Auto-Antibody Production During Experimental Atherosclerosis in ApoE-/- Mice.

Current models stipulate that B cells and antibodies function during atherosclerosis in two distinct ways based on antibody isotype, where IgM is protective and IgG is inflammatory. To examine this model, we generated ApoE-/- Aid-/- mice, which are unable to produce IgG antibodies due to the absence of activation-induced deaminase (AID) but maintain high plasma cholesterol due to the absence of apolipoprotein E (APOE). We saw a dramatic decrease in plaque formation in ApoE-/- Aid-/- mice compared to ApoE-/- mice. Rigorous analysis of serum antibodies revealed both ApoE-/- and ApoE-/- Aid-/- mice had substantially elevated titers of IgM antibodies compared to C57BL/6J controls, suggesting a more complex dynamic than previously described. Analysis of antigen specificity demonstrated that ApoE-/- Aid-/- mice had elevated titers of antibodies specific to malondialdehyde-oxidized low density lipoprotein (MDA-oxLDL), which has been shown to block macrophage recruitment into plaques. Conversely, ApoE-/- mice showed low levels of MDA-oxLDL specificity, but had antibodies specific to numerous self-proteins. We provide evidence for a hierarchical order of antibody specificity, where elevated levels of MDA-oxLDL specific IgM antibodies inhibit plaque formation. If the level of MDA-oxLDL specific IgM is insufficient, self-reactive IgM and IgG antibodies are generated against debris within the arterial plaque, resulting in increased inflammation and further plaque expansion.

Antibodies against apoB100 peptide 210 inhibit atherosclerosis in apoE-/- mice.

Atherosclerotic plaques are characterized by an accumulation and subsequent oxidation of LDL, resulting in adaptive immune responses against formed or exposed neoepitopes of the LDL particle. Autoantibodies against native p210, the 3136-3155 amino acid sequence of the LDL protein apolipoprotein B-100 (apoB100) are common in humans and have been associated with less severe atherosclerosis and decreased risk for cardiovascular events in clinical studies. However, whether apoB100 native p210 autoantibodies play a functional role in atherosclerosis is not known. In the present study we immunized apoE-/- mice with p210-PADRE peptide to induce an antibody response against native p210. We also injected mice with murine monoclonal IgG against native p210. Control groups were immunized with PADRE peptide alone or with control murine monoclonal IgG. Immunization with p210-PADRE induced an IgG1 antibody response against p210 that was associated with reduced atherosclerotic plaque formation in the aorta and reduced MDA-LDL content in the lesions. Treatment with monoclonal p210 IgG produced a similar reduction in atherosclerosis as immunization with p210-PADRE. Our findings support an atheroprotective role of antibodies against the apoB100 native p210 and suggest that vaccines that induce the expression of native p210 IgG represent a potential therapeutic strategy for lowering cardiovascular risk.

Antibodies to malondialdehyde-acetaldehyde modified low-density lipoprotein in patients with newly diagnosed inflammatory joint disease.

Objective:To assess antibodies to malondialdehyde-acetaldehyde-modified low-density lipoprotein (MAA-LDL) in patients with newly diagnosed inflammatory joint disease.Method: Patients with rheumatoid arthritis (RA), spondyloarthritis (SpA), and undifferentiated arthritis (UA), participating in the Northern Savo 2010 Study, were evaluated for metabolic syndrome (MetS), metabolic and inflammatory markers, antibodies to MAA-LDL, Aggregatibacter actinomycetemcomitans, and Porphyromonas gingivalis.Results: Among 135 newly diagnosed untreated patients, of whom 53 (39%) were diagnosed to have RA, 44 (33%) SpA, and 38 (28%) UA, 49%, 30%, and 47%, respectively, had MetS. After adjusting for age and gender, anti-MAA-LDL immunoglobulin (Ig)A (p = 0.009), IgG (p = 0.031), and IgM (p = 0.001) levels differed between the diagnostic categories, but not in patients with MetS present or absent. All antibody classes to MAA-LDL correlated with erythrocyte sedimentation rate (ESR), and IgA and IgG antibodies with high-sensitivity C-reactive protein (hs-CRP). IgA antibodies to MAA-LDL correlated with rheumatoid factor (RF), anti-citrullinated protein antibodies (ACPAs), fasting plasma glucose, IgA antibodies to A. actinomycetemcomitans, and in IgA and IgG antibodies to P. gingivalis.Conclusion: Among various arthritis groups, antibodies to MAA-LDL were most common in RA. Antibodies to modified lipoproteins were associated with inflammation measured by ESR and hs-CRP. IgA antibodies to MAA-LDL correlated with age, antibodies to periodontal bacteria, RF, ACPA, and fasting glucose. Associations between antibodies to MAA-LDL and antibodies to periodontal bacteria, RA-associated antibodies, inflammatory parameters, and plasma glucose already reflect cardiovascular burden in inflammatory joint diseases at diagnosis.

