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The prognosis in systemic lupus erythematosus (SLE) has improved due to better treatment and care, but cardiovascular disease (CVD) still remains an important clinical problem, since the risk of CVD in SLE is much higher than among controls. Atherosclerosis is the main cause of CVD in the general population, and in SLE, increased atherosclerosis, especially the prevalence of atherosclerotic plaques, has been demonstrated. Atherosclerosis is an inflammatory condition, where immunity plays an important role. Interestingly, oxidized low-density lipoprotein, defective clearance of dead cells, and inflammation, with a pro-inflammatory T-cell profile are characteristics of both atherosclerosis and SLE. In addition to atherosclerosis as an underlying cause of CVD in SLE, there are also other non-mutually exclusive mechanisms, and the most important of these are antiphospholipid antibodies (aPL) leading to the antiphospholipid antibody syndrome with both arterial and venous thrombosis. aPL can cause direct pro-inflammatory and prothrombotic effects on endothelial and other cells and also interfere with the coagulation, for example, by inhibiting annexin A5 from its antithrombotic and protective effects. Antibodies against phosphorylcholine (anti-PC) and other small lipid-related epitopes, sometimes called natural antibodies, are negatively associated with CVD and atherosclerosis in SLE. Taken together, a combination of traditional risk factors such as hypertension and dyslipidemia, and nontraditional ones, especially aPL, inflammation, and low anti-PC are implicated in the increased risk of CVD in SLE. Close monitoring of both traditional risk factors and nontraditional ones, including treatment of disease manifestations, not lest renal disease in SLE, is warranted.

Statins have pleiotropic effects, being both anti-inflammatory and immunomodulatory. Proprotein convertase subtilisin kexin 9 (PCSK9) targets the low-density lipoprotein receptor (LDLR), which increases LDL levels due to the lower expression of LDLR.Inhibition of PCSK9 by the use of antibodies represents a novel principle to lower LDL levels. LDL may have other properties than being a cholesterol carrier but is well established as a risk factor for cardiovascular disease and atherosclerosis. In atherosclerosis, the plaques are characterized by activated T cells and dendritic cells (DCs), dead cells, and OxLDL. The latter may be an important cause of the inflammation typical of atherosclerosis, by promoting a proinflammatory immune activation. This is inhibited by PCSK9 inhibition, and an anti-inflammatory type of immune activation is induced. OxLDL is raised in systemic lupus erythematosus (SLE), where both CVD and atherosclerosis are much increased compared to the general population. PCSK9 is reported to be associated with disease activity and complications in SLE. Also in other rheumatoid arthritis, PCSK9 may play a role.PCSK9 has pleiotropic effects, being implicated in inflammation and immunity. Inhibition of PCSK9 is therefore interesting to study further as a potential therapy against inflammation and autoimmunity.

Obesity associates with reduced life expectancy, type 2 diabetes, hypertension and cardiovascular disease, and is characterized by chronic inflammation. Phosphorylcholine (PC) is an epitope on oxidized low-density lipoprotein, dead cells and some microorganisms. Antibodies against PC (anti-PC) have anti-inflammatory properties. Here, we explored the role of anti-PC in hospitalized versus non-hospitalized obese. One-hundred-and-twenty-eight obese (BMI ≥ 30 kg/m2) individuals (59.8 (± 5.5) years, 53.9% women) from the Malmö Diet and Cancer Cardiovascular Cohort were examined and IgM, IgG1 and IgG2 anti-PC were analyzed by ELISA. Individuals with at least one recorded history of hospitalization prior to study baseline were considered hospitalized obese (HO). Associations between IgM, IgG1 and IgG2 anti-PC and HO (n = 32)/non-hospitalized obese (NHO) (n = 96), but also with metabolic syndrome and diabetes were analysed using logistic regressions. Both IgM and IgG1 anti-PC were inversely associated with HO, also after controlling for age and sex. When further adjusted for waist circumference, systolic blood pressure, glucose levels and smoking status, only IgG1 anti-PC remained significantly associated with HO. In multivariate models, each 1 standard deviation of increment in anti-PC IgG1 levels was inversely associated with prevalence of HO (odds ratio 0.57; CI 95% 0.33–0.98; p = 0.044). IgG2 anti-PC did not show any associations with HO. Low levels of IgM and IgG1 anti-PC are associated with higher risk of being a HO individual independent of sex and age, IgG1 anti-PC also independently of diabetes and metabolic syndrome. The anti-inflammatory properties of these antibodies may be related to inflammation in obesity and its complications.

Background The increased risk of cardiovascular events (CVE) in rheumatoid arthritis (RA) is not fully explained by traditional risk factors. Immuno-inflammatory mechanisms and autoantibodies could be involved in the pathogenesis of atherosclerotic disease. It has been suggested that anti-phosphorylcholine antibodies (anti-PC) of the IgM subclass may have atheroprotective effects. Here, we aimed to investigate the association between levels of IgM anti-PC antibodies with CVE in patients with early RA. Methods The study population was derived from the BARFOT early RA cohort, recruited in 1994–1999. The outcome of incident CVE (AMI, angina pectoris, coronary intervention, ischemic stroke, TIA) was tracked through the Swedish Hospital Discharge and the National Cause of Death Registries. Sera collected at inclusion and the 2-year visit were analyzed with ELISA to determine levels of anti-PC IgM. The Kaplan-Meier estimates and Cox proportional hazards regression models were used to compare CV outcome in the groups categorized by baseline median level of IgM anti-PC. Results In all, 653 patients with early RA, 68% women, mean (SD) age 54.8 (14.7) years, DAS28 5.2 (1.3), 68% seropositive, and without prevalent CVD, were included. During the follow-up of mean 11.7 years, 141 incident CVE were recorded. Baseline IgM anti-PC above median was associated with a reduction in risk of incident CVE in patients aged below 55 years at inclusion, HR 0.360 (95% CI, 0.142–0.916); in males, HR 0.558 (0.325–0.958); in patients with BMI above 30 kg/m2, HR 0.235 (0.065–0.842); and in those who did not achieve DAS28 remission at 1 year, HR 0.592 (0.379–0.924). The pattern of associations was confirmed in the models with AUC IgM anti-PC over 2 years. Conclusion Protective effects of higher levels of innate IgM anti-PC autoantibodies on CVE were detected in younger patients with RA and those at high risk of CVE: males, presence of obesity, and non-remission at 1 year.

