Neutrophil subsets and their gene signature associate with vascular inflammation and coronary atherosclerosis in lupus

Neutrophils display distinct post-translational modifications in response to varied pathological stimuli

Neutrophils play a vital role in the innate immunity by perform effector functions through phagocytosis, degranulation, and forming extracellular traps. However, over-functioning of neutrophils has been associated with sterile inflammation such as Type 2 Diabetes, atherosclerosis, cancer and autoimmune disorders. Neutrophils exhibiting phenotypical and functional heterogeneity in both homeostatic and pathological conditions suggests distinct signaling pathways are activated in disease-specific stimuli and alter neutrophil functions. Hence, we examined mass spectrometry based post-translational modifications (PTM) of neutrophil proteins in response to pathologically significant stimuli, including high glucose, homocysteine and bacterial lipopolysaccharides representing diabetes-indicator, an activator of thrombosis and pathogen-associated molecule, respectively. Our data revealed that these aforesaid stimulators differentially deamidate, citrullinate, acetylate and methylate neutrophil proteins and align to distinct biological functions associated with degranulation, platelet activation, innate immune responses and metabolic alterations. The PTM patterns in response to high glucose showed an association with neutrophils extracellular traps (NETs) formation, homocysteine induced proteins PTM associated with signaling of systemic lupus erythematosus and lipopolysaccharides induced PTMs were involved in pathways related to cardiomyopathies. Our study provides novel insights into neutrophil PTM patterns and functions in response to varied pathological stimuli, which may serve as a resource to design therapeutic strategies for the management of neutrophil-centred diseases.

Vascular damage in systemic lupus erythematosus

Vascular disease is a major cause of morbidity and mortality in patients with systemic autoimmune diseases, particularly systemic lupus erythematosus (SLE). Although comorbid cardiovascular risk factors are frequently present in patients with SLE, they do not explain the high burden of premature vascular disease. Profound innate and adaptive immune dysregulation seems to be the primary driver of accelerated vascular damage in SLE. In particular, evidence suggests that dysregulation of type 1 interferon (IFN-I) and aberrant neutrophils have key roles in the pathogenesis of vascular damage. IFN-I promotes endothelial dysfunction directly via effects on endothelial cells and indirectly via priming of immune cells that contribute to vascular damage. SLE neutrophils are vasculopathic in part because of their increased ability to form immunostimulatory neutrophil extracellular traps. Despite improvements in clinical care, cardiovascular disease remains the leading cause of mortality among patients with SLE, and treatments that improve vascular outcomes are urgently needed. Improved understanding of the mechanisms of vascular injury in inflammatory conditions such as SLE could also have implications for common cardiovascular diseases, such as atherosclerosis and hypertension, and may ultimately lead to personalized therapeutic approaches to the prevention and treatment of this potentially fatal complication.

Low density neutrophils and neutrophil extracellular traps (NETs) are new inflammatory players in heart failure

BACKGROUND

Heart failure with reduced (HFrEF) or preserved ejection fraction (HFpEF) is characterized by low-grade chronic inflammation. Circulating neutrophils regroup two subtypes termed high- and low-density neutrophils (HDNs and LDNs). LDNs represent less than 2% of total neutrophil under physiological conditions, but their count increase in multiple pathologies, releasing more inflammatory cytokines and neutrophil extracellular traps (NETs). The aims of this study were to assess the differential count and role of HDNs, LDNs and NETs-related activities in HF patients.

METHODS

HDNs and LDNs were isolated from human blood by density gradient and purified by FACS and their counts obtained by flow cytometry. NETs formation (NETosis) was quantified by confocal microscopy. Circulating inflammatory and NETosis biomarkers were measured by ELISA. Neutrophil adhesion onto human extracellular matrix (hECM) was assessed by optical microscopy.

RESULTS

A total of 140 individuals were enrolled, including 33 healthy volunteers (HV), 41 HFrEF (19 stable patients and 22 presenting acute decompensated HF; ADHF) and 66 HFpEF patients (36 stable patients and 30 presenting HF decompensation). HDNs and LDNs counts were significantly increased up to 39% and 2740% respectively in HF patients compared to HV. In HF patients, the correlations between LDNs counts and circulating inflammatory (CRP, IL-6 and -8), Troponin T, NT-proBNP and NETosis components were all significant. In vitro, LDNs expressed more H3Cit and NETs and were more pro-adhesive, with ADHFpEF patients presenting the highest pro-inflammatory profile.

CONCLUSIONS

HFpEF patients present higher levels of circulating LDNs and NETs related activities, which are the highest in the context of acute HF decompensation.

The Link Between Dysregulated Immunometabolism and Vascular Damage: Implications for the Development of Atherosclerosis in Systemic Lupus Erythematosus and Other Rheumatic Diseases

A bimodal pattern of mortality in systemic lupus erythematosus (SLE) exists. Early-stage deaths are predominantly caused by infection, whereas later-stage deaths are mainly caused by atherosclerotic disease. Further, although SLE-related mortality has reduced considerably in recent years, cardiovascular (CV) events remain one of the leading causes of death in people with SLE. Accelerated atherosclerosis in SLE is attributed to both an increase in traditional CV risk factors and the inflammatory effects of SLE itself. Many of these changes occur within the microenvironment of the vascular-immune interface, the site of atherosclerotic plaque development. Here, an intimate interaction between endothelial cells, vascular smooth muscle cells, and immune cells dictates physiological vs pathological responses to a chronic type 1 interferon environment. Low-density neutrophils (LDNs) have also been implicated in eliciting vasculature-damaging effects at such lesion sites. These changes are thought to be governed by dysfunctional metabolism of immune cells in this niche due at least in part to the chronic induction of type 1 interferons. Understanding these novel pathophysiological mechanisms and metabolic pathways may unveil potential innovative pharmacological targets and therapeutic opportunities for atherosclerosis, as well as shed light on the development of premature atherosclerosis in patients with SLE who develop CV events.

The neutrophil-to-lymphocyte ratio is associated with coronary heart disease risk in adults: A population-based study

The purpose of this study was to look at any connections that could exist between neutrophil-lymphocyte ratio and coronary heart disease. We performed a cross-sectional research of 13732 participants in the National Health and Nutrition Examination Survey who were 40 or older. Multivariate logistic regression models investigated the relationship between neutrophil-to-lymphocyte ratio levels and coronary heart disease risk. To investigate potential nonlinear connections, smoothed curve fitting was used. When a nonlinear relationship was discovered, the inflexion point was determined using a recursive method. After controlling for relevant confounders, neutrophil-to-lymphocyte ratio was independently linked to a higher risk of coronary heart disease (OR = 1.74, 95% CI:1.30-2.33, P = 0.0002). Subgroup analyses showed statistically significant positive associations between neutrophil-to-lymphocyte ratio and coronary heart disease risk in women (OR = 1.25, 95% CI:1.09-1.43), participants 60 years of age and older (OR = 1.09, 95% CI:1.00-1.19), smoking status for every day or not at all (OR = 1.23, 95% CI:1.00-1.52; OR = 1.09, 95% CI:1.00-1.19), alcohol use status for moderate alcohol use (OR = 1.11, 95% CI:1.00-1.22), body mass index >30 kg/m2 (OR = 1.42, 95% CI:1.10-1.82), hypertensive (OR = 1.11, 95% CI:1.02-1.22), and individuals without diabetes (OR = 1.17, 95% CI:1.06-1.31). A positive correlation between neutrophil-to-lymphocyte ratio levels and coronary heart disease risk was also seen by smoothing curve fitting, with an inflexion point of 1.08 that was statistically significant (P<0.05). Our research shows elevated neutrophil-to-lymphocyte ratio levels are linked to a higher risk of coronary heart disease.

Lumbar disc herniation is an independent predictor of plaque burden in the patients with unstable angina

Objective

Assessing the impact of lumbar disc herniation (LDH) on the plaque burden of coronary atherosclerosis is our objective.

