Accelerated atherosclerosis in SLE: mechanisms and prevention approaches

Fatal attractions that trigger inflammation and drive atherosclerotic disease

BACKGROUND

Atherosclerosis is the salient, underlying cause of cardiovascular diseases, such as arrhythmia, coronary artery disease, cardiomyopathy, pulmonary embolism and myocardial infarction. In recent years, atherosclerosis pathophysiology has evolved from a lipid-based to an inflammation-centric ideology.

METHODS

This narrative review is comprised of review and original articles that were found through the PubMed search engine. The following search terms or amalgamation of terms were used: "cardiovascular disease," "atherosclerosis," "inflammation," "GRP78," "Hsp60," "oxidative low-density lipoproteins," "aldehyde dehydrogenase," "β2-glycoprotein," "lipoprotein lipase A," "human cytomegalovirus." "SARS-CoV-2," "chlamydia pneumonia," "autophagy," "thrombosis" and "therapeutics."

RESULTS

Emerging evidence supports the concept that atherosclerosis is associated with the interaction between cell surface expression of stress response chaperones, including GRP78 and Hsp60, and their respective autoantibodies. Moreover, various other autoantigens and their autoantibodies have displayed a compelling connection with the development of atherosclerosis, including oxidative low-density lipoproteins, aldehyde dehydrogenase, β2-glycoprotein and lipoprotein lipase A. Atherosclerosis progression is also concurrent with viral and bacterial activators of various diseases. This narrative review will focus on the contributions of human cytomegalovirus as well as SARS-CoV-2 and chlamydia pneumonia in atherosclerosis development. Notably, the interaction of an autoantigen with their respective autoantibodies or the presence of a foreign antigen can enhance inflammation development, which leads to atherosclerotic lesion progression.

CONCLUSION

We will highlight and discuss the complex role of the interaction between autoantigens and autoantibodies, and the presence of foreign antigens in the development of atherosclerotic lesions in relationship to pro-inflammatory responses.

Atherosclerosis as the Damocles' sword of human evolution: insights from nonhuman ape-like primates, ancient human remains, and isolated modern human populations

Atherosclerosis is the leading cause of death worldwide, and the predominant risk factors are advanced age and high-circulating low-density lipoprotein cholesterol (LDL-C). However, the findings of atherosclerosis in relatively young mummified remains and a lack of atherosclerosis in chimpanzees despite high LDL-C call into question the role of traditional cardiovascular risk factors. The inflammatory theory of atherosclerosis may explain the discrepancies between traditional risk factors and observed phenomena in current literature. Following the divergence from chimpanzees several millennia ago, loss of function mutations in immune regulatory genes and changes in gene expression have resulted in an overactive human immune system. The ubiquity of atherosclerosis in the modern era may reflect a selective pressure that enhanced the innate immune response at the cost of atherogenesis and other chronic disease states. Evidence provided from the fields of genetics, evolutionary biology, and paleoanthropology demonstrates a sort of circular dependency between inflammation, immune system functioning, and evolution at both a species and cellular level. More recently, the role of proinflammatory stimuli, somatic mutations, and the gene-environment effect appear to be underappreciated elements in the development and progression of atherosclerosis. Neurobiological stress, metabolic syndrome, and traditional cardiovascular risk factors may instead function as intermediary links between inflammation and atherosclerosis. Therefore, considering evolution as a mechanistic process and atherosclerosis as part of the inertia of evolution, greater insight into future preventative and therapeutic interventions for atherosclerosis can be gained by examining the past.

Regulatory B Cells Evaluation in Systemic Lupus Erythematosus Patients with Subclinical Atherosclerosis and Secondary Antiphospholipid Syndrome

Objectives

The current knowledge of human studies that address B cells in Systemic Lupus Erythematosus (SLE) patients with subclinical atherosclerosis remains insufficient. We aimed to evaluate the contribution of Breg cells in SLE and secondary antiphospholipid syndrome (APS) patients taking into consideration its relation to subclinical atherosclerosis and the disease activity.

