Altered lipoprotein metabolism in chronic inflammatory states: proinflammatory high-density lipoprotein and accelerated atherosclerosis in systemic lupus erythematosus and rheumatoid arthritis

Impaired metabolism predicts coronary artery calcification in women with systemic lupus erythematosus

BACKGROUND

Patients with systemic lupus erythematosus (SLE) exhibit a high risk for cardiovascular diseases (CVD) which is not fully explained by the classical Framingham risk factors. SLE is characterized by major metabolic alterations which can contribute to the elevated prevalence of CVD.

METHODS

A comprehensive analysis of the circulating metabolome and lipidome was conducted in a large cohort of 211 women with SLE who underwent a multi-detector computed tomography scan for quantification of coronary artery calcium (CAC), a robust predictor of coronary heart disease (CHD).

FINDINGS

Beyond traditional risk factors, including age and hypertension, disease activity and duration were independent risk factors for developing CAC in women with SLE. The presence of coronary calcium was associated with major alterations of circulating lipidome dominated by an elevated abundance of ceramides with very long chain fatty acids. Alterations in multiple metabolic pathways, including purine, arginine and proline metabolism, and microbiota-derived metabolites, were also associated with CAC in women with SLE. Logistic regression with bootstrapping of lipidomic and metabolomic variables were used to develop prognostic scores. Strikingly, combining metabolic and lipidomic variables with clinical and biological parameters markedly improved the prediction (area under the curve: 0.887, p < 0.001) of the presence of coronary calcium in women with SLE.

INTERPRETATION

The present study uncovers the contribution of disturbed metabolism to the presence of coronary artery calcium and the associated risk of CHD in SLE. Identification of novel lipid and metabolite biomarkers may help stratifying patients for reducing CVD morbidity and mortality in SLE.

FUNDING

INSERM and Sorbonne Université.

Potential role of anti-inflammatory HDL subclasses in metabolic unhealth/obesity

High-density lipoprotein (HDL) particles comprising heterogeneous subclasses of different functions exert anti-inflammatory effects by interacting with immune-response cells. However, the relationship of HDL subclasses with immune-response cells in metabolic unhealth/obesity has not been defined clearly. The purpose of this study was to delineate the relational changes of HDL subclasses with immune cells and inflammatory markers in metabolic unhealth/obesity to understand the role of anti-inflammatory HDL subclasses. A total of 316 participants were classified by metabolic health. HDL subclasses were detected by microfluidic chip electrophoresis. White blood cell (WBC) counts and lymphocytes were assessed using automatic haematology analyser. Levels of high-sensitivity C-reactive protein (hs-CRP) and interleukin 6 (IL-6) were measured. In our study, not only the distribution of HDL subclasses, but also HDL-related structural proteins changed with the deterioration of metabolic disease. Moreover, lymphocytes and inflammation factors significantly gradually increased. The level of HDL2b was negatively associated with WBC, lymphocytes and hs-CRP in multivariable linear regression analysis. In multinomial logistic regression analysis, high levels of HDL3 and low levels of HDL2b increased the probability of having an unfavourable metabolic unhealth/obesity status. We supposed that HDL2b particles may play anti-inflammation by negatively regulating lymphocytes activation. HDL2b may be a therapeutic target for future metabolic disease due to the anti-inflammatory effects.

HDL in Immune-Inflammatory Responses: Implications beyond Cardiovascular Diseases

High density lipoproteins (HDL) are heterogeneous particles composed by a vast array of proteins and lipids, mostly recognized for their cardiovascular (CV) protective effects. However, evidences from basic to clinical research have contributed to depict a role of HDL in the modulation of immune-inflammatory response thus paving the road to investigate their involvement in other diseases beyond those related to the CV system. HDL-C levels and HDL composition are indeed altered in patients with autoimmune diseases and usually associated to disease severity. At molecular levels, HDL have been shown to modulate the anti-inflammatory potential of endothelial cells and, by controlling the amount of cellular cholesterol, to interfere with the signaling through plasma membrane lipid rafts in immune cells. These findings, coupled to observations acquired from subjects carrying mutations in genes related to HDL system, have helped to elucidate the contribution of HDL beyond cholesterol efflux thus posing HDL-based therapies as a compelling interventional approach to limit the inflammatory burden of immune-inflammatory diseases.

Effect of Tocilizumab on LDL and HDL Characteristics in Patients with Rheumatoid Arthritis. An Observational Study

BACKGROUND

In patients with rheumatoid arthritis (RA), qualitative alterations of low and high-density lipoproteins (LDL and HDL, respectively) might partially explain their increased cardiovascular risk. Tocilizumab has been associated with an increase in lipids, including triglyceride (TG) and cholesterol levels. The aim of this study is to evaluate the effect of tocilizumab on certain LDL and HDL characteristics (oxidized LDL levels, HDL-associated enzymes, chemical composition of both total HDL and HDL3c subpopulation, and their capacity to promote cellular cholesterol efflux) at baseline and 3 months after the start of treatment in patients with RA.

METHODS

Twenty-eight RA patients (ACR/EULAR 2010 criteria) with indication of treatment with tocilizumab were included in the present study. Clinical assessment [Health assessment questionnaire (HAQ)], disease activity score 28 (DAS28), high-sensitivity C reactive protein (hsCRP) concentration, lipid profile, and lipoprotein (a) [Lp(a)] levels were evaluated in all patients at baseline and after 3 months of treatment with tocilizumab. Lipoprotein characteristics were evaluated through the levels of oxidized LDL (OxLDL), the activity of paraoxonase (PON) 1, the composition of total HDL and small, dense HDL3c subpopulation, and their ability to promote cellular cholesterol efflux.

RESULTS

After 3 months of treatment with tocilizumab, HAQ (- 23%, p < 0.05), DAS28 (- 49%, p < 0.001), and hsCRP (- 94%, p < 0.01) levels decreased significantly. Total cholesterol (TC), LDL-C, non-HDL-C, and apo B levels showed a significant increase after treatment (TC: + 7.0%, p < 0.01; LDL-C: + 10%, p < 0.01; non-HDL-C: + 9.9%, p < 0.01; and apo B: + 9.6%, p < 0.05). Decreases in Lp(a) and OxLDL levels were also observed after treatment [Lp(a): - 50%, p < 0.01; and oxLDL: - 5.4%, p < 0.05]. The latter was in accordance with the increment detected in PON activity. No changes were observed in HDL capacity to promote cholesterol efflux (p > 0.05) in the whole group.

CONCLUSIONS

Treatment with tocilizumab reduced hsCRP levels and displayed positive effects on certain lipoprotein-related parameters, such as a potent decrease inLp(a) and a reduction in OxLDL levels. Moreover, HDL capacity to promote cellular cholesterol efflux was maintained after 3 months of treatment.

