Targeting Inflammation as a Therapeutic Strategy in Accelerated Atherosclerosis in Rheumatoid Arthritis

Insights into the Role of Inflammation in the Management of Atherosclerosis

Atherosclerosis is the biological basis of ischemic heart disease and ischemic stroke, the leading causes of death in the world. After decades of studies, the understanding of atherosclerosis has evolved dramatically, and inflammation has been recognized as one of the most relevant pillars in all phases of atherosclerotic disease. Nevertheless, only recently, the trial CANTOS, and subsequent outcome studies with colchicine, finally provided proof-of-concept evidence that anti-inflammatory therapies were able to reduce cardiovascular events with no influence on lipid levels. These landmark studies inaugurated an era of clinical and pre-clinical studies of immunomodulatory strategies focused on reduction of cardiovascular risk. Although there are promising results in the field, selection of the most appropriate immunomodulatory therapy and identification of patients who could benefit the most, are still enormous challenges. Further research is imperative before we can finally advance towards regular use of anti-inflammatory agents to reduce atherosclerotic events in our clinical practice.

Inflammatory Mediators in Atherosclerotic Vascular Remodeling

Atherosclerotic vascular disease remains the most common cause of ischemia, myocardial infarction, and stroke. Vascular function is determined by structural and functional properties of the arterial vessel wall, which consists of three layers, namely the adventitia, media, and intima. Key cells in shaping the vascular wall architecture and warranting proper vessel function are vascular smooth muscle cells in the arterial media and endothelial cells lining the intima. Pathological alterations of this vessel wall architecture called vascular remodeling can lead to insufficient vascular function and subsequent ischemia and organ damage. One major pathomechanism driving this detrimental vascular remodeling is atherosclerosis, which is initiated by endothelial dysfunction allowing the accumulation of intimal lipids and leukocytes. Inflammatory mediators such as cytokines, chemokines, and modified lipids further drive vascular remodeling ultimately leading to thrombus formation and/or vessel occlusion which can cause major cardiovascular events. Although it is clear that vascular wall remodeling is an elementary mechanism of atherosclerotic vascular disease, the diverse underlying pathomechanisms and its consequences are still insufficiently understood.

Therapeutic strategies targeting inflammation and immunity in atherosclerosis: how to proceed?

Atherosclerosis is a chronic inflammatory disease of the arterial wall, characterized by the formation of plaques containing lipid, connective tissue and immune cells in the intima of large and medium-sized arteries. Over the past three decades, a substantial reduction in cardiovascular mortality has been achieved largely through LDL-cholesterol-lowering regimes and therapies targeting other traditional risk factors for cardiovascular disease, such as hypertension, smoking, diabetes mellitus and obesity. However, the overall benefits of targeting these risk factors have stagnated, and a huge global burden of cardiovascular disease remains. The indispensable role of immunological components in the establishment and chronicity of atherosclerosis has come to the forefront as a clinical target, with proof-of-principle studies demonstrating the benefit and challenges of targeting inflammation and the immune system in cardiovascular disease. In this Review, we provide an overview of the role of the immune system in atherosclerosis by discussing findings from preclinical research and clinical trials. We also identify important challenges that need to be addressed to advance the field and for successful clinical translation, including patient selection, identification of responders and non-responders to immunotherapies, implementation of patient immunophenotyping and potential surrogate end points for vascular inflammation. Finally, we provide strategic guidance for the translation of novel targets of immunotherapy into improvements in patient outcomes.

In this Review, the authors provide an overview of the immune cells involved in atherosclerosis, discuss preclinical research and published and ongoing clinical trials assessing the therapeutic potential of targeting the immune system in atherosclerosis, highlight emerging therapeutic targets from preclinical studies and identify challenges for successful clinical translation.

Inflammation is an important component of the pathophysiology of cardiovascular disease; an imbalance between pro-inflammatory and anti-inflammatory processes drives chronic inflammation and the formation of atherosclerotic plaques in the vessel wall.

Clinical trials assessing canakinumab and colchicine therapies in atherosclerotic cardiovascular disease have provided proof-of-principle of the benefits associated with therapeutic targeting of the immune system in atherosclerosis.