Methods

In this study, a total of 212 patients (age 46-80 years) with unstable angina (UA) who underwent coronary angiography (CAG) in our hospital from January 2018 to July 2022 due to UA were included. Patients were divided into LDH group (n = 106) and no LDH group (n = 106). Gensini scores were calculated to assess the plaque burden of coronary. Logistic analysis was used to examine potential risk variables linked to the Gensini score. The association between lumbar disc lesions grading and coronary plaque burden was analysed by Spearman's correlation test. LDH patients with higher plaque burden (n = 56) were further divided into evolocumab treatment group (n = 28) and conventional treatment group (n = 28). Cox regression analysis were performed.

Results

Patients with LDH had higher Gensini scores (P < 0.01) and triglyceride (TG) levels (P = 0.04), but HDL-C (P = 0.01) levels were lower. LDH was found to be an independent risk factor for higher Gensini scores (OR = 2.38, P < 0.01) by logistic analysis. The Spearman's correlation test suggested that the degree of lumbar disc lesions was related to the Gensini score and the level of blood lipid. Cox regression analysis showed that evolocumab treatment could significantly reduce the composite MACE events (cardiac death, nonfatal myocardial infarction, nonfatal stroke, and readmission due to angina) (HR = 0.26, P = 0.04) in higher coronary plaque burden patients.

Conclusion

LDH is an independent risk factor for the higher coronary plaque burden. Evolocumab treatment significantly reduced the occurrence of cardiovascular events in LDH patients with higher plaque burden. Additionally, our data indicate that LDH is associated with increased blood lipid, which may contribute to the development of plaque burden.

Urine proteomic signatures of histological class, activity, chronicity, and treatment response in lupus nephritis

Lupus nephritis (LN) is a pathologically heterogenous autoimmune disease linked to end-stage kidney disease and mortality. Better therapeutic strategies are needed as only 30%-40% of patients completely respond to treatment. Noninvasive biomarkers of intrarenal inflammation may guide more precise approaches. Because urine collects the byproducts of kidney inflammation, we studied the urine proteomic profiles of 225 patients with LN (573 samples) in the longitudinal Accelerating Medicines Partnership in RA/SLE cohort. Urinary biomarkers of monocyte/neutrophil degranulation (i.e., PR3, S100A8, azurocidin, catalase, cathepsins, MMP8), macrophage activation (i.e., CD163, CD206, galectin-1), wound healing/matrix degradation (i.e., nidogen-1, decorin), and IL-16 characterized the aggressive proliferative LN classes and significantly correlated with histological activity. A decline of these biomarkers after 3 months of treatment predicted the 1-year response more robustly than proteinuria, the standard of care (AUC: CD206 0.91, EGFR 0.9, CD163 0.89, proteinuria 0.8). Candidate biomarkers were validated and provide potentially treatable targets. We propose these biomarkers of intrarenal immunological activity as noninvasive tools to diagnose LN and guide treatment and as surrogate endpoints for clinical trials. These findings provide insights into the processes involved in LN activity. This data set is a public resource to generate and test hypotheses and validate biomarkers.

The Role of Neutrophil in COVID-19: Positive or Negative

BACKGROUND

Neutrophils are the first line of defense against pathogens. They are divided into multiple subpopulations during development and kill pathogens through various mechanisms. Neutrophils are considered one of the markers of severe COVID-19.

SUMMARY

In-depth research has revealed that neutrophil subpopulations have multiple complex functions. Different subsets of neutrophils play an important role in the progression of COVID-19.

KEY MESSAGES

In this review, we provide a detailed overview of the developmental processes of neutrophils at different stages and their recruitment and activation after SARS-CoV-2 infection, aiming to elucidate the changes in neutrophil subpopulations, characteristics, and functions after infection and provide a reference for mechanistic research on neutrophil subpopulations in the context of SARS-CoV-2 infection. In addition, we have also summarized research progress on potential targeted drugs for neutrophil immunotherapy, hoping to provide information that aids the development of therapeutic drugs for the clinical treatment of critically ill COVID-19 patients.

How Neutrophils Shape the Immune Response: Reassessing Their Multifaceted Role in Health and Disease

Neutrophils are the most abundant of the circulating immune cells and are the first to be recruited to sites of inflammation. Neutrophils are a heterogeneous group of immune cells from which are derived extracellular traps (NETs), reactive oxygen species, cytokines, chemokines, immunomodulatory factors, and alarmins that regulate the recruitment and phenotypes of neutrophils, macrophages, dendritic cells, T cells, and B cells. In addition, cytokine-stimulated neutrophils can express class II major histocompatibility complex and the internal machinery necessary for successful antigen presentation to memory CD4+ T cells. This may be relevant in the context of vaccine memory. Neutrophils thus emerge as orchestrators of immune responses that play a key role in determining the outcome of infections, vaccine efficacy, and chronic diseases like autoimmunity and cancer. This review aims to provide a synthesis of current evidence as regards the role of these functions of neutrophils in homeostasis and disease.

Changes in Arterial Stiffness Monitored Using the Cardio-Ankle Vascular Index in Patients with Rheumatic Disease Receiving Initial Glucocorticoid Therapy: A Clinical Pilot Study

Systemic inflammatory rheumatic diseases predispose to premature birth, accelerated atherosclerosis, and increased cardiovascular disease (CVD). While glucocorticoids (GCs) are used in various rheumatic diseases, and the associations between GC excess and increased prevalence of CVD complications are well established, the mechanisms underlying GCs' role in atheroma development are unclear. We conducted an observational study to address GC therapy's effect on arterial stiffness using the cardio-ankle vascular index (CAVI) in patients with rheumatic diseases. Twenty-eight patients with rheumatic disease received initial GC therapy with prednisolone at doses ranging from 20 to 60 mg/d. CAVI was examined at baseline and 3 and 6 months after GC therapy. Changes in CAVI and inflammatory parameters were evaluated. GC therapy increased the mean CAVI after 3 months but decreased it to pretreatment levels after 6 months. The mean CAVI substantially decreased with GC treatment in patients <65 years but increased in patients ≥65 years. Alterations in CAVI during the 6-month GC treatment negatively correlated with the lymphocyte-to-monocyte ratio (LMR) at baseline. Conversely, no correlation was observed between alterations in CAVI values and conventional inflammatory markers (C-reactive protein and erythrocyte sedimentation rate). Multivariate analysis of factors related to changes in CAVI highlighted young age, high prednisolone dosage, and LMR at baseline. GC temporarily exacerbates but eventually improves arterial stiffness in rheumatic diseases. Particularly in young patients, GC may improve arterial stiffness by reducing inflammation. Therefore, the LMR before GC therapy in rheumatic diseases may be a potential predictor of arterial stiffness.

Atherosclerosis in Systemic Lupus Erythematosus

PURPOSE OF THE REVIEW

Systemic lupus erythematosus (SLE) patients are at increased risk of cardiovascular disease (CVD) compared to the general population, despite most patients being young females, who are not classically considered to be at high risk for cardiovascular disease using traditional risk assessment tools. The purpose of this review is to discuss the pathophysiology of atherosclerosis in SLE and raise awareness of the relationship between SLE and CVD.

RECENT FINDINGS

The increased risk of CVD in SLE patients is multifactorial, due to proatherogenic lipid profiles, immune dysregulation and inflammation, side effects of lupus treatment, and microvascular dysfunction. Conventional CV risk models often underperform in the identification of SLE patients at high risk of atherosclerosis. The use of non-invasive imaging serves as a strategy to identify patients with evidence of subclinical CVD and in the evaluation of symptomatic patients. Identification of subclinical atherosclerosis allows for aggressive management of CV risk factors. SLE patients experience an increased risk of atherosclerotic CVD, which is not solely explained by traditional CV risk factors. It is imperative that clinicians are aware of this association to implement prompt detection and treatment of atherosclerotic CVD in SLE patients.

Advances in the management of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a severe multisystem autoimmune disease that can cause injury in almost every body system. While considered a classic example of autoimmunity, it is still relatively poorly understood. Treatment with immunosuppressive agents is challenging, as many agents are relatively non-specific, and the underlying disease is characterized by unpredictable flares and remissions. This State of The Art Review provides a comprehensive current summary of systemic lupus erythematosus based on recent literature. In basic and translational science, this summary includes the current state of genetics, epigenetics, differences by ancestry, and updates about the molecular and immunological pathogenesis of systemic lupus erythematosus. In clinical science, the summary includes updates in diagnosis and classification, clinical features and subphenotypes, and current guidelines and strategies for treatment. The paper also provides a comprehensive review of the large number of recent clinical trials in systemic lupus erythematosus. Current knowns and unknowns are presented, and potential directions for the future are suggested. Improved knowledge of immunological pathogenesis and the molecular differences that exist between patients should help to personalize treatment, minimize side effects, and achieve better outcomes in this difficult disease.

