Antibodies to citrullinated peptides and risk of coronary heart disease

Tumor Necrosis Factor Alpha Inhibitors and Cardiovascular Risk in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by an increased risk of cardiovascular events, due to the complex interplay between traditional and disease-related risk factors. Chronic inflammation and persistent disease activity are the key determinants of this risk, but despite great improvement in the disease management and prognosis, cardiovascular events are still the main cause of morbidity and mortality in RA cohorts1. In the last decades, the advent of new biological and targeted-synthetic DMARDs was accompanied by an improvement in disease activity control, but the role of each class of drugs on CVD risk is still a matter a debate. Since their approval for RA treatment, tumor necrosis factor alpha (TNFα) inhibitors have been widely investigated to better understand their effects on cardiovascular outcomes. The hypothesis that the reduction of chronic inflammation with any treatment may reduce the cardiovascular risk has been recently confuted by the direct comparison of TNFα-inhibitors and JAK inhibitors in patients with RA and coexisting risk factors for cardiovascular disease. The aim of this literature review is to add to the available evidence to analyze the relationship between TNFα-inhibitors and CVD risk in patients with RA and also provide some clinical scenarios to better explain the treatment dilemmas. In particular, while data on major cardiovascular events and thromboembolism seem consistent with an inflammation-mediated benefit with TNFα-inhibitors, there remain concerns about the use of this class of bDMARDs in patients with chronic heart failure.

Association of citrullination with the progression of aortic stenosis

Despite its clinical importance, biomarkers of disease activity in aortic stenosis (AS) are lacking. We investigated the association between anti-cyclic citrullinated peptide (CCP) antibodies and AS. All 678 patients who underwent echocardiography and anti-CCP antibody testing were analysed. Anti-CCP antibody status was categorized as negative, low-positive, and high-positive. In addition, aortic valve (AV) tissues were obtained from the patients with and without AS to analyze the presence of citrullinated proteins. At baseline, 241 (35.5%) subjects with AV degeneration had a higher rate of anti-CCP antibody positivity (42.7% versus 34.6%, p = 0.035) than those without AV degeneration. Out of the 331 (48.8%) subjects who underwent echocardiographic follow-up, progression of AS was observed in 34 (10.3%) patients, with a higher incidence in the high-positive group compared to the low-positive or negative group (19.0% vs. 11.3% vs. 8.4%, respectively; p = 0.041). On multivariable analysis, high anti-CCP antibody positivity was independently associated with progression to AS (odds ratio: 2.312; 95% confidence interval: 1.006-5.310; p = 0.048). Furthermore, immunohistochemistry and Western blotting revealed increased citrullination in diseased AV compared to normal AV tissue. This study demonstrated that a high positive anti-CCP antibody result is associated with AV degeneration and may be an independent factor for AS progression.

Atherosclerotic Cardiovascular Risk Stratification in the Rheumatic Diseases:: An Integrative, Multiparametric Approach

Cardiovascular disease (CVD) risk is increased in most inflammatory rheumatic diseases (IRDs), reiterating the role of inflammation in the initiation and progression of atherosclerosis. An inverse association of CVD risk with body weight and lipid levels has been described in IRDs. Coronary artery calcium scores, plaque burden and characteristics, and carotid plaques on ultrasound optimize CVD risk estimate in IRDs. Biomarkers of cardiac injury, autoantibodies, lipid biomarkers, and cytokines also improve risk assessment in IRDs. Machine learning and deep learning algorithms for phenotype and image analysis hold promise to improve CVD risk stratification in IRDs.

Role of Lipoprotein Levels and Function in Atherosclerosis Associated with Autoimmune Rheumatic Diseases

Immune and inflammatory mediators in autoimmune rheumatic diseases induce modification in the activity of enzymes pivotal for lipid metabolism and promote a proatherogenic serum lipid profile. However, disturbances in low- and high-density lipoprotein composition and increased lipid oxidation also occur. Therefore, lipoprotein dysfunction causes intracellular cholesterol accumulation in macrophages, smooth muscle cells, and platelets. Overall, both plaque progression and acute cardiovascular events are promoted. Single rheumatic diseases may present a particular pattern of lipid disturbances so that standard methods to evaluate cardiovascular risk may not be accurate enough. In general, antirheumatic drugs positively affect lipid metabolism in these patients.