The immunosuppressive adverse effects associated with the systemic use of anti-inflammatory drugs can be minimized through targeted delivery of anti-inflammatory drugs to the atherosclerotic plaque, defining the window of opportunity for treatment and identifying more specific targets for cardiovascular inflammation.

Implementing immunophenotyping in clinical trials in patients with atherosclerotic cardiovascular disease will allow the identification of immune signatures and the selection of patients with the highest probability of deriving benefit from a specific therapy.

Clinical stratification via novel risk factors and discovery of new surrogate markers of vascular inflammation are crucial for identifying new immunotherapeutic targets and their successful translation into the clinic.

Rheumatoid Arthritis Patients Have Better Outcomes Than Non-Rheumatoid Arthritis Patients When Hospitalized for Ischemic Stroke: Analysis of the National Inpatient Sample

OBJECTIVES

The aims of this study were to compare the outcomes of patients primarily admitted for ischemic stroke with and without a secondary diagnosis of RA.

METHODS

Data were abstracted from the National Inpatient Sample (NIS) 2016 and 2017 database. The NIS was searched for hospitalizations for adult patients with ischemic stroke as principal diagnosis with and without RA as secondary diagnosis using International Classification of Diseases, 10th Revision codes. The primary outcome was inpatient mortality. Hospital length of stay (LOS), total hospital charges, odds of receiving tissue plasminogen activator, and mechanical thrombectomy were secondary outcomes of interest. Multivariate logistic and linear regression analyses were used accordingly to adjust for confounders.

RESULTS

There were more than 71 million discharges included in the combined 2016 and 2017 NIS database. Of 525,570 patients with ischemic stroke, 8670 (1.7%) had RA. Hospitalizations for ischemic stroke with RA had less inpatient mortality (4.7% vs. 5.5%; adjusted odds ratio, 0.66; 95% confidence interval, 0.52-0.85; p = 0.001), shorter LOS (5.1 vs 5.7 days, p < 0.0001), lower mean total hospital charges ($61,626 vs. $70,345, p < 0.0001), and less odds of undergoing mechanical thrombectomy (3.9% vs. 5.1%; adjusted odds ratio, 0.55; 95% confidence interval, 0.42-0.72; p < 0.0001) compared with those without RA.

CONCLUSIONS

Hospitalizations for ischemic stroke with RA had less inpatient mortality, shorter LOS, lower total hospital charges, and less likelihood of undergoing mechanical thrombectomy compared with those without RA. However, the odds of receiving tissue plasminogen activator were similar between both groups. Further studies to understand its mechanism would be helpful.

Asymmetric Dimethylarginine: a Key Player in the Pathophysiology of Endothelial Dysfunction, Vascular Inflammation and Atherosclerosis in Rheumatoid Arthritis?

Patients with rheumatoid arthritis (RA), a chronic and disabling autoimmune condition that is characterized by articular and extra-articular manifestations and a pro-inflammatory and pro-oxidant state, suffer from premature atherosclerosis and excessive cardiovascular disease burden. A key step in the pathogenesis of atherosclerosis is impaired synthesis of the endogenous messenger nitric oxide (NO) by endothelial cells which, in turn, alters local homeostatic mechanisms and favors vascular damage and plaque deposition. While the exact mechanisms of endothelial dysfunction in RA remain to be established, there is good evidence that RA patients have relatively high circulating concentrations of the methylated arginine asymmetric dimethylarginine (ADMA), a potent endogenous inhibitor of endothelial NO synthase (eNOS). This review discusses the biological and pathophysiological role of ADMA, the interplay between ADMA, inflammation and oxidative stress, and the available evidence on the adverse impact of ADMA on endothelial function and atherosclerosis and potential ADMA-lowering therapies in RA patients.

Total ankle arthroplasty and ankle arthrodesis in rheumatic disease patients: An analysis of outcomes and complications using the National Inpatient Sample (NIS) database

INTRODUCTION

Rheumatoid arthritis (RA), can manifest as an inflammatory arthropathy in the ankle. As a result, this study sought to examine the role of RA with respect to complications in patients undergoing either total ankle arthroplasty or ankle arthrodesis by utilizing the National Inpatient Sample to assess for correlations.