Evaluation of Enhanced Lipid Oxidation and Compensatory Suppression using Natriuretic Peptide in Patients with Cardiovascular Diseases.

Malondialdehyde-modified low-density lipoprotein (MDA-LDL) is recognized as a surrogate marker of lipid oxidation and is associated with arteriosclerosis. However, there are limited reports on the relationship between heart failure and MDA-LDL. Therefore, we aimed to determine whether MDA-LDL is activated in patients with left ventricular (LV) dysfunction and examine our hypothesis that the B-type natriuretic peptide (BNP) masks the enhancement of MDA-LDL in patients with LV dysfunction by its strong antioxidative action. The study population comprised 2,976 patients with various cardiovascular diseases. Patients were divided into four groups depending on the LV ejection fraction (LVEF) or plasma BNP level. A nonparametric analysis with the Kruskal-Wallis test was used to perform an interquartile comparison. In addition, structural equation modeling and Bayesian estimation were used to compare the effects of LVEF and BNP on MDA-LDL. MDA-LDL levels did not significantly change (P > 0.05) with respect to the degree of LVEF among the four groups. In contrast, MDA-LDL levels were significantly decreased (P < 0.001) with respect to the degree of BNP among the four groups. A path model based on structural equation modeling clearly showed a significant effect of LVEF (standardized regression coefficient; ß: -0.107, P < 0.001) and BNP (ß: -0.114, P < 0.001) on MDA-LDL, with a significant inverse association between LVEF and BNP (correlation coefficient -0.436, P < 0.001). MDA-LDL should be activated in patients with LV dysfunction; however, BNP is thought to exert a strong compensatory suppression on lipid oxidation, masking the relationship between heart failure and lipid oxidation.

Increased Serum Malondialdehyde-Modified Low-Density Lipoprotein and Coronary Angiographic Progression After Drug-Eluting Stent Implantation in Patients With Stable Angina.

BACKGROUND: Cardiac events can occur after drug-eluting stent (DES) implantation due to coronary plaque progression at non-stented sites. Malondialdehyde-modified low-density lipoprotein (MDA-LDL) is suggested to be an atherogenic marker. This study investigated the relationship between serum MDA-LDL and angiographic progression after DES implantation.Methods and Results:In total, 207 patients who underwent percutaneous coronary intervention (PCI) using DES and follow-up coronary angiography were retrospectively analyzed. MDA-LDL was serially measured before PCI and at follow up. Persistent high MDA-LDL was defined as a MDA-LDL level more than the median value both before PCI and at follow up. Angiographic progression was assessed by serial analysis of quantitative coronary angiography. Angiographic progression occurred in 35 patients (16.9%). MDA-LDL before PCI was significantly higher in the progression group than the non-progression group in all patients (143.4±35.8 U/L vs. 103.0±33.5U/L, P<0.001) and in patients with controlled LDL-cholesterol (LDL-C <100 mg/dL both before PCI and at follow up; 121.8±32.7 U/L vs. 84.9±24.9 U/L, P<0.001). There were positive correlations between % diameter stenosis changes and serum MDA-LDL before PCI in all patients (r=0.33, P<0.01) and those with controlled LDL-C (r=0.23, P=0.04). In multivariate logistic regression analysis, persistent high MDA-LDL was an independent predictor of plaque progression. CONCLUSIONS: Increased serum MDA-LDL was associated with angiographic progression after DES implantation.