Methods

Thirty SLE patients and 23 controls were included. Systemic Lupus Erythematosus Disease Activity Index-2000 was estimated. Evaluation of Breg cells percentage using flow cytometry was done. All participants underwent carotid doppler ultrasound examination for measurements of the intima-media thickness of the common carotid artery (cIMT). The coronary artery calcium scoring was calculated using the Agatston method.

Results

The mean± SD of age was 32.60±8.34 years, while of the age of onset was 28.27±7.60 years. Twenty-three patients (76.7%) had subclinical atherosclerosis. There was a highly significant difference in Breg cells between SLE and APS patients with subclinical atherosclerosis and controls (P= 0.001, 0.005). SLE and APS patients had significantly higher mean cIMT than control (P=0.01, 0.050). Breg cells had 70% sensitivity and 87% specificity for diagnosing of SLE (P=0.01). Multivariate regression analysis indicated that low Breg cells were predictive for the disease activity (OR=1.76, 95% CI=1.21- 2.85; P= 0.01).

Conclusion

SLE patients had a high frequency of subclinical atherosclerosis, those and patients with secondary APS had a high risk of plaque formation. We found a contribution of Breg cells in SLE patients with subclinical atherosclerosis. Breg cells are considered a good predictor of diagnosis of SLE.

Cardiac and vascular complications in lupus: Is there a role for sex?

Systemic lupus erythematosus (SLE) is a common systemic autoimmune disorder and is characterized by autoantibody formation and subsequent immune complex deposition into target organs. SLE affects nearly nine women to every one man worldwide. Patients with SLE are at an enhanced risk for cardiovascular disease (CVD) morbidity and mortality. CVD is the leading cause of death worldwide and includes heart and blood vessel disorders, cerebrovascular disease, and rheumatic heart disease. Specific mechanisms by which cardiac and vascular pathophysiology develops in patients with SLE are still not fully known. Not only do we not understand this correlation between SLE and CVD, but there is also a critical gap in scientific knowledge on the contribution of sex. In this review, we will discuss the cardiac and vascular pathological disease states that are present in some patients with SLE. More importantly, we will discuss the potential mechanisms for the role of sex and sex hormones in the development of CVD with SLE.

Plasma and cerebrospinal fluid neurofilament light concentrations reflect neuronal damage in systemic lupus Erythematosus

BACKGROUND

Neuronal damage in systemic lupus erythematosus (SLE) is common, but the extent and mechanisms are unclear. Neurofilament light (NfL) concentrations rise in plasma and cerebrospinal fluid (CSF) during neuronal damage in various neurological disorders. In this cross-sectional study, plasma and CSF concentrations of NfL were explored as a marker of neuronal damage in SLE.

METHODS

Seventy-two consecutive SLE out-patients and 26 healthy controls, all female, aged < 55 years, underwent magnetic resonance imaging (MRI) and neurocognitive testing. NfL concentrations in plasma from all individuals and in CSF from 32 patients were measured with single-molecule array technology. Patients were assessed by a rheumatologist and neurologist to define neuropsychiatric involvement (NPSLE) according to three attribution models: SLICC A, SLICC B and ACR.