METHODS

Admissions for TAA and AA were extracted from the National Inpatient Sample using primary ICD-9-CM diagnosis codes. Patients aged 18-65 years with a duration of hospital stay of >3 days and isolated complications were included. Multivariable regression was then performed within matched groups to determine differences.

RESULTS

There was decreased risk of myocardial infarction, pulmonary embolism, surgical site infection, and urinary tract infection in patients with RA. Postoperative development of pneumonia was seen at a higher rate in patients with RA.

CONCLUSION

RA is not associated with a markedly increased complication burden in the appropriately chosen surgical candidate for ankle arthrodesis and ankle arthroplasty.

Disease Activity Score in 28 Joints Using GGT Permits a Dual Evaluation of Joint Activity and Cardiovascular Risk

OBJECTIVE

To identify the factors potentially associated with serum gamma-glutamyltransferase (GGT) elevation in patients with rheumatoid arthritis (RA).

METHODS

This is a cross-sectional monocentric study including RA patients over a 12-month period. Data on liver function, RA disease activity, and hepatotoxic and cardiovascular (CV) risk factors were systematically collected. To provide a simple tool to evaluate both joint disease activity and CV risk factors, we constructed the Disease Activity Score in 28 joints (DAS28)-GGT composite index by replacing erythrocyte sedimentation rate (ESR) with GGT.

RESULTS

Among the 129 included patients, 32 (25%) had isolated GGT increase. GGT correlated with age, C-reactive protein (CRP) levels, and body weight and were significantly increased in patients with alcohol intake, type 2 diabetes mellitus, hypertension, dyslipidemia, and metabolic syndrome. GGT levels also gradually increased with the number of CV risk factors and correlated with the Framingham CV risk score. The composite index DAS28-GGT remained a reliable marker of RA disease activity and accurately detected patients with CV risk factors. Conversely to the DAS28 and the DAS28-CRP, the DAS28-GGT steadily increased according to the number of CV risk factors and had an increased diagnostic value compared to the DAS28 and DAS28-CRP for the presence of at least 2 CV risk factors and a Framingham CV risk score greater than 10%.

CONCLUSION

GGT may be considered as a marker of systemic inflammation and CV risk in patients with RA. Based on these findings, we herein propose an original index, the DAS28-GGT, which is able to evaluate both joint disease activity and CV risk. This index will deserve further validation in prospective cohorts.

Rheumatoid Arthritis Does Not Negatively Impact Outcomes of Patients Admitted for Atrial Fibrillation

Objectives This study aimed to compare the outcomes of patients primarily admitted for atrial fibrillation (AF) with and without a secondary diagnosis of rheumatoid arthritis (RA). The primary outcome of interest was inpatient mortality. Hospital length of stay (LOS), total hospital charges, and odds of undergoing ablation and pharmacologic cardioversion were the secondary outcomes of interest. Methods Data were abstracted from the National Inpatient Sample (NIS) 2016 and 2017 databases. The NIS is the largest hospitalization database in the United States (US). The NIS was searched for hospitalizations for adult patients with AF as principal diagnosis with and without RA as secondary diagnosis using the International Classification of Diseases, 10th Revision (ICD-10) codes. Multivariate logistic and linear regression analysis was used accordingly to adjust for confounders. Results There were over 71 million discharges in the combined 2016 and 2017 NIS database. Out of 821,630 AF hospitalizations, 17,020 (2.1%) had RA. Hospitalizations for AF with RA had 0.18 days' decrease in adjusted mean LOS (p=0.014), and lower total hospital charges ($38,432 vs $39,175, p=0.018) compared to those without RA. AF hospitalizations with RA had similar inpatient mortality [1.1% vs 0.91%, adjusted odds ratio (AOR): 0.90, 95% CI: 0.63-1.27, p=0.540] and odds of undergoing ablation (3.5% vs 4.2%, AOR: 1.1, 95% CI: 0.87-1.30, p=0.549) and pharmacologic cardioversion (0.38% vs 0.38%, AOR: 1.00, 95% CI: 0.53-1.89, p=0.988) compared to those without RA. Conclusions Patients admitted for AF with coexisting RA were found to have lesser adjusted mean LOS and lower total hospital charges compared to those without RA. However, inpatient mortality and the odds of undergoing ablation and pharmacologic cardioversion were similar between both groups.

