Capillary dimension measured by computer-based digitalized image correlated with plasma endothelin-1 levels in patients with systemic sclerosis

Endothelin-1 as a Candidate Biomarker of Systemic Sclerosis: A GRADE-Assessed Systematic Review and Meta-Analysis With Meta-Regression

Background

There is an ongoing search for novel biomarkers of vascular dysfunction, extent of fibrosis and organ involvement in systemic sclerosis (SSc).

Objectives

We critically appraised the studies investigating the circulating concentrations of endothelin-1 in SSc patients and healthy controls.

Design

This was a systematic review with meta-analysis.

Data sources and methods

We searched electronic databases (PubMed, Scopus, and Web of Science) from inception to 15 June 2024. We assessed the risk of bias and the certainty of evidence using the JBI Critical Appraisal Checklist and GRADE, respectively.

Results

Endothelin-1 concentrations were significantly higher in SSc patients than in controls (26 studies; standardised mean difference, SMD = 0.98, 95% CI 0.73-1.23, P < .001; moderate certainty of evidence). In SSc patients, there were no significant differences in endothelin-1 concentrations between those with limited and diffuse cutaneous SSc (10 studies; SMD = 0.32, 95% CI -0.07 to 0.71 P = .11; very low certainty), and with and without digital ulcers (5 studies; SMD = 0.82, 95% CI -0.06 to 1.69, P = .066; very low certainty), pulmonary arterial hypertension (7 studies; SMD = 0.22, 95% CI -0.01 to 0.45, P = .066; very low certainty) or interstitial lung disease (3 studies; SMD = 0.09, 95% CI -0.18 to 0.35, P = .51; very low certainty). There was limited evidence in SSc patients with different video capillaroscopy pattern and telangiectasias. Subgroup and meta-regression analyses showed significant associations between the effect size and geographical location (studies investigating SSc patients and controls), year of publication (studies investigating SSc patients with limited and diffuse cutaneous SSc), and biological matrix assessed (studies investigating SSc patients with and without digital ulcers).

Conclusion

The results of this systematic review and meta-analysis highlight the potential role of endothelin-1 as a candidate biomarker of SSc. Further research is warranted to determine the utility of measuring endothelin-1 in SSc subgroups with different extent of fibrosis and organ involvement.

Registration

PROSPERO registration number - CRD42024566461.

Hybrid enhancement algorithm for nailfold images with large fields of view

Collecting and analyzing human nailfold images is an important component of studying human microcirculation. However, the large-field-of-view and high-resolution nailfold images captured by research microscopes introduce issues such as uneven brightness, low imaging contrast, and unclear vascular contours. To overcome these issues, this paper proposes a hybrid enhancement algorithm for nailfold images with large fields of view. First, adaptive histogram equalization with limited contrast (Clahe) is used to redistribute gray levels to enhance the brightness and contrast of images. Next, nonlocal means denoising (NL-means) is used to remove the noise amplified by Clahe algorithm. Finally, unsharp masking (Usm) is used to enhance the edge contour information of nailfold blood vessels. Comparing the enhanced images reveals that the hybrid enhancement algorithm improves the brightness and contrast of the nailfold image, makes the nailfold vessel contour more obvious, and the image noise continues to remain small, and it obtains the best visual effect. It is superior to other algorithms in terms of objective indicators and subjective evaluation.

Serum Biomarkers in Connective Tissue Disease-Associated Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a life-threatening complication of connective tissue diseases (CTDs) characterised by increased pulmonary arterial pressure and pulmonary vascular resistance. CTD-PAH is the result of a complex interplay among endothelial dysfunction and vascular remodelling, autoimmunity and inflammatory changes, ultimately leading to right heart dysfunction and failure. Due to the non-specific nature of the early symptoms and the lack of consensus on screening strategies-except for systemic sclerosis, with a yearly transthoracic echocardiography as recommended-CTD-PAH is often diagnosed at an advanced stage, when the pulmonary vessels are irreversibly damaged. According to the current guidelines, right heart catheterisation is the gold standard for the diagnosis of PAH; however, this technique is invasive, and may not be available in non-referral centres. Hence, there is a need for non-invasive tools to improve the early diagnosis and disease monitoring of CTD-PAH. Novel serum biomarkers may be an effective solution to this issue, as their detection is non-invasive, has a low cost and is reproducible. Our review aims to describe some of the most promising circulating biomarkers of CTD-PAH, classified according to their role in the pathophysiology of the disease.