Wechselwirkungen zwischen neuroendokrinem System und Immunsystem bei chronisch-entzündlichen Systemerkrankungen

Hormonelle und neuronale Signalwege können die Manifestation einer chronisch-entzündlichen Systemerkrankung entweder begünstigen oder verhindern. Bei bereits manifester Erkrankung modulieren Hormone und Neurotransmitter den Krankheitsverlauf, in dem sie die Krankheitsaktivität erhöhen oder abschwächen. Beispiele hierfür sind der entzündungshemmende Einfluss der körpereigenen und exogenen Glukokortikoide und die entzündungsfördernden Effekte von Stress bei chronisch-entzündlichen Systemerkrankungen. Bei chronisch-entzündlichen Systemerkrankungen ringt das aktivierte Immunsystem mit dem Gehirn und anderen Organsystemen um Energie, was zu vielfältigen Erkrankungsfolgen und Folgeerkrankungen führt: „sickness behaviour“ mit Fatigue-Symptomatik und depressiven Symptomen, Schlafstörungen, Anorexie, Fehl- und Mangelernährung, Knochenabbau, Muskelabbau und kachektische Fettsucht, Insulinresistenz mit Hyperinsulinämie (begleitet von einer Resistenz gegenüber dem Insulin-like growth factor 1), Dyslipidämie, Veränderungen der Steroidhormonachsen, Störungen der Hypothalamus-Hypophysen-Gonaden-Achse, erhöhter Sympathikotonus, herabgesetzte Aktivität des parasympathischen Nervensystems, arterielle Hypertonie und Volumenbelastung, Entzündungsanämie und zirkadiane Rhythmik der Symptomausprägung. Diese für die Patienten gravierenden Folgeerkrankungen, welche den chronisch-entzündlichen Systemerkrankungen inhärent sind, sollten konsequent therapiert werden.

Serum Metabolomic Signatures Can Predict Subclinical Atherosclerosis in Patients With Systemic Lupus Erythematosus

[Figure: see text].

High- density lipoprotein function is abnormal in idiopathic inflammatory myopathies

OBJECTIVE

Damage to the vascular endothelium is strongly implicated in the pathogenesis of idiopathic inflammatory myopathies (IIM). Normally, high-density lipoprotein (HDL) protects the vascular endothelium from damage from oxidized phospholipids, which accumulate under conditions of oxidative stress. The current work evaluated the antioxidant function of HDL in IIM patients.

METHODS

HDL's antioxidant function was measured in IIM patients using a cell-free assay, which assesses the ability of isolated patient HDL to inhibit oxidation of low-density lipoproteins and is reported as the HDL inflammatory index (HII). Cholesterol profiles were measured for all patients, and subgroup analysis included assessment of oxidized fatty acids in HDL and plasma MPO activity. A subgroup of IIM patients was compared with healthy controls.

RESULTS

The antioxidant function of HDL was significantly worse in patients with IIM (n = 95) compared with healthy controls (n = 41) [mean (S.d.) HII 1.12 (0.61) vs 0.82 (0.13), P < 0.0001]. Higher HII associated with higher plasma MPO activity [mean (S.d.) 13.2 (9.1) vs 9.1 (4.6), P = 0.0006] and higher oxidized fatty acids in HDL. Higher 5-hydroxyeicosatetraenoic acid in HDL correlated with worse diffusion capacity in patients with interstitial lung disease (r = -0.58, P = 0.02), and HDL's antioxidant function was most impaired in patients with autoantibodies against melanoma differentiation-associated protein 5 (MDA5) or anti-synthetase antibodies. In multivariate analysis including 182 IIM patients, higher HII was associated with higher disease activity and DM diagnosis.

CONCLUSION

The antioxidant function of HDL is abnormal in IIM patients and may warrant further investigation for its role in propagating microvascular inflammation and damage in this patient population.

Cardiovascular Consequences of Autoimmune Rheumatic Diseases

The increased risk of cardiovascular disease (CVD) among patients with autoimmune rheumatic diseases such as rheumatoid arthritis, spondyloarthritis and systemic lupus erythematosus has been extensively documented. Sub-clinical atherosclerosis can be assessed using various non-invasive imaging techniques. However, the mechanisms underlying the higher risk of atherosclerotic CVD in patients with autoimmune rheumatic diseases are not fully known, although they seem to include chronic low-grade systemic inflammation leading to prolonged endothelial activation, accompanied by a pro-thrombotic/pro-coagulant and autoantibody state. Furthermore, sub-clinical atherosclerosis is also influenced by other traditional risk factors for CVD. Including the individual components of the metabolic syndrome (MetS: obesity, impaired glucose metabolism, dyslipidemia and high blood pressure), the degree of which is higher in these patients than in controls. The aim of this narrative review is to discuss the CV manifestations and risk factors involved in the increased risk of CVD among patients with autoimmune rheumatic diseases.

Cardiovascular Disease in Spondyloarthritides

The spondyloarthritides are a group of chronic systemic inflammatory joint diseases, the main types being ankylosing spondylitis (AS) and psoriatic arthritis (PsA). Evidence accumulating during the last decades suggests that patients with AS or PsA carry an increased risk for cardiovascular disease and cardiovascular death. This risk appears to be mediated by systemic inflammation over and above classical cardiovascular risk factors. The excess cardiovascular risk in those patients has been formally acknowledged by scientific organizations, which have called physicians' attention to the matter. The application by Rheumatologists of new effective anti-rheumatic treatments and treat-to-target strategies seems to benefit patients from a cardiovascular point of view, as well. However, more data are needed in order to verify whether anti-rheumatic treatments do have an effect on cardiovascular risk and whether there are differences among them in this regard. Most importantly, a higher level of awareness of the cardiovascular risk is needed among patients and healthcare providers, better tools to recognize at-risk patients and, ultimately, commitment to address in parallel both the musculoskeletal and the cardiovascular aspect of the disease.

Interaction between high-density lipoproteins and inflammation: Function matters more than concentration!

High-density lipoprotein (HDL) plays an important role in lipid metabolism and especially contributes to the reverse cholesterol transport pathway. Over recent years it has become clear that the effect of HDL on immune-modulation is not only dependent on HDL concentration but also and perhaps even more so on HDL function. This review will provide a concise general introduction to HDL followed by an overview of post-translational modifications of HDL and a detailed overview of the role of HDL in inflammatory diseases. The clinical potential of HDL and its main apolipoprotein constituent, apoA-I, is also addressed in this context. Finally, some conclusions and remarks that are important for future HDL-based research and further development of HDL-focused therapies are discussed.

Untying the correlation between apolipoproteins and rheumatoid arthritis

AIM AND OBJECTIVE

The concentration of lipoproteins and apolipoprotein are extremely low in the synovial fluid of any healthy person as compared to the concentrations in plasma. However, in the synovial fluid of any diseased patient the amount of cholesterol and lipids is sharply increased. The current review defines the role of various apolipoproteins and lipoproteins and their constituent subfractions in the synovial fluid embarking its principal role in rheumatoid arthritis. It also explains the need to define synovial fluid lipids, lipoprotein particle subfractions and their constituent apolipoproteins in synovial fluid.

MATERIALS AND METHODS

Various research and review articles highlighting the role of apolipoproteins and lipoproteins were procured from medical websites mainly Pubmed, Medline, Science Direct, etc., and studied for the writing of the review paper.