Background Proprotein convertase subtilisin kexin 9 (PCSK9) targets the LDL-receptor (LDLR) which raises LDL-levels. In addition, PCSK9 has proinflammatory immunological effects. Here, we investigate the role of PCSK9 in relation to the inflammatory activity in patients with rheumatoid arthritis (RA). Methods PCSK9-levels were determined at baseline by ELISA in 160 patients with RA not previously treated with biologics. The patients started anti-TNF-α (adalimumab, infliximab, or etanercept) treatment and were followed-up for 1 year. Disease activity was determined by DAS28. Effects of PCSK9 on cytokine production from macrophages of healthy individuals and synoviocytes from RA patients and inhibition by anti-PCSK9 antibodies were studied in supernatants by ELISA. Results A significantly lower level of PCSK9 at baseline, p = 0.035, was observed in patients who reached remission within 1 year, defined as DAS28 p = 0.01) and adjusted analysis (p = 0.004). In vitro, PCSK9 induced TNF-alpha and IL-1beta in macrophages and monocyte chemoattractant protein-1 (MCP1) in synoviocytes. These effects were inhibited by anti-PCSK9 antibodies. Conclusions Low levels of PCSK9 at baseline are associated with being DAS28-responder to anti-TNF-α treatment in RA. An underlying cause could be that PCSK9 stimulates the production of proinflammatory cytokines from macrophages and synoviocytes, effects inhibited by anti-PCSK9 antibodies. PCSK9 could thus play an immunological role in RA.

Background Population-based levels of the chronic low-grade systemic inflammation biomarker, C-reactive protein (CRP), vary widely among traditional populations, despite their apparent absence of chronic conditions associated with chronic low-grade systemic inflammation, such as type 2 diabetes, metabolic syndrome and cardiovascular disease. We have previously reported an apparent absence of aforementioned conditions amongst the traditional Melanesian horticulturalists of Kitava, Trobriand Islands, Papua New Guinea. Our objective in this study was to clarify associations between chronic low-grade systemic inflammation and chronic cardiometabolic conditions by measuring CRP in a Kitava population sample. For comparison purposes, CRP was also measured in Swedish controls matched for age and gender. Methods Fasting levels of serum CRP were measured cross-sectionally in ≥ 40-year-old Kitavans (N = 79) and Swedish controls (N = 83). Results CRP was lower for Kitavans compared to Swedish controls (Mdn 0.5 mg/L range 0.1—48 mg/L and Mdn 1.1 mg/L range 0.1—33 mg/L, respectively, r = .18 p = .02). Among Kitavans, there were small negative associations between lnCRP for CRP values Conclusions Chronic low-grade systemic inflammation, measured as CRP, was lower among Kitavans compared to Swedish controls, indicating a lower and average cardiovascular risk, respectively, for these populations.

Chronic inflammatory diseases include cardiovascular disease (CVD), atherosclerosis, rheumatic and autoimmune diseases, and others, constituting a large part of the disease burden. It is therefore of major importance to improve understanding of underlying mechanisms, prediction, and treatment.Broad fields including atherosclerosis, immunology, and inflammation are covered, through searches on PubMed and background knowledge. Phosphorylcholine (PC) is both a danger-associated molecular pattern (DAMP), present on oxidized LDL (OxLDL) in atherosclerotic lesions and dead cells, and a pathogen associated molecular pattern (PAMP), present on microorganisms. IgM and IgG1 antibodies against PC (anti-PC) are associated with protection in several chronic inflammatory conditions, especially in CVD and atherosclerosis where most research has been done. PC-immunization ameliorates atherosclerosis in animal models and several potential underlying mechanisms have been proposed, including anti-inflammatory, decreased uptake of OxLDL in the artery wall, promotion of T regulatory cells. Anti-PC develops during the first years of life. Low levels of IgM and IgG1 anti-PC may be caused by lack of exposure to microorganisms, including nematodes and helminths among others.anti-PC could improve prediction of clinical outcome and raising anti-PC could be developed into a novel therapy.

Abs against phosphorylcholine (anti-PC) and Abs against malondialdehyde (anti-MDA) may be protective in chronic inflammation, like atherosclerosis and cardiovascular disease. It is not known how they develop early in life. Ab titers were measured using ELISA in healthy women (n = 105; born into life study) and their children. Plasma samples were collected from the mothers before conception and from the children at birth as well as at 1 and 2 y after birth. Extracted Abs were compared using a proteomics de novo sequencing approach. It was observed that children were born with very low levels of IgM anti-PC, whereas IgM anti-MDA was present at birth. Both IgM anti-PC and anti-MDA increased during the first 2 y of life, but IgM anti-PC in contrast to IgM anti-MDA was still significantly lower than in the mothers. IgG anti-PC decreased after 1 y but reached similar levels as mothers’ after 2 y, whereas IgG anti-MDA reached similar levels as mothers’ already after 1 y. Proteomics peptide sequencing analysis indicated large peptide sequence variation without specific clone expression during the early stage of life compared with the adult stage for which specific peptide sequences dominated. IgM anti-PC levels develop much slower than anti-MDA and are still relatively low at 2 y. We hypothesize that anti-PC is developed by a combination of preprogramming and exposure to the external world, in which infectious agents may play a role. For anti-MDA, preprogramming is likely to play a major role and at an earlier stage than for anti-PC.