RESULTS

Plasma and CSF NfL concentrations correlated strongly (r = 0.72, p < 0.001). Both NPSLE and non-NPSLE patients in all attribution models had higher plasma NfL concentrations compared with healthy controls (log-NfL, pg/ml, mean (SD); healthy controls (0.71 (0.17)); SLICC A model: NPSLE (0.87 (0.13), p = 0.003), non-NPSLE (0.83 (0.18), p = 0.005); SLICC B model: NPSLE (0.87 (0.14), p = 0.001), non-NPSLE (0.83 (0.18), p = 0.008); ACR model: NPSLE (0.86 (0.16), p < 0.001), non-NPSLE (0.81 (0.17), p = 0.044)). Plasma and CSF NfL concentrations did not differ between NPSLE and non-NPSLE patients. Higher plasma NfL concentrations correlated with larger CSF volumes on MRI (r = 0.34, p = 0.005), and was associated with poorer cognitive performance in the domains of simple attention, psychomotor speed and verbal memory. SLICC/ACR-Damage Index ≥1 was independently associated with higher plasma NfL concentrations (β = 0.074, p = 0.038). Higher plasma creatinine concentrations, anti-dsDNA-positivity, low complement C3 levels, or a history of renal involvement were associated with higher plasma NfL concentrations (β = 0.003, p = 0.009; β = 0.072, p = 0.031; β = 0.077, p = 0.027; β = 0.069, p = 0.047, respectively).

CONCLUSIONS

Higher plasma NfL concentrations in NPSLE and non-NPSLE patients may indicate a higher degree of neuronal damage in SLE in general, corresponding to cognitive impairment and organ damage development. Furthermore, our results may indicate a higher degree of neuronal breakdown in patients with active SLE, also without overt clinical symptoms. NfL may serve as an indicator of neuronal damage in SLE in further studies.

Dilated cardiomyopathy complicated by an intracavitary thrombus and acute heart failure: A rare presentation of systemic lupus erythematosus

Introduction

Cardiac manifestations during systemic lupus erythematosus (SLE) are diverse and often have major prognostic consequences. Lupus cardiomyopathy is an uncommon event in the course of SLE and initial clinical manifestation as decompensated dilated cardiomyopathy is very rare.

Case report

we report the case of a 52-years-old female who presented with acute onset decompensated dilated cardiomyopathy as the initial feature of SLE. The diagnosis was based on clinical, electrocardiographic, angiographic and biochemical characteristics.

Conclusion

Although rare, SLE cardiomyopathy deserves the attention due to its infrequent clinical presentation. It is a complex disease that requires prompt investigation and treatment, otherwise the damage is unrecoverable.

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Lupus cardiomyopathy is a rare entity and usually late clinical manifestation of Systemic Lupus Erythematosus that has been rarely reported in the literature.

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Diagnosis is based on clinical manifestations, electrocardiographic, echocardiographic, angiographic and biochemical characteristics.

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Lupus cardiomyopathy is a complex disease with multiple possible pathological processes that requires prompt investigation and treatment, otherwise the damage is unrecoverable.

The role of proprotein convertase subtilisin/kexin type 9 (PCSK9) in the pathophysiology of psoriasis and systemic lupus erythematosus

Inflammation and atherogenic dyslipidaemia are often observed in skin diseases and represent an increased risk of cardiovascular disorders. Proprotein convertase subtilisin/kexin type 9 plays an important role in the regulation of serum low-density lipoprotein cholesterol levels. Its biological role, however, seems to go much beyond the regulation of cholesterol metabolism. The article presents potential pathophysiological links between inflammatory process and lipid disorders based on the example of psoriasis and systemic lupus erythematosus.

The role of aspirin in the primary prevention of accelerated atherosclerosis in systemic autoimmune rheumatic diseases

Aspirin is the most commonly used medication worldwide. Beside its well-known anti-inflammatory effects, a role has emerged in the prevention of cardiovascular events. However, a significant benefit has been demonstrated in secondary cardiovascular prevention only, while there is limited evidence supporting a role in primary prevention. This discrepancy might depend on the that so far, the high-risk populations that will achieve the greatest benefits yet experiencing minimal harmful side effects have not been identified. Patients with autoimmune systemic rheumatic diseases have an increased risk of cardiovascular complications compared with the general population, which makes aspirin of potential value in these subjects. Moving from general aspects of aspirin pharmacology and specific issues in general population, the aim of this study is to review the evidence about the role of low-dose aspirin in primary cardiovascular prevention in autoimmune systemic rheumatic diseases.

