Correlation between brachial artery flow-mediated dilation and endothelial microparticle levels for identifying endothelial dysfunction in children with Kawasaki disease

Elevated circulating endothelial microparticles (EMPs) in prepubertal children born preterm

BACKGROUND

Endothelial microparticles (EMPs) act as early biomarkers of endothelial activation and damage. No studies have investigated EMPs in preterm-born individuals.

METHODS

Sixty-three preterm-born children and 52 children born full-term (controls) were studied. Circulating CD62E(+), CD144(+), and CD31(+)/CD42b(-) EMPs were measured in preterm-born children compared to controls; possible associations with cardiovascular risk factors and endothelial function parameters were also assessed.

RESULTS

Circulating CD62E(+), CD144(+), and CD31(+)/CD42b(-) EMPs were significantly higher in preterm-born children compared to controls (p = 0.003, p < 0.001, and p < 0.001, respectively). Preterm birth was recognized as an independent predictor of each EMP subpopulation studied; moreover, the mean pressure and velocity of pulmonary artery were independently correlated with CD62E(+) (β = 0.20, p = 0.04) and CD144(+) EMPs (β = 0.22, p = 0.02), respectively, whereas age (β = 0.21, p = 0.03) and being born SGA (β = 0.26, p = 0.01) correlated independently with CD31(+)/CD42b(-) EMPs in the study population. Furthermore, diastolic blood pressure (β = 0.24, p = 0.04), being born SGA (β = 0.24, p = 0.04) and the hyperemic peak velocity of the brachial artery (β = -0.65, p = 0.02) were independently associated with CD31(+)/CD42b(-) EMPs in the preterm-born group.

CONCLUSION

Circulating EMPs were higher in preterm-born children compared to children born full-term. Whether EMPs could act, in clinical practice, as a complementary tool for non-invasive evaluation of endothelium in preterm-born children, remains under investigation.

IMPACT

Circulating endothelial microparticles (EMPs) are small membrane vesicles released from endothelial cells and they act as novel biomarkers of endothelial activation and damage. No studies have investigated circulating EMPs in preterm-born individuals. Circulating EMPs were significantly higher in prepubertal preterm-born children compared to children born at term. In the preterm-born group, the hyperemic peak velocity of the brachial artery was independently associated with CD31(+)/CD42b(-) EMPs. Whether assessment of circulating EMPs could act, in clinical practice, as a complementary tool for non-invasive evaluation of endothelium in preterm-born children, remains to be defined in future investigations.

Evaluation of Carotid Artery Elasticity in Early Stage of Kawasaki Disease by Two-Dimensional Speckle Tracking Imaging: A Pilot Study

OBJECTIVES

Children with Kawasaki disease (KD) often develop impaired arterial function. The aim of the study was to assess the feasibility and efficacy of two-dimensional speckle tracking technique (2DSTI) for the evaluation of carotid artery elasticity in children with early-stage KD.

METHODS

Children with KD (n = 97), age and sex-matched children with fever (n = 18), and healthy controls (n = 24) were included. Children with KD were subsequently divided into a coronary artery lesion group (CAL group, 27 cases) and a noncoronary artery lesion group (nCAL group, 70 cases) based on the results of echocardiography. The carotid circumferential peak strain (CCS) and carotid intima-media thickness (CIMT) for the children in each group were measured, and the laboratory indicators for each group were collected.

RESULTS

The CCS of children with KD was lower than that of children with fever and healthy controls (P = .001 and .008), whereas CIMT was not significantly different among the groups. Moreover, the CCS of children in the CAL group was lower than that of children in the nCAL group and healthy controls (P = .001 and .000, respectively), whereas the CIMT of children in the CAL group was higher than that of children in the nCAL group (P = .014). In children with KD, CCS was negatively correlated with C-reactive protein (CRP) and alanine aminotransferase (ALT) (r = -.419, P = .001; and r = -.305, P = .003). However, CCS was negatively correlated with CRP (r = -.508, P = .007) but not ALT (r = -.176, P = .379) in children in the CAL group.

CONCLUSION

CCS determined based on 2DSTI can reflect changes in the carotid artery elasticity function in the early stage of KD.