An Asymptotic Analysis of the Malonyl-CoA Route to 3-Hydroxypropionic Acid in Genetically Engineered Microbes.

There has been recent interest in creating an efficient microbial production route for 3-hydroxypropionic acid, an important platform chemical. We develop and solve a mathematical model for the time-dependent metabolite concentrations in the malonyl-CoA pathway for 3-hydroxypropionic acid production in microbes, using a combination of numerical and asymptotic methods. This allows us to identify the most important targets for enzyme regulation therein under conditions of plentiful and sparse pyruvate, and to quantify their relative importance. In our model, we account for sinks of acetyl-CoA and malonyl-CoA to, for example, the citric acid cycle and fatty acid biosynthesis, respectively. Notably, in the plentiful pyruvate case we determine that there is a bifurcation in the asymptotic structure of the system, the crossing of which corresponds to a significant increase in 3-hydroxypropionic acid production. Moreover, we deduce that the most significant increases to 3-hydroxypropionic acid production can be obtained by up-regulating two specific enzymes in tandem, as the inherent nonlinearity of the system means that a solo up-regulation of either does not result in large increases in production. The types of issue arising here are prevalent in synthetic biology applications, and it is hoped that the system considered provides an instructive exemplar for broader applications.

Association of rheumatoid arthritis disease activity and antibodies to periodontal bacteria with serum lipoprotein profile in drug naive patients.

Objective: We investigated lipid concentrations, particle sizes and antibodies binding to periodontal bacteria Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis and to malondialdehyde-acetaldehyde (MAA) modified low-density lipoprotein in immunoglobulin (Ig) class A, G and M among patients with newly diagnosed rheumatoid arthritis (RA) in a population-based cohort.Methods: Concentrations and sizes of lipoprotein particles analysed by proton nuclear magnetic resonance spectroscopy and antibody levels to MAA modified low-density lipoprotein were studied at baseline and after one-year of follow-up. Serum Ig A and G class antibodies to periodontal bacteria were determined at baseline.Results: Sixty-three patients were divided into tertiles according to disease activity by disease activity score with 28 joint count and erythrocyte sedimentation rate (ESR) (<3.9, 3.9-4.7, >4.7). Small low-density lipoprotein concentration was lowest in the tertile with the highest disease activity. In high-density lipoprotein, the concentrations of total, medium and small particles decreased with disease activity. The particle size in low-density lipoprotein associated with disease activity and the presence of antibodies to P. gingivalis. Ig G and M antibodies to MAA modified low-density lipoprotein correlated with disease activity. Inflammation associated changes faded by one year.Conclusions: Drug naive RA patients had proatherogenic changes in lipid profiles, but they were reversible, when inflammation diminished.Key messagesPatients with drug naive rheumatoid arthritis showed proatherogenic lipid profiles.Reversible changes in lipid profiles can be achieved as response to inflammation suppression.Active therapy aimed at remission is essential in all patients with rheumatoid arthritis.

Structural insight into bi-functional malonyl-CoA reductase.

The bi-functional malonyl-CoA reductase is a key enzyme of the 3-hydroxypropionate bi-cycle for bacterial CO2 fixation, catalysing the reduction of malonyl-CoA to malonate semialdehyde and further reduction to 3-hydroxypropionate. Here, we report the crystal structure and the full-length architecture of malonyl-CoA reductase from Porphyrobacter dokdonensis. The malonyl-CoA reductase monomer of 1230 amino acids consists of four tandemly arranged short-chain dehydrogenases/reductases, with two catalytic and two non-catalytic short-chain dehydrogenases/reductases, and forms a homodimer through paring contact of two malonyl-CoA reductase monomers. The complex structures with its cofactors and substrates revealed that the malonyl-CoA substrate site is formed by the cooperation of two short-chain dehydrogenases/reductases and one novel extra domain, while only one catalytic short-chain dehydrogenase/reductase contributes to the formation of the malonic semialdehyde-binding site. The phylogenetic and structural analyses also suggest that the bacterial bi-functional malonyl-CoA has a structural origin that is completely different from the archaeal mono-functional malonyl-CoA and malonic semialdehyde reductase, and thereby constitute an efficient enzyme.

