The latest in systemic lupus erythematosus-accelerated atherosclerosis: related mechanisms inform assessment and therapy

A predictive model for premature atherosclerosis in systemic lupus erythematosus based on clinical characteristics

OBJECTIVE

Systemic lupus erythematosus (SLE) is associated with a significant risk of atherosclerotic cardiovascular disease, especially in the development of premature atherosclerosis. Specific prediction models for premature atherosclerosis in SLE patients are still limited. The objective of this study was to establish a predictive model for premature atherosclerosis in SLE.

METHOD

The study collected clinical and laboratory data from 148 SLE patients under the age of 55, between January 2021 and June 2023. The least absolute shrinkage and selection operator logistic regression model was utilized to identify potentially relevant features. Subsequently, a nomogram was developed using multivariable logistic analysis. The performance of the nomogram was evaluated through a receiver-operating characteristic curve, calibration curve, and decision curve analysis (DCA).

RESULTS

A total of 148 SLE patients who fulfilled the inclusion criteria were enrolled in the study, of whom 53 patients (35.81%) met the definition of premature atherosclerosis. Hypertension, antiphospholipid syndrome, azathioprine use, duration of glucocorticoid, and age of patients were included in the multivariable regression. The nomogram, based on the non-overfitting multivariable model, was internally validated and demonstrated sufficient clinical utility for assessing the risk of premature atherosclerosis (area under curve: 0.867).

CONCLUSIONS

The comprehensive nomogram constructed in this study serves as a useful and convenient tool for evaluating the risk of premature atherosclerosis in SLE patients. It is helpful for clinicians to early identify SLE patients with premature atherosclerosis and facilitates the implementation of more effective preventive measures. Key Points • SLE patients are at a significantly higher risk of developing premature atherosclerosis compared to the general population, and this risk persists even in cases with low disease activity. Traditional models used to evaluate and predict premature atherosclerosis in SLE patients often underestimate the risk. • This study establishes a comprehensive and visually orientated predictive model of premature atherosclerosis in SLE patients, based on clinical characteristics. • The scoring system allows for convenient and effective prediction of individual incidence of premature atherosclerosis, and could provide valuable information for identification and making further intervention decision.

Screening of potential biomarkers of system lupus erythematosus based on WGCNA and machine learning algorithms

Systemic lupus erythematosus (SLE) is an autoimmune disease involving multiple systems. Its recurrent episodes and fluctuating disease courses have a severe impact on patients. Biomarkers to predict disease prognosis and remission are still lacking in SLE. We downloaded the GSE50772 dataset from the Gene Expression Omnibus database and identified differentially expressed genes (DEGs) between SLE and healthy controls. Weighted gene co-expression network analysis was used to identify key gene modules and corresponding genes in SLE. The overlapped genes in DEGs and key modules are used as key genes for subsequent analysis. These key genes were analyzed using 3 machine learning algorithms, including the least absolute shrinkage and selection operator, support vector machine recursive elimination, and random forest algorithms. The overlapped genes were obtained as potential biomarkers for further analysis, investigating and validating the potential biomarkers' possible functions, regulatory mechanisms, diagnostic value, and expression levels. And finally studied the differences between groups in level of immune cell infiltration and explored the relationship between potential biomarkers and immunity. A total of 234 overlapped genes in DEGs and key modules are used as key genes for subsequent analysis. After taking the intersection of the key genes obtained by 3 algorithms, we got 4 potential biomarkers (ARID2, CYSTM1, DDIT3, and RNASE1) with high diagnostic values. Finally, further immune infiltration analysis showed differences in various immune cells in the SLE and healthy control samples. ARID2, CYSTM1, DDIT3, and RNASE1 can affect the immune function of SLE patients. ARID2, CYSTM1, DDIT3, and RNASE1 could be used as immune-related potential biomarkers and therapeutic or diagnostic targets for further research.