Recent advances in Extracellular Vesicles and their involvements in vasculitis

Systemic vasculitis is a heterogeneous group of multisystem autoimmune disorders characterized by inflammation of blood vessels. Although many progresses in diagnosis and immunotherapies have been achieved over the past decades, there are still many unanswered questions about vasculitis from pathological understanding to more advanced therapies. Extracellular vesicles (EVs) are double-layer phospholipid membrane vesicles harboring various cargoes. EVs can be classified into exosomes, microvesicles (MVs), and apoptotic bodies depending on their size and origin of cellular compartment. EVs can be released by almost all cell types and may be involved in physical and pathological processes including inflammation and autoimmune responses. In systemic vasculitis, EVs may have pathogenic involvement in inflammation, autoimmune responses, thrombosis, endothelium injury, angiogenesis and intimal hyperplasia. EV-associated redox reaction may also be involved in vasculitis pathogenesis by inducing inflammation, endothelial injury and thrombosis. Additionally, EVs may serve as specific biomarkers for diagnosis or monitoring of disease activity and therapeutic efficacy, i.e. AAV-associated renal involvement. In this review, we have discussed the recent advances of EVs, especially their roles in pathogenesis and clinical involvements in vasculitis.

Assessment of Endothelial Dysfunction in Acute and Convalescent Phases of Kawasaki Disease Using Automated Edge Detection Software: A Preliminary Study From North India

OBJECTIVE

The aim of this study was to assess endothelial dysfunction in acute and convalescent phases of Kawasaki disease (KD) using automated edge detection software.

METHODS

This was a case-control study to assess the flow-mediated dilatation (FMD) of brachial artery (BA) in patients with KD during acute phase and at least 3 months after diagnosis. A 10-MHz multifrequency linear array probe attached to a high-resolution ultrasound machine (PHILIPS Medical System-IU22) was used to acquire the images. Automated edge detection software was used to assess BA diameter.

RESULTS

A total of 16 children with KD and 16 healthy children were enrolled in the study. Mean ± SD maximum BA diameter was found to be significantly low during the acute stage of KD (2.56 ± 0.36 mm) as compared with the convalescence phase (2.93 mm ± 0.31) and in healthy controls (2.95 mm ± 0.56). The mean ± SD percentage change in the FMD was found to be significantly low in the acute phase of KD (12.32 ± 6.2) as compared with the convalescence phase of KD (17.99 ± 8.13) and healthy controls (26.88 ± 12.76). The mean ± SD percentage change in the FMD was also found to be significantly low in the convalescence phase of KD as compared with healthy controls.

CONCLUSIONS

The FMD of the BA is significantly reduced in patients during the acute and convalescence phase of KD as compared with normal healthy children. The endothelial dysfunction was present even in patients who had no obvious coronary artery abnormalities during the acute stage.

Predictive value of brachial artery flow-mediated dilation on coronary artery abnormality in acute stage of Kawasaki disease

Coronary artery abnormalities (CAAs) are a severe complication of Kawasaki disease (KD) that may lead to cardiovascular events. Given the evidence that brachial artery flow-mediated dilation (FMD) decreases in children after the onset of KD, we hypothesized that it could be an early marker of CAA development in the acute stage and investigated its relationship with variation in the coronary artery diameter. A total of 326 sex- and age-matched children were enrolled, including 120 with KD, 109 febrile children and 97 healthy controls. In this study, FMD was significantly decreased in the KD group compared with the febrile and healthy groups. FMD was lower in the CAA group than in the no coronary artery abnormality group. The comparison of FMD showed an obvious difference among the CAA subgroups. The FMD in the coronary aneurysm (CA) group showed a strong negative correlation with the pretreatment maximum coronary artery Z-score (preZmax). While preZmax was 2.5, the receiver operating characteristic curve indicated an optimal cutoff point of 3.44% for FMD. FMD ≤ 3.44% could be considered as a signal of coronary lesions in acute stage of KD.

Extracellular vesicles: a novel window into kidney function and disease

PURPOSE OF REVIEW

There has been an increasing interest in extracellular vesicles as potential diagnostic, prognostic or therapeutic biomarkers for various kidney diseases, as extracellular vesicles mediate cell-cell or intercellular communication. This review explores the current state of knowledge regarding extracellular vesicles as a tool for examining kidney physiology and disease.

RECENT FINDINGS

Urinary extracellular vesicles may be useful as biomarkers to detect abnormal function in renal endothelial and tubular cells as well as podocytes. Recent studies suggest that urinary extracellular vesicles may facilitate early diagnosis and/or monitoring in acute kidney injury, glomerular disease, autosomal dominanat polycyst kidney disease and urinary tract malignancies. Circulating extracellular vesicles may serve as biomarkers to assess cardiovascular disease.

SUMMARY

Urinary and circulating extracellular vesicles have gained significant interest as potential biomarkers of renal diseases. Analysis of extracellular vesicles may serve as a logical diagnostic approach for nephrologists as well as provide information about disease pathophysiology.