Elevated oxidized lipids, anti-lipid autoantibodies and oxidized lipid immune complexes in active SLE.

BACKGROUND: Here, we explore the serum levels of anti-oxidized lipid autoantibodies as well as immune complexes in patients with SLE and determine their correlation with disease. METHODS: Serum levels of oxidized-LDL immune complexes, autoantibodies to dsDNA, ox-LDL, MDA-LDL, 9-HODE, 13-HODE and POVPC were detected by ELISA in 64 SLE patients and 9 healthy controls. RESULTS: Active SLE patients exhibited increased serum levels of autoantibodies compared to healthy controls, including anti-MDA-LDL-IgG (p = .003), anti-ox-LDL-IgG (p = .004), anti-9-HODE-IgG (p = .001), anti-13-HODE-IgG (p = .0003), anti-POVPC-IgG (p = .001) and ox-LDL-IC (p = .003). Serum anti-ox-LDL-IgG was positively correlated with SLEDAI (r = 0.34; p = .01), and negatively with C3 (r = -0.40; p = .01). Anti-9-HODE-IgG and anti-POVPC-IgG were positively correlated with SLEDAI and negatively with C4. CONCLUSIONS: Active SLE patients exhibit significantly increased serum levels of IgG anti-oxidized-lipid autoantibodies. Coordinated elevation of oxidized lipids, autoantibodies to these lipids, and immune complexes of these lipid-antibody components could potentially serve as pathogenic drivers and serum markers of SLE disease activity.

Metabolic repair through emergence of new pathways in Escherichia coli.

Escherichia coli can derive all essential metabolites and cofactors through a highly evolved metabolic system. Damage of pathways may affect cell growth and physiology, but the strategies by which damaged metabolic pathways can be circumvented remain intriguing. Here, we use a ΔpanD (encoding for aspartate 1-decarboxylase) strain of E. coli that is unable to produce the ß-alanine required for CoA biosynthesis to demonstrate that metabolic systems can overcome pathway damage by extensively rerouting metabolic pathways and modifying existing enzymes for unnatural functions. Using directed cell evolution, rewiring and repurposing of uracil metabolism allowed formation of an alternative ß-alanine biosynthetic pathway. After this pathway was deleted, a second was evolved that used a gain-of-function mutation on ornithine decarboxylase (SpeC) to alter reaction and substrate specificity toward an oxidative decarboxylation-deamination reaction. After deletion of both pathways, yet another independent pathway emerged using polyamine biosynthesis, demonstrating the vast capacity of metabolic repair.

IgM anti-malondialdehyde low density lipoprotein antibody levels indicate coronary heart disease and necrotic core characteristics in the Nordic Diltiazem (NORDIL) study and the Integrated Imaging and Biomarker Study 3 (IBIS-3).

Background: Certain immunoglobulins (Ig) are proposed to have protective functions in atherosclerosis. Objectives: We tested whether serum levels of IgG and IgM autoantibodies against malondialdehyde low density lipoprotein (MDA-LDL) are associated with clinical coronary heart disease (CHD) and unfavorable plaque characteristics. Methods: NORDIL was a prospective study investigating adverse cardiovascular outcomes in hypertensive patients. IBIS-3 analyzed lesions in a non-culprit coronary artery with <50% stenosis using radiofrequency intravascular ultrasound (RF-IVUS) and near-infrared spectroscopy (NIRS). Imaging was repeated after a median of 386?days on rosuvastatin. Associations of antibodies with incident CHD and imaging parameters were assessed in the two sub-studies respectively. Findings: From 10,881 NORDIL patients, 87 had serum sampled at baseline and developed CHD over 4.5 years, matched to 227 controls. Higher titers of IgM anti-MDA-LDL had a protective effect on adverse outcomes, with odds ratio 0.29 (0.11, 0.76; p=0.012; p=0.016 for trend). Therefore, the effect was explored at the lesional level in IBIS-3. 143 patients had blood samples and RF-IVUS measurements available, and NIRS was performed in 90 of these. At baseline, IgM anti-MDA-LDL levels had a strong independent inverse relationship with lesional necrotic core volume (p=0.027) and percentage of plaque occupied by necrotic core (p=0.011), as well as lipid core burden index (p=0.024) in the worst 4 mm segment. Interpretation: Our study supports the hypothesis that lower circulating levels of IgM anti-MDA-LDL are associated with clinical CHD development, and for the first time relates these findings to atherosclerotic plaque characteristics that are linked to vulnerability.