Summary The risk of premature death is high among patients on haemodialysis (HD patients). We previously determined that immunoglobulin (Ig)M antibodies against phosphorylcholine (anti‐PC) are negatively associated with increased risk of cardiovascular disease (CVD), atherosclerosis, some autoimmune diseases and mortality among HD patients in this cohort. Here, we also study other subclasses and isotypes of anti‐PC in HD patients in relation to mortality, inflammation and gender. The study group is a cohort of 209 prevalent HD patients [median age = 66 years, interquartile range (IQR) = 51–74], vintage time = 29 months (IQR = 15–58; 56% men) with a mean follow‐up period of 41 months (IQR = 20–60). Fifty‐six per cent were men. We also divided patients into inflamed C‐reactive protein (CRP) > 5·6 mg/ml and non‐inflamed CRP. Antibody levels were determined by in‐house enzyme‐linked immunosorbent assay. IgG1 anti‐PC below median was significantly associated with increased all‐cause mortality (after adjustment for confounders: P = 0·02), while IgG, IgA and IgG2 anti‐PC were not associated with this outcome. Among non‐inflamed patients, IgM and IgG1 anti‐PC were significantly associated with mortality (P = 0·047 and 0·02). IgG1 anti‐PC was significantly associated with mortality among men (P = 0·03) and trending among women (P = 0·26). IgM (as previously reported) and IgG1 anti‐PC are negatively associated with survival among HD patients and non‐inflamed HD patients, but among inflamed patients there were no associations. IgG, IgA or IgG2 anti‐PC were not associated with survival in these groups and subgroups. Further studies are needed to determine if raising anti‐PC levels, especially IgM and IgG1 anti‐PC, through immunization is beneficial., Antibodies against phosphorylcholine (anti‐PC), especially IgMs, may protect against chronic inflammatory conditions including atherosclerosis, cardiovascular disease and autoimmune disease, being anti‐inflammatory. We here demonstrate that IgM (as previously reported) and IgG1 anti‐PC are negatively associated with survival among Haemodialysis (HD) patients and non‐inflamed HD patients (with CRP>5.6 mg/ml), but among inflamed patients there were no associations while IgG, IgA or IgG2 anti‐PC were not associated with survival. Raising anti‐PC levels, especially IgM and IgG1 anti‐PC, through immunization, may be a therapeutic possibility.

Antibodies against phosphorylcholine (anti-PC) are implicated as protection markers in atherosclerosis, cardiovascular disease (CVD), and other chronic inflammatory conditions. Mostly, these studies have been focused on IgM. In this study, we determined IgG, IgG1, and IgG2 anti-PC among 60-year-olds.Based on a 7-year follow-up of 60-year-olds (2,039 men and 2,193 women) from Stockholm County, we performed a nested case-control study of 209 incident CVD cases with 620 age- and sex-matched controls. Anti-PC was determined using ELISA. We predicted the binding affinity of PC with our fully human, in-house-produced IgG1 anti-PC clones (i.e., A01, D05, and E01) using the molecular docking and molecular dynamics simulation approach, to retrieve information regarding binding properties to PC.After adjustment for confounders, IgG and IgG2 anti-PC showed some significant associations, but IgG1 anti-PC was much stronger as a protection marker. IgG1 anti-PC was associated with an increased risk of CVD below 33rd, 25th, and 10th percentile and of stroke below 33rd and 25th, and of myocardial infarction (MI) below 10th percentile. Among men, a strong association with stroke was determined below the 33rd percentile [HR 9.20, CI (2.22-38.12);IgG1 anti-PC was a stronger protection marker than IgG anti-PC and IgG2 anti-PC and also separately for men. The molecular modeling approach helps in identifying the intrinsic properties of anti-PC clones and atomistic interactions with PC.

Background Phosphorylcholine (PC) is an important pro‐inflammatory damage‐associated molecular pattern. Previous data have shown that natural IgM anti‐PC protects against cardiovascular disease. We aimed to develop a monoclonal PC IgG antibody with anti‐inflammatory and anti‐atherosclerotic properties. Methods Using various techniques PC antibodies were validated and optimized. In vivo testing was performed in a femoral artery cuff model in ApoE3*Leiden mice. Safety studies are performed in rats and cynomolgus monkeys. Results A chimeric anti‐PC (PC‐mAb(T15), consisting of a human IgG1 Fc and a mouse T15/E06 Fab) was produced, and this was shown to bind specifically to epitopes in human atherosclerotic tissues. The cuff model results in rapid induction of inflammatory genes and altered expression of genes associated with ER stress and choline metabolism in the lesions. Treatment with PC‐mAb(T15) reduced accelerated atherosclerosis via reduced expression of endoplasmic reticulum stress markers and CCL2 production. Recombinant anti‐PC Fab fragments were identified by phage display and cloned into fully human IgG1 backbones creating a human monoclonal IgG1 anti‐PC (PC‐mAbs) that specifically bind PC, apoptotic cells and oxLDL. Based on preventing macrophage oxLDL uptake and CCL2 production, four monoclonal PC‐mAbs were selected, which to various extent reduced vascular inflammation and lesion development. Additional optimization and validation of two PC‐mAb antibodies resulted in selection of PC‐mAb X19‐A05, which inhibited accelerated atherosclerosis. Clinical grade production of this antibody (ATH3G10) significantly attenuated vascular inflammation and accelerated atherosclerosis and was tolerated in safety studies in rats and cynomolgus monkeys. Conclusions Chimeric anti‐PCs can prevent accelerated atherosclerosis by inhibiting vascular inflammation directly and through reduced macrophage oxLDL uptake resulting in decreased lesions. PC‐mAb represents a novel strategy for cardiovascular disease prevention. ISSN:0954-6820 ISSN:1365-2796

Visual Abstract, Highlights • MDA conjugated with HSA activates T cells from human atherosclerotic plaques through a direct mechanism. • MDA-HSA also induces maturation and activation of human dendritic cells, which in turn promote activation of autologous T cells from the same donor's plaques, although this effect appears somewhat weaker than the direct activation. • M1 polarization of macrophages, potentially an atherogenic effect, were also induced by MDA-HSA. • Heat shock protein 60 was induced in T cells by MDA-HSA, is atherogenic, and could promote dendritic cell/T cell activation. • Two peptide modifications of serum albumin in atherosclerotic patients’ HSA were similar to those generated by treatment of HSA with MDA in vitro., Summary Human dendritic cells were differentiated from blood monocytes and treated with malondialdehyde (MDA) conjugated with human serum albumin (HSA). Autologous T cells from human plaques or blood were co-cultured with the pre-treated dendritic cells or treated directly. MDA modifications were studied by mass spectrometry. MDA-HSA induced a pro-inflammatory DC-mediated T-cell activation and also a strong direct effect on T cells, inhibited by an inhibitor of oxidative stress and antibodies against MDA. Atherogenic heat shock protein-60 was strongly induced in T cells activated by MDA-HSA. Two peptide modifications in atherosclerotic patients' HSA were similar to those present in in vitro MDA-modified HSA.