Current Trends in Vascular Biomarkers for Systemic Sclerosis: A Narrative Review

Systemic sclerosis (SSc, scleroderma) is a multifaceted rare connective tissue disease whose pathogenesis is dominated by immune dysregulation, small vessel vasculopathy, impaired angiogenesis, and both cutaneous and visceral fibrosis. Microvascular impairment represents the initial event of the disease, preceding fibrosis by months or years and accounting for the main disabling and/or life-threatening clinical manifestations, including telangiectasias, pitting scars, periungual microvascular abnormalities (e.g., giant capillaries, hemorrhages, avascular areas, ramified/bushy capillaries) clinically detectable by nailfold videocapillaroscopy, ischemic digital ulcers, pulmonary arterial hypertension, and scleroderma renal crisis. Despite a variety of available treatment options, treatment of SSc-related vascular disease remains problematic, even considering SSc etherogenity and the quite narrow therapeutic window. In this context, plenty of studies have highlighted the great usefulness in clinical practice of vascular biomarkers allowing clinicians to assess the evolution of the pathological process affecting the vessels, as well as to predict the prognosis and the response to therapy. The current narrative review provides an up-to-date overview of the main candidate vascular biomarkers that have been proposed for SSc, focusing on their main reported associations with characteristic clinical vascular features of the disease.

Correlation between Microvascular Damage and Internal Organ Involvement in Scleroderma: Focus on Lung Damage and Endothelial Dysfunction

BACKGROUND

Systemic sclerosis (SSc) is an incurable connective tissue disease characterized by decreased peripheral blood perfusion due to microvascular damage and skin thickening/hardening. The microcirculation deficit is typically secondary to structural vessel damage, which can be assessed morphologically and functionally in a variety of ways, exploiting different technologies.

OBJECTIVE

This paper focuses on reviewing new studies regarding the correlation between microvascular damage, endothelial dysfunction, and internal organ involvement, particularly pulmonary changes in SSc.

METHODS

We critically reviewed the most recent literature on the correlation between blood perfusion and organ involvement.

RESULTS

Many papers have demonstrated the link between structural microcirculatory damage and pulmonary involvement; however, studies that have investigated correlations between microvascular functional impairment and internal organ damage are scarce. Overall, the literature supports the correlation between organ involvement and functional microcirculatory impairment in SSc patients.

CONCLUSIONS

Morphological and functional techniques appear to be emerging biomarkers in SSc, but obviously need further investigation.

The role of endothelin and RAS/ERK signaling in immunopathogenesis-related fibrosis in patients with systemic sclerosis: an updated review with therapeutic implications

Systemic sclerosis (SSc) is a disease of connective tissue with high rate of morbidity and mortality highlighted by extreme fibrosis affecting various organs such as the dermis, lungs, and heart. Until now, there is no specific cure for the fibrosis occurred in SSc disease. The SSc pathogenesis is yet unknown, but transforming growth factor beta (TGF-β), endothelin-1 (ET-1), and Ras-ERK1/2 cascade are the main factors contributing to the tissue fibrosis through extracellular matrix (ECM) accumulation. Several studies have hallmarked the association of ET-1 with or without TGF-β and Ras-ERK1/2 signaling in the development of SSc disease, vasculopathy, and fibrosis of the dermis, lungs, and several organs. Accordingly, different clinical and experimental studies have indicated the potential therapeutic role of ET-1 and Ras antagonists in these situations in SSc. In addition, ET-1 and connective tissue growth factor (CTGF) as a cofactor of the TGF-β cascade play a substantial initiative role in inducing fibrosis. Once initiated, TGF-β alone or in combination with ET-1 and CTGF can activate several kinase proteins such as the Ras-ERK1/2 pathway that serve as the fundamental factor for developing fibrosis. Furthermore, Salirasib is a synthetic small molecule that is able to inhibit all Ras forms. Therefore, it can be used as a potent therapeutic factor for fibrotic disorders. So, this review discusses the role of TGF-β/ET-1/Ras signaling and their involvement in SSc pathogenesis, particularly in its fibrotic situation.

The Relationship between Pulmonary Damage and Peripheral Vascular Manifestations in Systemic Sclerosis Patients

Systemic sclerosis (SSc) is an autoimmune disease, characterized by the presence of generalized vasculopathy and tissue fibrosis. Collagen vascular disorder in SSc is due to fibroblast and endothelial cell dysfunctions. This leads to collagen overproduction, vascular impairment and immune system abnormalities and, in the last stage, multi-organ damage. Thus, to avoid organ damage, which has a poor prognosis, all patients should be carefully evaluated and followed. This is particularly important in the initial disease phase, so as to facilitate early identification of any organ involvement and to allow for appropriate therapy. Pulmonary disease in SSc mainly involves interstitial lung disease (ILD) and pulmonary arterial hypertension (PAH). High-resolution computed tomography (HRCT) and pulmonary function tests (PFT) have been proposed to monitor parenchymal damage. Although transthoracic echocardiography is the most commonly used screening tool for PAH in SSc patients, definitive diagnosis necessitates confirmation by right heart catheterization (RHC). Moreover, some studies have demonstrated that nailfold videocapillaroscopy (NVC) provides an accurate evaluation of the microvascular damage in SSc and is able to predict internal organ involvement, such as lung impairment. This review provides an overview of the correlation between lung damage and microvascular involvement in SSc patients.