18 F-FDG PET/CT Reveals Localized Inflammation in Lupus Enteritis

ABSTRACT

Lupus enteritis is classified into the colon poly-ulcerative type and the small intestine ischemic serositis type. Colon poly-ulcerative lupus enteritis is a disease that is mainly due to mesenteric arteritis. In recent years, 18 F-FDG PET/CT has been frequently used to assess the extent of the disease in patients with systemic vasculitis. We present the case report of 18 F-FDG PET/CT results in a 57-year-old woman with colon poly-ulcerative lupus enteritis.

Neutrophil extracellular traps and long COVID

Post-acute COVID-19 sequelae, commonly known as long COVID, encompasses a range of systemic symptoms experienced by a significant number of COVID-19 survivors. The underlying pathophysiology of long COVID has become a topic of intense research discussion. While chronic inflammation in long COVID has received considerable attention, the role of neutrophils, which are the most abundant of all immune cells and primary responders to inflammation, has been unfortunately overlooked, perhaps due to their short lifespan. In this review, we discuss the emerging role of neutrophil extracellular traps (NETs) in the persistent inflammatory response observed in long COVID patients. We present early evidence linking the persistence of NETs to pulmonary fibrosis, cardiovascular abnormalities, and neurological dysfunction in long COVID. Several uncertainties require investigation in future studies. These include the mechanisms by which SARS-CoV-2 brings about sustained neutrophil activation phenotypes after infection resolution; whether the heterogeneity of neutrophils seen in acute SARS-CoV-2 infection persists into the chronic phase; whether the presence of autoantibodies in long COVID can induce NETs and protect them from degradation; whether NETs exert differential, organ-specific effects; specifically which NET components contribute to organ-specific pathologies, such as pulmonary fibrosis; and whether senescent cells can drive NET formation through their pro-inflammatory secretome in long COVID. Answering these questions may pave the way for the development of clinically applicable strategies targeting NETs, providing relief for this emerging health crisis.

Low-density granulocytes display immature cells with enhanced NET formation in people living with HIV

While the protective role of neutrophil extracellular traps (NETs) in limiting human immunodeficiency virus (HIV) spread to susceptible cells has been documented, there is comparatively little insight into whether NET formation is harmful in people living with HIV (PLWH). To gain insight into neutrophil dysregulation and the pathological role of NETs in HIV, we examined expressions of NET-associated markers [cell-free DNA (cfDNA) and citrullinated histone H3 (CitH3)] in the plasmas from a cohort of the Hawaii Aging with HIV-cardiovascular and HIV-seronegative (HIV-) individuals. In a subset of participants, circulating low-density granulocyte (LDG) levels and their maturation and activation status were analyzed via flow cytometry. We demonstrated higher plasma levels of CitH3 in PLWH compared to HIV- individuals. LDGs from PLWH had heightened CD66b, but reduced CD16 expression. The percentages and counts of CD10+ LDGs were significantly decreased in PLWH. In addition, the CD16Lo LDG subsets were enriched in PLWH, compared to HIV- group, indicating that immature LDGs are increased in PLWH. Moreover, LDGs from PLWH exhibited significantly higher NET forming capacity. In summary, our study presents evidence that LDGs from PLWH on ART display an immature and altered phenotype with increased NET formation. Among PLWH, plasma NET levels as well as LDG parameters correlated with blood markers for inflammation and coagulation, suggesting that neutrophil activation and NETs may exert proinflammatory and coagulation effects. Our data provide insights into the pathologic role of LDGs at least in part mediated through NET formation in PLWH.

State of current management of the heightened risk for atherosclerotic cardiovascular events in an established cohort of patients with lupus erythematosus

OBJECTIVE

Patients with lupus erythematosus (LE) are at heightened risk for clinical events, chiefly heart attacks and strokes, from atherosclerotic cardiovascular disease (ASCVD). We recently proposed new guidelines to assess and manage ASCVD event risk specifically in LE. Here, we examined current cardiovascular management in light of these new recommendations.

METHODS

We studied our entire UPenn Longitudinal Lupus Cohort of patients with cutaneous LE, without (CLE-only) or with (CLE+SLE) concurrent systemic LE, for whom we had full access to medical records (n=370, LE-ASCVD Study Cohort).

RESULTS

Of our LE-ASCVD Study Cohort, 336 out of 370 (90.8%) had a designated primary-care physician. By the new guidelines, the most recent low-density lipoprotein (LDL) levels were above-goal for 249 out of 370 (67.3%). Two-hundred sixty-six (71.9%) had hypertension, which was undertreated or untreated in 198 out of 266 (74.4%). Of current smokers, 51 out of 63 (81.0%) had no documented smoking cessation counselling or referrals. Diabetes and triglyceridaemia were generally well managed. Of the cohort, 278 qualified for two widely used online estimators of ASCVD event risk in primary prevention: the ACC-ASCVD Risk Estimator Plus and QRisk3. We also stratified these 278 patients into our recently defined categories of ASCVD event risk in LE. These three methods for estimating ASCVD event risk showed clinically meaningful discordance for 169 out of 278 (60.8%). The documented rate of ASCVD events in the first 10 years after enrolment was 13.5% (95% CI 8.9%, 17.9%), similar between CLE-only and CLE+SLE, indicating an at-risk population despite the preponderance of women and an average age at enrolment of only 47 years.

CONCLUSION

Patients with CLE-only or CLE+SLE are undertreated compared with the new guidelines and, accordingly, they experience a significant burden of ASCVD events. Moreover, it is unclear how to accurately assess their future ASCVD event risk, except that it is substantial. Efforts are underway to improve ASCVD event risk estimation and guideline implementation in patients with lupus.

Deep stratification by transcriptome molecular characters for precision treatment of patients with systemic lupus erythematosus

OBJECTIVES

To leverage the high clinical heterogeneity of systemic lupus erythematosus (SLE), we developed and validated a new stratification scheme by integrating genome-scale transcriptomic profiles to identify patient subtypes sharing similar transcriptomic markers and drug targets.

METHODS

A normalized compendium of transcription profiles was created from peripheral blood mononuclear cells (PBMCs) of 1046 SLE patients and 86 healthy controls (HCs), covering an intersection of 13 689 genes from six microarray datasets. Upregulated differentially expressed genes were subjected to functional and network analysis in which samples were grouped using unsupervised clustering to identify patient subtypes. Then, clustering stability was evaluated by the stratification of six integrated RNA-sequencing datasets using the same method. Finally, the Xgboost classifier was applied to the independent datasets to identify factors associated with treatment outcomes.

RESULTS

Based on 278 upregulated DEGs of the transcript profiles, SLE patients were classified into three subtypes (subtype A-C) each with distinct molecular and cellular signatures. Neutrophil activation-related pathways were markedly activated in subtype A (named NE-driving), whereas lymphocyte and IFN-related pathways were more enriched in subtype B (IFN-driving). As the most severe subtype, subtype C [NE-IFN-dual-driving (Dual-driving)] shared functional mechanisms with both NE-driving and IFN-driving, which was closely associated with clinical features and could be used to predict the responses of treatment.

CONCLUSION

We developed the largest cohesive SLE transcriptomic compendium for deep stratification using the most comprehensive microarray and RNA sequencing datasets to date. This result could guide future design of molecular diagnosis and the development of stratified therapy for SLE patients.