CONCLUSION

Mainly apolipoproteins A-1, B and E are prominently increased in chronic inflammatory joint disorders. Several theories have been proposed to understand the source of increase of lipids and apolipoproteins in synovial fluid of the diseased patients compared to healthy individuals, yet the precise mechanism is still not lucid. Lipoproteins are believed to play both functional role and pathological role in the synovial fluid. The activated T-lymphocytes in patients of RA lead to activation of inflammatory cytokines such as tumor necrosis factor and interleukins which embark to be the principal mechanism for induction of the disease. It can be thus concluded that the apolipoproteins prevent the activation of monocytes by blocking their contact of activation and thus play critical role in management of RA by inhibiting the production of proinflammatory cytokines.

Atherogenic index of plasma predicts cerebrovascular accident occurrence in antineutrophil cytoplasmic antibody-associated vasculitis

Background

To investigate whether atherogenic index of plasma (AIP) at diagnosis is associated with the occurrence of cerebrovascular accident (CVA) or coronary artery disease (CAD) in antineutrophil cytoplasmic antibody-associated vasculitis (AAV).

Methods

The medical records of 167 AAV patients on initial diagnosis was reviewed, and 300 healthy controls were included. AIP was calculated using the following equation: AIP = Log (triglyceride [mg/dL] / high-density lipoprotein cholesterol [mg/dL]). AAV patients were divided into two groups according to the AIP cut-off of 0.11. The event of stroke, transient ischemic attack, and cerebral hemorrhage was recorded as CVA, and CAD events consisted of either myocardial infarction and angina pectoris. CVA- and CAD- free survival rate between those with AIP ≥ 0.11 and < 0.11 were compared by the Kaplan-Meier analysis, and Cox hazard analysis was conducted to identify predictors of CVA.

Results

The median age of AAV patients were 59.0 years, and 54 (32.3%) patients were male. One-hundred and fifteen (68.9%) patients had AIP < 0.11 and 52 (31.1%) had AIP ≥ 0.11. The mean Birmingham vasculitis activity score in AAV patients with AIP < 0.11 was lower than that seen in patients with AIP ≥ 0.11 (12.0 vs. 14.0, P = 0.041). AAV patients had a significantly higher AIP compared to controls (mean − 0.01 vs. -0.10, P < 0.001). During follow-up, the occurrence of CVA and CAD was observed in 16 (9.6%) and 14 (8.4%) patients, respectively. In Kaplan-Meier analysis, AAV patients with AIP ≥ 0.11 had significantly lower CVA-free survival rates than in those with AIP < 0.11 (P = 0.027), whereas there was no difference in CAD according to AIP (P = 0.390). Multivariable Cox analysis indicated that AIP ≥ 0.11 at diagnosis was the sole predictor of CVA (Hazard ratio 3.392, 95% confidence interval 1.076, 10.696, P = 0.037).

Conclusions

AIP is significantly higher in AAV patients than in healthy controls, and AIP ≥ 0.11 at diagnosis is a significant predictor of CVA during follow-up. Stringent surveillance should be provided in AAV patients with AIP ≥ 0.11 regarding the occurrence of CVA.

Trial registration

Retrospectively registered (4–2017-0673).

High-density lipoprotein functionality in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a heterogeneous disease which is characterized with excessive inflammation and autoantibodies, macrophage and complement activation, and subsequently immunologically mediated tissue damage. In spite of improved treatments of SLE, these patients experience premature atherosclerosis and the rate of mortality among them remains high. Autoantibodies and circulating immune complexes might contribute to the pathogenesis of atherosclerosis by injuring the endothelium, as well as inducing pro-inflammatory and pro-adhesive endothelial cell phenotypes, as well as altering the metabolism of lipoproteins involved in atherogenesis. Hence, high levels of atherogenic lipoproteins (like low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL)) and low levels of high-density lipoprotein (HDL-C) are important risk factors for atherosclerotic cardiovascular complications in SLE patients but these traditional risk factors fail to fully explain the increased risk of cardiovascular disease (CVD) in these patients. The exact mechanism by which inflammation decreases HDL levels is not defined, but decreases in apoA-I production and lecithin cholesterol acyltransferase (LCAT) activity, as well as increased serum amyloid A (SAA), endothelial lipase and secretory phospholipase A2 activity (PLA2) could all contribute. In addition, during inflammation multiple changes in HDL structure occur, leading to alterations in HDL function which may be implicated in the CVD complications of SLE. Therefore, this review will aim to identify the mechanisms implicated in HDL dysfunction which occurs in SLE patients.

Identification of Haptoglobin as a Potential Biomarker in Young Adults with Acute Myocardial Infarction by Proteomic Analysis

Background

Acute myocardial infarction (AMI) molecular research in young adults is still limited. The aim of this study is to identify AMI proteomic biomarker(s) in young adults.

Methods

This study comprised of two phases namely discovery and verification. In the discovery phase, proteins in the pooled plasma samples from young male adults between 18 and 45 years (10 AMI patients and 10 controls) were separated using two-dimensional electrophoresis. The protein spots that were expressed differently in the AMI patients were identified via matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry. The plasma concentrations of these proteins were quantified using enzyme-linked immunosorbent assay during the verification phase (40 AMI patients and 80 controls).

Results

Haptoglobin (Hp), apolipoprotein AI (Apo AI) and apolipoprotein AIV (Apo AIV) were up-regulated in the discovery phase. In the verification phase, the plasma concentration of Hp was significantly higher in AMI patients than the controls (P < 0.001). Logistic regression showed an association between Hp and AMI in young adults (odds ratio [OR] = 1.016, 95% CI: 1.002–1.030, P = 0.025) independent of other AMI risk factors. Hp was significantly correlated with high sensitivity C-reactive protein (hs-CRP) (r = 0.424, P < 0.001).

Conclusion

In young adults with AMI, plasma Hp concentrations were elevated and it is independently associated with AMI. A positive correlation with hs-CRP suggests Hp could be a potential biomarker of AMI in young adults.

Classical Activation of Macrophages Leads to Lipid Droplet Formation Without de novo Fatty Acid Synthesis

Altered lipid metabolism in macrophages is associated with various important inflammatory conditions. Although lipid metabolism is an important target for therapeutic intervention, the metabolic requirement involved in lipid accumulation during pro-inflammatory activation of macrophages remains incompletely characterized. We show here that macrophage activation with IFNγ results in increased aerobic glycolysis, iNOS-dependent inhibition of respiration, and accumulation of triacylglycerol. Surprisingly, metabolite tracing with ¹³C-labeled glucose revealed that the glucose contributed to the glycerol groups in triacylglycerol (TAG), rather than to de novo synthesis of fatty acids. This is in stark contrast to the otherwise similar metabolism of cancer cells, and previous results obtained in activated macrophages and dendritic cells. Our results establish a novel metabolic pathway whereby glucose provides glycerol to the headgroup of TAG during classical macrophage activation.