Relevance of Nrf2 and heme oxygenase-1 in articular diseases

Joint conditions pose an important public health problem as they are a leading cause of pain, functional limitation and physical disability. Oxidative stress is related to the pathogenesis of many chronic diseases affecting the joints such as rheumatoid arthritis and osteoarthritis. Cells have developed adaptive protection mechanisms to maintain homeostasis such as nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2) which regulates the transcription of many genes involved in redox balance, detoxification, metabolism and inflammation. Activation of Nrf2 results in the synthesis of heme oxygenase-1 (HO-1) leading to the formation of a number of bioactive metabolites, mainly CO, biliverdin and bilirubin. Ample evidence supports the notion that Nrf2 and HO-1 can confer protection against oxidative stress and inflammatory and immune responses in joint tissues. As a consequence, this pathway may control the activation and metabolism of articular cells to play a regulatory role in joint destruction thus offering new opportunities for better treatments. Further studies are necessary to identify improved strategies to regulate Nrf2 and HO-1 activation in order to enable the development of drugs with therapeutic applications in joint diseases.

Sex and Cardiovascular Involvement in Inflammatory Joint Diseases

The term inflammatory joint disease (IJD) encompasses a group of chronic conditions with predominant joint involvement. They share an increased risk of cardiovascular (CV) complications. However, the implication of the sex in the risk of CV disease in IJD has not been specifically addressed. The aim of this work is to assess the influence of sex on the clinical expression of CV manifestations associated to IJD. With this objective, an update of the current knowledge of the sex influence on CV disease in patients with IJD was conducted. A PubMed database search of the most relevant literature on this topic was performed mainly based on studies published in English over the last 10 years. Although most studies on IJD were not specifically designed to address sex differences regarding CV complications, it seems that men with rheumatoid arthritis (RA) are at higher risk of pericarditis, ischemic heart disease, heart failure (HF) with reduced ejection fraction (EF), and CV mortality than women with RA. In contrast, HF with preserved EF and diastolic dysfunction is more frequent in women with RA. Men with ankylosing spondylitis present more frequently disorders of the conduction system and aortic valvulopathy than women. A limited number of studies addressed CV differences according to sex in psoriatic arthritis. Although there are some differences according to sex in the clinical expression of CV complications in patients with IJD, much research is still needed to better identify the implication of sex in the risk of CV disease in these patients.

The Effect of Puerarin on Carotid Intima-media Thickness in Patients With Active Rheumatoid Arthritis: ARandomized Controlled Trial

PURPOSE

Cardiovascular and diabetic complications are the main causes of death in patients with rheumatoid arthritis (RA). Puerarin has potential protective effects against subclinical atherosclerosis and insulin resistance, but the clinical evidence is still not sufficient to draw definitive conclusions. Therefore, we performed the clinical trial to assess the effect of puerarin on carotid intima-media thickness (CIMT) in RA.

METHODS

This is an open, controlled, randomized, and parallel-group comparison study of 119 patients with a definite diagnose of active RA. All 119 consecutive patients with RA receiving routine antirheumatic care were randomized to receive treatment with (n = 60; 16 males and 44 females; mean age, 52.97 years; 95% CI, 49.78-56.15 years) or without (n = 59; 17 males and 42 females; mean age, 54.05 years; 95% CI, 50.03-58.07 years) 400mg of puerarin. The effects of both interventions on CIMT, homeostasis model assessment of insulin resistance (HOMA-IR) value, and possible adverse events were assessed and compared at entry, 12 weeks, and 24 weeks. The collected data were processed and assessed using ANCOVA, paired t test, repeated-measure ANOVA, one-way ANOVA, Pearson's χ² test, Fisher exact test, Kaplan-Meier survival analysis, Pearson correlation, and LOESS (locally weighted smoothing) regression analysis.