Advanced methods and novel biomarkers in autoimmune diseases ‑ a review of the recent years progress in systemic lupus erythematosus

There are several autoimmune and rheumatic diseases affecting different organs of the human body. Multiple sclerosis (MS) mainly affects brain, rheumatoid arthritis (RA) mainly affects joints, Type 1 diabetes (T1D) mainly affects pancreas, Sjogren's syndrome (SS) mainly affects salivary glands, while systemic lupus erythematosus (SLE) affects almost every organ of the body. Autoimmune diseases are characterized by production of autoantibodies, activation of immune cells, increased expression of pro-inflammatory cytokines, and activation of type I interferons. Despite improvements in treatments and diagnostic tools, the time it takes for the patients to be diagnosed is too long, and the main treatment for these diseases is still non-specific anti-inflammatory drugs. Thus, there is an urgent need for better biomarkers, as well as tailored, personalized treatment. This review focus on SLE and the organs affected in this disease. We have used the results from various rheumatic and autoimmune diseases and the organs involved with an aim to identify advanced methods and possible biomarkers to be utilized in the diagnosis of SLE, disease monitoring, and response to treatment.

Low-density granulocytes are related to shorter pregnancy duration but not to interferon alpha protein blood levels in systemic lupus erythematosus

BACKGROUND

An increased risk of pregnancy complications is seen in women with systemic lupus erythematosus (SLE), but the specific immunopathological drivers are still unclear. Hallmarks of SLE are granulocyte activation, type I interferon (IFN) overproduction, and autoantibodies. Here we examined whether low-density granulocytes (LDG) and granulocyte activation increase during pregnancy, and related the results to IFNα protein levels, autoantibody profile, and gestational age at birth.

METHODS

Repeated blood samples were collected during pregnancy in trimesters one, two, and three from 69 women with SLE and 27 healthy pregnant women (HC). Nineteen of the SLE women were also sampled late postpartum. LDG proportions and granulocyte activation (CD62L shedding) were measured by flow cytometry. Plasma IFNα protein concentrations were quantified by single molecule array (Simoa) immune assay. Clinical data were obtained from medical records.

RESULTS

Women with SLE had higher LDG proportions and increased IFNα protein levels compared to HC throughout pregnancy, but neither LDG fractions nor IFNα levels differed during pregnancy compared to postpartum in SLE. Granulocyte activation status was higher in SLE relative to HC pregnancies, and it was increased during pregnancy compared to after pregnancy in SLE. Higher LDG proportions in SLE were associated with antiphospholipid positivity but not to IFNα protein levels. Finally, higher LDG proportions in trimester three correlated independently with lower gestational age at birth in SLE.

CONCLUSION

Our results suggest that SLE pregnancy results in increased peripheral granulocyte priming, and that higher LDG proportions late in pregnancy are related to shorter pregnancy duration but not to IFNα blood levels in SLE.

Neutrophil sub-types in maintaining immune homeostasis during steady state, infections and sterile inflammation

INTRODUCTION

Neutrophils are component of innate immune system and a) eliminate pathogens b) maintain immune homeostasis by regulating other immune cells and c) contribute to the resolution of inflammation. Neutrophil mediated inflammation has been described in pathogenesis of various diseases. This indicates neutrophils do not represent homogeneous population but perform multiple functions through confined subsets. Hence, in the present review we summarize various studies describing the heterogeneous nature of neutrophils and associated functions during steady state and pathological conditions.

METHODOLOGY

We performed extensive literature review with key words 'Neutrophil subpopulations' 'Neutrophil subsets', Neutrophil and infections', 'Neutrophil and metabolic disorders', 'Neutrophil heterogeneity' in PUBMED.

RESULTS

Neutrophil subtypes are characterized based on buoyancy, cell surface markers, localization and maturity. Recent advances in high throughput technologies indicate the existence of functionally diverse subsets of neutrophils in bone marrow, blood and tissues in both steady state and pathological conditions. Further, we found proportions of these subsets significantly vary in pathological conditions. Interestingly, stimulus specific activation of signalling pathways in neutrophils have been demonstrated.

CONCLUSION

Neutrophil sub-populations differ among diseases and hence, mechanisms regulating formation, sustenance, proportions and functions of these sub-types vary between physiological and pathological conditions. Hence, mechanistic insights of neutrophil subsets in disease specific manner may facilitate development of neutrophil-targeted therapies.

Cutaneous Lupus Erythematosus: An Update on Pathogenesis and Future Therapeutic Directions

Lupus erythematosus comprises a spectrum of autoimmune diseases that may affect various organs (systemic lupus erythematosus [SLE]) or the skin only (cutaneous lupus erythematosus [CLE]). Typical combinations of clinical, histological and serological findings define clinical subtypes of CLE, yet there is high interindividual variation. Skin lesions arise in the course of triggers such as ultraviolet (UV) light exposure, smoking or drugs; keratinocytes, cytotoxic T cells and plasmacytoid dendritic cells (pDCs) establish a self-perpetuating interplay between the innate and adaptive immune system that is pivotal for the pathogenesis of CLE. Therefore, treatment relies on avoidance of triggers and UV protection, topical therapies (glucocorticosteroids, calcineurin inhibitors) and rather unspecific immunosuppressive or immunomodulatory drugs. Yet, the advent of licensed targeted therapies for SLE might also open new perspectives in the management of CLE. The heterogeneity of CLE might be attributable to individual variables and we speculate that the prevailing inflammatory signature defined by either T cells, B cells, pDCs, a strong lesional type I interferon (IFN) response, or combinations of the above might be suitable to predict therapeutic response to targeted treatment. Therefore, pretherapeutic histological assessment of the inflammatory infiltrate could stratify patients with refractory CLE for T-cell-directed therapies (e.g. dapirolizumab pegol), B-cell-directed therapies (e.g. belimumab), pDC-directed therapies (e.g. litifilimab) or IFN-directed therapies (e.g. anifrolumab). Moreover, Janus kinase (JAK) and spleen tyrosine kinase (SYK) inhibitors might broaden the therapeutic armamentarium in the near future. A close interdisciplinary exchange with rheumatologists and nephrologists is mandatory for optimal treatment of lupus patients to define the best therapeutic strategy.

Low-density granulocytes in systemic autoimmunity and autoinflammation

A body of evidence has re-energized the interest on the role neutrophils in inflammatory and autoimmune conditions. For decades, neutrophils have been considered a homogenous population. Nevertheless, accumulating evidence suggests that neutrophils are more versatile and heterogeneous than initially considered. The notion of neutrophil heterogeneity has been supported by the identification of low-density granulocytes (LDGs) in systemic lupus erythematosus (SLE) and other systemic autoimmune and autoinflammatory conditions. Transcriptomic, epigenetic, proteomic, and functional analyses support that LDGs are a distinct subset of proinflammatory neutrophils implicated in the pathogenesis of SLE and other autoimmune diseases. Importantly, it remains incompletely characterized whether LDGs detected in other inflammatory/autoimmune conditions display the same phenotype that those present in SLE. A shared feature of LDGs across diseases is their association with vascular damage, an important contributor to morbidity and mortality in chronic inflammatory conditions. Additionally, the lack of specific markers to identify LDGs in circulation or in tissue, makes it a challenge to elucidate their role in the pathogenesis of inflammatory and autoimmune conditions. In this review, we aim to examine the evidence on the biology and the putative pathogenic role of LDGs in systemic autoimmune diseases.

Circulating Calprotectin (cCLP) in autoimmune diseases

BACKGROUND AND AIM

Calprotectin (CLP) is a heterodimeric complex formed by two S100 proteins (S100A8/A9), which plays a pivotal role in innate immunity. Due to its intrinsic cytotoxic and proinflammatory properties, CLP controls cell differentiation, proliferation and NETosis and has been associated with a wide range of rheumatic diseases. Our review summarizes the widespread interest in circulating CLP (cCLP) as a biomarker of neutrophil-related inflammation, in autoimmune rheumatic disease (ARD) and non-ARD.

METHODS

A thorough literature review was performed using PubMed and EMBASE databases searching for circulating calprotectin and synonyms S100A8/A9, myeloid-related protein 8/14 (MRP8/MRP14), calgranulin A/B and L1 protein in addition to specific ARDs and autoimmune non-rheumatic diseases. We selected only English-language articles and excluded abstracts without the main text.