Immunization with gingipain A hemagglutinin domain of Porphyromonas gingivalis induces IgM antibodies binding to malondialdehyde-acetaldehyde modified low-density lipoprotein.

Treatment of periodontitis has beneficial effects on systemic inflammation markers that relate to progression of atherosclerosis. We aimed to investigate whether immunization with A hemagglutinin domain (Rgp44) of Porphyromonas gingivalis (Pg), a major etiologic agent of periodontitis, would lead to an antibody response cross-reacting with oxidized low-density lipoprotein (OxLDL) and how it would affect the progression of atherosclerosis in low-density lipoprotein receptor-deficient (LDLR-/-) mice. The data revealed a prominent IgM but not IgG response to malondialdehyde-acetaldehyde modified LDL (MAA-LDL) after Rgp44 and Pg immunizations, implying that Rgp44/Pg and MAA adducts may share cross-reactive epitopes that prompt IgM antibody production and consequently confer atheroprotection. A significant negative association was observed between atherosclerotic lesion and plasma IgA to Rgp44 in Rgp44 immunized mice, supporting further the anti-atherogenic effect of Rgp44 immunization. Plasma IgA levels to Rgp44 and to Pg in both Rgp44- and Pg-immunized mice were significantly higher than those in saline control, suggesting that IgA to Rgp44 could be a surrogate marker of immunization in Pg-immunized mice. Distinct antibody responses in plasma IgA levels to MAA-LDL, to Pg lipopolysaccharides (Pg-LPS), and to phosphocholine (PCho) were observed after Rgp44 and Pg immunizations, indicating that different immunogenic components between Rpg44 and Pg may behave differently in regard of their roles in the development of atherosclerosis. Immunization with Rgp44 also displayed atheroprotective features in modulation of plaque size through association with plasma levels of IL-1α whereas whole Pg bacteria achieved through regulation of anti-inflammatory cytokine levels of IL-5 and IL-10. The present study may contribute to refining therapeutic approaches aiming to modulate immune responses and inflammatory/anti-inflammatory processes in atherosclerosis.

Immune complexes containing malondialdehyde (MDA) LDL induce apoptosis in human macrophages.

Immune complexes (IC) containing predominantly malondialdehyde-LDL and the corresponding autoantibodies (MDA-LDL IC) predict acute cardiovascular events, while IC rich in oxidized LDL (oxLDL IC) predict cardiovascular disease progression. Our objective was to determine mechanisms that could explain these prognostic differences. We compared the effects of the interaction of oxLDL, MDA-LDL and the corresponding IC with human macrophages focusing on apoptosis, metalloproteinases, and proinflammatory cytokines. MDA-LDL IC induced higher degrees of apoptosis, higher levels of caspase-3 expression, and increased expression and release of MMP-1 and TNF compared to MDA-LDL, oxLDL, and oxLDL IC. The pro-apoptotic effects of MDA-LDL IC were inhibited by blocking TNFR 1 or FcγRI. Blocking FcγRI abrogated the induction and expression of MMPs and proinflammatory cytokines by MDA-LDL IC. In conclusion, the interaction of MDA-LDL IC with FcγRI triggers macrophage apoptosis and increased expression and release of TNF and MMP-1, which can lead to the rupture of unstable plaques.

Impact of malondialdehyde-modified low-density lipoprotein on coronary plaque vulnerability in patients not receiving lipid-lowering therapy: a whole coronary analysis with multislice-computed tomography.