Disease-modifying anti-rheumatic drugs improve the cardiovascular profile in patients with rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease affecting about 0. 5–1% of the adult population and manifesting as persistent synovitis, systemic inflammation and production of autoantibodies. Patients affected by RA not only experience chronic disease progression, but are also burdened by a 1.5-fold increased cardiovascular (CV) risk, which is comparable to the risk experienced by patients with type 2 diabetes mellitus. RA patients also have a higher incidence and prevalence of coronary artery disease (CAD). Although RA patients frequently present traditional CV risk factors such as insulin resistance and active smoking, previous studies have clarified the pivotal role of chronic inflammation–driven by proinflammatory cytokines such as interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-alpha)–in accelerating the process of atherosclerosis and impairing the coagulation system. Over the last years, a number of studies have shown that disease-modifying anti-rheumatic drugs (DMARDs) reducing the inflammatory state in general improve the CV risk, however some drugs may carry some apparent negative effects. Thus, RA is a model of disease in which targeting inflammation may counteract the progression of atherosclerosis and reduce CV risk. Clinical and experimental evidence indicates that the management of RA patients should be tailored based on the positive and negative effects of DMARDs on CV risk together with the individual traditional CV risk profile. The identification of genetic, biochemical and clinical biomarkers, predictive of evolution and response to treatment, will be the next challenge for a precision approach to reduce the burden of the disease.

Rheumatoid factor IgM autoantibodies control IgG homeostasis

Rheumatoid arthritis is an autoimmune disease characterized by joint inflammation due to autoantibodies targeting multiple self-proteins. Most patients with poor prognosis show elevated titers of IgM antibodies specifically binding to IgG. Such autoreactive antibodies are referred to as rheumatoid factor (RF). However, their biological function and contribution to disease progression remains elusive. We have recently shown that autoreactive antibodies are present in healthy individuals and play an important role in regulating physiological processes. This regulatory mechanism is determined by the class and affinity of the autoreactive antibody, as low-affinity autoreactive IgM neutralizes the recognized autoantigen while high-affinity IgM protects its autoantigen from degradation. Here, we show that RFs possessing a high affinity and mono-specificity to IgG have a stabilizing effect on IgG, whereas low-affinity polyreactive RFs neutralize IgG in vivo. These results suggest that autoreactive IgM antibodies recognizing IgG play a crucial role in regulating IgG homeostasis and that a disbalance between IgM-mediated IgG degradation and stabilization might affect the onset and progression of autoimmune diseases. Consequently, restoring this balance using low-affinity anti-IgG IgM might be a promising therapeutic approach for autoimmune diseases involving autoreactive IgG.

Patients with seronegative rheumatoid arthritis have a different phenotype than seropositive patients: A clinical and ultrasound study

Introduction

Rheumatoid arthritis (RA) is an inflammatory disease whose clinical phenotype largely depends on the presence of rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPA). Seronegative RA appears to be a less severe disease, but this remains controversial. This study aimed to assess whether seronegative patients show a less severe disease than seropositive patients.

Methods

A cross-sectional study was conducted on RA outpatients from a single center. Clinical activity scales, laboratory evaluations, and cardiovascular risk scores were assessed. Musculoskeletal ultrasound (US) examinations were performed.

Results

One hundred and fourteen patients were enrolled. Eighty-five were seropositive (76% women) and 29 seronegative (93% women). Seropositive patients had a younger age at disease onset (43 ± 14 vs. 54 ± 11; p = 0.001) and used sulfasalazine (47 vs. 17%; p = 0.004) and glucocorticoids (36 vs. 10%; p = 0.007) more frequently. No differences in clinical activity scales and in 10-year cardiovascular risk were observed. Pathological US data were found more frequently in seropositive patients in the 2^nd metacarpophalangeal (MCP) joint, both in grayscale (71 vs. 38%; p = 0.008) and in power Doppler (PD; 53 vs. 9%; p < 0.001); erosions (36 vs. 9%; p = 0.020) were also more frequent. We found greater severity of PD signals in the 2nd MCP and 3rd MCP joints of the seropositive patients, while synovitis severity was higher only in the 2nd MCP joints. The percentage of total joints with erosions (9 vs. 1%; p < 0.001) and 2nd MCP joints with erosions (25 vs. 7%; p < 0.001) was higher in seropositive patients.