Soluble Biomarkers for Prediction of Vascular and Gastrointestinal Disease Severity in Patients with Systemic Sclerosis

Purpose of Review

Disease severity biomarkers in patients with systemic sclerosis (SSc) provide an early and noninvasive screening tool to identify patients at increased risk for internal organ involvement that may impact diagnostic testing and treatment decisions. This review will focus on soluble SSc vascular and gastrointestinal disease biomarkers.

Recent Findings

Due to high morbidity and mortality associated with SSc pulmonary hypertension, multiple biomarkers are currently under investigation including serum autoantibodies, chemistries [such as N-terminal pro-brain natriuretic peptide (NT-proBNP)], proteins [midkine (MDK) and follistatin-like 3 (FSTL3)], chemokines [C-X-C motif ligand 4 (CXCL4) and C-C motif ligand 21 (CCL21)], plasma growth factors [vascular endothelial growth factor (VEGF) and placental growth factor (PlGF)], cell adhesion molecules [vascular cell adhesion molecule 1 (VCAM-1)], and endothelial microparticles [CD144+ endothelial microparticle (CD144+ EMP)]. A subset of these have also been proposed as SSc digital ulcer biomarkers [anti-endothelin-1 type A receptor (anti-ETAR), PlGF, and NT-proBNP]. A combination of NT-proBNP and high sensitivity cardiac troponins T (hs-cTnT) and I (hs-cTnI) may be useful for assessing primary SSc cardiac involvement. Putative SSc renal disease biomarkers include VEGF and endostatin levels; while anti-U1 and U3 ribonucleoprotein (anti-U1- and anti-U3-RNP) antibodies and fecal-calprotectin (F-calprotectin) are associated with GI involvement.

Summary

Serum autoantibodies are the mainstay SSc severity biomarkers, but new biomarkers are under investigation.

Potential Biomarkers in Systemic Sclerosis: A Literature Review and Update

Systemic sclerosis (SSc) is a chronic autoimmune disease characterized by dysregulation of the immune system, vascular damage, and fibrosis of the skin and internal organs. Patients with SSc show a heterogeneous phenotype and a range of clinical courses. Therefore, biomarkers that are helpful for precise diagnosis, prediction of clinical course, and evaluation of the therapeutic responsiveness of disease are required in clinical practice. SSc-specific autoantibodies are currently used for diagnosis and prediction of clinical features, as other biomarkers have not yet been fully vetted. Krebs von den Lungen-6 (KL-6), surfactant protein-D (SP-D), and CCL18 have been considered as serum biomarkers of SSc-related interstitial lung disease. Moreover, levels of circulating brain natriuretic peptide (BNP) and N-terminal pro-brain natriuretic peptide (NT-proBNP) can provide diagnostic information and indicate the severity of pulmonary arterial hypertension. Assessment of several serum/plasma cytokines, chemokines, growth factors, adhesion molecules, and other molecules may also reflect the activity or progression of fibrosis and vascular involvement in affected organs. Recently, microRNAs have also been implicated as possible circulating indicators of SSc. In this review, we focus on several potential SSc biomarkers and discuss their clinical utility.

Nailfold capillaroscopic changes in patients with chronic viral hepatitis

BACKGROUND

Nailfold capillaroscopy is a highly sensitive, inexpensive, simple, safe, and noninvasive technique used in the investigation of the microcirculation. However, the diseases having a vasculitic component can cause changes in the nailfold capillaries like viral hepatitis, the microvascular characteristics of the nailfold area in HBV and HCV infected individuals have not been systematically investigated. In this study, we investigated possible dermoscopic differences in the vascular appearance of the nailfold capillaries and their association with the disease's clinical status.

METHOD

A hundred and forty-seven patients and 147 healthy controls were enrolled in this study. The patients' group consisted of chronic viral hepatitis B (CHB: 54 cases), chronic hepatitis C (CHC: 36 cases) and carrier of hepatitis B virus infection (CRHB: 57 cases). Nailfold capillaroscopy was performed using a digital dermoscope (Molemax II, X30). All capillaroscopy images were evaluated for capillary density, capillary loop enlargement, capillary tortuosities, branching vessels, micro hemorrhages, avascular areas and splinter hemorrhages, and routine laboratory examinations of all patients were performed.

RESULTS

Statistical differences in all of the categories of capillary morphology were prominent between the capillary abnormalities of Hepatitis B and the control group, also the capillary abnormality was significant between hepatitis C and the control group (p < 0.01). None of the 147 healthy control had any nailfold capillary changes. There was a significant difference between the CHB-Control and CRHB-Control groups in all of the capillaroscopic changes (p < 0.01). The avascular area was also the most common finding in Hepatitis C and Hepatitis B infected individuals, and capillary dilatation (CD), capillary tortuosity (CT) and capillary enlargement (CE) were the major nailfold capillary changes in both of two diseases.