High-Density Lipoprotein in Lupus: Disease Biomarkers and Potential Therapeutic Strategy

Systemic lupus erythematosus (SLE) patients exhibit accelerated development of atherosclerosis and increased incidents of cardiovascular disease (CVD) that cannot be explained by traditional risk factors alone. Accumulating evidence suggests that reduced levels of high-density lipoproteins (HDLs), along with altered HDL composition and function, may contribute to the accelerated atherosclerosis in SLE patients. Normally, HDLs play various atheroprotective roles through facilitating cholesterol efflux, inhibiting vascular inflammation, and scavenging oxidative species. However, systemic inflammation, oxidative stress, and autoimmunity in SLE patients induce changes in HDL size distribution and proteomic and lipidomic signatures. These compositional changes in HDLs result in the formation of proinflammatory, dysfunctional HDL. These lupus-altered HDLs have impaired antiatherogenic function with reduced cholesterol efflux capacities, impaired antioxidation abilities, and diminished antiinflammatory properties. In fact, dysfunctional HDL may promote atherogenesis by inducing inflammation. Thus, dysfunctional HDLs could be an important biomarker of accelerated atherosclerosis in lupus. Additionally, HDL-targeted therapies, especially infusion of reconstituted HDLs, may serve as a potential therapeutic intervention for SLE patients with CVD.

Regulation of ABCA1-mediated cholesterol efflux by sphingosine-1-phosphate signaling in macrophages

Sphingolipid and cholesterol metabolism are closely associated at the structural, biochemical, and functional levels. Although HDL-associated sphingosine-1-phosphate (S1P) contributes to several HDL functions, and S1P signaling regulates glucose and lipid metabolism, no study has addressed the involvement of S1P in cholesterol efflux. Here, we show that sphingosine kinase (Sphk) activity was induced by the LXR agonist 22(R)-hydroxycholesterol and required for the stimulation of ABCA1-mediated cholesterol efflux to apolipoprotein A-I. In support, pharmacological Sphk inhibition and Sphk2 but not Sphk1 deficiency abrogated efflux. The involved mechanism included stimulation of both transcriptional and functional ABCA1 regulatory pathways and depended for the latter on the S1P receptor 3 (S1P3). Accordingly, S1P3-deficient macrophages were resistant to 22(R)-hydroxycholesterol-stimulated cholesterol efflux. The inability of excess exogenous S1P to further increase efflux was consistent with tonic S1P3 signaling by a pool of constitutively generated Sphk-derived S1P dynamically regulating cholesterol efflux. In summary, we have established S1P as a previously unrecognized intermediate in LXR-stimulated ABCA1-mediated cholesterol efflux and identified S1P/S1P3 signaling as a positive-feedback regulator of cholesterol efflux. This constitutes a novel regulatory mechanism of cholesterol efflux by sphingolipids.

Potent anti-inflammatory properties of HDL in vascular smooth muscle cells mediated by HDL-S1P and their impairment in coronary artery disease due to lower HDL-S1P: a new aspect of HDL dysfunction and its therapy

Dysfunctional HDL is associated with coronary artery disease (CAD), but its effect on inflammation in vascular smooth muscle cells (VSMCs) in atherosclerosis is unknown. We investigated the effect of healthy human HDL and CAD-HDL on TNF-α-driven inflammation in VSMCs and examined whether HDL-associated sphingosine-1-phosphate (HDL-S1P) could modulate inflammation with the aim of designing novel HDL-based anti-inflammatory strategies. Healthy human HDL, human CAD-HDL, and mouse HDL were isolated by ultracentrifugation, S1P was measured by liquid chromatography-tandem mass spectrometry, and TNF-α-induced inflammation was characterized by gene expression and analysis of NF-κB-dependent signaling. Mechanisms of S1P interference with TNF-α were assessed by S1P receptor antagonists, mouse knockouts, and short interfering RNA. We observed that healthy HDL potently inhibited the induction of TNF-α-stimulated inflammatory genes, such as iNOS (inducible NO synthase) and MMP9 (matrix metalloproteinase 9), a process that was entirely dependent on HDL-S1P, as evidenced by loss-of-function using S1P-less HDL and mimicked by genuine S1P. Inhibition was based on suppression of TNF-α-activated Akt signaling resulting in reduced IkBαSer32 and p65Ser534 NF-κB phosphorylation based on a persistent phosphatase and tensin homolog activation by S1P through the S1P receptor 2. Intriguingly, S1P suppressed inflammation even hours after initial TNF-α stimulation. The anti-inflammatory effect of healthy HDL correlated with HDL-S1P content and was superior to that of CAD-HDL featuring lower HDL-S1P. Nevertheless, therapeutic loading of HDL with S1P completely restored the anti-inflammatory capacity of CAD-HDL and greatly boosted that of both healthy and CAD-HDL. Suppression of inflammation by HDL-S1P defines a novel pathophysiologic characteristic that distinguishes functional from dysfunctional HDL. The anti-inflammatory HDL function can be boosted by S1P-loading and exploited by S1P receptor-targeting to prevent and even turn off ongoing inflammation.-Keul, P., Polzin, A., Kaiser, K., Gräler, M., Dannenberg, L., Daum, G., Heusch, G., Levkau, B. Potent anti-inflammatory properties of HDL in vascular smooth muscle cells mediated by HDL-S1P and their impairment in coronary artery disease due to lower HDL-S1P: a new aspect of HDL dysfunction and its therapy.

B-cell activating factor and related genetic variants in lupus related atherosclerosis

BACKGROUND

Systemic lupus erythematosus (SLE) is a chronic systemic autoimmune disease with an increased atherosclerotic risk compared to healthy population, partially explained by traditional cardiovascular (CV) risk factors. Recent data suggest B-cell activating factor (BAFF) as an important contributor in the pathogenesis of both SLE and atherosclerosis. The aim of the current study is to explore whether serum BAFF levels along with variants of the BAFF gene increase lupus related atherosclerotic risk.

PATIENTS-METHODS

250 SLE patients underwent assessment of plaque formation and/or intimal media thickness (IMT) measurements in carotid and femoral arteries by ultrasound. Disease related features and CV traditional risk factors were also assessed. Serum BAFF levels were determined by commercially available ELISA and five single nucleotide polymorphisms (SNPs) of the BAFF gene (rs1224141, rs12583006, rs9514828, rs1041569 and the rs9514827) were evaluated by PCR-based assays in all patients and 200 healthy controls (HC) of similar age and sex distribution. SLE patients were further divided in high and low BAFF groups on the basis of the upper quartile level of the distribution (1358 pg/ml). Genotype and haplotype frequencies in SLE patients and HC were determined by SNPStats and SHEsis software.

RESULTS

High-BAFF SLE group displayed increased rates of both plaque formation and arterial wall thickening (defined as IMT>0.90 mm) compared to patients with low BAFF levels (58.1% vs 43.6%, p:0.048 and 38.6% vs 23.2%, p-value: 0.024, respectively). The association remained significant after disease related features were taken into account (ORs [95%CI]: 2.2 [1.0-5.1] and 2.5 [1.1-5.5] for plaque formation and arterial wall thickening, respectively). Moreover, the presence of the AA genotype of the rs12583006 BAFF gene variant increased susceptibility for both lupus and lupus related plaque formation (ORs [95%CI]: 2.8 [1.1-7.1], and 4.4 [1.3-15.4] in the codominant model, respectively). Finally, the haplotype TTTAT was found to be protective for plaque formation among SLE patients (OR 0.3 [0.1-0.9]. No associations between BAFF gene variants with arterial wall thickening were detected.