Conclusion

RA patients show a differentiated phenotype according to their ACPA and RF status. In seronegative patients, RA begins later in life and has a lower requirement for antirheumatic therapies. On US evaluation, seropositive patients show more joint damage, especially in MCP joints. Despite this, long-term cardiovascular risk is similar among RA patients, regardless of their RF and ACPA status.

Cardiovascular Diseases and Periodontitis

Periodontitis is a chronic inflammatory disease of the tooth-supporting connective tissue and alveolar bone that is initiated by a bacterial biofilm in periodontal pockets. It affects about half of adults in the Western world, and is associated with a range of systemic comorbidities, e.g., cardiovascular disease (CVD), diabetes and rheumatoid arthritis, and these diseases share overlapping systemic and target tissue inflammatory mechanisms. Indeed, mounting evidence has indicated that their association is causal and built on the presence of systemic low-grade inflammation (LGI). Prior research linking periodontitis to CVD has mainly been derived from experimental studies, observational data, and small interventional trials with surrogate markers of CVD, e.g., endothelial dysfunction. However, recent data from randomised studies have demonstrated that intensive treatment of periodontitis can reduce blood pressure in patients with hypertension in conjunction with reduction of systemic inflammatory markers. Furthermore, targeted anti-inflammatory therapy has been shown to reduce recurrent events in patients with established CVD and LGI. Along this line, the concept of residual inflammatory risk has emerged as an independent new risk factor for atherothrombotic CVD. The present review summarizes translational evidence indicating that periodontitis is a risk factor for CVD dependent on LGI, and we conclude that treatment of periodontitis is likely to contribute importantly to reduction of residual inflammatory risk.

Role of protein deimination in cardiovascular diseases: potential new avenues for diagnostic and prognostic biomarkers

INTRODUCTION

Arginine deimination (citrullination) is a post-translational modification catalyzed by a family of peptidyl arginine deiminase (PAD) enzymes. Cell-based functional studies and animal models have manifested the key role of PADs in various cardiovascular diseases (CVDs).

AREA COVERED

This review summarizes the latest developments in the role of PADs in CVD pathogenesis. It focuses on the PAD functions and diverse citrullinated proteins in cardiovascular conditions like deep vein thrombosis, ischemia/reperfusion, and atherosclerosis. Identification of PAD isoforms and citrullinated targets are essential for directing diagnosis and clinical intervention. Finally, anti-citrullinated protein antibodies (ACPAs) are addressed as an independent risk factor for cardiovascular events. A search of PubMed biomedical literature from the past ten years was performed with a combination of the following keywords: PAD/PADI, deimination/citrullination, autoimmune, fibrosis, NET, neutrophil, macrophage, inflammation, inflammasome, cardiovascular, heart disease, myocardial infarction, ischemia, atherosclerosis, thrombosis, and aging. Additional papers from retrieved articles were also considered.

EXPERT OPINION

PADs are unique family of enzymes that converts peptidyl-arginine to -citrulline in protein permanently. Overexpression or increased activity of PAD has been observed in various CVDs with acute and chronic inflammation as the background. Importantly, far beyond being simply involved in forming neutrophil extracellular traps (NETs), accumulating evidence indicated PAD activation as a trigger for numerous processes, such as transcriptional regulation, endothelial dysfunction, and thrombus formation. In summary, the findings so far have testified the important role of deimination in cardiovascular biology, while more basic and translational studies are essential to further exploration.