CONCLUSION

Nailfold capillary abnormalities are one of the extrahepatic dermatologic finding which could be a sign of the endothelial tissue damage in chronic viral hepatitis, we do not have any data about the effects of these two usual infections on the nailfold capillary morphology. This is the first study evaluating the microvasculature abnormalities of the nailfold capillaries in hepatitis B and hepatitis C infected individuals by capillaroscopic examination.

Microangiopathy in Naifold Videocapillaroscopy and Its Relations to sE- Selectin, Endothelin-1, and hsCRP as Putative Endothelium Dysfunction Markers among Adolescents with Raynaud's Phenomenon

The aim of this study was to analyze the relationship between the qualitative abnormalities on nailfold videocapillaroscopy (NVC), and the concentrations of selected biomarkers (sE-selectin, endothelin-1, high-sensitivity c-reactive protein (hsCRP)) and lipid metabolism parameters in children and adolescents with Raynaud’s phenomenon (RP). Raynaud’s phenomenon, to assess whether nailfold capillary changes may reflect the degree of systemic blood vessel abnormalities. The study group included 66 patients (34 undifferentiated—uRP and 32 secondary—sRP) aged 6–19 years and the control group. In both groups, NVC was performed and the selected biomarkers were measured (sE-selectin, endothelin-1, hsCRP) and lipid profile. Endothelin-1, sE-selectin and hsCRP concentrations in patients from both RP groups were significantly higher; concentration of HDL fraction was significantly lower compared with the control group. The analysis of multiple linear regression demonstrated that megacapillaries most strongly determine the sE-selectin value (p = 0.04) and hsCRP (p = 0.03). Both the total cholesterol and low-density lipoprotein (LDL) fraction concentrations were determined by the presence of avascular areas (p = 0.02). In conclusion, specific pathologic NVC changes were associated with higher endothelial damage biomarkers concentration and adverse changes in the lipid profile.

Diagnostic value of nailfold videocapillaroscopy in systemic sclerosis secondary pulmonary arterial hypertension: a meta-analysis

BACKGROUND

Microvascular changes play a decisive role in systemic sclerosis (SSc) and occur early in the course of the disease. Pulmonary arterial hypertension (PAH) represents one of the main clinical expressions of the vascular changes in SSc, and the abnormal changes, especially capillary density and capillary width, are detectable at nailfold videocapillaroscopy (NVC).

AIMS

To investigate the differences in capillary nailfold changes in SSc patients with and without PAH and to estimate the early diagnostic value of NVC in SSc secondary PAH (SSc-PAH).

METHODS

A comprehensive literature search of MEDLINE and PUBMED was performed to identify published studies without language restrictions. The methodological quality of the included studies was evaluated. The pooled specificity, sensitivity, positive likelihood rate, negative likelihood rate, diagnostic odds ratio, area under the curve and Q value were found using Meta-Disc version 1.4 software packages. Finally, seven studies were included in this meta-analysis.

RESULTS

The meta-analysis demonstrated that the diagnostic odds ratio, area under the curve and Q value were 5.84 (95% confidence interval: 1.95-17.54), 0.79 and 0.72 respectively. It indicated that the microvascular changes detected at NVC were significant in SSc-PAH and especially showed significantly lower capillary density and higher capillary width.

CONCLUSION

The NVC may be a valuable tool for the early diagnosis of SSc-PAH. It can detect the early microvascular changes associated with the risk of PAH and has a significant role in the early prediction of SSc-PAH.

Image enhancement effect on inter and intra-observer reliability of nailfold capillary assessment

BACKGROUND

Nailfold capillaroscopy (NC) is a diagnostic imaging technique that is used to assess the blood capillary network in the nailfold area. NC is routinely used for patients with microcirculation problems, such as systemic sclerosis and other connective tissue diseases. Experts commonly use subjective evaluation as a reference point in images of nailfold video capillaroscopy, so it is important to reduce the inherent ambiguities in human judgment and diagnosis. Image quality is an important factor that affects measurement error and assessment time of NC images.

OBJECTIVE

In this study, a new image enhancement technique was introduced and evaluated subjectively.

METHODS

In total, 475 nailfold video capillaroscopy images from 18 healthy subjects and 41 systemic lupus erythematosus patients were used. The images were randomly divided into two sets, one each with 275 and 200. Eight independent observers who were familiar with the capillaroscopy technique participated in this study. The set of 275 images was evaluated by three observers with the forced-choice pairwise comparison method. Elliptic broken line (EBL) was used to count the number of capillaries. The intra- and inter-observer reliability of the original and enhanced images was evaluated on 200 images by five observers.