CONCLUSIONS

High BAFF serum levels in the upper 4th quartile as well as BAFF genetic variants seem to increase susceptibility for both lupus and lupus related subclinical atherosclerosis implying B-cell hyperactivity as a potential contributor in the pronounced lupus related atherosclerotic risk.

PhosphoLipid transfer protein (PLTP) exerts a direct pro-inflammatory effect on rheumatoid arthritis (RA) fibroblasts-like-synoviocytes (FLS) independently of its lipid transfer activity

Rheumatoid arthritis (RA) is a chronic inflammatory rheumatic disease with modification of lipids profile and an increased risk of cardiovascular events related to inflammation. Plasma phospholipid transfer protein (PLTP) exerts a lipid transfer activity through its active form. PLTP can also bind to receptors such as ATP-binding cassette transporter A1 (ABCA1). In addition to its role in lipoprotein metabolism and atherosclerosis, the latest advances came in support of a complex role of PLTP in the regulation of the inflammatory response, both with pro-inflammatory or anti-inflammatory properties. The aim of the present study was to decipher the role of PLTP in joint inflammation and to assess its relevance in the context of RA. PLTP expression was examined by western-blot and by immunochemistry. ABCA1 expression was analyzed by flow cytometry. Lipid transfer activity of PLTP and pro-inflammatory cytokines were measured in sera and synovial fluid (SF) from RA patients and controls (healthy subjects or osteoarthritis patients [OA]). FLS were treated with both lipid-transfer active form and inactive form of recombinant human PLTP. IL-8, IL-6, VEGF and MMP3 produced by FLS were assessed by ELISA, and proliferation by measuring ³H-Thymidine incorporation. RA synovial tissues showed higher PLTP staining than OA and PLTP protein levels were also significantly higher in RA-FLS. In addition, RA, unlike OA patients, displayed elevated levels of PLTP activity in SF, which correlated with pro-inflammatory cytokines. Both lipid-transfer active and inactive forms of PLTP significantly increased the production of cytokines and proliferation of FLS. ABCA1 was expressed on RAFLS and PLTP activated STAT3 pathway. To conclude, PLTP is highly expressed in the joints of RA patients and may directly trigger inflammation and FLS proliferation, independently of its lipid transfer activity. These results suggest a pro-inflammatory role for PLTP in RA.

Variables associated with subclinical atherosclerosis in a cohort of rheumatoid arthritis patients: Sex-specific associations and differential effects of disease activity and age

OBJECTIVE

To advance the study of variables associated with subclinical atherosclerosis in rheumatoid arthritis (RA) with special consideration for the degree of disease activity, age and gender.

METHODS

The carotid intima-media thickness (cIMT) and the presence of carotid atherosclerotic plaques along with clinical and biochemical characteristics were determined in 214 RA patients.

RESULTS

Adjusted analysis reveals that men had a 0.059 mm significantly increased cIMT compared with women (p = 0.001; R2 = 3.8%) and that age was associated with cIMT (β = 0.0048 mm; p = 0.0001; R2 = 16%). Interestingly, we observed a significant interaction between gender and age. Thus, the effect of age on cIMT was significantly increased (12%) in men compared with women (p-value for interaction term = 0.041). Moreover, adjusted multivariable linear regression analysis revealed that disease activity score (DAS28) was significantly associated with cIMT in women (β = 0.021; p = 0.018: R2 = 0.03) but not men. In particular, women with high disease activity had a 0.079 mm increased cIMT compared with women in remission (p = 0.026). In addition, men in remission had a 0.134 mm increased cIMT compared with women in remission (p = 0.003; R2 = 8.7%). Active patients did not exhibit differences in cIMT values. Furthermore, 43% of patients presented carotid plaques. The variables independently associated with carotid plaques were age, smoking, health assessment questionnaire, erythrocyte sedimentation rate and rheumatoid factor (p<0.0001; R2 = 46%).

CONCLUSION

In our cohort of patients with RA, DAS28 and age are differentially associated with cIMT in men and women. Our findings could explain the contradictory results that have previously been published in the literature.

Cardiovascular disease in systemic lupus erythematosus: A comprehensive update

Heightened rates of both cardiovascular (CV) events and subclinical atherosclerosis, documented by imaging and vascular function techniques are well established in systemic lupus erythematosus (SLE). While traditional CV factors such as smoking, dyslipidemia, diabetes mellitus (DM), hypertension, central obesity and hyperhomocysteinemia have been reported to be prevalent in lupus patients, they do not fully explain the high rates of ischemic events so far reported, implying that other factors inherent to disease itself could account for the enhanced risk, including disease duration, activity and chronicity, psychosocial factors, medications, genetic variants and altered immunological mechanisms. Though the exact pathogenesis of atherosclerosis in the setting of lupus remains ill defined, an imbalance between endothelial damage and atheroprotection seems to be a central event. Insults leading to endothelial damage in the setting of lupus include oxidized low density lipoprotein (oxLDL), autoantibodies against endothelial cells and phospholipids, type I interferons (IFN) and neutrophil extracellular traps (NETs) directly or through activation of type I IFN pathway. Increased oxidative stress, reduced levels of the normally antioxidant high density lipoprotein (HDL), increased levels of proinflammatory HDL (piHDL) and reduced paraoxonase activity have been related to increased oxLDL levels. On the other hand, impaired atheroprotective mechanisms in lupus include decreased capacity of endothelial repair-partly mediated by type I IFN- and dampened production of atheroprotective autoantibodies. In the present review, traditional and disease related risk factors for CV disease (CVD) in the setting of chronic autoimmune disorders with special focus on SLE will be discussed.

Relapsing-remitting multiple sclerosis patients display an altered lipoprotein profile with dysfunctional HDL

Lipoproteins modulate innate and adaptive immune responses. In the chronic inflammatory disease multiple sclerosis (MS), reports on lipoprotein level alterations are inconsistent and it is unclear whether lipoprotein function is affected. Using nuclear magnetic resonance (NMR) spectroscopy, we analysed the lipoprotein profile of relapsing-remitting (RR) MS patients, progressive MS patients and healthy controls (HC). We observed smaller LDL in RRMS patients compared to healthy controls and to progressive MS patients. Furthermore, low-BMI (BMI ≤ 23 kg/m²) RRMS patients show increased levels of small HDL (sHDL), accompanied by larger, triglyceride (TG)-rich VLDL, and a higher lipoprotein insulin resistance (LP-IR) index. These alterations coincide with a reduced serum capacity to accept cholesterol via ATP-binding cassette (ABC) transporter G1, an impaired ability of HDL₃ to suppress inflammatory activity of human monocytes, and modifications of HDL₃’s main protein component ApoA-I. In summary, lipoprotein levels and function are altered in RRMS patients, especially in low-BMI patients, which may contribute to disease progression in these patients.