RESULTS

High cCLP serum levels are associated with worse structural outcomes in rheumatoid arthritis and to a lesser extent, in spondyloarthritis. In addition, cCLP can predict disease relapse in some autoimmune diseases including systemic lupus erythematosus (SLE), anti-neutrophil cytoplasmic antibodies-associated vasculitis (AAV) and some severe manifestations of connective tissue diseases, such as glomerulonephritis in SLE, AAV, juvenile idiopathic arthritis, adult-onset Still's disease and lung fibrosis in systemic sclerosis. Therefore, cCLP levels enable the identification of patients who need an accurate and tight follow-up. The clinical usefulness of cCLP as an inflammatory marker has been suggested for inflammatory/autoimmune non-rheumatic diseases, and especially for the monitoring of the inflammatory bowel diseases patients. Currently, there are only a few studies that evaluated the cCLP efficacy as a clinical biomarker in inflammatory/autoimmune non-rheumatic diseases with controversial results. Future studies are warranted to better clarify the role of cCLP in relation to the disease severity in myasthenia gravis, multiple sclerosis, chronic inflammatory demyelinating polyneuropathy, Graves' orbitopathy, autoimmune bullous diseases and uveitis.

CONCLUSION

Our literature review supports a relevant role of cCLP as potential prognostic biomarker mirroring local or systemic inflammation, especially in chronic inflammatory rheumatic diseases.

Increased levels of low density neutrophils (LDNs) in myocardial infarction

BACKGROUND

Recent evidence suggests that neutrophils are highly plastic cells that can display heterogeneous phenotypes. Low-density neutrophils (LDNs) have been described in many inflammatory conditions, and are thought to represent an immature, hyperactivated subtype of neutrophils. Neutrophils are significantly involved in the inflammatory response to myocardial infarction (MI), although we do not know the extent to which LDNs exist, or function, in MI. This study sought to determine the frequency and phenotype of LDNs in MI patients, compared to healthy subjects (HS).

METHODS

LDNs and normal-density neutrophils (NDNs) were isolated from the peripheral blood of MI subjects (n = 12) and HSs (n = 12) using density gradient centrifugation. LDNs and NDNs were analysed by flow cytometry to identify neutrophils (CD66b⁺CD15⁺CD14^-CD3^-CD19^- cells) and examine neutrophil activation (CD11b, CD66b and CD15) and maturity (CD33 and CD16).

RESULTS

We identified LDNs within the peripheral blood mononuclear cell (PBMC) fraction of blood, and this population is significantly enriched in MI patients (1.04 ± 0.75% of PBMCs), compared to HS (0.29 ± 0.24%, p = .003). Across both cohorts, LDNs express significantly higher levels of CD66b and CD15, indicating a heightened state of activation compared to NDNs. In this study, LDNs were described as CD33^highCD16^low, compared to CD33^lowCD16^high NDNs, indicating the immaturity of this neutrophil subtype.

CONCLUSIONS

An increase in the frequency of hyperactivated, immature LDNs is an immunological feature of MI. We highlight a potential pathological role of LDNs in MI, which underscores the need to expand our current understanding of this subtype in MI and other cardiovascular diseases (CVDs).

Immune mechanisms associated with cardiovascular disease in systemic lupus erythematosus: A path to potential biomarkers

Systemic lupus erythematosus (SLE) patients display an increased risk of cardiovascular disease (CVD). With the improved clinical management of other classical severe manifestation of the disease, CVD is becoming one of the most relevant complications of SLE, and it is an important factor causing morbidity and mortality. Several immune constituents have been shown to be involved in the pathogenesis of atherosclerosis and endothelial damage in SLE patients, including specific circulating cell populations, autoantibodies, and inflammatory mediators. In this review, we summarize the presentation of CVD in SLE and the role of the autoimmune responses present in SLE patients in the induction of atherogenesis, endothelial impairment and cardiac disease. Additionally, we discuss the utility of these immune mediators as early CVD biomarkers and targets for clinical intervention in SLE patients.

Establishment of a lipid metabolism disorder model in ApoEb mutant zebrafish

BACKGROUND AND AIMS

ApoEb is a zebrafish homologous to mammalian ApoE, whose deficiency would lead to lipid metabolism disorders (LMDs) like atherosclerosis. We attempted to knock out the zebrafish ApoEb, then establish a zebrafish model with LMD.

METHODS

ApoEb was knocked out using the CRISPR/Cas9 system, and the accumulation of lipids was confirmed by Oil Red O staining, confocal imaging, and lipid measurements. The lipid-lowering effects of simvastatin (SIM), ezetimibe (EZE) and Xuezhikang (XZK), an extract derived from red yeast rice, were evaluated through in vivo imaging in zebrafish larvae.

RESULTS

In the ApoEb mutant, significant vascular lipid deposition occurred, and lipid measurement performed in the whole-body homogenate of larvae and adult plasma showed significantly increased lipid levels. SIM, EZE and XZK apparently relieved hyperlipidemia in ApoEb mutants, and XZK had a significant inhibitory effect on the recruitment of neutrophils and macrophages.

CONCLUSIONS

In this study, an LMD model has been established in ApoEb mutant zebrafish. We suggest that this versatile model could be applied in studying hypercholesterolemia and related vascular pathology in the context of early atherosclerosis, as well as the physiological function of ApoE.

Non-Traditional Pro-Inflammatory and Pro-Atherosclerotic Risk Factors Related to Systemic Lupus Erythematosus

Cardiovascular diseases (CVD) are one of the leading causes of high mortality in patients with systemic lupus erythematosus (SLE). The Framingham risk score and other traditional risk factors do not fully reflect the CVD risk in SLE patients. Therefore, in order to stratify these high-risk patients, additional biomarkers for subclinical CVD are needed. The mechanisms of atherogenesis in SLE are still being investigated. During the past decades, many reports recognized that inflammation plays a crucial role in the development of atherosclerosis. The aim of this report is to present novel proinflammatory and pro-atherosclerotic risk factors that are closely related to SLE inflammation and which determine an increased risk for the occurrence of early cardiovascular events.

Neutrophil extracellular traps in systemic autoimmune and autoinflammatory diseases

Systemic autoimmune diseases are characterized by the failure of the immune system to differentiate self from non-self. These conditions are associated with significant morbidity and mortality, and they can affect many organs and systems, having significant clinical heterogeneity. Recent discoveries have highlighted that neutrophils, and in particular the neutrophil extracellular traps that they can release upon activation, can have central roles in the initiation and perpetuation of systemic autoimmune disorders and orchestrate complex inflammatory responses that lead to organ damage. Dysregulation of neutrophil cell death can lead to the modification of autoantigens and their presentation to the adaptive immune system. Furthermore, subsets of neutrophils that seem to be more prevalent in patients with systemic autoimmune disorders can promote vascular damage and increased oxidative stress. With the emergence of new technologies allowing for improved assessments of neutrophils, the complexity of neutrophil biology and its dysregulation is now starting to be understood. In this Review, we provide an overview of the roles of neutrophils in systemic autoimmune and autoinflammatory diseases and address putative therapeutic targets that may be explored based on this new knowledge.

Circulating Ageing Neutrophils as a Marker of Asymptomatic Polyvascular Atherosclerosis in Statin-Naïve Patients without Established Cardiovascular Disease

Background: Current data on the possible involvement of aging neutrophils in atherogenesis are limited. This study aimed to research the diagnostic value of aging neutrophils in their relation to subclinical atherosclerosis in statin-naïve patients without established atherosclerotic cardiovascular diseases (ASCVD). Methods: The study was carried out on 151 statin-naïve patients aged 40–64 years old without ASCVD. All patients underwent duplex scanning of the carotid arteries, lower limb arteries and abdominal aorta. Phenotyping and differentiation of neutrophil subpopulations were performed through flow cytometry (Navios 6/2, Beckman Coulter, USA). Results: The number of CD62L^loCXCR4^hi-neutrophils is known to be significantly higher in patients with subclinical atherosclerosis compared with patients without atherosclerosis (p = 0.006). An increase in the number of CD62L^loCXCR4^hi-neutrophils above cut-off values makes it possible to predict atherosclerosis in at least one vascular bed with sensitivity of 35.4–50.5% and specificity of 80.0–92.1%, in two vascular beds with sensitivity of 44.7–84.4% and specificity of 80.8–33.3%. Conclusion: In statin-naïve patients 40–64 years old without established ASCVD with subclinical atherosclerosis, there is an increase in circulating CD62L^loCXCR4^hi-neutrophils. It was also concluded that the increase in the number of circulating CD62L^loCXCR4^hi-neutrophils demonstrated moderate diagnostic efficiency (AUC 0.617–0.656) in relation to the detection of subclinical atherosclerosis, including polyvascular atherosclerosis.