Vulnerable plaque disruption was suggested as a primary cause of acute coronary syndrome. This study investigated the impact of malondialdehyde-modified low-density lipoprotein (MDA-LDL) on whole coronary plaque vulnerability, based on multislice-computed tomography (MSCT). We included 197 patients that were not receiving lipid-lowering therapy. We retrospectively analyzed MSCT and MDA-LDL measurements. We defined a CT-derived vulnerable plaque as a plaque with a remodeling index > 1.10 and a mean CT density value < 30 HU. Vulnerable plaques were detected in 60 patients (30%). Patients with vulnerable plaques had significantly higher MDA-LDL levels than patients without vulnerable plaques (151.3 ± 42.3 vs. 118.5 ± 41.7 U/L, p < 0.01). A univariate regression analysis showed that vulnerable plaques were significantly related to MDA-LDL levels [10 U/L groups, odds ratio (OR): 1.19; p < 0.01] and in a multivariate model (10 U/L groups, OR: 1.18; p < 0.01). Patients with multivessel vulnerable plaques had significantly higher MDA-LDL levels than those with single-vessel involvement or no vulnerable plaque (172.4 ± 28.5 vs. 142.8 ± 44.2 vs. 118.5 ± 41.7 U/L, respectively; p < 0.01). MDA-LDL difference was observed for all LDL tertiles (bottom; 128.9 ± 41.1 vs. 97.3 ± 25.0 U/L, p < 0.01, middle; 142.6 ± 42.7 vs. 122.5 ± 35.1 U/L, p = 0.05, top; 166.0 ± 38.1 vs. 143.5 ± 51.6 U/L, p = 0.05). Increased MDA-LDL levels were associated with the presence and extent of vulnerable plaques, regardless of LDL levels.

Evaluation of Malondialdehyde Low-Density Lipoprotein Stratified by Low-Density Lipoprotein Cholesterol.

BACKGROUND: Malondialdehyde low-density lipoprotein (MDA-LDL) is a major form of oxidized LDL and considered to be more atherogenic than LDL. Information on major determinants of MDA-LDL and their association in subjects who are not under treatment for diabetes mellitus and dyslipidemia is limited. METHODS: This study included 778 Japanese subjects who were not taking medication for diabetes mellitus and dyslipidemia. All subjects underwent an annual health examination that included MDA-LDL analysis. Study subjects were divided into four groups according to mean values of LDL-C and MDA-LDL, and the metabolic profile was compared. RESULTS: LDL cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were mainly associated with MDA-LDL. When subjects were stratified based on LDL-C levels, small dense LDL-C and MDA-LDL levels increased as LDL-C levels increased. Comparison of the characteristics of study subjects in the same LDL-C level group revealed that subjects with high MDA-LDL showed high metabolic risk in all LDL-C groups, particularly notable in the group with LDL-C levels < 120 mg/dL. CONCLUSIONS: Our data indicated that high LDL-C and low HDL-C levels were independently associated with high MDA-LDL. To prevent high MDA-LDL, it is important to lower LDL-C level as well as to increase HDL-C even in subjects with low LDL-C level by lifestyle modification.

Additional consumption of one egg per day increases serum lutein plus zeaxanthin concentration and lowers oxidized low-density lipoprotein in moderately hypercholesterolemic males.

The egg is a nutrient-dense food and contains antioxidative carotenoids, lutein and zeaxanthin, but its impact on serum cholesterol levels has been a matter of concern, especially for individuals who have high serum cholesterol levels. We conducted this study to determine whether and how the daily additional consumption of one egg affects serum lipid profiles and parameters of LDL oxidation in moderately hypercholesterolemic males. Nineteen male Japanese adults (total cholesterol [TC]>5.2mmol/L) participated, consuming one soft boiled egg per day for 4weeks in addition to their habitual diet. Despite the significant increase in their intake of dietary cholesterol during the intervention period, the subjects' serum concentrations of TC and low-density lipoprotein cholesterol (LDL-C) did not increase. Their serum malondialdehyde modified low-density lipoprotein (MDA-LDL) concentrations were significantly decreased and their LDL oxidation lag times, reflecting the resistance of free-radical-induced LDL lipid peroxidation (ex vivo), was prolonged after 2 and 4weeks. At weeks 2 and 4, the subjects' serum lutein+zeaxanthin concentrations were significantly higher than their baseline values and showed both an inverse relation with MDA-LDL and a positive relationship with the LDL oxidation lag time. These data showed that in moderately hypercholesterolemic males, the additional consumption of one egg per day for 4weeks did not have adverse effects on serum TC or LDL-C, and it might reduce the susceptibility of LDL to oxidation through an increase in the serum lutein and zeaxanthin concentrations.