Cardiovascular Involvement in Kawasaki Disease Is Much More Than Mere Coronary Arteritis

Kawasaki disease (KD) is now a common cause of acquired heart disease in children. Coronary artery involvement is the most serious complication in children with KD. Several non-coronary complications have now been identified in this condition but these are often overlooked. Myocarditis is an integral component of KD and may be more common than coronary artery abnormalities. Pericardial involvement and valvular abnormalities have also been observed in patients with KD. KD shock syndrome is now being increasingly recognized and may be difficult to differentiate clinically from toxic shock syndrome. Endothelial dysfunction has been reported both during acute stage and also on follow-up. This may be a potentially modifiable cardiovascular risk factor.

Reproducibility of endothelial microparticles in children and adolescents

Aim: We assessed reproducibility of endothelial microparticles (EMPs) enumeration among youth. Methods & results: Four microparticle (MP) indices - total MP per microliter platelet free plasma (PFP), total EMPs per microliter PFP, percent activated EMPs and percent lactadherin positive (LACT[+]) of total EMPs - were measured at two visits (baseline and 7 ± 3 days follow-up) to determine reproducibility overall and by obesity status. We examined CD31+ or CD144+ with CD41-EMP events of size 0.3-1.0 μm. No statistically significant differences were observed between visits for any of the four MP indices. The within-participant and between-participant coefficient of variation was acceptable (range: 1.13-2.37) with good intraclass-correlation coefficient for all indices except total MP per microliter (range: 0.10-1.00). Conclusion: Total EMPs per microliter PFP, percent-activated EMPs and percent LACT(+) of total EMPs are reproducible among youth.

Current State of Precision Medicine in Primary Systemic Vasculitides

Precision medicine (PM) is an emerging data-driven health care approach that integrates phenotypic, genomic, epigenetic, and environmental factors unique to an individual. The goal of PM is to facilitate diagnosis, predict effective therapy, and avoid adverse reactions specific for each patient. The forefront of PM is in oncology; nonetheless, it is developing in other fields of medicine, including rheumatology. Recent studies on elucidating the genetic architecture of polygenic and monogenic rheumatological diseases have made PM possible by enabling physicians to customize medical treatment through the incorporation of clinical features and genetic data. For complex inflammatory disorders, the prevailing paradigm is that disease susceptibility is due to additive effects of common reduced-penetrance gene variants and environmental factors. Efforts have been made to calculate cumulative genetic risk score (GRS) and to relate specific susceptibility alleles for use of target therapies. The discovery of rare patients with single-gene high-penetrance mutations informed our understanding of pathways driving systemic inflammation. Here, we review the advances in practicing PM in patients with primary systemic vasculitides (PSVs). We summarize recent genetic studies and discuss current knowledge on the contribution of epigenetic factors and extracellular vesicles (EVs) in disease progression and treatment response. Implementation of PM in PSVs is a developing field that will require analysis of a large cohort of patients to validate data from genomics, transcriptomics, metabolomics, proteomics, and epigenomics studies for accurate disease profiling. This multi-omics approach to study disease pathogeneses should ultimately provide a powerful tool for stratification of patients to receive tailored optimal therapies and for monitoring their disease activity.

Platelets in Kawasaki disease: Is this only a numbers game or something beyond?

Kawasaki disease (KD) is a medium vessel vasculitis with predilection to cause coronary artery abnormalities. KD is now the most common cause of acquired heart disease in developed countries. Thrombocytosis is consistently found in patients with KD, usually in 2nd to 3rd week of illness. Thrombocytopenia has occasionally been reported in the acute phase of KD. An increase or decrease in platelet number in patients with KD was initially considered to be a benign phenomenon. However, recent literature on platelet biology in KD has suggested that platelets are not only increasing but are rather activated. This phenomenon has been found to increase the risk of thrombosis in these patients. Similarly a fall in platelet counts during acute stage of KD has also been found to be associated with increased severity of disease. In this review, we update on the current best understanding about pathogenic role of platelets in patients with KD.