Association of Obstructive Sleep Apnea Syndrome (OSA/OSAHS) with Coronary Atherosclerosis Risk: Systematic Review and Meta-Analysis

Objective

Obstructive sleep apnea syndrome (OSA) is the most common type of sleep disorders. This study aimed to systematically review the correlation between OSA and the risk of coronary atherosclerosis.

Methods

Literature on case-control studies on the relationship between coronary heart disease (CHD) and sleep apnea syndrome was collected and collated, and the incidence of SAS in CHD and non-CHD patients was observed and compared. RevMan 5.2 analysis software and Stata12SE analysis software were used for heterogeneity test and combination analysis of the included studies. The results were expressed with odds ratio (OR), 95% confidence intervals (CI) were calculated, and publication bias and sensitivity tests were evaluated.

Results

There was a statistical difference in OSA associated with the risk of coronary atherosclerosis between the experimental group and the control group [OR = 1.38, 95% CI (1.18, 1.62), P < 0.0001, I ² = 0%, Z = 3.93]. OSA associated with vascular endothelial injury [OR = 3.59, 95% CI (3.00, 4.29), P < 0.00001, I ² = 90%, Z = 14.09]. OSA is associated with vascular oxidation emergency [OR = 2.19, 95% CI (2.05, 2.33), P < 0.00001, I ² = 94%, Z = 23.40]; OSA is associated with chronic vascular inflammation [OR = 1.70, 95% CI (1.39, 2.07), P < 0.00001, I ² = 16%, Z = 5.18].

Conclusion

The incidence of obstructive sleep apnea in patients with CHD was higher than that in non-CHD patients, and obstructive sleep apnea was a risk factor for CHD.

Systemic consequences of abnormal cholesterol handling: Interdependent pathways of inflammation and dyslipidemia

Metabolic conditions such as obesity and associated comorbidities are increasing in prevalence worldwide. In chronically inflamed pathologies, metabolic conditions are linked to early onset cardiovascular disease, which remains the leading cause of death despite decades of research. In recent years, studies focused on the interdependent pathways connecting metabolism and the immune response have highlighted that dysregulated cholesterol trafficking instigates an overactive, systemic inflammatory response, thereby perpetuating early development of cardiovascular disease. In this review, we will discuss the overlapping pathways connecting cholesterol trafficking with innate immunity and present evidence that cholesterol accumulation in the bone marrow may drive systemic inflammation in chronically inflamed pathologies. Lastly, we will review the current therapeutic strategies that target both inflammation and cholesterol transport, and how biologic therapy restores lipoprotein function and mitigates the immune response.

Single-Cell Analysis Reveals the Range of Transcriptional States of Circulating Human Neutrophils

Neutrophils are the most abundant leukocytes in human blood and are essential components of innate immunity. Until recently, neutrophils were considered homogeneous and transcriptionally inactive cells, but both concepts are being challenged. Single-cell RNA sequencing (scRNA-seq) offers an unbiased view of cells along a continuum of transcriptional states. However, the use of scRNA-seq to characterize neutrophils has proven technically difficult, explaining in part the paucity of published single-cell data on neutrophils. We have found that modifications to the data analysis pipeline, rather than to the existing scRNA-seq chemistries, can significantly increase the detection of human neutrophils in scRNA-seq. We have then applied a modified pipeline to the study of human peripheral blood neutrophils. Our findings indicate that circulating human neutrophils are transcriptionally heterogeneous cells, which can be classified into one of four transcriptional clusters that are reproducible among healthy human subjects. We demonstrate that peripheral blood neutrophils shift from relatively immature (Nh0) cells, through a transitional phenotype (Nh1), into one of two end points defined by either relative transcriptional inactivity (Nh2) or high expression of type I IFN-inducible genes (Nh3). Transitions among states are characterized by the expression of specific transcription factors. By simultaneously measuring surface proteins and intracellular transcripts at the single-cell level, we show that these transcriptional subsets are independent of the canonical surface proteins that are commonly used to define and characterize human neutrophils. These findings provide a new view of human neutrophil heterogeneity, with potential implications for the characterization of neutrophils in health and disease.

Differentiating central nervous system demyelinating disorders: The role of clinical, laboratory, imaging characteristics and peripheral blood type I interferon activity

Objective: While multiple sclerosis (MS) is considered the cornerstone of autoimmune demyelinating CNS disorders, systemic autoimmune diseases (SADs) are important MS mimickers. We sought to explore whether distinct clinical, laboratory, and imaging characteristics along with quantitation of peripheral blood type I interferon (IFN) activity could aid in differentiating between them.

Methods: A total of 193 consecutive patients with imaging features suggesting the presence of CNS demyelinating disease with or without relevant clinical manifestations underwent full clinical, laboratory, and imaging evaluation, including testing for specific antibodies against 15 cellular antigens. Expression analysis of type I IFN-inducible genes (MX-1, IFIT-1, and IFI44) was performed by real-time PCR, and a type I IFN score, reflecting type I IFN peripheral activity, was calculated. After joint neurological/rheumatological evaluation and 1 year of follow-up, patients were classified into MS spectrum and CNS autoimmune disorders.

Results: While 66.3% (n = 128) of the patients were diagnosed with MS spectrum disorders (predominantly relapsing–remitting MS), 24.9% (n = 48) were included in the CNS autoimmune group, and out of those, one-fourth met the criteria for SAD (6.7% of the cohort, n = 13); the rest (18.1% of the cohort, n = 35), despite showing evidence of systemic autoimmunity, did not fulfill SAD criteria and comprised the “demyelinating disease with autoimmune features” (DAF) subgroup. Compared to the MS spectrum, CNS autoimmune patients were older, more frequently females, with increased rates of hypertension/hyperlipidemia, family history of autoimmunity, cortical dysfunction, anti-nuclear antibody titers ≥1/320, anticardiolipin IgM positivity, and atypical for MS magnetic resonance imaging lesions. Conversely, lower rates of infratentorial and callosal MRI lesions, CSF T2 oligoclonal bands, and IgG-index positivity were observed in CNS autoimmune patients. Patients fulfilling SAD criteria, but not the DAF group, had significantly higher peripheral blood type I IFN scores at baseline compared to MS spectrum [median (IQR)]: 50.18 (152.50) vs. −0.64 (6.75), p-value: 0.0001.

Conclusion: Our study suggests that underlying systemic autoimmunity is not uncommon in patients evaluated for possible CNS demyelination. Distinct clinical, imaging and laboratory characteristics can aid in early differentiation between MS and CNS-involving systemic autoimmunity allowing for optimal therapeutic strategies. Activated type I IFN pathway could represent a key mediator among MS-like-presenting SADs and therefore a potential therapeutic target.

Peroxisome proliferator activated receptor-γ agonist pioglitazone improves vascular and metabolic dysfunction in systemic lupus erythematosus

OBJECTIVES

Premature cardiovascular events in systemic lupus erythematosus (SLE) contribute to morbidity and mortality, with no effective preventive strategies described to date. Immune dysregulation and metabolic disturbances appear to play prominent roles in the induction of vascular disease in SLE. The peroxisome proliferator activated receptor-gamma agonist pioglitazone (PGZ suppresses vascular damage and immune dysregulation in murine lupus and improves endothelial dysfunction in other inflammatory diseases. We hypothesised that PGZ could improve vascular dysfunction and cardiometabolic parameters in SLE.

METHODS

Eighty SLE subjects with mild to severe disease activity were randomised to a sequence of PGZ followed by placebo for 3 months, or vice versa, in a double-blind, cross-over design with a 2-month wash-out period. Primary endpoints were parameters of endothelial function and arterial inflammation, measured by multimodal assessments. Additional outcome measures of disease activity, neutrophil dysregulation, metabolic disturbances and gene expression studies were performed.

