. Despite the high prevalence of fibrosis, currently there exist few therapeutic options, and importantly, there is a paucity of in vitro models to accurately study fibrosis. This review discusses the multifaceted nature of fibrosis from the viewpoint of developing organ-on-chip (OoC) disease models, focusing on five key features: the ECM component, inflammation, mechanical cues, hypoxia, and vascularization. The potential of OoC technology is explored for better modeling these features in the context of studying fibrotic diseases and the interplay between various key features is emphasized. This paper reviews how organ-specific fibrotic diseases are modeled in OoC platforms, which elements are included in these existing models, and the avenues for novel research directions are highlighted. Finally, this review concludes with a perspective on how to address the current gap with respect to the inclusion of multiple features to yield more sophisticated and relevant models of fibrotic diseases in an OoC format.

Association between systemic sclerosis and risk of cerebrovascular and cardiovascular disease: a meta-analysis

We aimed to evaluate the association between systemic sclerosis (SSc) and major cerebrovascular/cardiovascular risks through a systematic approach. Databases were systematically searched from their inception to October 10, 2023 for studies comparing cerebrovascular/cardiovascular event rates between patients with SSc and controls. The primary outcome was the stroke risk in patients with SSc. Secondary outcomes included risk of myocardial infarction (MI), cardiovascular disease (CVD), peripheral vascular disease (PVD), and venous thromboembolism (VTE). Seventeen studies with 6,642,297 participants were included. SSc was associated with a significantly increased risk of stroke (HR, 1.64; 95% confidence interval [CI], 1.35-2.01), CVD (HR, 2.12; 95% CI, 1.36-3.3), MI (HR, 2.15; 95% CI, 1.23-3.77), VTE (HR, 2.75; 95% CI, 1.77-4.28), and PVD (HR, 5.23; 95% CI, 4.25-6.45). Subgroup analysis revealed a significantly increased stroke risk in the non-Asian group (HR, 1.55; 95% CI, 1.26-1.9), while the Asian group displayed a higher but not statistically significant risk (HR, 1.86; 95% CI, 0.97-3.55). The study found that SSc is associated with a significantly increased risk of cerebrovascular/cardiovascular events. These findings highlight the importance of vasculopathy in SSc and suggest the need for enhanced clinical monitoring and preventive measures in this high-risk population.

Association between systemic sclerosis and venous thromboembolism, pulmonary embolism, and deep vein thrombosis: a meta-analysis

OBJECTIVE

This study aimed to analyze the published data pertaining to the correlation between venous thromboembolism (VTE) and systemic sclerosis (SSc).

METHODS

We conducted manual searches and explored MEDLINE, EMBASE, and Cochrane databases to review papers reporting the risk of VTE in patients with SSc. A meta-analysis was performed exploring the relative risks (RRs) of deep vein thrombosis (DVT), pulmonary embolism (PE), and VTE in these individuals.

RESULTS

Six trials that included 41,105 patients with SSc were eligible for inclusion. A meta-analysis of the six included studies revealed a statistically significant correlation (RR 2.372, 95% confidence interval [CI] = 1.608-3.500, p < 0.001) between the risk of VTE and SSc. Regional subgroup study revealed a strong correlation between SSc and VTE risk in Americans, Europeans, and Asians. Additionally, a significant correlation between SSc and PE risk was observed (RR 3.154, 95% CI = 1.320-7.539, p = 0.010). Finally, the meta-analysis revealed a substantial correlation (RR 5.190, 95% CI = 1.513-17.01, p = 0.009) between the risk of DVT and SSc.

CONCLUSION

This meta-analysis showed that SSc is linked to an increased risk of DVT, PE, and VTE. This finding underscores the importance of close monitoring for the emergence of these conditions in patients with SSc.

The contribution of endothelial cells to tissue fibrosis

PURPOSE OF REVIEW

Tissue fibrosis is an increasingly prevalent condition associated with various diseases and heavily impacting on global morbidity and mortality rates. Growing evidence indicates that common cellular and molecular mechanisms may drive fibrosis of diverse cause and affecting different organs. The scope of this review is to highlight recent findings in support for an important role of vascular endothelial cells in the pathogenesis of fibrosis, with a special focus on systemic sclerosis as a prototypic multisystem fibrotic disorder.

RECENT FINDINGS

Although transition of fibroblasts to chronically activated myofibroblasts is widely considered the central profibrotic switch, the endothelial cell involvement in development and progression of fibrosis has been increasingly recognized over the last few years. Endothelial cells can contribute to the fibrotic process either directly by acting as source of myofibroblasts through endothelial-to-myofibroblast transition (EndMT) and concomitant microvascular rarefaction, or indirectly by becoming senescent and/or secreting a variety of profibrotic and proinflammatory mediators with consequent fibroblast activation and recruitment of inflammatory/immune cells that further promote fibrosis.

SUMMARY

An in-depth understanding of the mechanisms underlying EndMT or the acquisition of a profibrotic secretory phenotype by endothelial cells will provide the rationale for novel endothelial cell reprogramming-based therapeutic approaches to prevent and/or treat fibrosis.

Digital Ulcers and Ventricular Arrhythmias as Red Flags to Predict Replacement Myocardial Fibrosis in Systemic Sclerosis

BACKGROUND

Cardiac involvement in systemic sclerosis (SSc) affects the prognosis of the disease. Echocardiography is the first line imaging tool to detect cardiac involvement, but it is not able to routinely detect myocardial fibrosis. Late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) is the gold standard for replacement myocardial fibrosis assessment, but its availability is currently limited.

AIM

We aimed to assess the clinical and instrumental parameters that would be useful for predicting the presence of LGE-CMR, to achieve a better selection of patients with SSc that could benefit from third-level CMR imaging.

METHODS

344 SSc patients underwent a comprehensive echocardiogram and LGE-CMR on the same day; for 189 patients, a 24 h ECG Holter monitoring was available.

RESULTS

CMR showed non-junctional replacement myocardial fibrosis via LGE in 25.1% patients. A history of digital ulcers (OR 2.188; 95% C.I. 1.069-4.481) and ventricular arrhythmias at ECG Holter monitoring (OR 3.086; 95% C.I. 1.191-7.998) were independent predictors of replacement myocardial fibrosis.

CONCLUSIONS

CMR can detect patterns of clinical and subclinical cardiac involvement, which are frequent in SSc. A history of digital ulcers and evidence of ventricular arrhythmias at ECG Holter monitoring are red flags for the presence of replacement myocardial fibrosis in CMR. The association between digital ulcers and myocardial fibrosis suggests that a similar pathological substrate of abnormal vascular function may underlie peripheral vascular and cardiac complications.