Background and Aims Brown bears (Ursus arctos) hibernate for 5-6 months during winter, but in spite of kidney insufficiency, dyslipidemia, insulin resistance and inactivity they do not seem to develop atherosclerosis or cardiovascular disease (CVD). Antibodies against phosphorylcholine (anti-PC) are associated with protection in atherosclerosis, CVD and uremia. Potential underlying protective mechanisms include anti-inflammatory effects, inhibition of cell death, promotion of T regulatory cells, clearance of dead cells and inhibition of oxidized Low density lipoprotein (OxLDL)-uptake in macrophages in atherosclerotic plaques. PC is an important antigen on nematodes, parasites, some bacteria, dead and dying cells and OxLDL. Method Paired serum from 12 brown bears sampled during winter and summer were analyzed for metabolic parameters and for IgM, IgG, IgG1/2 and IgA anti-PC by enzyme linked immunosorbent assay (ELISA). Differences in antibody levels between winter and summer were determined by paired Student´s t test or Wilcoxon´s signed rank test (when not normally distributed). Results As expected, marked differences in metabolic parameters were found comparing median summer vs winter values; Cholesterol 5.9 vs 11.3 mmol/L; p Conclusion Anti-PC (strikingly so for IgA and IgG1) are significantly raised during hibernation as compared to levels during summer. We hypothesize that these changes contribute to the protection of arteries, but also kidneys and other organs, during the metabolic vulnerable hibernation period. Our observation may represent a natural immunization with microorganisms, preventing atherosclerosis during a period of severe kidney insufficiency and could have therapeutic implications for patients with chronic kidney disease.

OBJECTIVE: Clinical heterogeneity, a hallmark of systemic autoimmune diseases, impedes early diagnosis and effective treatment, issues that may be addressed if patients could be classified into groups defined by molecular pattern. This study was undertaken to identify molecular clusters for reclassifying systemic autoimmune diseases independently of clinical diagnosis. METHODS: Unsupervised clustering of integrated whole blood transcriptome and methylome cross-sectional data on 955 patients with 7 systemic autoimmune diseases and 267 healthy controls was undertaken. In addition, an inception cohort was prospectively followed up for 6 or 14 months to validate the results and analyze whether or not cluster assignment changed over time. RESULTS: Four clusters were identified and validated. Three were pathologic, representing "inflammatory," "lymphoid," and "interferon" patterns. Each included all diagnoses and was defined by genetic, clinical, serologic, and cellular features. A fourth cluster with no specific molecular pattern was associated with low disease activity and included healthy controls. A longitudinal and independent inception cohort showed a relapse-remission pattern, where patients remained in their pathologic cluster, moving only to the healthy one, thus showing that the molecular clusters remained stable over time and that single pathogenic molecular signatures characterized each individual patient. CONCLUSION: Patients with systemic autoimmune diseases can be jointly stratified into 3 stable disease clusters with specific molecular patterns differentiating different molecular disease mechanisms. These results have important implications for future clinical trials and the study of nonresponse to therapy, marking a paradigm shift in our view of systemic autoimmune diseases. ispartof: ARTHRITIS & RHEUMATOLOGY vol:73 issue:6 pages:1073-1085 ispartof: location:United States status: published

Brown bears (Ursus arctos) hibernate for 5–6 months during winter, but despite kidney insufficiency, dyslipidemia and inactivity they do not seem to develop atherosclerosis or cardiovascular disease (CVD). IgM antibodies against phosphorylcholine (anti-PC) and malondialdehyde (anti-MDA) are associated with less atherosclerosis, CVD and mortality in uremia in humans and have anti-inflammatory and other potentially protective properties. PC but not MDA is exposed on different types of microorganisms. We determine anti-PC and anti-MDA in brown bears in summer and winter. Paired serum samples from 12 free ranging Swedish brown bears were collected during hibernation in winter and during active state in summer and analyzed for IgM, IgG, IgG1/2 and IgA anti-PC and anti-MDA by enzyme linked immunosorbent assay (ELISA). When determined as arbitrary units (median set at 100 for summer samples), significantly raised levels were observed in winter for anti-PC subclasses and isotypes, and for IgA anti-PC the difference was striking; 100 IQR (85.9–107.9) vs 782.3, IQR (422.8–1586.0; p

Background The risk of cardiovascular disease (CVD) and atherosclerosis is very high in SLE. This is a clinical problem, and could also shed light on immunity and atherosclerosis in general. IgM antibodies against phosphorylcholine (anti-PC) may be protective in atherosclerosis, cardiovascular disease (CVD) and systemic lupus erythematosus (SLE). We here study IgG1 and IgG2 anti-PC, with focus on atherosclerosis and SLE. Methods We determined anti-PC by ELISA in 116 SLE-patients and 110 age- and sex-matched controls. For functional studies, we used three in-house generated, fully human monoclonal IgG1 anti-PC (A01, D05, E01). Apoptosis was induced in Jurkat T-cells and pre-incubated with A01, D05, E01 or isotype control IgG1 and effects on efferocytosis by human macrophages studied. Anti-PC peptide/protein characterization was determined using a proteomics de novo sequencing approach. Results IgG1 but not IgG2 anti-PC levels were higher among SLE patients (p=0.02). IgG1 anti-PC was negatively associated with SLICC and SLEDAI (OR: 2,978 CI: 0.876–10.098, OR: 5.108 CI 1.3 20.067 respectively) and negatively associated with CVD, atherosclerotic plaques and echolucent (potentially vulnerable plaques) but the association for the two former was not significant after controlling for confounders. D05 had maximum effect on macrophage efferocytosis efficiency, followed by A01 and E01. The monoclonal antibodies showed differential binding specificity to PC and PC associated neo-epitopes. Peptide analysis showed difference in the CDR3 region of the three anti-PC IgG1 clones which are crucial for recognition of PC on apoptotic cell surface and other neo-epitopes. Conclusion Anti-PC IgG1 is negatively associated with disease activity, and disease damage in SLE, but the negative association with CVD is also dependent on confounding risk factors. One potential underlying mechanism could be increased clearance of dead cells. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Swedish Heart and Lung Foundation, Reumatikerfonden