RESULT

Except for eight images, all observers preferred the enhanced images in the visual quality comparison method. The intra-class correlation coefficient (ICC) of intra- and inter-observer reliability increased from 0.76-0.84 to 0.82-0.89, respectively, when using the enhancement method.

CONCLUSION

By improving the image quality, more capillary details will be visible, and an observer can document more details that may not be visible in the original image and can do so more efficiently.

Biomarkers for Pulmonary Vascular Remodeling in Systemic Sclerosis: A Pathophysiological Approach

Pulmonary arterial hypertension (PAH) is a severe complication of systemic sclerosis (SSc) associated with high morbidity and mortality. There are several biomarkers of SSc-PAH, reflecting endothelial physiology, inflammation, immune activation, extracellular matrix, metabolic changes, or cardiac involvement. Biomarkers associated with diagnosis, disease severity and progression have been identified, however, very few have been tested in a prospective setting. Some antinuclear antibodies such as nucleosome antibodies (NUC), anti-centromere antibodies (CENP-A/B) and anti-U3-ribonucleoprotein (anti-U3-RNP) are associated with PAH while anti-U1-ribonucleoprotein (anti-U1-RNP) is associated with a reduced PAH risk. Anti-endothelin receptor and angiotensin-1 receptor antibodies might be good markers of SSc-PAH and progression of pulmonary vasculopathy. Regarding the markers reflecting immune activation and inflammation, there are many inconsistent results. CXCL-4 was associated with SSc progression including PAH and lung fibrosis. Growth differentiation factor (GDF)-15 was associated with PAH and mortality but is not specific for SSc. Among the metabolites, kynurenine was identified as diagnostic marker for PAH, however, its pathologic role in the disease is unclear. Endostatin, an angiostatic factor, was associated with heart failure and poor prognosis. Established heart related markers, such as N-terminal fragment of A-type natriuretic peptide/brain natriuretic peptide (NT-proANP, NT-proBNP) or troponin I/T are elevated in SSc-PAH but are not specific for the right ventricle and may be increased to the same extent in left heart disease. Taken together, there is no universal specific biomarker for SSc-PAH, however, there is a pattern of markers that is strongly associated with a risk of vascular complications in SSc patients. Further comprehensive, multicenter and prospective studies are warranted to develop reliable algorithms for detection and prognosis of SSc-PAH.

Advances in nailfold capillaroscopic analysis in systemic sclerosis

Systemic sclerosis is an autoimmune connective tissue disease characterized by early and persistent microvascular impairment which leads to functional and organic manifestations, with progressive fibrosis of the skin and internal organs. Morphological and functional assessment of the peripheral microvasculature is a must, not only for diagnosis but also for the prognosis and therapeutical follow-up of systemic sclerosis patients, as reported in recent studies. Nailfold videocapillaroscopy is the validated technique for the study of scleroderma microangiopathy as it is able to detect peripheral microvascular morphology and both classify and score the capillary abnormalities into different microangiopathy patterns ('Early', 'Active' and 'Late'). Indeed, the possibility to early diagnose and follow the microvascular changes and the safety of the technique have made nailfold videocapillaroscopy a mandatory tool for patient evaluation and included its assessment in the new systemic sclerosis classification criteria. Important links between nailfold videocapillaroscopy patterns and systemic sclerosis clinical manifestations have been described.

Endothelin-1, α-Klotho, 25(OH) Vit D levels and severity of disease in scleroderma patients

Considering the role of endothelin-1 (ET-1) in tissue remodeling and fibrosis during the development of scleroderma as well as the effect of α-Klotho in pathogenesis of calcinosis and/or endothelial cell injury and its correlation with severity of disease, this study aimed to evaluate serum ET-1, α-Klotho and 25(OH) vitamin D levels in patients with limited and diffuse scleroderma compared to healthy subjects. In this cross-sectional study, 60 scleroderma patients according to the ACR/EULAR 2013 criteria and 60 age- and sex-matched healthy controls were included. In patients, clinical examination was performed and Medsger severity scale was assessed. Serum ET-1, soluble α-Klotho and 25(OH)D₃ levels were measured using ELISA kits. The mean ± SD age of patients and controls was 46.2 ± 9.6 and 47.2 ± 7.0 years, respectively. Compared to healthy controls, serum ET-1 was significantly higher in SSc patients (p = 0.001); whilst serum α-Klotho and 25(OH)D₃ were significantly lower in patients (p = 0.001). The most common organs involved in patients were skin, lung, peripheral vascular and gastrointestinal system and the severity of involvement was mainly mild and/or moderate. There were no significant differences in serum ET-1 and α-Klotho levels according to the severity of different organ involvement (p > 0.05). There was no significant correlation between presence or absence of calcinosis and negative or positivity of auto-antibodies with ET-1, α-Klotho and 25(OH)D₃ levels. Although our study revealed higher serum ET-1 and lower serum α-Klotho levels in SSc patients compared to healthy controls, there were not any significant correlations between their serum levels with severity of organ involvement.