Extracellular vesicles in autoimmune vasculitis - Little dirts light the fire in blood vessels

Systemic vasculitis is diverse group of autoimmune disorders which are characterized by inflammation of blood vessel walls with deep aching and burning pain. Their underlying etiology and pathophysiology still remain poorly understood. Extracellular vesicles (EVs), including exosomes, microvesicles (MVs), and apoptotic bodies, are membrane vesicular structures that are released either during cell activation, or when cells undergo programmed cell death, including apoptosis, necroptosis, and pyroptosis. Although EVs were thought as cell dusts, but now they have been found to be potently active since they harbor bioactive molecules, such as proteins, lipids, nucleic acids, or multi-molecular complexes. EVs can serve as novel mediators for cell-to-cell communications by delivery bioactive molecules from their parental cells to the recipient cells. Earlier studies mainly focused on MVs budding from membrane surface. Recent studies demonstrated that EVs may also carry molecules from cytoplasm or even from nucleus of their parental cells, and these EVs may carry autoantigens and are important in vasculitis. EVs may play important roles in vasculitis through their potential pathogenic involvements in inflammation, autoimmune responses, procoagulation, endothelial dysfunction/damage, angiogenesis, and intimal hyperplasia. EVs have also been used as specific biomarkers for diagnostic use or disease severity monitoring. In this review, we have focused on the aspects of EV biology most relevant to the pathogenesis of vasculitis, discussed their perspective insights, and summarized the exist literature on EV relevant studies in vasculitis, therefore provides an integration of current knowledge regarding the novel role of EVs in systemic vasculitis.

MiR-223-3p Alleviates Vascular Endothelial Injury by Targeting IL6ST in Kawasaki Disease

Background: Kawasaki disease (KD) is a self-limiting illness with acute systematic vascular inflammation. It causes pathological changes in mostly medium and small-sized arteries, especially the arteria coronaria, which adds the risk of developing coronary heart disease in adults. Materials and methods: We detected the miR-223-3p expression in 30 KD patients combined with 12 normal controls using miRNA microarrays and RT-PCR. A KD mouse model was constructed using Candida albicans water insoluble substance (CAWS). We also checked the miR-223-3p's expression using qRT-PCR. The Luciferase reporting system was implemented to validate the correlation between miR-223-3p and Interleukin-6 receptor subunit beta (IL-6ST). TNF-α was used to stimulate human coronary artery endothelial cells (HCAECs), and miR-223-3p activator or inhibitor and KD serum were used to treat HCAECs. A Western blotting automatic quantitative analysis protein imprinting system was used to test the expression of signal transducer and the activator of transcription 3 (STAT3), phosphorylated-signal transducer and the activator of transcription 3 (pSTAT3) and NF-κB p65. Results: Clinical trials found that miR-223-3p expressions were markedly different (more than 2-fold) between the acute KD group and the control group. E-selectin and intercellular cell adhesion molecule-1 (ICAM-1) levels were also significantly higher (about 2-fold) in KD especially with coronary artery lesions. MiR-223-3p could alleviate vascular endothelial damage in KD mice, and IL-6 (Interleukin-6), E-selectin and ICAM-1 were simultaneously negative. The values of IL-6, E-selectin, and ICAM-1 mRNA expressions decreased, while the value of IL-6ST was increased between the agonist treated mice and KD mice. The RT-qPCR consequences displayed that miR-223-3p explored the highest expression on the third day in both the KD mice as well as the agonist group. MiR-223-3p can directly combine with IL-6ST 3' untranslatable regions (UTR) and held back the IL-6's expression. Overexpression of miR-223 down regulated IL6ST expression and decreased the expression of p-STAT3 and NF-κB p65, while the miR-223 inhibitor could reverse the above process. Conclusion: MiR-223-3p is an important regulatory factor of vascular endothelial damage in KD and could possibly become a potential target of KD treatment in the future.

MicroRNA-145-5p and microRNA-320a encapsulated in endothelial microparticles contribute to the progression of vasculitis in acute Kawasaki Disease

Kawasaki Disease (KD) is an acute inflammatory disease that takes the form of systemic vasculitis. Endothelial microparticles (EMPs) have been recognized as an important transcellular delivery system. We hypothesized whether EMPs are involved in vasculitis in acute KD. Fifty patients with acute KD were enrolled, divided into two subgroups: those with coronary artery lesions (CAL) (n = 5) and those without CAL (NCAL) (n = 45). EMPs were measured using flow cytometry, and microRNA (miR) expression profiling was performed by microRNA array. The percentage of EMPs in acute KD was significantly higher than in controls (P < 0.0001). EMPs in patients with CAL rapidly increased after the initial treatment, and was significantly higher than those in NCAL (P < 0.001). In patients with CAL, we identified 2 specific miRs encapsulated in EMPs, hsa-miR-145-5p and hsa-miR-320a, which are predicted to affect monocyte function using in silico analysis, and were demonstrated to upregulate inflammatory cytokine mRNAs in THP-1 monocytes. In situ hybridization confirmed that hsa-miR-145-5p was preferentially expressed in CAL. EMPs may serve as a sensitive marker for the severity of vasculitis in acute KD. Moreover, these 2 specific miRs encapsulated in EMPs might be involved in inflammatory cytokine regulation and the pathogenesis of vasculitis in acute KD.