Background Low-density lipoprotein (LDL) levels are increased by proprotein convertase subtilisin kexin 9 (PCSK9) which targets the LDL receptor. We recently reported that PCSK9 ameliorates dendritic cell (DC) activation by oxidized LDL (OxLDL), which is abundant in atherosclerotic plaques and is also associated with cardiovascular disease (CVD) in systemic lupus erythematosus (SLE). Here, we investigated the role of PCSK9 in SLE. Methods PCSK9 levels were determined by ELISA among SLE patients ( N = 109) and age- and sex-matched population-based controls ( N = 91). Common carotid intima–media thickness (IMT) and plaque occurrence were determined by B-mode ultrasound. Plaques were graded by echogenicity. Human peripheral blood monocytes from SLE patients or controls were differentiated into DCs. The effects of PCSK9 and its inhibition by silencing were studied. Results PCSK9 levels were non-significantly higher among SLE-patients compared to controls but significantly associated with SLE disease activity, as determined by the Systemic Lupus Activity Measure ( p = 0.020) or the SLE Disease Activity Index ( p = 0.0178). There was no association between PCSK9 levels and atherosclerosis as determined by IMT, prevalence of plaques or echolucent (potentially vulnerable) plaques. PCSK9 levels were significantly associated with CVD among SLE patients but not after adjusting for age. OxLDL induced PCSK9 in DCs and DC maturation with increased expression of CD86 and HLA-DR. The effects were significantly stronger in DCs from SLE patients than from controls. Silencing of PCSK9 abolished OxLDL-induced DC maturation. Conclusions PCSK9 is associated with disease activity in SLE. One underlying cause could be OxLDL promoting DC activation which depends on PCSK9. OxLDL induces PCSK9 – an effect which is higher among SLE patients. PCSK9 could play an unexpected immunological role in SLE.

International audience; Antiphospholipid (aPL) autoantibodies are uncommon in systemic autoimmune diseases (SADs). However, the European PRECISESADS study provides the opportunity to better characterize this rare association. The study was composed of 1818 patients with SADs including 453 with systemic lupus erythematosus (SLE), 359 with rheumatoid arthritis (RA), 385 with systemic sclerosis (SSc), 367 with Sjögren's syndrome (SjS), 94 with mixed connective tissue disease (MCTD), and 160 with undifferentiated connective tissue disease (UCTD). Assays used for aPL determination include the lupus anticoagulant (LAC) analysis using the dilute Russell's viper venom time (dRVVT) assay plus anti-cardiolipin (aCL) and anti-aβ2GPI autoantibodies of IgG and IgM isotype. Information regarding clinical and biological characteristics of SAD patients was available. Among SAD patients, the prevalence of aPL differs significantly between two groups: SLE (57.6%) and non-SLE SADs (13.7%, p

Background Clinical heterogeneity, a hallmark of systemic autoimmune diseases (SADs) impedes early diagnosis and effective treatment, issues that may be addressed if patients could be grouped into a molecular defined stratification. Methods With the aim of reclassifying SADs independently of the clinical diagnoses, unsupervised clustering of integrated whole blood transcriptome and methylome cross-sectional data of 918 patients with 7 SADs and 263 healthy controls was undertaken. An inception cohort prospectively followed for 6 and 14 months was studied to validate the results in early cases and analyze if cluster assignment was modified with time. Results Four clusters were identified Three aberrant clusters were ‘acute phase inflammatory’, ‘T cell immunity’, and ‘interferon’, each including all diagnoses, were defined by genetic, clinical, serological and cellular features. A fourth cluster showed no specific molecular pattern, to which 74% of healthy controls clustered with patients. The inception cohort showed that most patients were either assigned always to the same cluster or moved from the healthy-like cluster to a single aberrant cluster resembling the relapsing-remitting dynamic of these diseases, showing that single aberrant molecular signatures characterize each individual patient. Conclusions Patients with SADs share molecular signatures and can be therefore stratified into three disease clusters differentiating each patient into a specific molecular disease pathway. Such assignment is stable with time. These results have important implications for understanding disease progression and therapy design marking a paradigm shift in our view of SADs. Acknowledgment This work has been supported through a grant from the Innovative Medicines Initiative Joint Undertaking No. 115565 and in-kind and in-cash contributions from the EFPIA partners. G.B. is supported by the Instituto de Salud Carlos III (ISCIII, Spanish Health Ministry), through the Sara Borrell subprogram (CD18/00153). The authors would like to particularly express their gratitude to the patients, nurses and many others who helped directly or indirectly in the consecution of this study.

SUMMARYBackgroundClinical heterogeneity, a hallmark of systemic autoimmune diseases (SADs) impedes early diagnosis and effective treatment, issues that may be addressed if patients could be grouped into a molecular defined stratification.MethodsWith the aim of reclassifying SADs independently of the clinical diagnoses, unsupervised clustering of integrated whole blood transcriptome and methylome cross-sectional data of 918 patients with 7 SADs and 263 healthy controls was undertaken. In addition, an inception cohort was prospectively followed for 6 and 14 months to validate the results and analyze if cluster assignment changed or not with time.ResultsFour clusters were identified. Three clusters were aberrant, representing ‘inflammatory’, ‘lymphoid’, and ‘interferon’ patterns each including all diagnoses and defined by genetic, clinical, serological and cellular features. A fourth cluster showed no specific molecular pattern and accumulated also healthy controls. An independent inception cohort showed that with time, the molecular clusters remain stable, showing that single aberrant molecular signatures characterize each individual patient.ConclusionsPatients with SADs can be jointly stratified into three stable disease clusters with specific molecular patterns differentiating different molecular disease mechanisms. These results have important implications for future clinical trials and the study of therapy non-responsiveness marking a paradigm shift in the view of SADs.

Objectives In systemic lupus erythematosus (SLE) there are typically many autoantibodies. The disease heterogeneity could be better understood with discovery of phenotype-specific antigens targeted by autoantibodies. We here aimed to identify novel autoantigens potentially related to SLE disease and a major complication, atherosclerosis. Methods Antigen microarrays were used to profile IgG autoantibody reactivity against 77 protein fragments (20–140 amino acids (aa) long, median 89 aa) produced within the Human Protein Atlas project, in serum samples from SLE patients ( n = 107) and age- and sex-matched population-based controls ( n = 107). Common carotid intima-media thickness, plaque occurrence and echogenicity were determined by B-mode ultrasound. Results We determined significant differences between patients and controls in IgG reactivity against four proteins. In patients compared to controls, there was an increase of IgG reactivity against zinc finger protein 688 (ZNF688), early B cell factor 2 (EBF2), crystallin, alpha B (CRYAB) and tumor necrosis factor receptor superfamily member 13C (TNFRSF13C). Of these four antigens, only anti-ZNF688 was associated with carotid atherosclerosis (plaque occurrence) and vulnerable plaques in SLE. There was a weak association between anti-EBF2 and SLE disease activity but no significant associations were determined for other measured IgG reactivity. Conclusions In this discovery screening we here demonstrate new candidate autoantigens with differential reactivity (reflecting autoantibody levels) in SLE patients and in controls and in relation to atherosclerosis in SLE.