Cardiovascular risk in rheumatoid arthritis: assessment, management and next steps

Rheumatoid arthritis (RA) is associated with increased cardiovascular (CV) morbidity and mortality which cannot be fully explained by traditional CV risk factors; cumulative inflammatory burden and antirheumatic medication-related cardiotoxicity seem to be important contributors. Despite the acknowledgment and appreciation of CV disease burden in RA, optimal management of individuals with RA represents a challenging task which remains suboptimal. To address this need, the European League Against Rheumatism (EULAR) published recommendations suggesting the adaptation of traditional risk scores by using a multiplication factor of 1.5 if two of three specific criteria are fulfilled. Such guidance requires proper coordination of several medical specialties, including general practitioners, rheumatologists, cardiologists, exercise physiologists and psychologists to achieve a desirable result. Tight control of disease activity, management of traditional risk factors and lifestyle modification represent, amongst others, the most important steps in improving CV disease outcomes in RA patients. Rather than enumerating studies and guidelines, this review attempts to critically appraise current literature, highlighting future perspectives of CV risk management in RA.

Accelerated transformation of macrophage-derived foam cells in the presence of collagen-induced arthritis mice serum is associated with dyslipidemia

OBJECTIVE

Atherosclerosis characterized by accumulation of foam cells in the arterial intimal layer is accelerated in rheumatoid arthritis (RA) patients. We and others have previously demonstrated that serum from RA patients and collagen-induced arthritis (CIA) mice had proatherogenic features that might lead to progression of atherosclerosis. Here we further examined the effects of serum from CIA mice on the transformation of macrophage-derived foam cells, and investigated potential mechanism.

METHODS

DBA/1j mice were used to establish CIA model. Murine peritoneal macrophages and macrophage cell line RAW264.7 were treated with different dilute concentrations of mice serum.

RESULTS

CIA mice serum increased cholesterol influx and accumulation in murine macrophages, and markedly up-regulated scavenger receptor CD36 expression in the cells, but had no effect on intracellular lipid efflux. Neutralizing monocyte chemotactic protein (MCP)-1, the most significant altered cytokine we observed between normal and CIA mice serum to CIA mice could not reverse these effects. However, administering simvastatin to CIA mice could lower high-density lipoprotein-cholesterol (HDL-C) level and elevate oxidized low-density lipoprotein (ox-LDL) level in CIA mice serum, with attendant decreased lipid accumulation as well as CD36 expression in murine macrophages.

CONCLUSION

Accelerated transformation of macrophage-derived foam cells via up-regulated CD36 expression is related to dyslipidemia rather than elevated inflammatory factor MCP-1 level in CIA mice serum. Decreased HDL-C and higher ox-LDL levels in CIA mice serum may link RA to atherosclerosis.

Functional implications of disease-specific variants in loci jointly associated with coeliac disease and rheumatoid arthritis

Hundreds of genomic loci have been associated with a significant number of immune-mediated diseases, and a large proportion of these associated loci are shared among traits. Both the molecular mechanisms by which these loci confer disease susceptibility and the extent to which shared loci are implicated in a common pathogenesis are unknown. We therefore sought to dissect the functional components at loci shared between two autoimmune diseases: coeliac disease (CeD) and rheumatoid arthritis (RA). We used a cohort of 12 381 CeD cases and 7827 controls, and another cohort of 13 819 RA cases and 12 897 controls, all genotyped with the Immunochip platform. In the joint analysis, we replicated 19 previously identified loci shared by CeD and RA and discovered five new non-HLA loci shared by CeD and RA. Our fine-mapping results indicate that in nine of 24 shared loci the associated variants are distinct in the two diseases. Using cell-type-specific histone markers, we observed that loci which pointed to the same variants in both diseases were enriched for marks of promoters active in CD14+ and CD34+ immune cells (P < 0.001), while loci pointing to distinct variants in one of the two diseases showed enrichment for marks of more specialized cell types, like CD4+ regulatory T cells in CeD (P < 0.0001) compared with Th17 and CD15+ in RA (P = 0.0029).

High-density lipoprotein attenuates Th1 and th17 autoimmune responses by modulating dendritic cell maturation and function

Aberrant levels and function of the potent anti-inflammatory high-density lipoprotein (HDL) and accelerated atherosclerosis have been reported in patients with autoimmune inflammatory diseases. Whether HDL affects the development of an autoimmune response remains elusive. In this study, we used apolipoprotein A-I-deficient (apoA-I(-/-)) mice, characterized by diminished circulating HDL levels, to delineate the role of HDL in autoimmunity. ApoA-I(-/-) mice exhibited increased severity of Ag-induced arthritis compared with wild-type mice, and this was associated with elevated Th1 and Th17 cell reactivity in the draining lymph nodes. Furthermore, reconstituted HDL (rHDL) attenuated IFN-γ and IL-17 secretion by Ag-specific T cells upon stimulation of draining lymph nodes in vitro. The suppressive effects of rHDL were mediated through modulation of dendritic cell (DC) function. Specifically, rHDL-treated DCs demonstrated an immature phenotype characterized by downregulated costimulatory molecules, the release of low amounts of proinflammatory cytokines, and failure to promote T cell proliferation in vitro. The mechanism of action involved the inhibition of NF-κB nuclear translocation and the decrease of Myd88 mRNA levels by rHDL. Finally, modulation of DC function by rHDL was critically dependent on the presence of scavenger receptor class B type I and ATP Binding Cassette Transporter A1, but not the ATP Binding Cassette Transporter G1. These findings reveal a novel role of HDL in the regulation of adaptive inflammatory responses through suppression of DC function that could be exploited therapeutically in autoimmune inflammatory diseases.

Impact of systemic inflammation and autoimmune diseases on apoA-I and HDL plasma levels and functions

The cholesterol of high-density lipoproteins (HDLs) and its major proteic component, apoA-I, have been widely investigated as potential predictors of acute cardiovascular (CV) events. In particular, HDL cholesterol levels were shown to be inversely and independently associated with the risk of acute CV diseases in different patient populations, including autoimmune and chronic inflammatory disorders. Some relevant and direct anti-inflammatory activities of HDL have been also recently identified targeting both immune and vascular cell subsets. These studies recently highlighted the improvement of HDL function (instead of circulating levels) as a promising treatment strategy to reduce inflammation and associated CV risk in several diseases, such as systemic lupus erythematosus and rheumatoid arthritis. In these diseases, anti-inflammatory treatments targeting HDL function might improve both disease activity and CV risk. In this narrative review, we will focus on the pathophysiological relevance of HDL and apoA-I levels/functions in different acute and chronic inflammatory pathophysiological conditions.

Altered lipidome and antioxidative activity of small, dense HDL in normolipidemic rheumatoid arthritis: relevance of inflammation

OBJECTIVE

High-density lipoprotein (HDL) particles exert potent antiatherogenic activities, including antioxidative actions, which are relevant to attenuation of atherosclerosis progression. Such activities are enriched in small, dense HDL and can be compromised under conditions of chronic inflammation like rheumatoid arthritis (RA). However, structure-function relationships of HDL largely remain indeterminate.

METHODS

The relationships between HDL structure and function were evaluated in normolipidemic patients with active RA (DAS28 > 3.2; n = 12) and in normolipidemic age-matched controls (n = 10). Small, dense HDL3b and 3c particles were isolated from plasma or serum by density gradient ultracentrifugation and their physicochemical characteristics, lipidome (by LC/MS/MS) and antioxidative function (as protection of normolipidemic LDL from free radical-induced oxidation) were evaluated.