RESULTS

Seventy-two subjects completed the study. PGZ was associated with a significant reduction in Cardio-Ankle Vascular Index (a measure of arterial stiffness) compared with placebo. Various metabolic parameters improved with PGZ, including insulin resistance and lipoprotein profiles. Circulating neutrophil extracellular trap levels also significantly decreased with PGZ compared with placebo. Most adverse events experienced while on PGZ were mild and resolved with reduction in PGZ dose.

CONCLUSION

PGZ was well tolerated and induced significant improvement in vascular stiffness and cardiometabolic parameters in SLE. The results suggest that PGZ should be further explored as a modulator of cardiovascular disease risk in SLE.

TRIAL REGISTRATION NUMBER

NCT02338999.

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.

Cardiovascular Complications in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an auto-immune disease of a relapsing-remitting nature that can cause multiorgan damage depending on several factors, mainly the disease activity. Young age women are the most likely to be affected by the disease and the female-to-male prevalence ratio is approximately 1:10. As the number of SLE patients has been increasing in the last few decades, the annual number of deaths due to the disease and its complications has increased as well, and one of the most important systems to which high mortality is attributed is the cardiovascular system, leading to premature atherosclerosis and other events such as endocarditis and valve disease. In addition to the classical cardiovascular risk factors, studies have found a positive correlation between SLE and other cardio-harmful diseases such as metabolic syndrome and dyslipidemia. Moreover, some of the medications used in the treatment of SLE place a heavy burden on the heart. The article reviews the shared pathophysiology of SLE and cardiovascular disease along with the most common SLE- associated cardiac risks, events, and management.

Asymptomatic coronary artery disease assessed by coronary computed tomography in patients with systemic lupus erythematosus: A systematic review and meta-analysis

BACKGROUND

Coronary artery disease (CAD) assessed by coronary computed tomography (CT) in patients with systemic lupus erythematosus (SLE) has been investigated in several studies, but with conflicting results. The aim of this systematic review and meta-analysis of the literature was synthesize the evidence on this topic.

METHODS

The relevant literature was identified and evaluated from inception until January 2021 in PubMed, Embase, Web of Science and Cochrane library. Studies reporting coronary artery calcification (CAC), and its prevalence and extent using the coronary calcium score (CCS) were included. Data extracted from eligible studies were used to calculate effect estimates (ESs) and 95% confidence intervals (95%CI) and weighted mean differences (WMD) with 95%CI.

RESULTS

Twenty-four studies were eligible for inclusion. For the CAC prevalence, 11 studies were included (918 SLE patients and 3952 controls) and the pooled prevalence for the random effect was 29.8% (95%CI 25.7-32.9%) for SLE patients and 11.8% (95%CI 16.2-20.4%) in controls (RR 2.22, 95%CI 1.42 to 3.48; p= 0.0005) and no significant increase in the WMD for CCS (MD= 0.32, 95%CI -5.55 to 6.20, p= 0.91) compared with controls in seven studies. Greater organ damage and glucocorticoid use has been associated with a higher CCS. According to two studies, the coronary CT angiography calcified and non-calcified plaque burden were increased in SLE patients compared with controls.

CONCLUSIONS

In SLE, asymptomatic CAD by CAC is more prevalent and there is more multivessel disease compared with controls without lupus. However, the extent of CAC was not increased in SLE patients.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021228710.

Cardiovascular disease risk and pathogenesis in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) often features extensive cardiovascular (CV) comorbidity and patients with SLE are at significantly increased risk of CV event occurrence and CV-related mortality. While the specific mechanisms leading to this increased cardiovascular disease (CVD) risk remain to be fully characterized, this heightened risk cannot be fully explained by traditional CV risk factors and is likely driven by immunologic and inflammatory features of SLE. Widespread innate and adaptive immune dysregulation characterize SLE, and factors including excessive type I interferon burden, inappropriate formation and ineffective clearance of neutrophil extracellular traps, and autoantibody formation have been linked to clinical and metabolic features impacting CV risk in SLE and may represent pathogenic drivers of SLE-related CVD. Indeed, functional and phenotypic aberrations in almost every immune cell type are present in SLE and may impact CVD progression. As understanding of the contribution of SLE-specific factors to CVD in SLE improves, improved screening and monitoring of CV risk alongside development of therapeutic treatments aimed at prevention of CVD in SLE patients are required and remain the focus of several ongoing studies and lines of inquiry.

Coronary Microvascular Dysfunction in Patients With Systemic Lupus Erythematosus and Chest Pain

Chest pain is a common symptom in patients with systemic lupus erythematosus, an autoimmune disease that is associated with increased cardiovascular morbidity and mortality. While chest pain mechanisms can be multifactorial and often attributed to non-coronary or non-cardiac cardiac etiologies, emerging evidence suggests that ischemia with no obstructive coronary arteries (INOCA) is a prevalent condition in patients with chest pain and no obstructive coronary artery disease. Coronary microvascular dysfunction is reported in approximately half of SLE patients with suspected INOCA. In this mini review, we highlight the cardiovascular risk assessment, mechanisms of INOCA, and diagnostic approach for patients with SLE and suspected CMD.

The Causal Relationship Between Blood Lipids and Systemic Lupus Erythematosus Risk: A Bidirectional Two-Sample Mendelian Randomization Study

Background: Although observational studies have demonstrated that blood lipids were associated with systemic lupus erythematosus (SLE), the causality of this association remains elusive as traditional observational studies were prone to confounding and reverse causality biases. Here, this study attempted to reveal the potential causal link between SLE and the levels of four blood lipids (HDL cholesterol, LDL cholesterol, TG, and TC).

Methods: Bidirectional two-sample Mendelian randomization (MR) was employed to explore the unconfounded causal associations between the four blood lipids and SLE. In addition, regression-based Multivariate MR (MVMR) to quantify the possible mediation effects of blood lipids on SLE. After a rigorous evaluation of the quality of studies, the single-nucleotide polymorphisms (SNPs) associated with the four blood lipids were selected from the Global Lipids Genetic Consortium (GLGC) consisted of 188,577 individuals of European ancestry, and the SNPs related to SLE were selected from a large-scale genome-wide association study (GWAS) database named IEU GWAS. Subsequently, MR analyses were conducted with inverse-variance weighted (IVW), weighted median, weighted mode, simple mode, and MR-Egger regression. Sensitivity analyses were performed to verify whether heterogeneity and pleiotropy led to bias in the MR results.

Results: Bidirectional two-sample MR results demonstrated that there was no significant causal association between SLE and the four blood lipids (When setting SLE as outcome, HDL cholesterol and SLE, IVW OR: 1.32, 95% CI: 1.05∼1.66, p = 1.78E-02; LDL cholesterol and SLE, IVW OR: 1.26, 95% CI: 1.04∼1.53, p = 2.04E-02; TG and SLE, IVW OR: 1.04, 95% CI: 0.71∼1.51, p = 8.44E-01; TC and SLE, IVW OR: 1.07, 95% CI: 0.89∼1.29, p = 4.42E-01; When setting SLE as exposure, SLE and HDL cholesterol, IVW OR: 1.00, 95% CI: 0.99∼1.01, p = 9.51E-01; SLE and LDL cholesterol, IVW OR: 0.99, 95% CI: 0.98∼1.00, p = 3.14E-01; SLE and TG, IVW OR: 0.99, 95% CI: 0.98∼1.00, p = 1.30E-02; SLE and TC, IVW OR: 0.99, 95% CI: 0.98∼1.00, p = 1.56E-01). Our MVMR analysis also provided little evidence that genetically determined lipid traits were significantly associated with the risk of SLE (HDL cholesterol and SLE, p = 9.63E-02; LDL cholesterol and SLE, p = 9.63E-02; TG and SLE, p = 8.44E-01; TC and SLE, p = 4.42E-01).

Conclusion: In conclusion, these data provide evidence that genetic changes in lipid traits are not significantly associated with SLE risk in the European population.

