Paul Richard Julian Ames

Subclinical atherosclerosis in Behcet's disease: A systematic review and meta-analysis.

OBJECTIVE To evaluate subclinical atherosclerosis in Behcet disease (BD), we performed a systematic review and meta-analysis of studies where atherosclerosis was determined by flow-mediated dilatation (FMD) and endothelial-mediated dilatation (EMD) and by measurement of intima media thickness (IMT) of carotid arteries. METHODS Systematic search of EMBASE and PubMed databases from January 2000 to January 2014 according to PRISMA guidelines. RESULTS Nine studies met the inclusion criteria on FMD/EMD, 11 on IMT and 4 on both. BD had lower FMD than controls (SMD = -0.89, 95% CI: -0.660 to -1.11, p < 0.001), which was confirmed by subgroup analyses on active and inactive patients (SMD = -1.17, 95% CI: -1.45 to -0.89 and SMD = -0.72, 95% CI: -0.97 to -0.46, p = 0.0001 for both). EMD was lower in BD but with a large estimate (SMD = 0.38, 95% CI: -0.79 to -0.03, p = 0.06, I(2) = 82.2%). IMT was greater in BD and the large estimate (SMD = 0.95, 95% CI: 0.63-1.28, p < 0.0001, I(2) = 87.6%) persisted after subgroup analysis on active and inactive patients (I(2) = 88.4% and 86.7%, respectively). Pooling IMT studies by a Newcastle Ottawa Scale of 5 and 6/7 yielded lower estimates (SMD = 0.54, 95% CI: 0.32-0.75, p < 0.0001, I(2) = 58.7% and SMD = 1.72, 95% CI: 1.35-2.09 p < 0.05, I(2) = 48.6%). CONCLUSIONS FMD is impaired in BD even in inactive state and IMT is greater despite a degree of statistical heterogeneity that reflects the clinical heterogeneity of BD. Future prospective studies should account for risk stratification of atherosclerosis in BD.

Extended‐release niacin increases anti‐apolipoprotein A‐I antibodies that block the antioxidant effect of high‐density lipoprotein–cholesterol: the EXPLORE clinical trial

Aims Extended‐release niacin (ERN) is the most effective agent for increasing high‐density lipoprotein–cholesterol (HDL‐C). Having previously identified anti‐HDL antibodies, we investigated whether ERN affected the antioxidant capacity of HDL and whether ERN was associated with the production of antibodies against HDL (aHDL) and apolipoprotein A‐I (aApoA‐I). Methods Twenty‐one patients older than 18 years, with HDL‐C ≤40 mg dl–1 (men) or ≤50 mg dl–1 (women) were randomly assigned to receive daily ERN (n = 10) or placebo (n = 11) for two sequential 12‐week periods, with 4 weeks of wash‐out before cross‐over. Primary outcome was change of paraoxonase‐1 (PON1) activity and secondary outcomes were changes in aHDL and aApoA‐I antibodies. Clinical Trial Unique Identifier: EudraCT 2006–006889‐42. Results The effect of ERN on PON1 activity was nonsignificant (coefficient estimate 20.83 U l–1, 95% confidence interval [CI] –9.88 to 51.53; P = 0.184). ERN was associated with an increase in HDL‐C levels (coefficient estimate 5.21 mg dl–1, 95% CI 1.16 to 9.25; P = 0.012) and its subclasses HDL2 (coefficient estimate 2.46 mg dl–1, 95% CI 0.57 to 4.34; P = 0.011) and HDL3 (coefficient estimate 2.73 mg dl–1, 95% CI 0.47 to 4.98; P = 0.018). ERN was significantly associated with the production of aApoA‐I antibodies (coefficient estimate 0.25 &mgr;g ml–1, 95% CI 0.09–0.40; P = 0.001). aApoA‐I titres at baseline were correlated with decreased PON activity. Conclusions The rise in HDL‐C achieved with ERN was not matched by improved antioxidant capacity, eventually hampered by the emergence of aApoA‐I antibodies. These results may explain why Niacin and other lipid lowering agents fail to reduce cardiovascular risk.