RESULTS

As expected, active RA patients featured significantly elevated plasma levels of high-sensitivity C-reactive protein (hsCRP; p < 0.001) and serum amyloid A (SAA; p < 0.01) relative to controls. Antioxidative activity and weight % chemical composition of small, dense HDL did not differ between RA patients and controls (p > 0.05), whereas HDL phosphosphingolipidome was significantly altered in RA. Subgroup analyses revealed that RA patients featuring high levels of inflammation (hsCRP>10 mg/l) possessed small, dense HDL with reduced antioxidative activities (p < 0.01). Furthermore, antioxidative activity of HDL was inversely correlated with plasma hsCRP (p < 0.01).

CONCLUSIONS

These data revealed that (i) despite normolipidemic state, the lipidome of small, dense HDL was altered in RA and (ii) high levels of inflammation can be responsible for the functional deficiency of small, dense HDL in RA.

Inflammation, lipid metabolism and cardiovascular risk in rheumatoid arthritis: A qualitative relationship?

Life expectancy in patients with rheumatoid arthritis (RA) is reduced compared to the general population owing to an increase in cardiovascular diseases (CVD) not fully explained by traditional cardiovascular risk factors. In recent years, interest has been focused on the alterations in lipid metabolism in relation to chronic inflammation as one of the possible mechanisms involved in the pathogenesis of atherosclerosis of RA patients. Research regarding this issue has revealed quantitative alterations in lipoproteins during the acute-phase reaction, and has also demonstrated structural alterations in these lipoproteins which affect their functional abilities. Although many alterations in lipid metabolism have been described in this regard, these structural changes associated with inflammation are particularly important in high-density lipoproteins as they affect their cardioprotective functions. In this respect, excessive oxidation in low-density lipoprotein (LDL) and increased lipoprotein(a) with a predominance of smaller apolipoprotein(a) isoforms has also been reported. This article will discuss proinflammatory high-density lipoproteins (piHDL), oxidized LDL and lipoprotein(a). Elevated concentrations of these lipoproteins with marked pro-atherogenic properties have been observed in RA patients, which could help to explain the increased cardiovascular risk of these patients.

Marked independent relationship between circulating interleukin-6 concentrations and endothelial activation in rheumatoid arthritis

We examined the potential impact of conventional compared with nonconventional cardiovascular risk factors including interleukin-6 levels on endothelial activation in RA. Circulating soluble E-selectin, vascular cell adhesion molecule-1, intercellular adhesion molecule-1, and monocyte chemoattractant protein-1 concentrations were measured in 217 African patients (112 black and 105 white) with RA. In comprehensive confounder adjusted mixed regression models, 5 conventional and 4 nonconventional cardiovascular risk factors were associated (P = 0.05 to <0.0001) with endothelial activation. Interleukin-6 was the only risk factor related to each endothelial activation molecule and independently contributed by 18% and significantly more than other risk factors to the variation in overall endothelial activation as estimated by an SD (z) score of endothelial activation molecule concentrations. The independent interleukin-6-overall endothelial activation relationships were reproduced in various subgroups. Interleukin-6 concentrations relate consistently, markedly, and to a larger extent than other cardiovascular risk factors to endothelial activation in RA. Assessment of interleukin-6 concentrations may enhance cardiovascular risk stratification in RA.

Definitions of and contributions to cardiovascular disease in systemic lupus erythematosus

Patients with systemic lupus erythematosus (SLE) have a significantly increased risk of cardiovascular disease (CVD). Increased prevalence of atherosclerosis may explain part of this enhanced risk, but SLE related CVD can also result from other mechanisms. Vascular events may be the result of several pathophysiologic mechanisms; some can be caused by atherosclerosis, others may be primarily thrombotic, and some may be due to ongoing inflammation. The traditional risk factors are of importance for the development of CVD in lupus. However, lupus-related factors, such as endothelial dysfunction and inflammation, renal impairment and disease activity, lupus phenotype, autoantibodies and genetic predisposition are equally or even more important. Risk factors may also contribute separately or in combination to increase the risk of atherosclerosis and clinical CVD in SLE. Studies investigating risk factors for CVD in SLE vary with respect to definition of outcome, it is, e.g. common that the terms atherosclerosis and clinical CVD are used interchangeably. Varying definitions and outcomes may thus explain divergent results of different studies and make comparisons difficult. This review summarizes some of the current knowledge regarding risk factors and mechanisms for atherosclerosis and clinical CVD in SLE. Aspects on the importance of CVD definitions and outcomes are briefly discussed.

Cardiovascular disease in rheumatoid arthritis

RA can manifest in a variety of cardiac complications, including pericarditis, valvular disease, cardiomyopathy, and amyloidosis. Subclinical involvement is higher than anticipated. CVD is also prevalent in patients with RA, with onset in early disease. Several disease-specific risk factors, like seropositivity, disease activity, and medications, are implicated in the pathogenesis of CVD in RA. Cardiovascular risk assessment in RA varies from the general population. Some traditional risk factors like BMI and lipid levels apply differently to the RA population. Statins are useful in managing dyslipidemia in RA. There is good evidence to support cardiovascular risk reduction with methotrexate and TNF-I use if good disease control is achieved.

Higher circulating levels of OxLDL % of LDL are associated with subclinical atherosclerosis in female patients with systemic lupus erythematosus

Because systemic lupus erythematosus (SLE) is associated with a high risk of atherosclerosis, a process that involves low-density lipoprotein (LDL) oxidation, we examined the hypothesis that raised fraction of LDL that is converted to oxidized (Ox) LDL expressed in OxLDL % of LDL (OxLDL %) is associated with the subclinical atherosclerosis in SLE. A cohort of 60 SLE patients with no previous history of cardiovascular disease had carotid artery ultrasound to identify plaques and to measure intima-media thickness (IMT). Forty females with rheumatoid arthritis (RA) were also enrolled in the study to serve as a control group. Plasma OxLDL concentrations were measured, and the OxLDL % of LDL were calculated. Traditional and SLE-related risk factors for atherosclerosis were evaluated. OxLDL % were significantly higher in SLE patients compared to patients with RA (p = 0.0311). OxLDL % were significantly higher in SLE patients with plaques than in those without plaques (p < 0.001). SLE patients in the highest IMT quartile have higher OxLDL % than patients in the lower three quartiles (p < 0.001). The odd ratio (OR) for the OxLDL % in patients with plaques was 6.143 (p < 0.001) when compared to patient without plaques, while OR for the OxLDL % was 8.34 (p < 0.001) in the patients with highest IMT quartile as compared to patients in the lower three quartiles after adjustment for confounding factors in logistic regression analysis. Our data provide evidence of an association between the circulating levels of OxLDL % of LDL with the risk for developing atherosclerosis in patients with SLE.