Biomarkers in systemic sclerosis: Their potential to predict clinical courses

The concept of a biomarker was defined as "a characteristic marker that is objectively measured and evaluated as an indicator of normal biological processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention" by the National Institutes of Health Biomarkers Definitions Working group in 2001. Clinical features, disease progress, therapeutic response and prognosis are heterogeneous among patients with systemic sclerosis (SSc). Therefore, biomarkers that can predict these matters are required for the progress of clinical practice. At present, SSc-specific autoantibodies are the most useful biomarkers for diagnosis and predicting clinical features. Otherwise, biomarkers specific only for SSc have not been identified yet. The glycoprotein krebs von den Lungen-6, surfactant protein-D and CCL18 are promising serum biomarkers of SSc-related interstitial lung diseases. Serum/plasma levels of brain natriuretic peptide and serum N-terminal pro-brain natriuretic peptide have been used as biomarkers for SSc-related pulmonary arterial hypertension. Other potential serum/plasma biomarkers for fibrosis and vascular involvement of SSc are connective tissue growth factor, interleukin-6, CCL2, CXCL4, intercellular adhesion molecule (ICAM)-1, P-selectin, vascular endothelial growth factor, von Willebrand factor, endostatin, endoglin and endothelin-1. In our multicenter prospective studies of Japanese early SSc, serum ICAM-1 levels were predictive for subsequent respiratory dysfunction and serum levels of CXCL8 and P-selectin were predictive for subsequent physical disability. Further large, multicenter, prospective, longitudinal studies will be needed to identify and validate critical biomarkers of SSc.

Capillary density: An important parameter in nailfold capillaroscopy

Nailfold capillaroscopy is one of the various noninvasive bioengineering methods used to investigate skin microcirculation. It is an effective examination for assessing microvascular changes in the peripheral circulation; hence it has a significant role for the diagnosis of Systemic sclerosis with the classic changes of giant capillaries as well as the decline in capillary density with capillary dropout. The decline in capillary density is one of microangiopathic features existing in connective tissue disease. It is detectable with nailfold capillaroscopy. This parameter is assessed by applying quantitative measurement. In this article, we reviewed a common method for calculating the capillary density and the relation between the number of capillaries as well as the existence of digital ulcers, pulmonary arterial hypertension, autoantibodies, scleroderma patterns and different scoring system.

Nailfold capillaroscopy assessment of microcirculation abnormalities and endothelial dysfunction in children with primary or secondary Raynaud syndrome

Raynaud syndrome (RS) manifests as episodes of transient spasms of peripheral blood vessels, most often in response to cold. The reason of that symptom (primary RS (pRS)) usually cannot be found but may be accompanied by some autoimmune diseases (secondary RS (sRS)). In this study, we assessed microcapillary status and serum concentrations of chosen cytokines, adhesive molecules, and nitric oxide (NO) in patients with pRS and sRS in comparison with healthy children. Eighty-six patients with RS were enrolled into the study, including 52 with pRS and 34 with sRS. The control group consisted of 29 healthy children. A decrease in myorelaxative and anticoagulant abilities was observed, with simultaneous prevalence of vasopressor substances and procoagulative activity. Therefore, several important factors such as endothelin-1 (ET-1), E-selectin (E-sel), interleukin-18 (IL-18), and nitrogen oxide (NO) were also analyzed. Two types of capillaroscopy status were determined: normal and microangiopathic. There was a significant relationship between presence of microangiopathy and higher serum ET-1 (p = 0.018) and E-sel (p = 0.021) levels. Similarly, we have found a correlation between presence of ANA and higher ET-1 (p = 0.005), but not E-sel (p = 0.241). In patients with pRS, we found significant relationship between ANA and higher ET-1 (p = 0.008). No such relations were observed in sRS patients. Our data indicates that external factor-induced vasoconstrictive effects dominated in pRS, whereas in sRS in the course of connective tissue diseases, it was accompanied by coexistent vasodilation due to endothelial dysfunction. The latter phenomenon is at least partially dependent on insufficient NO release.

Quantitative analysis of nailfold capillary morphology in patients with fibromyalgia

BACKGROUND/AIMS

Nailfold capillaroscopy (NFC) has been used to examine morphological and functional microcirculation changes in connective tissue diseases. It has been demonstrated that NFC patterns reflect abnormal microvascular dynamics, which may play a role in fibromyalgia (FM) syndrome. The aim of this study was to determine NFC patterns in FM, and their association with clinical features of FM.