Clinical relevance of antiphospholipid antibodies in systemic sclerosis: A systematic review and meta-analysis

OBJECTIVE To evaluate the clinical relevance of antiphospholipid antibodies (aPL) in systemic sclerosis (SSc). METHODS A systematic search of EMBASE and PubMed databases from January 1983 to July 2016 was carried out according to PRISMA guidelines whereas Peto׳s odds ratio (OR) for rare events was used for the meta-analysis. RESULTS The pooled prevalence of participants positive for IgG and IgM anticardiolipin (aCL) antibodies was higher in SSc than controls (12.8% vs 1.6% and 7.8% vs 0.6%; p < 0.0001 for both) as was that of IgG and IgM anti-beta-2-glycoprotein-I antibodies (aβ2GPI) (6.1% vs 0.58%, p < 0.0001; 3.5% vs 0.3%, p = 0.001). The pooled prevalence of pulmonary arterial hypertension (PAH) was more common in SSc positive than negative patients for aCL (IgG/IgM combined) (26.5% vs 10.9%, p < 0.0001) whereas the pooled prevalence of renal disease (RD) was more common in IgG aCL positive than negative patients (36.3% vs 10.9%, p = 0.02). The pooled prevalence of thrombosis was higher in IgG aCL, IgM aCL, and IgM aβ2GPI positive than negative SSc patients (12.6% vs 1.4%, p < 0.0001), (15.1% vs 2.7%, p = 0.002) and (15% vs 0.78%, p = 0.009), respectively. The pooled prevalence of digital infarction/ischemia (DI) was higher in IgG aCL and IgM positive than negative SSc (52.8% vs 39.8%, p = 0.002) and (68.1% vs 29%, p = 0.07). CONCLUSIONS A strong relationship exists between aCL and aβ2GPI of IgG/IgM isotype and SSc; patients positive for these antibodies are more likely to suffer from PAH, RD, thrombosis, and DI. However, data expressed as frequency of aPL positive patients rather than average antibody titers preclude further insight into the relevance of these assumptions.

DNA damage by lipid peroxidation products: implications in cancer, inflammation and autoimmunity

Oxidative stress and lipid peroxidation (LPO) induced by inflammation, excess metal storage and excess caloric intake cause generalized DNA damage, producing genotoxic and mutagenic effects. The consequent deregulation of cell homeostasis is implicated in the pathogenesis of a number of malignancies and degenerative diseases. Reactive aldehydes produced by LPO, such as malondialdehyde, acrolein, crotonaldehyde and 4-hydroxy-2-nonenal, react with DNA bases, generating promutagenic exocyclic DNA adducts, which likely contribute to the mutagenic and carcinogenic effects associated with oxidative stress-induced LPO. However, reactive aldehydes, when added to tumor cells, can exert an anticancerous effect. They act, analogously to other chemotherapeutic drugs, by forming DNA adducts and, in this way, they drive the tumor cells toward apoptosis. The aldehyde-DNA adducts, which can be observed during inflammation, play an important role by inducing epigenetic changes which, in turn, can modulate the inflammatory process. The pathogenic role of the adducts formed by the products of LPO with biological macromolecules in the breaking of immunological tolerance to self antigens and in the development of autoimmunity has been supported by a wealth of evidence. The instrumental role of the adducts of reactive LPO products with self protein antigens in the sensitization of autoreactive cells to the respective unmodified proteins and in the intermolecular spreading of the autoimmune responses to aldehyde-modified and native DNA is well documented. In contrast, further investigation is required in order to establish whether the formation of adducts of LPO products with DNA might incite substantial immune responsivity and might be instrumental for the spreading of the immunological responses from aldehyde-modified DNA to native DNA and similarly modified, unmodified and/or structurally analogous self protein antigens, thus leading to autoimmunity.

Survival in primary antiphospholipid syndrome. A single-centre cohort study.

The vascular mortality of antiphospholipid syndrome (APS) ranges from 1.4 % to 5.5 %, but its predictors are poorly known. It was the study objective to evaluate the impact of baseline lupus anticoagulant assays, IgG anticardiolipin (aCL), plasma fibrinogen (FNG) and von Willebrand factor (VWF), platelets (PLT) and of genetic polymorphisms of methylenetetrahydrofolate reductase C677T, of prothrombin G20210A and of paraoxonase-1 Q192R on survival in primary APS (PAPS). Cohort study on 77 thrombotic PAPS and 33 asymptomatic carriers of aPL (PCaPL) seen from 1989 to 2015 and persistently positive for aPL as per annual review. At baseline all participants were tested twice for the ratios of kaolin clotting time (KCTr), activated partial thromboplastin time (aPTTr), dilute Russell viper venom time (DRVVTr), IgG aCL, FNG, VWF and once for PLT. All thrombotic PAPS were on warfarin with regular INR monitoring. During follow-up 11 PAPS deceased (D-PAPS) of recurrent thrombosis mostly arterial, despite adequate anticoagulation yielding an overall vascular mortality of 10 %. D-PAPS had the strongest baseline aPTTr and DRVVTr and the highest mean baseline IgG aCL, FNG, VWF and PLT. Cox proportional hazards model identified baseline DRVVTr and FNG as main predictors of mortality with adjusted hazard ratios of 5.75 (95 % confidence interval [CI]: 1.5, 22.4) and of 1.03 (95 %CI: 1.01, 1.04), respectively. In conclusion, plasma DRVVTr and FNG are strongly associated with the risk of vascular death in PAPS; while FNG lowering agents exist further research should be directed at therapeutic strategies able to dampen aPL production.