Management of cardiovascular risk in patients with rheumatoid arthritis: evidence and expert opinion

The risk of cardiovascular morbidity and mortality is increased in rheumatoid arthritis. The classical cardiovascular risk factors, including smoking, hypertension, dyslipidaemia, insulin resistance and diabetes mellitus, obesity and physical inactivity do not appear to explain the excess cardiovascular risk in rheumatoid arthritis, although they do contribute, albeit in a different way or to a lesser extent, to rheumatoid arthritis in comparison with the general population. A very important link between rheumatoid arthritis and cardiovascular disease is inflammation as it plays a key role in all stages of atherosclerosis: from endothelial dysfunction to plaque rupture and thrombosis. It also has an influence on and accentuates some traditional cardiovascular risk factors, such as dyslipidaemia, obesity and insulin resistance. To date, the exact pathophysiologic mechanism by which this relation between cardiovascular disease and rheumatoid arthritis can be explained is not completely clear. Cardiovascular risk management in rheumatoid arthritis is mandatory. Unfortunately, the way this should be done remains a point of discussion. In this review issues regarding cardiovascular risk in rheumatoid arthritis and its management will be addressed, according to evidence presented in the latest studies and our own experience-based opinion.

Omega-3 in SLE: a double-blind, placebo-controlled randomized clinical trial of endothelial dysfunction and disease activity in systemic lupus erythematosus

Accelerated atherosclerosis remains a major cause of death in late systemic lupus erythematosus (SLE). Omega-3 has been reported to have benefit for endothelial dysfunction, one of the earliest stages of atherosclerosis, and to reduce disease activity in SLE. We performed a randomized, double-blind placebo-controlled trial to examine the effect of Omega-3 on endothelial function, disease activity, inflammatory markers and lipids in SLE. SLE patients (n = 85, mean age 47, 55% Caucasian, 38% African-American, 94% female) were randomly assigned to 3 g of Omega-3 (Lovaza, GSK) versus placebo for 12 weeks. Endothelial function was measured at baseline and at 12 weeks using flow-mediated dilation, calculated using high-resolution B-mode ultrasound of the brachial artery diameter in response to vasoactive stimuli (hyperemia). Disease activity was measured using the physician global assessment and SELENA-SLEDAI score. Inflammatory markers (sICAM-1, sVCAM-1, IL-6) and fasting lipid profile were done at baseline and 12-week follow-up. There was no difference between the treatment groups with respect to changes in flow-mediated dilation parameters or disease activity. An average increase in LDL cholesterol of 3.11 mg/dL (±21.99) was found with Omega-3 versus a decrease of 1.87 mg/dL (±18.29) with placebo (p = 0.0266). In this trial, Omega-3 did not improve endothelial function, disease activity, nor reduce inflammatory markers in SLE. Longer trials might be required if there are delayed clinical effects. There was evidence that Omega-3 may increase LDL cholesterol, but not the LDL/HDL ratio.

Newer therapeutic strategies to alter high-density lipoprotein level and function

Measurements of low levels of high-density lipoprotein (HDL) cholesterol have been identified as a risk factor for premature coronary artery disease, however, to date, current pharmacologic approaches for raising HDL have provided little benefit, if at all, in reducing cardiovascular outcomes. It has been shown that HDL can modify many aspects of plaque pathogenesis. Its most established role is in reverse cholesterol transportation, but HDL can also affect oxidation, inflammation, cellular adhesion, and vasodilatation. Considering these potential benefits of HDL, newer treatments have been developed to modify HDL activity, which include the use of oral cholesteryl ester transfer protein inhibitors, apolipoprotein (apo)A-I infusions, apoA-I mimetics, drugs to increase apoA-I synthesis, and agonists of the liver X receptor. These new therapies are reviewed in this article.

High-density lipoproteins and the immune system

High-density lipoprotein (HDL) plays a major role in vasodilation and in the reduction of low-density lipoprotein (LDL) oxidation, inflammation, apoptosis, thrombosis, and infection; however, HDL is now less functional in these roles under certain conditions. This paper focuses on HDL, its anti-inflammation behavior, and the mechanisms by which HDL interacts with components of the innate and adaptive immune systems. Genome-wide association studies (GWAS) and proteomic studies have elucidated important molecules involved in the interaction between HDL and the immune system. An understanding of these mechanisms is expected to be useful for the prevention and treatment of chronic inflammation due to metabolic syndrome, atherosclerosis, or various autoimmune diseases.

Dyslipidemia and changes in lipid profiles associated with rheumatoid arthritis and initiation of anti-tumor necrosis factor therapy

OBJECTIVE

To investigate the frequency of lipid testing in clinical practice and to explore the relationship between rheumatoid arthritis (RA), dyslipidemia, and other cardiovascular (CV) risk factors with RA treatment.

METHODS

Patients in this retrospective database study were ages ≥18 years and had ≥2 physician diagnoses for RA or osteoarthritis (OA; comparator group) between March 2004 and March 2008. Outcomes of interest included the percentage of RA and OA patients receiving lipid tests, lipid profiles (total cholesterol, low-density lipoprotein [LDL] cholesterol, and high-density lipoprotein [HDL] cholesterol) of RA versus OA patients, and lipid profiles of RA patients before and after initiation with a tumor necrosis factor (TNF) inhibitor. We used multivariable regression to control potential confounders between the cohorts.

RESULTS

Over a median ≥2-year followup, fewer RA patients than OA patients had ≥1 lipid test (62.0% [95% confidence interval (95% CI) 61.5-62.5] versus 69.8% [95% CI 69.5-70.1]). Mean total cholesterol and LDL cholesterol were each 4 mg/dl lower in the RA cohort (P < 0.0001); HDL cholesterol was similar between the cohorts. Across the RA cohort, 25.2% of patients had suboptimal LDL cholesterol levels (≥130 mg/dl). Among RA patients not receiving lipid-lowering therapy who initiated TNF inhibitor therapy (n = 96), mean total cholesterol and LDL cholesterol increased by 5.4 and 4.0 mg/dl, respectively.

CONCLUSION

Patients with RA were less likely to be tested for hyperlipidemia and had more favorable lipid profiles than patients with OA. TNF inhibitor therapy modestly increased all lipid parameters. Additional studies are needed to determine the effect of traditional CV risk factors and inflammation and the impact of biologic agents on CV outcomes in RA patients.

Traditional cardiovascular risk factors, inflammation and cardiovascular risk in rheumatoid arthritis

Multiple studies demonstrate an increased cardiovascular (CV) risk associated with RA compared with the general population. While part of this risk appears to be mediated by RA-specific factors, such as long-term inflammation, traditional CV comorbidities also play an important role. We review evidence from previous studies of the relationship between RA and traditional CV comorbidities such as dyslipidaemia, obesity, insulin resistance and diabetes, hypertension, cigarette smoking and physical inactivity. We examine the prevalence and consider the effect of inflammation and RA treatments on these risk factors. Finally, we discuss three widely used CV risk estimators, the Framingham Risk Score, Reynolds Risk Score and the Systematic Coronary Risk Evaluation, and their performance in patients with RA. The traditional CV risk factors that appear to differ significantly between RA cases and controls include insulin resistance, abnormal fat distribution, cigarette smoking and lack of physical activity. Dyslipidaemia, diabetes and hypertension may also be elevated in RA; however, the evidence is conflicting. Overall, we found that the majority of information regarding CV risk factors in RA stems from data collected as covariates for studies on CV disease. A gap in knowledge exists regarding detailed information on individual risk factors in RA, their prevalence and modifications that occur as a result of inflammation or treatment. More studies are needed to develop methods for accurate CV risk estimation in RA.