Antibodies against Phosphorylcholine-Implications for Chronic Inflammatory Diseases

Atherosclerosis and its main consequence, cardiovascular disease (CVD) are nowadays regarded as chronic inflammatory disease conditions, and CVD is the main cause of death in the world. Other examples of chronic inflammation are rheumatic and other autoimmune conditions, but also diabetes, obesity, and even osteoarthritis among others. In addition, infectious diseases can have traits in common with these conditions. Systemic lupus erythematosus (SLE) is a prototypical autoimmune disease, where atherosclerosis is increased and the risk of CVD is very high. This is a clinical problem but could also shed light on the role of the immune system in atherosclerosis and CVD. Underlying mechanisms are of major interest and these are only partially known. Phosphorylcholine (PC) is a small lipid-related antigen, which is both a danger associated molecular pattern (DAMP), and a pathogen associated molecular pattern (PAMP). Antibodies against PC are ubiquitous and 5-10% of circulating IgM is IgM anti-PC. Anti-PC, especially IgM and IgG1 anti-PC, has been associated with protection in the chronic inflammatory conditions mentioned above, and develops during the first years of life, while being present at very low levels at birth. Animal experiments with immunization to raise anti-PC ameliorate atherosclerosis and other chronic inflammatory conditions. Potential mechanisms include anti-inflammatory, immune modulatory, clearance of dead cells and protection against infectious agents. An intriguing possibility is to raise anti-PC levels through immunization, to prevent and/or ameliorate chronic inflammation.

Systemic lupus erythematosus and cardiovascular disease

The prognosis in systemic lupus erythematosus (SLE) has improved due to better treatment and care, but cardiovascular disease (CVD) still remains an important clinical problem, since the risk of CVD in SLE is much higher than among controls. Atherosclerosis is the main cause of CVD in the general population, and in SLE, increased atherosclerosis, especially the prevalence of atherosclerotic plaques, has been demonstrated. Atherosclerosis is an inflammatory condition, where immunity plays an important role. Interestingly, oxidized low-density lipoprotein, defective clearance of dead cells, and inflammation, with a pro-inflammatory T-cell profile are characteristics of both atherosclerosis and SLE. In addition to atherosclerosis as an underlying cause of CVD in SLE, there are also other non-mutually exclusive mechanisms, and the most important of these are antiphospholipid antibodies (aPL) leading to the antiphospholipid antibody syndrome with both arterial and venous thrombosis. aPL can cause direct pro-inflammatory and prothrombotic effects on endothelial and other cells and also interfere with the coagulation, for example, by inhibiting annexin A5 from its antithrombotic and protective effects. Antibodies against phosphorylcholine (anti-PC) and other small lipid-related epitopes, sometimes called natural antibodies, are negatively associated with CVD and atherosclerosis in SLE. Taken together, a combination of traditional risk factors such as hypertension and dyslipidemia, and nontraditional ones, especially aPL, inflammation, and low anti-PC are implicated in the increased risk of CVD in SLE. Close monitoring of both traditional risk factors and nontraditional ones, including treatment of disease manifestations, not lest renal disease in SLE, is warranted.

Mechanistic insight into premature atherosclerosis and cardiovascular complications in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is associated with a significant risk of cardiovascular disease (CVD), which substantially increases disease mortality and morbidity. The overall mechanisms associated with the development of premature atherosclerosis and CVD in SLE remain unclear, but has been considered as a result of an intricate interplay between the profound immune dysregulation and traditional CVD risk factors. Aberrant systemic inflammation in SLE may lead to an abnormal lipid profile and dysfunction, which can further fuel the pro-atherosclerotic environment. The existence of a strong imbalance between endothelial damage and vascular repair/angiogenesis promotes vascular injury, which is the early step in the progression of atherosclerotic CVD. Profound innate and adaptive immune dysregulation, characterized by excessive type I interferon burden, aberrant macrophage, platelet and complements activation, neutrophil dysregulation and neutrophil extracellular traps formation, uncontrolled T cell activation, and excessive autoantibody production and immune complex formation, have been proposed to promote accelerated CVD in SLE. While designing targeted therapies to correct the dysregulated immune activation may be beneficial in the treatment of SLE-related CVD, much additional work is needed to determine how to translate these findings into clinical practice. Additionally, a number of biomarkers display diagnostic potentials in improving CVD risk stratification in SLE, further prospective studies will help understand which biomarker(s) will be the most impactful one(s) in assessing SLE-linked CVD. Continued efforts to identify novel mechanisms and to establish criteria for assessing CVD risk as well as predicting CVD progression are in great need to improve CVD outcomes in SLE.

Endothelial Dysfunction in Systemic Lupus Erythematosus and Systemic Sclerosis: A Common Trigger for Different Microvascular Diseases

This review describes the complex interplay between inflammation, vasculopathy and fibrosis that involve the heart and peripheral small vessels, leading to endothelial stiffness, vascular damage, and early aging in patients with systemic lupus erythematosus and systemic sclerosis, which represents two different models of vascular dysfunction among systemic autoimmune diseases. In fact, despite the fact that diagnostic methods and therapies have been significantly improved in the last years, affected patients show an excess of cardiovascular mortality if compared with the general population. In addition, we provide a complete overview on the new techniques which are used for the evaluation of endothelial dysfunction in a preclinical phase, which could represent a new approach in the assessment of cardiovascular risk in these patients.