Background Activated T cells and dendritic cells (DCs) occur in atherosclerotic plaques. Proprotein convertase subtilisin kexin 9 (PCSK9) targets the LDL-receptor (LDLR) and results in increased LDL levels. We here investigate immune effects of PCSK9 on OxLDL induced DC maturation and T-cell activation. Methods T cells were isolated from carotid specimens of patients undergoing carotid endarterectomy or from peripheral blood of healthy individuals. Human peripheral blood monocytes were differentiated into DCs. Naive T cells were cocultured with pretreated DCs. The effects of PCSK9 and its inhibition by silencing were studied. Results OxLDL induced PCSK9 in DCs and promoted DC maturation with increased expressions of CD80, CD83, CD86 and HLA-DR and the scavenger receptors LOX-1 and CD36. T cells exposed to OxLDL-treated DCs proliferated and produced IFN-γ and IL-17, thus with polarization to Th1 and/or Th17 subsets. Silencing of PCSK9 reversed the OxLDL effects on DCs and T cells. DC maturation was repressed, and the production of TNF-α, IL-1β and IL-6 was limited, while TGF-β and IL-10 secretion and T regulatory cells were induced. OxLDL induced miRNA let-7c, miR-27a, miR-27b, miR-185. Silencing PCSK9 repressed miR-27a and to a lesser extent let-7c. PCSK9 silencing enhanced SOCS1 expression induced by OxLDL. Experiments on T cells from carotid atherosclerotic plaques or healthy individuals showed similar results. Conclusions We demonstrate immunological effects of PCSK9 in relation to activation and maturation of DCs and plaque T cells by OxLDL, a central player in atherosclerosis. This may directly influence atherosclerosis and cardiovascular disease, independent of LDL lowering.

Phosphorylcholine (PC) is an epitope on oxidized low-density lipoprotein (oxLDL), apoptotic cells and several pathogens like Streptococcus pneumoniae. Immunoglobulin M against PC (IgM anti-PC) has the ability to inhibit uptake of oxLDL by macrophages and increase clearance of apoptotic cells. From our genome-wide association studies (GWASs) in four European-ancestry cohorts, six single nucleotide polymorphisms (SNPs) in 11q24.1 were discovered (in 3002 individuals) and replicated (in 646 individuals) to be associated with serum level of IgM anti-PC (the leading SNP rs35923643-G, combined β = 0.19, 95% confidence interval 0.13–0.24, P = 4.3 × 10(−11)). The haplotype tagged by rs35923643-G (or its proxy SNP rs735665-A) is also known as the top risk allele for chronic lymphocytic leukemia (CLL), and a main increasing allele for general IgM. By using summary GWAS results of IgM anti-PC and CLL in the polygenic risk score (PRS) analysis, PRS on the basis of IgM anti-PC risk alleles positively associated with CLL risk (explained 0.6% of CLL variance, P = 1.2 × 10(−15)). Functional prediction suggested that rs35923643-G might impede the binding of Runt-related transcription factor 3, a tumor suppressor playing a central role in the immune regulation of cancers. Contrary to the expectations from the shared genetics between IgM anti-PC and CLL, an inverse relationship at the phenotypic level was found in a nested case–control study (30 CLL cases with 90 age- and sex-matched controls), potentially reflecting reverse causation. The suggested function of the top variant as well as the phenotypic association between IgM anti-PC and CLL risk needs replication and motivates further studies.

International audience; OBJECTIVE: Mutations in the ACP5 gene, which encodes tartrate-resistant acid phosphatase (TRAP), cause the immuno-osseous disorder spondyloenchondrodysplasia, which includes as disease features systemic lupus erythematosus (SLE) and a type I interferon (IFN) signature. Our aims were to identify TRAP substrates, determine the consequences of TRAP deficiency in immune cells, and assess whether ACP5 mutations are enriched in sporadic cases of SLE. METHODS: Interaction between TRAP and its binding partners was tested by a yeast 2-hybrid screening, confocal microscopy, and immunoprecipitation/Western blotting. TRAP knockdown was performed using small interfering RNA. Phosphorylation of osteopontin (OPN) was analyzed by mass spectrometry. Nucleotide sequence analysis of ACP5 was performed by Sanger sequencing or next-generation sequencing. RESULTS: TRAP and OPN colocalized and interacted in human macrophages and plasmacytoid dendritic cells (PDCs). TRAP dephosphorylated 3 serine residues on specific OPN peptides. TRAP knockdown resulted in increased OPN phosphorylation and increased nuclear translocation of IRF7 and P65, with resultant heightened expression of IFN-stimulated genes and IL6 and TNF following Toll-like receptor 9 stimulation. An excess of heterozygous ACP5 missense variants was observed in SLE compared to controls (P = 0.04), and transfection experiments revealed a significant reduction in TRAP activity in a number of variants. CONCLUSION: Our findings indicate that TRAP and OPN colocalize and that OPN is a substrate for TRAP in human immune cells. TRAP deficiency in PDCs leads to increased IFNα production, providing at least a partial explanation for how ACP5 mutations cause lupus in the context of spondyloenchondrodysplasia. Detection of ACP5 missense variants in a lupus cohort suggests that impaired TRAP functioning may increase susceptibility to sporadic lupus.