FINDINGS

No significant adverse effects occurred concerning the use of puerarin, and both interventions were generally well tolerated in all the patients. A tiny but significant decrease of CIMT was observed in puerarin-treated patients at 24 weeks (-0.003 mm; 95% CI, -0.005 to -0.001vs 0.019 mm; 95% CI, -0.002 to 0.040; P < 0.001). At 24 weeks, insulin resistance was indicated with more pronounced improvement in the puerarin group versus the control group (homeostasis model assessment, -0.40; 95% CI, -0.47 to -0.33vs -0.05; 95% CI, -0.08 to -0.01; P < 0.001). Correlation analysis indicated an interaction between the parallel reductions in CIMT and insulin resistance in the puerarin group (r = 0.878, P < 0.001) but not in the control group.

IMPLICATIONS

In the study, 24 weeks of treatment with 400mg of puerarin exerted a significant effect against CIMT progression in patients with active RA, which may be associated with the improvement of insulin resistance. Puerarin holds promise as a drug candidate for the prevention and treatment of cardiometabolic comorbidities in patients with active RA. However, more strictly designed trials, such as double-blind and placebo-controlled trials, are still required. ClinicalTrials.gov identifier: NCT02254655.

The Prevalence of Atherosclerosis in Those with Inflammatory Connective Tissue Disease by Race, Age, and Traditional Risk Factors

Systemic inflammation promotes cardiovascular disease. Inflammatory connective tissue diseases (CTD) like lupus and rheumatoid arthritis associate with cardiovascular risk, but it is unknown whether particular groups of patients have enhanced propensity for atherosclerotic cardiovascular disease (ASCVD) associated with their CTD. Analysis of aggregate health record data at a large U.S. academic center identified CTD and ASCVD status for 287,467 African American and white adults. ASCVD prevalence in those with CTD was 29.7% for African Americans and 14.7% for white patients with prevalence ratios, compared to those without CTD, of 3.1 and 1.8, respectively. When different types of CTD were analyzed individually (rheumatoid arthritis; lupus; scleroderma; Sjögren Syndrome; dermatomyositis/polymyositis; unspecified/mixed CTD; other inflammatory arthropathy), increased ASCVD rates were found in nearly all subsets, always with higher prevalence ratios in African Americans. The prevalence ratio of ASCVD was particularly high in young African Americans. Furthermore, individuals lacking traditional cardiovascular risk factors had more ASCVD if they had CTD (prevalence ratio 2.9). Multivariate analysis confirmed a positive interaction between CTD and African-American race and a negative interaction between CTD and age. The factors driving the observed disproportionate CTD-associated ASCVD in African Americans, young adults, and those without traditional risk factors warrant further study.

Development of Cardiovascular Quality Indicators for Rheumatoid Arthritis: Results from an International Expert Panel Using a Novel Online Process

OBJECTIVE

Patients with rheumatoid arthritis (RA) have a high risk of premature cardiovascular disease (CVD). We developed CVD quality indicators (QI) for screening and use in rheumatology clinics.

METHODS

A systematic review was conducted of the literature on CVD risk reduction in RA and the general population. Based on the best practices identified from this review, a draft set of 12 candidate QI were presented to a Canadian panel of rheumatologists and cardiologists (n = 6) from 3 academic centers to achieve consensus on the QI specifications. The resulting 11 QI were then evaluated by an online modified-Delphi panel of multidisciplinary health professionals and patients (n = 43) to determine their relevance, validity, and feasibility in 3 rounds of online voting and threaded discussion using a modified RAND/University of California, Los Angeles Appropriateness Methodology.

RESULTS

Response rates for the online panel were 86%. All 11 QI were rated as highly relevant, valid, and feasible (median rating ≥ 7 on a 1-9 scale), with no significant disagreement. The final QI set addresses the following themes: communication to primary care about increased CV risk in RA; CV risk assessment; defining smoking status and providing cessation counseling; screening and addressing hypertension, dyslipidemia, and diabetes; exercise recommendations; body mass index screening and lifestyle counseling; minimizing corticosteroid use; and communicating to patients at high risk of CVD about the risks/benefits of nonsteroidal antiinflammatory drugs.

CONCLUSION

Eleven QI for CVD care in patients with RA have been developed and are rated as highly relevant, valid, and feasible by an international multidisciplinary panel.