Accelerated Atherosclerosis in Systemic Lupus Erythematosus: Role of Fibroblast Growth Factor 23- Phosphate Axis

PURPOSE

Despite management advances, accelerated atherosclerotic cardiovascular disease (ACVD) remains a major cause of morbimortality in systemic lupus erythematosus (SLE) patients; that is not fully explained by traditional risk factors. Fibroblast growth factor-23 (FGF23) is a bone-derived phosphaturic hormone with multiple klotho-dependent and independent effects, including promotion of atherosclerosis and vascular calcification, particularly in the context of chronic kidney disease. Increased circulating FGF23 was reported in SLE patients, particularly with lupus nephritis (LN); but its atherogenic role in these disorders was not explored.

SUBJECTS AND METHODS

Three study groups of predominantly middle-aged females were categorized by the 2012 SLE International Collaborating Clinics (SLICC) criteria as SLE (without LN), LN, or controls matching for traditional CVD risk profile. Measures of SLE activity, damage, steroid therapy, and glomerular filtration rate were calculated. Fasting blood samples were checked for serum lipid profile, anti-DNA, urea, creatinine, uric acid, proteins, albumin, calcium, phosphorus, C3, C4, CRP, vitamin-D3, intact parathyroid hormone and FGF23 (iFGF23). By carotid ultrasonography, mean common carotid artery intima-media thickness (CC-IMT), plaque score (PS) and internal carotid resistive index (ICRI) were recorded.

RESULTS

CC-IMT, ICRI and serum iFGF23 differed along the study groups (LN>SLE>controls). In both SLE and LN patients, serum iFGF23 had a significant positive correlation with serum phosphorus, CC-IMT and PS. On multivariate analysis, the strongest predictor of increased CC-IMT was cumulative steroid dose in SLE and serum iFGF23 in LN patients. Most significant independent predictors of increased serum iFGF23 were hyperphosphatemia in SLE and proteinuria in LN patients.

CONCLUSION

FGF23-phosphate axis has a key role in accelerated ACVD in SLE patients. Serum phosphorus and iFGF23 should be included in ACVD risk profile assessment of these patients. Prospective studies shall define the role of dietary and/or pharmacologic control of hyperphosphatemia and proteinuria in reducing circulating iFGF23 and ACVD in them.

Exposure levels of mycophenolic acid are associated with comorbidities in children with systemic lupus erythematosus

INTRODUCTION

Little is known about the relationship between exposure levels of mycophenolic acid (MPA), the active metabolite of mycophenolate mofetil (MMF), and comorbidities of systemic lupus erythematosus (SLE) in children. This study aims to explore this association.

METHODS

Longitudinal data from SLE children, who were taking MMF for immunosuppression and under therapeutic drug monitoring (TDM), were retrospectively collected. Area under the concentration-time curve of mycophenolic acid (MPA) over 24 hours (AUC_0-24h) was estimated with Bayesian methods. Logistic regression and random forest models were used to explore the association between comorbidities and MPA exposure levels.

RESULTS

This study included 107 children with 358 times of follow-up (median age 169.02 months). The incidence of diabetes, acute kidney injury (AKI), or pneumonia was significantly associated with AUC_0-24h (odds ratio [OR] 0.991, 95% confidence interval [CI] 0.982-0.999), SLE duration (OR 1.012, 95% CI 1.002-1.022), lymphocyte percentage (OR 0.959, 95% CI 0.925-0.991), plasma albumin levels (OR 0.891, 95% CI 0.843-0.940), use of aspirin (OR 0.292, 95% CI 0.126-0.633) and hydroxychloroquine (OR 0.407, 95% CI 0.184-0.906). The random forest model showed that albumin and AUC_0-24h were two important predictors. The case group (with the three comorbidities) had a mean AUC_0-24h of 73.63 mg · h/L, while the control group had a mean AUC_0-24h of 100.39 mg · h/L.

CONCLUSIONS

Increased levels of MPA exposure are associated with decreased incidence odds of diabetes, AKI or pneumonia in SLE children. An AUC_0-24h of 100.39 mg · h/L or an AUC_0-12h of 50.20 mg · h/L could be used as the targeted exposure level for clinical practice.