Antibodies against HDL Components in Ischaemic Stroke and Coronary Artery Disease

Quantitative and qualitative defects of high-density lipoprotein (HDL) are important in atherogenesis. In this study, we investigated whether antibodies against HDL components had additional value to conventional cardiovascular risk factors for the diagnosis of ischaemic stroke (IS) and coronary artery disease (CAD). Cross-sectional study was conducted on 53 patients with IS, 51 with CAD and 55 healthy controls, and in vitro studies to validate findings of the clinical study. We determined serum immunoglobulin G (IgG) antibodies against HDL (aHDL), apolipoproteins (aApoA-I, aApoA-II and aApoC-I) and paraoxonase-1 (aPON1) as well as PON1 activity (PON1a), total antioxidant capacity and biomarkers of endothelial activation (serum nitric oxide metabolites, 3-nitrotyrosine, VCAM-1 and ICAM-1); in vitro assays tested the capacity of IgG aHDL purified from high titer patients to inhibit PON1a and to reverse protective effect of HDL on endothelial cells. IgG aHDL, aApoA-I and aPON1 were higher in IS and CAD than controls (p < 0.001), predicted negatively PON1a and positively VCAM-1 and ICAM-1. By adding IgG aHDL and aApoA-I to a traditional cardiovascular risk factors model for IS and by adding IgG aHDL in a similar model for CAD, we obtained better discrimination of IS and CAD from healthy controls. IgG aHDL purified from IS and CAD inhibited PON1a by 38% (p < 0.01) and abrogated the protective effect of HDL on VCAM-1 expression by 126% compared with non-specific human IgG (p < 0.001). IgG against HDL components interfere with the antioxidant and anti-inflammatory properties of HDL and may represent novel biomarkers for vascular disease that need to be investigated in prospective studies.

Oxidative/nitrative stress in the pathogenesis of systemic sclerosis: are antioxidants beneficial?

Abstract Systemic sclerosis (SSc) is a multisystem autoimmune disease: characterised from the clinical side by progressive vasculopathy and fibrosis of the skin and different organs and from the biochemical side by fibroblast deregulation with excessive production of collagen and increased expression of nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4). The latter contributes to an overproduction of reactive oxygen species that through an autocrine loop maintains NOX4 in a state of activation. Reactive oxygen and nitrogen species are implicated in the origin and perpetuation of several clinical manifestations of SSc having vascular damage in common; attempts to dampen oxidative and nitrative stress through different agents with antioxidant properties have not translated into a sustained clinical benefit. Objective of this narrative review is to describe the origin and clinical implications of oxidative and nitrative stress in SSc, with particular focus on the central role of NOX4 and its interactions, to re-evaluate the antioxidant approaches so far used to limit disease progression, to appraise the complexity of antioxidant treatment and to touch on novel pathways elements of which may represent specific treatment targets in the not so distant future.

Predictive Value of Oxidized Low-Density Lipoprotein/β2-Glycoprotein-I Complexes (oxLDL/β2GPI) in Nonautoimmune Atherothrombosis