METHODS

A total of 67 patients with FM, and 30 age- and sex-matched healthy controls, were included. Nailfold capillary patterns were quantitatively analyzed using computerized NFC. The parameters of interest were as follows: number of capillaries within the central 3 mm, deletion score, apical limb width, capillary width, and capillary dimension. Capillary dimension was determined by calculating the number of capillaries using the Adobe Photoshop version 7.0.

RESULTS

FM patients had a lower number of capillaries and higher deletion scores on NFC compared to healthy controls (17.3 ± 1.7 vs. 21.8 ± 2.9, p < 0.05; 2.2 ± 0.9 vs. 0.7 ± 0.6, p < 0.05, respectively). Both apical limb width (µm) and capillary width (µm) were significantly decreased in FM patients (1.1 ± 0.2 vs. 3.7 ± 0.6; 5.4 ± 0.5 vs. 7.5 ± 1.4, respectively), indicating that FM patients have abnormally decreased digital capillary diameter and density. Interestingly, there was no difference in capillary dimension between the two groups, suggesting that the length or tortuosity of capillaries in FM patients is increased to compensate for diminished microcirculation.

CONCLUSIONS

FM patients had altered capillary density and diameter in the digits. Diminished microcirculation on NFC may alter capillary density and increase tortuosity.

The Association of Nailfold Capillaroscopy with Systemic Matrix Metalloproteinase-9 Concentration in Normal-Tension Glaucoma

PURPOSE

To investigate the association of nailfold capillaroscopy, heart rate variability (HRV), and clinical characteristics of glaucoma with the plasma matrix metalloproteinase-9 (MMP-9) level in normal-tension glaucoma (NTG).

MATERIALS AND METHODS

We conducted a prospective, cross-sectional study on 25 patients with NTG. Subjects with systemic diseases were excluded. The patients underwent a complete ophthalmic examination and were referred to the Rheumatology Department, where nailfold capillaroscopy and HRV assessment were performed. The patients were assigned to the lowest and highest HRV groups according to the standard deviation value of the qualified normal-to-normal intervals of the HRV assessment. Blood samples from all the subjects were assayed for MMP-9 concentrations.

RESULTS

The systemic MMP-9 level was significantly associated with the nailfold capillaroscopy result (ρ = 0.439, p = 0.032). Of the 25 patients, seven had optic disc hemorrhage (ODH). The mean MMP-9 concentration was 4375.6 ± 2923.2 pg/ml in ODH patients and 5932.1 ± 1265.4 pg/ml in patients without ODH. However, there was no significant association of HRV parameters or disc hemorrhage with the systemic MMP-9 level.

CONCLUSIONS

The systemic MMP-9 level was associated with the nailfold capillaroscopy results in patients with NTG but had no direct association with ODH.

Vascular biomarkers and correlation with peripheral vasculopathy in systemic sclerosis

Vascular disease is a hallmark of systemic sclerosis (SSc). It is present in every patient, being responsible both for the earliest clinical manifestations and the major life-threatening complications of the disease, and thus determining important morbidity and mortality. In SSc, progressive vascular injury leads to vascular tone dysfunction and reduced capillary blood flow, with consequent tissue ischemia and chronic hypoxia. These phenomena are often accompanied by abnormal levels of vascular factors. Microangiopathy in SSc may be easily assessed by nailfold videocapillaroscopy. The variety of derangements detected in the nailfold capillaries is accompanied by abnormal levels of different vascular mediators and appears to be the best evaluable predictor of the development of peripheral vascular complications, such as digital ulcers. The purpose of this review is to summarize in SSc the most relevant vascular biomarkers and the main associations between vascular biomarkers and capillaroscopic parameters and/or the presence of digital ulcers. Vascular biomarkers could become useful predictive factors of vascular damage in SSc, allowing an earlier management of vascular complications.

A PRISMA-driven systematic review for predictive risk factors of digital ulcers in systemic sclerosis patients

Vasculopathy has a major role in the pathogenesis and tissue injury in systemic sclerosis (SSc). Raynaud's phenomenon (RP) is frequently the first clinical manifestation of SSc preceding by years other clinical manifestations. RP in SSc patients is frequent, often very severe and long lasting. The repeated bouts of RP lead to prolonged digital ischemia that may progress to digital ulceration or in extreme to critical digital ischemia with gangrene. Digital ulcers (DU) are a true burden for all patients. They are very painful, with a long and slow healing course, have high risk of infection and are extremely disabling. In adults, up to 40-50% of patients will experience at least one DU in the course of the disease and of these 31-71% will have recurrent ulcers. In order to try to identify predictive risk factors for DU in SSc patients, an extensive literature review was conducted, according to the guidelines proposed at the PRISMA statement. MEDLINE database (PubMed) and Thomson Reuters Web of Knowledge platform were searched for articles published in peer-reviewed journals since 1990 with the last search run on June 2014 and published in English language. The keyword search terms included: digital ulcer/s, systemic sclerosis, scleroderma, digital scars, ischemic complications, autoantibodies, biomarkers, endothelium dysfunction, endothelin-1, vascular endothelial growth factor (VEGF), endostatin, ADMA, endoglin, angiostatin, and capillaroscopy. The following criteria were included: (1) cohorts of SSc patients including patients with DU, (2) endothelium dysfunction and angiogenesis biomarkers compared with a healthy control group, (3) autoantibodies, capillary morphology and distribution, endothelium dysfunction and angiogenesis biomarkers compared between patients with and without digital ulcers, (4) detailed description of the statistical methods used to conclude for predictive factors, and (5) English language. Our search provided a total of 376 citations. Of these, 297 studies were discarded for not meeting the criteria proposed.