The role of neutrophil extracellular traps in rheumatic diseases

Rheumatic diseases are a collection of disorders defined by the presence of inflammation and destruction of joints and internal organs. A common feature of these diseases is the presence of autoantibodies targeting molecules commonly expressed in neutrophils. These preformed mediators are released by neutrophils but not by other immune cells such as macrophages. Neutrophils, major players in the host innate immune response, initiate a cell death mechanism termed neutrophil extracellular trap (NET) formation as a way to ensnare pathogens. NETs are also a source of released self-molecules found in rheumatic diseases. Subsequently, research on the role of NETs in the onset, progression and resolution of inflammation in rheumatic diseases has intensified. This Review has two aims. First, it aims to highlight the mechanisms required for the generation of NETs, the research landscape of which is rapidly changing. Second, it aims to discuss the role of neutrophils and NETs in systemic lupus erythematosus, vasculitis (specifically anti-neutrophil cytoplasmic autoantibody-associated vasculitis), rheumatoid arthritis and gout. Our goal is to clarify the field of NET research in rheumatic diseases in the hope of improving the therapeutic approaches utilized for these diseases.

Incidence of cardiovascular risk factors in female patients with systemic lupus erythematosus: a 3-year follow-up cohort

Objectives

To evaluate the incidence and variability of traditional coronary artery disease (CAD) risk factors in a cohort of lupus patients and to investigate if prednisone use predicts an increase in the number of risk factors.

Methods

A total of 151 women, 37.8 ± 11.1 (mean ± SD) years old at baseline, were reevaluated after a median period of 39 (interquartile range 36.5–42.0) months. The cumulative incidence of traditional risk factors, the incidence rate (with 95% confidence interval) of hypertension, diabetes, dyslipidemia and hypertriglyceridemia, and the frequency of the risk factors’ disappearance were calculated. Metabolic syndrome (MetS) and Framingham risk score (FRS) were computed. Logistic regression was used to investigate if maximum or cumulative prednisone dose used during follow-up predicted an increase in the cardiometabolic risk factors’ number.

Results

The cumulative incidence of risk factors varied from 39.1% (abdominal obesity) to zero (smoking), and the incidence rate varied from 133.2 (87.8–178.6) per 1000 person-years (dyslipidemia) to 10.4 (1.3–19.5) per 1000 person-years (diabetes). The cumulative incidence for MetS was 18.8%, and 11.7% of 143 patients with low FRS at baseline (T1) were classified in the high-risk category at the end of the study (T2). Dyslipidemia was the most variable risk factor, with 43.5% disappearance at T2. The maximum prednisone dose used during follow-up was borderline ( p = 0.050) for prediction of an increase in the number of cardiometabolic risk factors in an adjusted model for antimalarial use, modified Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) and age.

Conclusion

The authors described high incidence and variability of CAD risk factors in female lupus patients, with higher prednisone dose being borderline for an increase in the number of cardiometabolic risk factors.

Protective Effects of Hydroxychloroquine against Accelerated Atherosclerosis in Systemic Lupus Erythematosus

Cardiovascular (CV) morbidity and mortality are a challenge in management of patients with systemic lupus erythematosus (SLE). Higher risk of CV disease in SLE patients is mostly related to accelerated atherosclerosis. Nevertheless, high prevalence of traditional cardiovascular risk factors in SLE patients does not fully explain the increased CV risk. Despite the pathological bases of accelerated atherosclerosis are not fully understood, it is thought that this process is driven by the complex interplay between SLE and atherosclerosis pathogenesis. Hydroxychloroquine (HCQ) is a cornerstone in treatment of SLE patients and has been thought to exert a broad spectrum of beneficial effects on disease activity, prevention of damage accrual, and mortality. Furthermore, HCQ is thought to protect against accelerated atherosclerosis targeting toll-like receptor signaling, cytokine production, T-cell and monocyte activation, oxidative stress, and endothelial dysfunction. HCQ was also described to have beneficial effects on traditional CV risk factors, such as dyslipidemia and diabetes. In conclusion, despite lacking randomized controlled trials unambiguously proving the protection of HCQ against accelerated atherosclerosis and incidence of CV events in SLE patients, evidence analyzed in this review is in favor of its beneficial effect.

