Microcirculation dynamics in systemic vasculitis: evidence of impaired microvascular response regardless of cardiovascular risk factors

Characterization of microvessels in the human forehead dermis using intravascular dual perfusion and immunofluorescence staining

Skin microcirculation provides essential insights in clinical practice. However, the specific characteristics and distribution patterns of dermal microarterioles and microvenules remain insufficiently explored. This study aimed to analyze their structural differences and distribution in the human forehead skin using an innovative intravascular dual perfusion technique combined with immunofluorescence staining to distinguish microvessel types within the dermis. Using two post-mortem cadaver specimens, lead oxide-gelatin perfusion was applied to label microarterioles, and latex was used for microvenules. Tissue sections underwent hematoxylin and eosin and immunofluorescence staining, with cluster of differentiation 31 (CD31) serving as a general vascular marker and monocarboxylate transporter 1 (MCT1) as a venule-specific marker. The analysis revealed significant structural differences between dermal layers: vessels in the deep dermis had larger diameters and thicker walls than those in the superficial layer, while microvessel density was higher in the superficial dermis. These findings demonstrate distinct patterns and significant differences in microvessel distribution between the superficial and deep dermal layers, reflecting their layer-specific functional demands. Furthermore, MCT1 was identified as a specific marker for microvenules, and a novel method combining CD31 and MCT1 immunofluorescent staining was introduced to differentiate dermal microarterioles from microvenules. These results offer valuable implications for surgical planning, skin grafting, and diagnostics related to microcirculation.

Residual Traditional Risk in Non-Traditional Atherosclerotic Diseases

Individuals with chronic inflammatory and immune disorders are at an increased risk of atherosclerotic events and premature cardiovascular (CV) disease. Despite extensive literature exploring the relationship between "non-traditional" atherosclerotic conditions and CV risk, many aspects remain unresolved, including the underlying mechanisms promoting the "non-traditional CV risk", the development of an innovative and comprehensive CV risk assessment tool, and recommendations for tailored interventions. This review aims to evaluate the available evidence on key "non-traditional" CV risk-enhancer conditions, with a focus on assessing and managing CV risk factors. We conducted a comprehensive review of 412 original articles, narrative and systematic reviews, and meta-analyses addressing the CV risk associated with "non-traditional" atherosclerotic conditions. The analysis examined the underlying mechanisms of these relationships and identified strategies for assessing and mitigating elevated risk. A major challenge highlighted is the difficulty in quantifying the contribution of individual risk factors and disease-specific elements to CV risk. While evidence supports the cardiovascular benefits of statins beyond lipid lowering, such as pleiotropic and endothelial effects, current guidelines lack specific recommendations for the use of statins or other therapies targeting non-traditional CV risk factors. Additionally, the absence of validated cardiovascular risk scores that incorporate non-traditional risk factors hinders accurate CV risk evaluation and management. The growing prevalence of "non-traditional CV risk-enhancer conditions" underscores the need for improved awareness of CV risk assessment and management. A thorough understanding of all contributing factors, including disease-specific elements, is crucial for accurate prediction of cardiovascular disease (CVD) risk. This represents an essential foundation for informed decision-making in primary and secondary prevention. We advocate for future research to focus on developing innovative, disease-specific CV risk assessment tools that incorporate non-traditional risk factors, recognizing this as a promising avenue for translational and clinical outcome research.

Integrated bioinformatic analysis of the shared molecular mechanisms between ANCA-associated vasculitis and atherosclerosis

BACKGROUND AND OBJECTIVE

Accumulated evidence supports the tendency of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis(AAV) to coexist with atherosclerosis (AS). However, the common etiology of these two diseases remains unclear. This study aims to explore the mechanisms underlying the concurrent occurrence of ANCA and AS.

METHODS

Microarray data of AAV and AS were examined in a comprehensive gene expression database. Weighted gene co-expression network analysis (WGCNA) and differential gene expression analysis (GEO2R) were performed to identify common genes between AAV and AS. Based on the co-expressed genes, functional enrichment analysis, protein-protein interaction (PPI) network analysis, and identification of hub genes (HGs) were conducted. Subsequently, co-expression analysis of HGs was performed, and their expression and diagnostic value were validated. We further explored immune cell infiltration and analyzed the correlation between HGs and infiltrating immune cells. Finally, the reliability of the selected pathways was verified.