Coronary artery aneurysm regression after Kawasaki disease and associated risk factors: a 3-year follow-up study in East China

Kawasaki disease (KD) is the leading cause of acquired heart disease due to its complicated coronary artery lesions. Up to now, few studies were focused on the status of persistent coronary artery aneurysms (CAA) in KD patients. The present study was designed to identify the coronary artery outcomes and seek the risk factors associated with the regression of CAA in KD patients. One hundred and twenty KD patients with CAA hospitalized in Children's Hospital of Soochow University from Jan 2008 to Dec 2013 were prospectively studied by a 3-year follow-up. Data regarding demographic, clinical, laboratory, and echocardiographic characteristics were documented and further analyzed. It was estimated that 39.2% of the patients had complete regression of CAA within 4 weeks, 59.2% within 8 weeks, and 70.0% within 16 weeks. No fatal cardiac events occurred. We found patients who aged ≤ 1 year, received initial intravenous immunoglobulin (IVIG) treatment after the 10th day of illness, and IVIG non-responders were associated with the regression of persistent CAA. The relative risks were 1.55, 1.87, and 1.88, respectively. Age, initial IVIG treatment, and IVIG response were risk factors of persistent CAA, and more attention should be paid on these patients.

Methods to evaluate arterial structure and function in children - State-of-the art knowledge

BACKGROUND

With increasing rates of hypertension, obesity, and diabetes in the pediatric population, wide available, and reproducible methods are necessary to evaluate arterial structure and function in children and adolescents.

METHODS

MEDLINE/Pubmed was searched for articles published in years 2012-2017 on methodology of, current knowledge on, and limitations of the most commonly used methods to evaluate central, proximal and coronary arteries, as well as endothelial function in pediatric patients.

RESULTS

Among 1528 records screened (including 1475 records from years 2012 to 2017) 139 papers were found suitable for the review. Following methods were discussed in this review article: ultrasound measurements of the intima-media thickness, coronary calcium scoring using computed tomography, arterial stiffness measurements (pulse wave velocity and pulse wave analysis, carotid artery distensibility, pulse pressure, and ambulatory arterial stiffness index), ankle-brachial index, and methods to evaluate vascular endothelial function (flow-mediated vasodilation, peripheral arterial tonometry, Doppler laser flowmetry, and cellular and soluble markers of endothelial dysfunction).

CONCLUSIONS

Ultrasonographic measurement of carotid intima-media thickness and measurement of pulse wave velocity (by oscillometry or applanation tonometry) are highly reproducible methods applicable for both research and clinical practice with proved applicability for children aged ≥6 years or with height ≥120cm. Evaluation of ambulatory arterial stiffness index by ambulatory blood pressure monitoring is another promising option in pediatric high-risk patients. Clearly, further studies are necessary to evaluate usefulness of these and other methods for the detection of subclinical arterial damage in children.

[Research advances in association between vitamin D and Kawasaki disease and related mechanisms of action]

Vitamin D is an important steroid hormone, which has a wide biological effect and is the protective factor against cardiovascular disease and other diseases. At present, the etiology and pathogenesis of Kawasaki disease (KD) remain unknown, but recent studies have shown that vitamin D insufficiency or deficiency is associated with KD. Vitamin D insufficiency or deficiency may affect KD via its influence on inflammatory response, adipokine, endothelial function, platelet function, and DNA methylation and increase the risk of coronary artery lesions. This article reviews the research advances in the association between vitamin D and KD and possible mechanisms of action.

Extracellular Vesicles in Renal Diseases: More than Novel Biomarkers?

Extracellular vesicles from the urine and circulation have gained significant interest as potential diagnostic biomarkers in renal diseases. Urinary extracellular vesicles contain proteins from all sections of the nephron, whereas most studied circulating extracellular vesicles are derived from platelets, immune cells, and the endothelium. In addition to their diagnostic role as markers of kidney and vascular damage, extracellular vesicles may have functional significance in renal health and disease by facilitating communication between cells and protecting against kidney injury and bacterial infection in the urinary tract. However, the current understanding of extracellular vesicles has derived mostly from studies with very small numbers of patients or in vitro data. Moreover, accurate assessment of these vesicles remains a challenge, in part because of a lack of consensus in the methodologies to measure extracellular vesicles and the inability of most techniques to capture the entire size range of these vesicles. However, newer techniques and standardized protocols to improve the detection of extracellular vesicles are in development. A clearer understanding of the composition and biology of extracellular vesicles will provide insights into their pathophysiologic, diagnostic, and therapeutic roles.