Background: IgM antibodies against phosphorylcholine (anti-PC) may be protective in atherosclerosis, cardiovascular disease (CVD) and systemic lupus erythematosus (SLE). Less is known about other anti-PC isotypes and subclasses. In this study, we study the role of IgG1 and IgG2 anti-PC, with focus on atherosclerosis and SLE. Objectives: To study the role of IgG1 and IgG2 anti-PC, with focus on atherosclerosis and SLE, both in a clinical setting and by experimental studies, where we use our in-house produced monoclonal IgG1 anti-PC. Methods: We determined IgG1 and IgG2 anti-PC in our SLE cohort study (SLEVIC), among 116 SLE-patients from Karolinska University Hospital Huddinge and 110 population controls matched for age and gender. The level of antibodies was measured by ELISA. For functional studies, we used three of our in-house generated, fully human monoclonal IgG1 anti-PC (A01, D05, E01). Primary human macrophages were derived from peripheral blood. Apoptosis was induced in Jurkat T-cells and pre-incubated with A01, D05, E01 or isotype control IgG1 and effect on phagocytosis by marcophages studied. Anti-PC peptide/protein characterization was determined in anti-PC clones compared to isotype control using a proteomics de novo sequencing approach. Results: IgG1 but not IgG2 anti-PC levels were higher among SLE patients than controls (p=0.02). IgG1 anti-PC was negatively associated with prevalence of atherosclerotic plaques, below 10thpercentile, (OR: 2.48, CI: 0.69-9.00). IgG1 Anti-PC was negatively associated with CVD, SLICC and SLEDAI (OR: 4.74 CI: 1.29-17.39, OR: 2,978 CI: 0.876-10.098, OR: 5.108 CI 1.3 20.067 respectively). Monoclonal D05 had maximum effect on macrophage efferocytosis efficiency, followed by A01 and E01. This is because anti-PC IgG1s bind to phosphorylcholine exposed on apoptotic cells and facilitate the uptake by macrophage. The in-house produced monoclonal antibodies showed differential binding specificity to PC and PC associated neo-epitopes. Peptide analysis showed difference in the CDR3 region of the three anti-PC IgG1 clones which are crucial for recognition of the phosphorylcholine on the apoptotic cell surface and other neo-epitopes. Conclusion: anti-PC IgG1 is negatively associated with disease activity and atherosclerosis in SLE. One potential underlying mechanism could be increased phagocytosis and clearance of dead cells. Our findings raise the possibility of prevention and/or treatment of SLE (and atherosclerosis) to raise anti-PC levels, by passive or active immunization. References: [1] Frostegard J. Immunity, atherosclerosis and cardiovascular disease. BMC Med. 2013;11:117. [2] Anania C, Gustafsson T, Hua X, Su J, Vikstrom M, de Faire U, Heimburger M, Jogestrand T and Frostegard J. Increased prevalence of vulnerable atherosclerotic plaques and low levels of natural IgM antibodies against phosphorylcholine in patients with systemic lupus erythematosus. Arthritis Res Ther. 2010;12:R214. Disclosure of Interests: Divya Thiagarajan: None declared, Nina Oparina: None declared, Johanna Steen: None declared, Mizanur Rahman: None declared, Max Vikstrom: None declared, Roman Zubarev: None declared, Susanna Lundstrom: None declared, Johan Frostegard Shareholder of: Minor shareholder and inventor in startup-company Athera Biotechnologies, but they do not produce drugs yet and rheumatology is not in their focus.

Background: Measurement of carotid intima-media thickness (cIMT) is promoted as one of the tools for cardiovascular (CV) risk assessment in primary prevention in general population. The diagnosis of systemic lupus erythematosus (SLE) is a strong risk factor for premature CV events and mortality. Whether assessment of cIMT has a value for prediction of CV morbidity and mortality in patients with SLE compared with population controls of similar age and sex is not established. Objectives: To examine association of cIMT with risk of incident CV events and mortality in SLE and controls. Methods: We used the cross-sectional SLEVIC (SLE vascular impact cohort study) cohort of consecutive patients with SLE aged Event-free survival rates in patients and controls were compared using Kaplan-Meier curves. Relative hazard ratios from Cox proportional-hazards regression models were used to estimate the effect of cIMT measurement on the outcome. Results: At inclusion, mean age (SD) of the included 99 patients was 47 (13) years, 87% females, mean disease duration 12 (9) years, SLEDAI 4.0, and SLICC/ACR 1.0. Mean age of included 109 controls was 49 (12) years, 91% females. Baseline mean (SD) cIMT did not differ between the groups (p=0.345) and was 607 (127) µm in patients and 623 (118) µm in controls. During follow-up, 12 patients and 4 controls were defined with the outcome. The outcome was reached more often in patients than in controls, p=0.022. The mean time to outcome (SD) was 9.9 (0.2) years for patients and 10.3 (0.1) years for controls. The hazard rate (HR) for the combined outcome of CV event and mortality was 3.7-fold (95% CI, 1.2–11.5) higher in patients than in controls, adjusted for age, sex and smoking history, p=0.025. A higher baseline mean cIMT was significantly associated with the outcome, HR 1.0 (95% CI, 1.0-1.01) per 1.0 µm increase in cIMT, p=0.040, irrespective of the group. Additional adjustment for traditional risk factors, disease duration, treatments, presence of anti-phospholipid antibodies and defining with carotid plaque yielded similar risk estimates. Conclusion: In this analysis we confirm an elevated long-term risk of important adverse clinical events in patients with SLE compared with controls. A measure of cIMT is associated with incident CV event and mortality. This suggests that assessment with carotid ultrasound may have a value for CV risk stratification and would encourage validation in large-cohort prospective populations. Disclosure of Inter: Sofia Ajeganova: None declared, Ingiald Hafstrom: None declared, Johan Frostegard Shareholder of: Minor shareholder and inventor in startup-company Athera Biotechnologies, but they do not produce drugs yet and rheumatology is not in their focus.