RESULTS

The results of the common gene analysis suggest that immune and inflammatory responses may be common features in the pathophysiology of AAV and AS. Through the interaction of different analysis results, we confirmed five HGs (CYBB, FCER1G, TYROBP, IL10RA, CSF1R). The CytoHubba plugin and HG validation demonstrated the reliability of the selected five HGs. Co-expression network analysis revealed that these five HGs could influence monocyte migration. Analysis of immune cell infiltration showed that monocytes in ANCA and M0 macrophages in AS constituted a higher proportion of all infiltrating immune cells, with significant differences in infiltration. We also found significant positive correlations between CYBB, FCER1G, TYROBP, IL10RA, CSF1R, and monocytes/M0 macrophages in AAV, as well as between CYBB, FCER1G, TYROBP, IL10RA, CSF1R, and M0 macrophages in AS.

CONCLUSION

These five HGs can promote monocyte differentiation into macrophages, leading to the concurrent occurrence of AAV and AS. Our study provides insights into the mechanisms underlying the coexistence of AAV and AS.

Skin Microvascular Dysfunction in Type 2 Diabetes Mellitus Using Laser Speckle Contrast Analysis and Association with Carotid Intima-Media Thickness

Background: It is established that diabetes mellitus (DM) is characterized by increased cardiovascular risk associated with subclinical atherosclerosis as well as microvascular alterations. Laser speckle contrast analysis (LASCA) is an innovative, non-invasive method for assessing skin microvascular function. Objectives: We sought to assess skin microvascular function in patients with type 2 DM and matched controls. Methods: Consecutive patients with DM and individuals matched for age, sex and BMI were included in the study. Skin microvascular perfusion was assessed, using LASCA, during baseline, a 5 min occlusion period and a 5 min reperfusion period. Carotid intima-media thickness (cIMT) was measured as a surrogate marker of macrocirculation. Results: In total, 18 patients with DM and 22 in the control group were enrolled. No statistically significant differences were observed in baseline flux, peak flux and percentage decrease during arterial occlusion. During reperfusion, individuals with DM exhibited a smaller peak magnitude compared to controls (147.0 ± 64.7% vs. 189.4 ± 46.0%, respectively; p < 0.05). Moreover, cIMT was higher in patients with DM compared to controls (0.68 ± 0.09 mm vs. 0.60 ± 0.08 mm, respectively, p < 0.01) and was negatively correlated with skin microvascular reactivity in the univariate analysis. In the multivariate analysis, glucose and office systolic blood pressure levels remained significant predictors of microvascular reactivity. Conclusions: Our study shows that patients with type 2 DM exhibit impaired skin microvascular function compared to controls. Furthermore, glucose levels and blood pressure play a key role in microvascular dysfunction. However, additional studies are needed to address the clinical significance of early microvascular changes in DM.

Clinical Significance of Altered Vascular Morphology and Function in Normotension

PURPOSE OF REVIEW

To review current literature examining the presence of subclinical micro- and macrovascular alterations in normotensive individuals and their clinical significance in terms of hypertension prediction. Emphasis is placed on alterations that can be detected in peripheral vascular beds using non-invasive, easily applicable methodology, as these are in general easier to capture and evaluate in clinical practice compared to more complex invasive or functional tests.

RECENT FINDINGS

Arterial stiffness, increased carotid intima-media thickness, and altered retinal microvascular diameters predict the progression from the normotensive to the hypertensive state. By contrast, there is substantial lack of relevant prospective studies for skin microvascular alterations. Although conclusions regarding causality cannot be safely deduced from available studies, detection of morphological and functional vascular alterations in normotensive individuals emerges as a sensitive indicator of progression to hypertension and hence increased CVD risk. An increasing amount of evidence suggests that early detection of subclinical micro- and macrovascular alterations would be clinically useful for the early identification of individuals at high risk for future hypertension onset. Methodological issues and gaps in knowledge need to be addressed before detection of such changes could guide the development of strategies to prevent new-onset hypertension in normotensive individuals.