Circulating malondialdehyde-modified low-density lipoprotein (MDA-LDL) as a novel predictor of clinical outcome after endovascular therapy in patients with peripheral artery disease (PAD).

BACKGROUND AND AIMS: Despite advances in the treatment of peripheral artery disease (PAD), cardiovascular events and death rates remain high. This study aimed at identifying markers of outcome in patients with PAD undergoing endovascular therapy (EVT). METHODS: Consecutive patients undergoing EVT were recruited. Markers of oxidative stress (malondialdehyde-modified low-density lipoprotein [MDA-LDL]), inflammation (IL-6; high-sensitivity C-reactive protein [hsCRP]) and fibrinolysis (D-dimer) were measured pre-EVT and at post-EVT time-points to 36 h. Clinical follow-up assessed major cardiovascular and/or limb events. RESULTS: In the 35 patients enrolled, mean MDA-LDL levels decreased from a baseline level of 106.2 U/L to 72.6 U/L immediately post-EVT (p<0.0001); levels remained significantly reduced at all time-points. IL-6, hsCRP and D-dimer increased and were significantly higher at the 36 h time-point. A significant, negative association was seen between decreased MDA-LDL and pre-EVT hsCRP levels (r = -0.42, p=0.012). Clinical follow-up data were obtained for a mean period of 16 months. MDA-LDL ratios (obtained by comparison of post- and pre-EVT values) allowed assessment of high (≥0.495) and low (<0.495) ratio groups. A significantly higher rate of major adverse events, including limb-related events or death, was seen in the low ratio group (p<0.001). Cox proportional hazard analysis including traditional risk factors indicated that this ratio is a significant predictor of clinical endpoints (HR = 0.4210, p=0.0154). An association with clinical outcome was not observed with the other candidate biomarkers. CONCLUSIONS: Assessment of pre- and post-EVT MDA-LDL levels is a promising marker of clinical outcome in patients with PAD.

Relationship of Autoantibodies to MDA-LDL and ApoB-Immune Complexes to Sex, Ethnicity, Subclinical Atherosclerosis, and Cardiovascular Events.

OBJECTIVE: Modifications of lipid constituents within atherosclerotic lesions generate neoepitopes that activate innate and adaptive immune responses. We aimed to define the prevalence, distribution, and relationship of autoantibody titers of oxidized lipoproteins to subclinical atherosclerosis and major adverse cardiovascular events (MACE) in different ethnic groups. APPROACH AND RESULTS: IgG and IgM autoantibodies to malondialdehyde-modified low-density lipoprotein (MDA-LDL) and apolipoprotein B-100-immune complexes were measured in 3509 individuals (1814 blacks, 1031 whites, 589 Hispanics, and 85 no race identifier) from the Dallas Heart Study with median 10.5-year follow-up. Coronary artery calcium score, abdominal aortic plaque by magnetic resonance imaging, and MACE were quantified. IgG MDA-LDL and IgG and IgM apolipoprotein B-100-immune complexes were significantly different between groups, with blacks having the highest levels of IgG MDA-LDL and IgG apolipoprotein B-100-immune complexes and Hispanics having the highest levels of IgM apolipoprotein B-100-immune complexes (P<0.001 for all). IgGs tended to be higher and IgMs lower with age for all markers. In multivariable-adjusted binary logistic regression analysis, a doubling of IgG MDA-LDL levels was associated with prevalent coronary artery calcium score >10 Agatston units (odds ratio [95% confidence interval], 1.21 [1.07-1.36]; P=0.002). Multivariable-adjusted Cox regression analysis revealed that IgG MDA-LDL was independently associated with time to incident MACE in the entire group (hazard ratio [95% confidence interval], 1.76 [1.16-2.72]; P=0.009 for fourth versus first quartile). This effect was particularly prominent in black subjects (hazard ratio [95% confidence interval], 2.52 [1.39-4.57]; P=0.002). CONCLUSIONS: Autoantibodies to oxidized lipoproteins and immune complexes with apoB-100 lipoproteins vary significantly by sex, age, and ethnicity. Higher baseline IgG MDA-LDL titers independently associate with new MACE. These findings may contribute to the understanding of differences in ethnic-specific MACE events.