Raynaud's phenomenon: from molecular pathogenesis to therapy

Raynaud's phenomenon (RP) is a well defined clinical syndrome characterized by recurrent episodes of digital vasospasm triggered by exposure to physical/chemical or emotional stress. RP has been classified as primary or secondary, depending on whether it occurs as an isolated condition (pRP) or is associated to an underlying disease, mainly a connective tissue disease (CTD-RP). In both cases, it manifests with unique "triple" (pallor, cyanosis and erythema), or "double" color changes. pRP is usually a benign condition, while sRP can evolve and be complicated by acral digital ulcers and gangrene, which may require surgical treatment. The pathogenesis of RP has not yet been entirely clarified, nor is it known whether autoantibodies have a role in RP. Even so, recent advances in our understanding of the pathophysiology have highlighted novel potential therapeutic targets. The aim of this review is to discuss the etiology, epidemiology, risk factors, clinical manifestations, recently disclosed pathogenic mechanisms underlying RP and their correlation with the available therapeutic options, focusing primarily on pRP and CTD-RP.

A systematic overview on the use and relevance of capillaroscopy in systemic sclerosis

Capillaroscopy is a non-invasive and safe technique that allows the detection and quantification of the early microvascular abnormalities that characterize secondary Raynaud's phenomenon. The well-established role of capillaroscopy for the early diagnosis of systemic sclerosis, its inclusion in the classification criteria, combined with its predictive value for clinical complications of the disease and its potential for monitoring disease progression and treatment response, makes nailfold capillaroscopy an important assessment in clinical practice and research. Capillaroscopy provides a unique window into the microcirculation and its application in diseases in which a microvascular component is suspected; it also may provide new insights into their pathophysiology and natural history.

Endothelin-1 in systemic sclerosis

INTRODUCTION

Scleroderma is a systemic disorder with unknown etiology most notably characterized by skin thickening and organ damage. Endothelin-1 (ET-1) plays a role in skin fibrosis. The aim of this study was survey and comparison of ET-1 level in Systemic Sclerosis (SSc) patients with and without digital ulcer.

MATERIAL AND METHODS

A cross-sectional analytical study conducted among the 95 patients with scleroderma in 2006 who were referred to the Rheumatology clinic in Shariati hospital of Tehran. The questionnaire was completed for every patient. Plasma level of endothelin-1 was also measured in all of them. The data was analyzed using SPSS software and statistical tests.

RESULTS

The result indicated, relationship among digital ulcers and digital pitting scars with plasma level of ET-1 were significant (P value < 0.05). We could not find any significant relationship between age and plasma level of ET-1.

CONCLUSION

These data indicate plasma level of ET-1 in scleroderma patients with digital ulcer was higher than patients without digital ulcer. Thus, increase in plasma level of ET-1 could be effective in vascular damage, fibrosis, and skin thickness.

Pulmonary arterial hypertension in systemic sclerosis is associated with profound impairment of microvascular endothelium-dependent vasodilatation

OBJECTIVE

Impaired microvascular function may contribute to organ complications in patients with systemic sclerosis (SSc). We investigated whether SSc patients with and without pulmonary arterial hypertension (PAH) show a graded impairment of microvascular function compared to healthy controls.

METHODS

Twenty-two patients with SSc and 22 controls were studied. All patients underwent right heart catheterization; 6 had no PAH (SSc-nonPAH) and 16 had PAH (SSc-PAH). Acetylcholine (ACh)-mediated endothelium-dependent vasodilatation and sodium nitroprusside (SNP)-mediated endothelium-independent vasodilatation were assessed by iontophoresis combined with laser Doppler flowmetry.

RESULTS

Compared to sex- and age-matched controls, ACh-mediated vasodilatation was reduced in SSc-PAH (340.4% vs 79.5%, respectively; p < 0.01), but not in SSc-nonPAH (340.4% vs 397.9%; p = 0.90). No significant differences were present between the groups in SNP-mediated vasodilatation.

CONCLUSION

Systemic microvascular endothelium-dependent vasodilatation is markedly reduced in SSc complicated by PAH.