Introduction: Lipid oxidation is a definite feature of atherosclerosis, and oxidized low-density lipoprotein (oxLDL) is not only highly immunogenic but toxic to several cell types. Beta-2-glycoprotein-I (β2GPI) dampens oxLDL toxicity by forming binary oxLDL/β2GPI complexes. We evaluated whether circulating oxLDL/β2GPI complexes are associated to atherosclerosis-related events (ARE) and to venous thromboembolism (VTE). Methods: In a cross-sectional case–control study, cases were (a) 57 consecutive patients (male/female [M/F] 33/24, mean age 57 [10] years) attending a thrombosis unit for ARE (myocardial infarction [MI] n = 20, peripheral vascular disease n = 7, and ischemic strokes n = 30); (b) 52 consecutive patients (M/F 22/30, mean age 55 [17] years) attending the same unit for unprovoked (VTE); (c) normal controls comprised 90 participants (M/F 35/55, mean age 41 [15] years); and (d) oxLDL/β2GPI complexes were measured by immunoassay and resulting levels divided into quartiles. Results: The odds ratio (OR) of ARE was greater in the fourth and second quartiles than in the first quartile (8.5 and 6.0, respectively); the OR of developing MI was greatest in the fourth quartile (17.8). By multivariable analysis with age, sex, smoking, lipid status, statin, and ARE phenotypes as independent variables and oxLDL/β2GPI as the dependent variable, only MI predicted oxLDL/β2GPI (P < .0001). Conclusions: OxLDL/β2GPI may be regarded as a marker of ARE, in particular of MI.

Platelet-activating factor acetylhydrolase in primary antiphospholipid syndrome

The interesting article by Fabris et al. shows that individuals screened for antiphospholipid antibodies (aPL) because of a thrombotic or obstetric history exhibit higher plateletactivating factor acetylhydrolase (PAF-AH) in plasma than control blood donors (p < 0.0001); amongst the aPL-positive participants, those lupus anticoagulant positive had higher PAF-AH than LA-negative patients (p = 0.03) and those positive for IgG anti-beta2 glycoprotein-I antibodies (aβ2GPI) presented with higher PAF-AH than patients positive for isolated IgM aβ2GPI (p = 0.03) [1]. To expand on this topic, we measured PAF-AH in 27 consecutive thrombotic primary antiphospholipid syndrome (PAPS) patients, in 17 thrombotic patients with inherited thrombophilia (IT) and in 23 healthy controls had given written consent for their plasma samples to be stored for research purposes (Table 1). In all participants, we measured IgG anticardiolipin (Cambridge Life Sciences, UK), IgG aβ2GPI (Corgenix, Denver, USA), β2GPI-oxidised low-density lipoprotein (β2GPI-oxLDL) complex and IgG anti-β2GPI-oxLDL by previously described immunoassays [2, 3], and PAF-AH by an established method [4]. Lipid profiles were normal in all participants according to measurements done two to three months earlier than the present measurements. Table 1 shows the results: IgG aPL were elevated by definition in the PAPS group but median PAF-AH was lower in PAPS compared to the other groups (p = 0.03); PAFAH correlated (Spearman rank) positively to β2GPI-oxLDL

Predictors of mortality in primary antiphospholipid syndrome

The vascular mortality of antiphospholipid syndrome (APS) ranges from 1.4 % to 5.5 %, but its predictors are poorly known. It was the study objective to evaluate the impact of baseline lupus anticoagulant assays, IgG anticardiolipin (aCL), plasma fibrinogen (FNG) and von Willebrand factor (VWF), platelets (PLT) and of genetic polymorphisms of methylenetetrahydrofolate reductase C677T, of prothrombin G20210A and of paraoxonase-1 Q192R on survival in primary APS (PAPS). Cohort study on 77 thrombotic PAPS and 33 asymptomatic carriers of aPL (PCaPL) seen from 1989 to 2015 and persistently positive for aPL as per annual review. At baseline all participants were tested twice for the ratios of kaolin clotting time (KCTr), activated partial thromboplastin time (aPTTr), dilute Russell viper venom time (DRVVTr), IgG aCL, FNG, VWF and once for PLT. All thrombotic PAPS were on warfarin with regular INR monitoring. During follow-up 11 PAPS deceased (D-PAPS) of recurrent thrombosis mostly arterial, despite adequate anticoagulation yielding an overall vascular mortality of 10 %. D-PAPS had the strongest baseline aPTTr and DRVVTr and the highest mean baseline IgG aCL, FNG, VWF and PLT. Cox proportional hazards model identified baseline DRVVTr and FNG as main predictors of mortality with adjusted hazard ratios of 5.75 (95 % confidence interval [CI]: 1.5, 22.4) and of 1.03 (95 %CI: 1.01, 1.04), respectively. In conclusion, plasma DRVVTr and FNG are strongly associated with the risk of vascular death in PAPS; while FNG lowering agents exist further research should be directed at therapeutic strategies able to dampen aPL production.