Determinants of brachial-ankle pulse wave velocity in Chinese patients with rheumatoid arthritis

Objective. To investigate the relationship between Brachial-ankle pulse wave velocity (baPWV), and its associated risk factors in Chinese patients with RA. Methods. 138 Chinese RA patients and 150 healthy subjects were included. baPWV of all the participants was measured. RA related factors were determined, as well as traditional cardiovascular risk factors. Results. baPWV was significant higher in RA group (1705.44 ± 429.20 cm/s) compared to the healthy control group (1386.23 ± 411.09 cm/s) (P < 0.001). Compared with low baPWV group, high baPWV group patients were significantly older (P = 0.008) and taller (P = 0.033). Serum cholesterol (P = 0.035), triglycerides (P = 0.004), and LDL level (P = 0.006) were significantly higher in high baPWV group patients compared with low baPWV group patients. The baPWV of RA patients was positively correlated with age (r = 0.439, P < 0.001), and serum cholesterol level (r = 0.231, P = 0.035), serum triglycerides level (r = 0.293, P < 0.001), serum LDL level (r = 0.323, P = 0.003). Meanwhile, baPWV negatively correlated with the height of RA patients (r = −0.253, P = 0.043). Multivariate regression analysis showed that baPWV of RA group was independently associated with age and serum triglycerides level. Conclusions. The old age and high level of serum triglycerides may be the major determinants of arterial stiffness in Chinese RA patients.

Rheumatoid arthritis increases the risk of deep vein thrombosis and pulmonary thromboembolism: a nationwide cohort study

OBJECTIVE

Studies on the association between rheumatoid arthritis (RA) and deep vein thrombosis (DVT) and pulmonary thromboembolism (PE) are scarce. This study identifies the effects of RA on the risks of developing DVT and PE in a nationwide prospective cohort study.

METHODS

We studied the entire Taiwan population from 1998 to 2008, with a follow-up period extending to the end of 2010. We identified patients with RA using the catastrophic illness registry of the Taiwan National Health Insurance Research Database (NHIRD). We also selected a comparison cohort that was randomly frequency-matched by age (each 5-year span), sex and index year from the general population. We analysed the risks of DVT and PE using Cox proportional hazards regression models, including sex, age and comorbidities.

RESULTS

From 23.74 million people in the cohort, 29 238 RA patients (77% women, mean age of 52.4 years) and 1 16 952 controls were followed 1 93 753 and 7 92 941 person-years, respectively. The risk of developing DVT and PE was 3.36-fold and 2.07-fold, respectively, in patients with RA compared with patients without RA, after adjusting for age, sex and comorbidities. The multiplicative increased risks of DVT and PE were also significant in patients with RA with any comorbidity.

CONCLUSIONS

This nationwide prospective cohort study demonstrates that DVT and PE risks significantly increased in patients with RA compared with those of the general population.

Rheumatoid arthritis and risk of acute myocardial infarction--a nationwide retrospective cohort study

OBJECTIVES

Rheumatoid arthritis (RA) imposes substantial social costs, including an increased risk of work-related disability and accelerated cardiovascular diseases. The aim of the study is to determine the risk of acute myocardial infarction (AMI) associated with RA in a nationwide retrospective cohort study.

METHODS

Using the catastrophic illness registry of the Taiwan National Health Insurance Research Database (NHIRD), we identified patients with RA from 1998 to 2010. We also randomly selected non-RA controls frequency-matched by age, sex, and index year from the general population free of RA. The risk of AMI was analyzed using Cox proportional hazards regression models including sex, age, and comorbidities.

RESULTS

From a total of 23.74 million people in the cohort, 29,260 RA patients and 117,040 controls were followed for 193,987 and 792,254 person-years, respectively. The incidence density rate increased in all groups of RA patients than those of the controls. RA patients had a 1.33-fold higher overall incidence of AMI than controls, with an adjusted hazard ration of 1.38. Although the overall adjusted hazard ratio of AMI increased with age, the age-specific RA patients to controls incidence rate ratio was higher for younger RA patients. Subjects with comorbidities of hypertension, diabetes hyperlipidemia, CVA, COPD, or ESRD had increased risk of AMI. Subjects with ESRD had the highest hazard of AMI.