Malondialdehyde-Modified Low Density Lipoprotein as Oxidative-Stress Marker in Vasospastic Angina Patients.

Vasospastic angina (VSA) is caused by endothelial dysfunction and hypercontraction of vascular smooth muscle cells. Although oxidative-stress can induce endothelial dysfunction, the relationship of VSA and the oxidative-stress marker malondialdehyde-modified low density lipoprotein (MDA-LDL) remains unclear. PURPOSE: Serum MDA-LDL was evaluated in candidate VSA patients.The subjects were 84 patients admitted to our hospital because of chest pain at rest. We stratified the patients into 3 groups; definite VSA, suspected VSA, and unlikely VSA according to a Japanese Circulation Society (JCS) guideline. The patients classified as definite VSA or suspected VSA were considered as "clinical VSA".Forty cases were classified as definite VSA, 35 as suspected VSA, and 9 as unlikely VSA. Thus, clinical VSA was the diagnosis in 75 cases. The patient characteristics showed that the average age of the patients was 60.2 years old (men, 61%). The serum MDA-LDL level of the clinical VSA group (126.3 ± 38.0 U/L) was significantly higher than the unlikely VSA group (98.7 ± 31.1 U/L). Serum MDA-LDL was positively correlated with total cholesterol (T-Chol), lowdensity lipoprotein cholesterol (LDL-C), triglycerides, and fasting blood glucose. Multivariate analysis showed that serum MDA-LDL was the most predictive marker for making a diagnosis of clinical VSA (Odds ratio 1.064, 95% confidence interval 1.014-1.145, P = 0.008). In a population with positive or borderline ECG change, the positive rate in the acetylcholine provocation test was significantly higher in the MDA-LDL higher group compared to the MDA-LDL lower group (81% versus 37%, P = 0.032).: Serum MDA-LDL might be a useful biomarker of VSA and have additional value for the diagnosis of clinical VSA.

A blood-based biomarker panel to risk-stratify mild traumatic brain injury.

Mild traumatic brain injury (TBI) accounts for the vast majority of the nearly two million brain injuries suffered in the United States each year. Mild TBI is commonly classified as complicated (radiographic evidence of intracranial injury) or uncomplicated (radiographically negative). Such a distinction is important because it helps to determine the need for further neuroimaging, potential admission, or neurosurgical intervention. Unfortunately, imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI) are costly and not without some risk. The purpose of this study was to screen 87 serum biomarkers to identify a select panel of biomarkers that would predict the presence of intracranial injury as determined by initial brain CT. Serum was collected from 110 patients who sustained a mild TBI within 24 hours of blood draw. Two models were created. In the broad inclusive model, 72kDa type IV collagenase (MMP-2), C-reactive protein (CRP), creatine kinase B type (CKBB), fatty acid binding protein-heart (hFABP), granulocyte-macrophage colony-stimulating factor (GM-CSF) and malondialdehyde modified low density lipoprotein (MDA-LDL) significantly predicted injury visualized on CT, yielding an overall c-statistic of 0.975 and a negative predictive value (NPV) of 98.6. In the parsimonious model, MMP-2, CRP, and CKBB type significantly predicted injury visualized on CT, yielding an overall c-statistic of 0.964 and a negative predictive value (NPV) of 97.2. These results suggest that a serum based biomarker panel can accurately differentiate patients with complicated mild TBI from those with uncomplicated mild TBI. Such a panel could be useful to guide early triage decisions, including the need for further evaluation or admission, especially in those environments in which resources are limited.