Background: In SLE accelerated progression of carotid plaque and contribution of inflammatory factors for premature vascular changes have been reported. Effect of classical risk factors on progression of carotid intima-media thickness (cIMT) in patients with SLE in comparison with population controls is not clear. Objectives: To examine in SLE and population controls (1)prevalence of risk factors overtime; (2)evolution of cIMT; (3)risk factors promoting cIMT evolution. Methods: The study sample originated from the SLEVIC cohort (SLE vascular impact cohort study) which included consecutive patients with SLE and age and sex matched population controls. Seven years after inclusion all participants were asked to take part in the follow-up investigation. The standardized data collection and carotid ultrasound were performed at two assessments, 7 years apart. Effect of risk factors on cIMT overtime was examined with linear mixed models adjusted for age, sex and traditional CV risk factors. Results: A total of 77 patients with SLE (68% of original cohort), 87% females, at inclusion mean age 47 years, disease duration 11.4 years, SLEDAI 3.0, SLICC/ACR 1.1, and 74 controls (61% of original cohort), 89% females, mean age 51years, completed 7-years follow-up. At inclusion, patients with SLE were younger and had lower levels of LDL than controls but were more likely to have hypertension and higher levels of triglycerides (TG). Between the assessments both groups were measured with an increase in blood pressure, levels of total cholesterol (TC), LDL, but at follow-up the patients still had lower TC, LDL and HDL levels and higher TG than controls. At both assessments, patients used more frequent antihypertensive and aspirin than controls, p The mean cIMT increased statistically significant in patients and controls, average absolute progression of 0.009 mm/year in patients and 0.011 mm/year in controls, p In multivariate analysis, the patients showed a statistically significant association between mean cIMT overtime and higher systolic blood pressure, lower levels of HDL, higher TC/HDL- and LDL/HDL-ratio, higher triglycerides, dyslipidemia and detection with (any) carotid plaque at inclusion. In the control group, lower levels of HDL, history of dyslipidemia and finding with bilateral plaque at inclusion were associated with cIMT overtime. At follow-up, hypertension and blood lipid measures in patients (with exception for TG) and HDL in controls were still significantly associated with cIMT overtime. Of all, the strongest association was shown for HDL in both patients and controls. Effect of other cardio-metabolic risk factors at inclusion and cumulative risks were not significant after adjustment for age and sex. In the patients, history of nephritis at inclusion and follow-up, and a higher average dose of prednisone used since diagnosis, but not other treatments, were associated with cIMT overtime. Conclusion: We observed similar progression of cIMT over 7 years in patients with long-standing mild well-controlled SLE disease and population controls. Our findings suggest importance of recognition with dyslipidemia and hypertension, and support recommendation to limit use of corticosteroids in patients with SLE as a part of CV risk management. The factors protecting or promoting atherosclerotic progression should be further explored. Disclosure of Interests: Sofia Ajeganova: None declared, Thomas Gustafsson: None declared, Tomas Jogestrand: None declared, Ingiald Hafstrom: None declared, Johan Frostegard Shareholder of: Minor shareholder and inventor in startup-company Athera Biotechnologies, but they do not produce drugs yet and rheumatology is not in their focus.

Background Patients with chronic kidney disease stage 5 (CKD5) are predisposed to vascular calcification (VC), but the combined effect of factors associated with VC was sparsely investigated. We applied the relaxed linear separability (RLS) feature selection model to identify features that concomitantly associate with VC in CKD5 patients. Methods Epigastric arteries collected during surgery from living donor kidney transplant recipients were examined to score the histological extent of medial VC. Sixty-two phenotypic features in 152 patients were entered into RLS model to differentiate between no-minimal VC (n = 93; score 0-1) and moderate-extensive VC (n = 59; score 2-3). The subset of features associated with VC was selected on the basis of cross-validation procedure. The strength of association of the selected features with VC was expressed by the absolute value of 'RLS factor'. Results Among 62 features, a subset of 17 features provided optimal prediction of VC with 89% of patients correctly classified into their groups. The 17 features included traditional risk factors (diabetes, age, cholesterol, BMI and male sex) and markers of bone metabolism, endothelial function, metabolites, serum antibodies and mitochondrial-derived peptide. Positive RLS factors range from 1.26 to 4.05 indicating features associated with increased risk of VC, and negative RLS factors range from -0.95 to -1.83 indicating features associated with reduced risk of VC. Conclusion The RLS model identified 17 features including novel biomarkers and traditional risk factors that together concomitantly associated with medial VC. These results may inform further investigations of factors promoting VC in CKD5 patients.

Objective Immunoglobulin M antibodies against phosphorylcholine (anti‐PCs) may be protective in atherosclerosis, cardiovascular disease (CVD), and systemic lupus erythematosus (SLE). We study immunoglobulin G1 (IgG1) and immunoglobulin G2 (IgG2) anti‐PCs, with a focus on atherosclerosis and SLE. Methods We determined anti‐PCs by using the enzyme‐linked immunosorbent assay in 116 patients with SLE and 110 age‐ and sex‐matched controls. For functional studies, we used three in‐house–generated, fully human monoclonal IgG1 anti‐PCs (A01, D05, and E01). Apoptosis was induced in Jurkat T cells and preincubated with A01, D05, E01, or IgG1 isotype control, and effects on efferocytosis by human macrophages were studied. Anti‐PC peptide/protein characterization was determined using a proteomics de novo sequencing approach. Results IgG1, but not IgG2, anti‐PC levels were higher among patients with SLE (P = 0.02). IgG1 anti‐PCs were negatively associated with Systemic Lupus International Collaborating Clinics (SLICC) damage index and Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) scores (odds ratio [OR]: 2.978 [confidence interval (CI): 0.876‐10.098] and OR: 5.108 [CI 1.3‐20.067], respectively) and negatively associated with CVD, atherosclerotic plaques, and echolucent plaques (potentially vulnerable plaques), but the association for the two former was not significant after controlling for confounders. D05 had a maximum effect on macrophage efferocytosis efficiency, followed by A01 and E01. The monoclonal antibodies showed differential binding specificity to PC and PC‐associated neoepitopes. A peptide analysis showed a difference in the complementarity‐determining region 3 of the three IgG1 anti‐PC clones that are crucial for recognition of PC on apoptotic cell surfaces and other neoepitopes. Conclusion IgG1 anti‐PCs are negatively associated with disease activity and disease damage in SLE, but the negative association with CVD is also dependent on confounding risk factors. One potential underlying mechanism could be increased clearance of dead cells., What is already known about this subject? •Low levels of immunoglobulin M antibodies against phosphorylcholine (anti‐PCs) is more common in patients with systemic lupus erythematosus (SLE) compared with controls and is associated with increased prevalence of vulnerable plaque among patients with SLE. What does this study add? Immunoglobulin G1 (IgG1) anti‐PCs are negatively associated with disease activity, disease damage, cardiovascular disease, and measures of atherosclerosis in SLE.We have produced in‐house, fully human monoclonal antibodies of the IgG1 isotype that increase apoptotic cell uptake efficiently and reduce inflammation induced by lipopolysaccharide. Effects varied depending on the clone used.A peptide analysis showed a difference in the complementarity‐determining region 3 of the three IgG1 anti‐PC clones that are crucial for the recognition of phosphorylcholine (PC) on apoptotic cell surfaces and other neoepitopes. How might this impact clinical practice or future developments? Measurement of IgG1 anti‐PCs, along with other autoantibodies, could improve prevention in patients with SLE with vascular implications.Anti‐PCs could be developed as a novel treatment in SLE, either as monoclonal antibodies or as a vaccine with PC.