Evaluation of Impact of Interferon-Induced Helicase C Domain-Containing Protein 1 Gene in Egyptian Systemic Lupus Erythematosus Patients and its Relationship With Vascular Manifestations of the Disease

Objectives

This study aims to investigate the impact of interferon-induced helicase C domain-containing protein 1 (IFIH1) gene single nucleotide polymorphism on interferon pathway signaling in systemic lupus erythematosus (SLE) patients specifically with vascular affection.

Patients and methods

The cross-sectional study included 30 consecutive SLE patients (2 males, 28 females; mean age 28±3.4 years; range 16 to 40 years) diagnosed according to the American College of Rheumatology revised criteria and 10 healthy age- and sex-matched controls (2 males, 8 females; mean age 27±2.5 years; range 22 to 23 years). SLE patients and controls were compared in terms of quantitative reverse transcriptase polymerase chain reaction gene expression of IFIH1 gene, von Willebrand factor, carotid intima-media thickness, and ankle brachial index.

Results

Interferon-induced helicase C domain-containing protein 1 gene expression was significantly higher in SLE patients than controls (1.7±0.6 and 0.5±0.2, respectively) (p<0.0001). IFIH1 gene expression was highly related to vascular complication with a cutoff point at 1.74 and it positively correlated with other endothelial dysfunction markers.

Conclusion

Interferon-induced helicase C domain-containing protein 1 gene (single nucleotide polymorphism 1990670) is associated with SLE in Egyptian patients. Expression of IFIH1 gene is related to disease activity and may serve as a novel predictor of vascular affection in SLE.

Fine tuning of immunometabolism for the treatment of rheumatic diseases

All immune cells depend on specific and efficient metabolic pathways to mount an appropriate response. Over the past decade, the field of immunometabolism has expanded our understanding of the various means by which cells modulate metabolism to achieve the effector functions necessary to fight infection or maintain homeostasis. Harnessing these metabolic pathways to manipulate inappropriate immune responses as a therapeutic strategy in cancer and autoimmunity has received increasing scrutiny by the scientific community. Fine tuning immunometabolism to provide the desired response, or prevent a deleterious response, is an attractive alternative to chemotherapy or overt immunosuppression. The various metabolic pathways used by immune cells in rheumatoid arthritis, systemic lupus erythematosus and osteoarthritis offer numerous opportunities for selective targeting of specific immune cell subsets to manipulate cellular metabolism for therapeutic benefit in these rheumatologic diseases.

Cholesterol-Independent Suppression of Lymphocyte Activation, Autoimmunity, and Glomerulonephritis by Apolipoprotein A-I in Normocholesterolemic Lupus-Prone Mice

Apolipoprotein (Apo)A-I, the major lipid-binding protein of high-density lipoprotein, can prevent autoimmunity and suppress inflammation in hypercholesterolemic mice by attenuating lymphocyte cholesterol accumulation and removing tissue-oxidized lipids. However, whether ApoA-I mediates immune-suppressive or anti-inflammatory effects under normocholesterolemic conditions and the mechanisms involved remain unresolved. We transferred bone marrow from systemic lupus erythematosus (SLE)-prone Sle123 mice into normal, ApoA-I-knockout (ApoA-I(-/-)) and ApoA-I-transgenic (ApoA-I(tg)) mice. Increased ApoA-I in ApoA-I(tg) mice suppressed CD4(+) T and B cell activation without changing lymphocyte cholesterol levels or reducing major ApoA-I-binding oxidized fatty acids. Unexpectedly, oxidized fatty acid peroxisome proliferator-activated receptor γ ligands 13- and 9-hydroxyoctadecadienoic acid were increased in lymphocytes of autoimmune ApoA-I(tg) mice. ApoA-I reduced Th1 cells independently of changes in CD4(+)Foxp3(+) regulatory T cells or CD11c(+) dendritic cell activation and migration. Follicular helper T cells, germinal center B cells, and autoantibodies were also lower in ApoA-I(tg) mice. Transgenic ApoA-I also improved SLE-mediated glomerulonephritis. However, ApoA-I deficiency did not have the opposite effects on autoimmunity or glomerulonephritis, possibly as the result of compensatory increases in ApoE on high-density lipoprotein. We conclude that, although compensatory mechanisms prevent the proinflammatory effects of ApoA-I deficiency in normocholesterolemic mice, increasing ApoA-I can attenuate lymphocyte activation and autoimmunity in SLE independently of cholesterol transport, possibly through oxidized fatty acid peroxisome proliferator-activated receptor γ ligands, and it can reduce renal inflammation in glomerulonephritis.