CONCLUSION

This nationwide retrospective cohort study indicates that AMI risk increased by 38% in RA patients compared to the general population. Comorbidities increase the AMI risk independently.

Plasmacytoid dendritic cells: biomarkers or potential therapeutic targets in atherosclerosis?

Plasmacytoid dendritic cells (pDCs) represent a unique subset of dendritic cells that play distinct and critical roles in the immune response. Importantly, pDCs play a pivotal role in several chronic autoimmune diseases strongly characterized by an increased risk of vascular pathology. Clinical studies have shown that pDCs are detectable in atherosclerotic plaques and others have suggested an association between reduced numbers of circulating pDCs and cardiovascular events. Although the causal relationship between pDCs and atherosclerosis is still uncertain, recent results from mouse models are starting to define the specific role(s) of pDCs in the disease process. In this review, we will discuss the role of pDCs in innate and adaptive immunity, the emerging evidence demonstrating the contribution of pDCs to vascular pathology and we will consider the possible impact of pDCs on the acceleration of atherosclerosis in chronic inflammatory autoimmune diseases. Finally, we will discuss how pDCs could be targeted for therapeutic utility.

Atherosclerosis and rheumatoid arthritis: more than a simple association

In the last decades a large amount of evidence linked rheumatoid arthritis (RA) to atherosclerosis. In fact, RA patients have an increased risk of cardiovascular events that is not fully explained by other classic cardiovascular risk factors. RA and atherosclerosis may share several common pathomechanisms and inflammation undoubtedly plays a primary role. The proinflammatory cytokines such as tumor necrosis factor alpha and interleukin-6, involved in the pathogenesis of RA, are also independently predictive of subsequent cardiovascular disease (CVD). In RA, inflammation alters HDL constituents and the concentration of LDL and HDL, thus facilitating atherosclerosis and CVD events. On the other hand, also the increase of oxidative processes, frequently observed in RA, induces atherosclerosis. Interestingly, some genetic polymorphisms associated with RA occurrence enhance atherosclerosis, however, other polymorphisms associated with RA susceptibility do not increase CVD risk. Several other mechanisms may influence atherosclerotic processes in RA. Moreover, atherosclerosis may be directly mediated also by underlying autoimmune processes, and indirectly by the occurrence of metabolic syndrome and impaired physical activity. Finally, the effects of RA therapies on cardiovascular system in general and on atherosclerosis in particular are really wide and different. However, the starting point of every RA treatment is that disease control, or better remission, is the best way we have for the reduction of CVD occurrence.

Alpha-lipoic acid attenuates atherosclerotic lesions and inhibits proliferation of vascular smooth muscle cells through targeting of the Ras/MEK/ERK signaling pathway

An infectious burden has been suggested to be associated with atherosclerosis in humans, based on the shared and underlying inflammatory responses during infection and atherosclerosis. However, the efficacy of anti-atherogenic drugs is yet to be tested against atherosclerosis in a scenario involving an infectious burden. We have examined alpha-lipoic acid (ALA) for anti-atherogenic effects in a hypercholesterolemic diet-induced atherosclerotic mouse model with inflammatory stimulation. C57BL/6 mice were fed with a hypercholesterolemic diet for 12 weeks to induce atherosclerosis. Lipopolysaccharide was intraperitoneally injected for the 1st week of study to simulate underlying infectious burden during development of atherosclerosis. ALA treatment alleviated atherosclerotic pathologies and reduced serum cholesterol and inflammatory cytokines. Consistently, atherosclerotic markers were improved by ALA treatment. In addition, ALA attenuated the proliferation and migration of vascular smooth muscle cells upon platelet-derived growth factor stimulation through the targeting of the Ras-MEK1/2-ERK1/2 pathway. This study demonstrates the efficacy of ALA on atherosclerosis with immunological complication, by showing that ALA modulates multiple pathogenic aspects of atherosclerosis induced by a hypercholesterolemic diet with inflammatory stimulation consisting of hypercholesterolemia, inflammation and VSMC activation.