Cardiovascular disease risk and pathogenesis in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) often features extensive cardiovascular (CV) comorbidity and patients with SLE are at significantly increased risk of CV event occurrence and CV-related mortality. While the specific mechanisms leading to this increased cardiovascular disease (CVD) risk remain to be fully characterized, this heightened risk cannot be fully explained by traditional CV risk factors and is likely driven by immunologic and inflammatory features of SLE. Widespread innate and adaptive immune dysregulation characterize SLE, and factors including excessive type I interferon burden, inappropriate formation and ineffective clearance of neutrophil extracellular traps, and autoantibody formation have been linked to clinical and metabolic features impacting CV risk in SLE and may represent pathogenic drivers of SLE-related CVD. Indeed, functional and phenotypic aberrations in almost every immune cell type are present in SLE and may impact CVD progression. As understanding of the contribution of SLE-specific factors to CVD in SLE improves, improved screening and monitoring of CV risk alongside development of therapeutic treatments aimed at prevention of CVD in SLE patients are required and remain the focus of several ongoing studies and lines of inquiry.

Hydroxychloroquine increased cholesterol transfer to high-density lipoprotein in systemic lupus erythematosus: A possible mechanism for the reversal of atherosclerosis in the disease

INTRODUCTION

The beneficial effect of hydroxychloroquine (HCQ) in decreasing LDL levels on Systemic Lupus Erythematosus (SLE) is well defined. The influence of this drug on HDL levels is still under debate and information about its effect on cholesterol reverse transport is lacking.

OBJECTIVE

To evaluate the effects of HCQ on HDL levels and the transfer of lipids to this lipoprotein in SLE.

METHODS

Nineteen SLE patients using only HCQ (SLE WITH HCQ), 19 SLE patients without any therapy (SLE WITHOUT THERAPY), and 19 healthy controls (CONTROL) were included. All three groups were premenopausal women age- and gender-matched. Serum lipids and apolipoproteins were determined by commercial kits. An in vitro transfer of four lipids (¹⁴C-Phospolipid, ³H-Cholesteryl ester, ³H-Triglyceride, and ¹⁴C-Unesterified cholesterol) from a radioactively labeled nanoemulsion donor to HDL was performed in all participants.

RESULTS

Groups had comparable mean age, weight, height, BMI(body mass index), and waist circumference (p > .05). Mean HDL levels were higher in SLE WITH HCQ group compared to SLE WITHOUT THERAPY(58.37 ± 14.04 vs 49.79 ± 8.0 mg/dL; p < .05) but lower than CONTROL (58.37 ± 14.04 vs 68.58 ± 9.99 mg/dL; p < .05). Total cholesterol (TC) and LDL levels were also significantly lower in SLE WITH HCQ compared SLE WITHOUT THERAPY(148.16 ± 16.43 vs 167.11 ± 30.18 mg/dL; p < .05, 75.05 ± 22.52 vs 96.05 ± 25.63 mg/dL; p < .05) and CONTROL (148.16 ± 16.43 vs 174.11 ± 23.70 mg/dL; p < .05, 75.05 ± 22.52 vs 88.53 ± 20.24 mg/dL; p < .05). The in vitro lipid transfer to HDL study revealed a significant difference among the three groups (p = .002) with a higher transfer of unesterified cholesterol(UC) in SLE WITH HCQ compared to SLE WITHOUT THERAPY(5.40 ± 1.05% vs. 4.44 ± 1.05%; p < .05). The latter was significantly decreased compared to CONTROL (5.40 ± 1.05% vs. 5.99 ± 1.71%; p < .05).The percentages of transfer of triacylglycerol (4.93 ± 0.69% vs. 4.50 ± 0.69% vs. 5.14 ± 1.01%; p = .054), esterified cholesterol (5.24 ± 0.70% vs. 4.96 ± 0.89% vs. 5.69 ± 1.27%; p = .079), and phospholipid (15.67 ± 1.03% vs. 15.34 ± 1.44% vs. 16.47 ± 1.89%; p = .066) were similar among groups.

CONCLUSION

The present study is the first to demonstrate that HCQ promoted a higher transfer of unesterified cholesterol which may account for the increased HDL levels in lupus patients under HCQ. This desirable effect may underlie the reported reduced atherosclerosis in SLE.

Lipid Metabolism: Immune Regulation and Therapeutic Prospectives in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a heterogeneous disease characterized by the production of abnormal autoantibodies and immune complexes that can affect the organ and organ systems, particularly the kidneys and the cardiovascular system. Emerging evidence suggests that dysregulated lipid metabolism, especially in key effector cells, such as T cells, B cells, and innate immune cells, exerts complex effects on the pathogenesis and progression of SLE. Beyond their important roles as membrane components and energy storage, different lipids can also modulate different cellular processes, such as proliferation, differentiation, and survival. In this review, we summarize altered lipid metabolism and the associated mechanisms involved in the pathogenesis and progression of SLE. Furthermore, we discuss the recent progress in the role of lipid metabolism as a potential therapeutic target in SLE.

Updates in the Impact of Chronic Systemic Inflammation on Vascular Inflammation by Positron Emission Tomography (PET)

PURPOSE OF REVIEW

In this review, we focus on the clinical and epidemiological studies pertaining to systemic and vascular inflammation by positron emission tomography (PET) in patients with chronic inflammatory conditions such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), human immunodeficiency virus (HIV), and psoriasis to highlight the importance of chronic systemic inflammation on vascular inflammation by PET in these disease states.

RECENT FINDINGS

Recent clinical and translation advancements have demonstrated the durable relationship between chronic systemic inflammation and cardiovascular disease (CVD). In chronic inflammatory states, this relationship is robustly evident in the form of increased vascular inflammation, yet traditional risk estimates often underestimate the subclinical cardiovascular risk conferred by chronic inflammation. PET has emerged as a novel, non-invasive imaging modality capable of both quantifying the degree of systemic and vascular inflammation and detecting residual inflammation prior to cardiovascular events. We begin by demonstrating the role of inflammation in the pathogenesis of atherosclerosis, discussing how PET has been utilized to measure systemic and vascular inflammation and their effect on subclinical atherosclerosis, and finally reviewing recent applications of PET in constructing improved risk stratification for patients at high risk for stroke and CVD.

Low-Density Granulocytes in Immune-Mediated Inflammatory Diseases

Low-density granulocytes (LDGs), a distinct subset of neutrophils that colocalize with peripheral blood mononuclear cells after density gradient centrifugation, have been observed in many immune-mediated diseases. LDGs are considered highly proinflammatory because of enhanced spontaneous formation of neutrophil extracellular traps, endothelial toxicity, and cytokine production. Concomitantly, increased numbers of LDGs are associated with the severity of many immune-mediated inflammatory diseases. Recent studies, with the help of advanced transcriptomic technologies, demonstrated that LDGs were a mixed cell population composed of immature subset and mature subset, and these two subsets showed different pathogenic features. In this review, we summarize the current knowledge on the composition, origin, and pathogenic properties of LDGs in several immune-mediated inflammatory diseases and discuss potential medical interventions targeting LDGs.

The role of neutrophils in rheumatic disease-associated vascular inflammation

Vascular pathologies underpin and intertwine autoimmune rheumatic diseases and cardiovascular conditions, and atherosclerosis is increasingly recognized as the leading cause of morbidity in conditions such as systemic lupus erythematosus (SLE), rheumatoid arthritis and antineutrophil cytoplasmic antibody-associated vasculitis. Neutrophils, important cells in the innate immune system, exert their functional effects in tissues via a variety of mechanisms, including the generation of neutrophil extracellular traps and the production of reactive oxygen species. Neutrophils have been implicated in the pathogenesis of several rheumatic diseases, and can also intimately interact with the vascular system, either through modulating endothelial barriers at the blood-vessel interface, or through associations with platelets. Emerging data suggest that neutrophils also have an important role maintaining homeostasis in individual organs and can protect the vascular system. Furthermore, studies using high-dimensional omics technologies have advanced our understanding of neutrophil diversity, and immature neutrophils are receiving new attention in rheumatic diseases including SLE and systemic vasculitis. Developments in genomic, imaging and organoid technologies are beginning to enable more in-depth investigations into the pathophysiology of vascular inflammation in rheumatic diseases, making now a good time to re-examine the full scope of roles of neutrophils in these processes.