Cardiovascular risk factors, burden of disease and preventive strategies in patients with systemic lupus erythematosus: a literature review

INTRODUCTION

Risk of developing cardiovascular disease (CVD) is increased in systemic lupus erythematosus (SLE) compared with the general population. Traditional risk factors cannot account for the totality of CV events and adequate prevention may be challenging.

AREAS COVERED

This review summarizes traditional and emerging risk factors of CVD in SLE patients and goes over potential pathogenic mechanisms involved in CVD development. Role of commonly used drugs and preventive strategies exploitable in everyday clinical practice are also discussed.

EXPERT OPINION

SLE-related risk factors involve both disease- and treatment-related features, including disease activity, disease phenotype, corticosteroid misuse and alterations of innate and adaptive immunity. Primary prevention is mandatory in management of lupus patients through appropriate disease control, corticosteroid tapering, use of antimalarials and eventually vitamin D supplementation.

Dysregulated CD4+ T cells from SLE-susceptible mice are sufficient to accelerate atherosclerosis in LDLr-/- mice

OBJECTIVE

Accelerated atherosclerosis is a major source of morbidity in systemic lupus erythematosus (SLE). However, the cause of SLE-accelerated atherosclerosis remains unclear.

METHODS

CD4(+) T cells from C57/Bl/6 (B6) or SLE-susceptible B6.Sle1.2.3 (B6.SLE) mice were transferred into LDLr(-/-), Rag(-/-) mice. T cells were examined for cytokine production and expression of interleukin-10 receptor (IL-10R) and functional markers. T cells were isolated based on FoxP3(GFP) expression and transferred to LDLr(-/-), Rag(-/-) mice to establish a role for B6.SLE effector T cells (Teff) in atherosclerosis.

RESULTS

Mice receiving whole B6.SLE CD4(+) T cells displayed no other SLE phenotype; however, atherosclerosis was increased nearly 40%. We noted dysregulated IL-17 production and reduced frequency of IL-10R expression by B6.SLE regulatory T cells (Treg). Functional assays indicated resistance of B6.SLE Teff to suppression by both B6.SLE and B6 Treg. Transfer experiments with CD4(+)FoxP3(-) Teff and CD4(+)FoxP3(+) Treg from B6.SLE and B6 mice, respectively, resulted in increased atherosclerosis compared with B6 Teff and Treg recipients. Treg isolated from mice receiving B6.SLE Teff with B6 Treg had increased production of IL-17 and fewer expressed IL-10R compared with B6 Teff and Treg transfer.

CONCLUSIONS

Transfer of B6.SLE Teff to LDLr(-/-), Rag(-/-) mice results in accelerated atherosclerosis independent of the source of Treg. In addition, the presence of B6.SLE Teff resulted in more IL-17-producing Treg and fewer expressing IL-10R, suggesting that B6.SLE Teff may mediate phenotypic changes in Treg. To our knowledge, this is the first study to provide direct evidence of the role of B6.SLE Teff in accelerating atherosclerosis through resistance to Treg suppression.