Vascular calcium signalling and ageing

Changes in cellular Ca²⁺ levels have major influences on vascular function and blood pressure regulation. Vascular smooth muscle cells (SMCs) and endothelial cells (ECs) orchestrate vascular activity in distinct ways, often involving highly specific fluctuations in Ca²⁺ signalling. Ageing is a major risk factor for cardiovascular diseases, but the impact of ageing per se on vascular Ca²⁺ signalling has received insufficient attention. We reviewed the literature for age-related changes in Ca²⁺ signalling in relation to vascular structure and function. Vascular tone dysregulation in several vascular beds has been linked to abnormal expression or activity of SMC voltage-gated Ca²⁺ channels, Ca²⁺ -activated K⁺ channels or TRPC6 channels. Some of these effects were linked to altered caveolae density, microRNA expression or 20-HETE abundance. Intracellular store Ca²⁺ handling was suppressed in ageing mainly via reduced expression of intracellular Ca²⁺ release channels, and Ca²⁺ reuptake or efflux pumps. An increase in mitochondrial Ca²⁺ uptake, leading to oxidative stress, could also play a role in SMC hypercontractility and structural remodelling in ageing. In ECs, ageing entailed diverse effects on spontaneous and evoked Ca²⁺ transients, as well as structural changes at the EC-SMC interface. The concerted effects of altered Ca²⁺ signalling on myogenic tone, endothelium-dependent vasodilatation, and vascular structure are likely to contribute to blood pressure dysregulation and blood flow distribution deficits in critical organs. With the increase in the world's ageing population, future studies should be directed at solving specific ageing-induced Ca²⁺ signalling deficits to combat the imminent accelerated vascular ageing and increased risk of cardiovascular diseases.

Disease activity influences the reclassification of rheumatoid arthritis into very high cardiovascular risk

BACKGROUND

Previous studies have shown that risk chart algorithms, such as the Systematic Coronary Risk Assessment (SCORE), often underestimate the actual cardiovascular (CV) risk of patients with rheumatoid arthritis (RA). In contrast, carotid ultrasound was found to be useful to identify RA patients at high CV. In the present study, we aimed to determine if specific disease features influence the CV risk reclassification of RA patients assessed by SCORE risk charts and carotid ultrasound.

METHODS

1279 RA patients without previous CV events, diabetes, or chronic kidney disease were studied. Disease characteristics including disease activity scores, CV comorbidity, SCORE calculation, and the presence of carotid plaque by carotid ultrasound were assessed. A multivariable regression analysis was performed to evaluate if the reclassification into very high CV risk category was independently associated with specific features of the disease including disease activity. Additionally, a prediction model for reclassification was constructed in RA patients.

RESULTS

After carotid ultrasound assessments, 54% of the patients had carotid plaque and consequently fulfilled definition for very high CV risk. Disease activity was statistically significantly associated with reclassification after fully multivariable analysis. A predictive model containing the presence of dyslipidemia and hypertension, an age exceeding 54 years, and a DAS28-ESR score equal or higher than 2.6 yielded the highest discrimination for reclassification.

CONCLUSION

Reclassification into very high CV risk after carotid ultrasound assessment occurs in more than the half of patients with RA. This reclassification can be independently explained by the activity of the disease.

Biologics and atherosclerotic cardiovascular risk in rheumatoid arthritis: a review of evidence and mechanistic insights

Introduction: Cardiovascular disease is a leading comorbidity in rheumatoid arthritis. Timely introduction of biologic therapies in a treat-to-target approach has optimized disease-related outcomes and attenuated accrual of comorbidities, including cardiovascular risk.Areas covered: A literature search in MEDLINE (via PubMed) was performed between January 2009 and November 2020. This manuscript explores recent developments in atherosclerotic cardiovascular risk in RA compared with non-RA individuals; it synopsizes differences in vascular function and inflammation, prevalence, burden, vulnerability, and progression of atherosclerotic plaque and their underlying cellular and molecular mechanisms. Finally, it reviews the recent literature on cardioprotective benefits of biologics and draws mechanistic links with inhibition of new plaque formation, stabilization of high-risk lesions and improvement in endothelial function, arterial stiffness, lipid metabolism, and traditional cardiac risk factors.Expert opinion: Increasing evidence points to a solid cardioprotective influence of earlier, longer, and ongoing use of biologic treatments in RA. Nevertheless, the precise mechanistic effects of plaque progression and remodeling, vascular stiffness, endothelial dysfunction, lipid metabolism, and traditional cardiac risk factors are less rigorously characterized.

Left ventricular hypertrophy predicts poorer cardiovascular outcome in normotensive normoglycemic patients with rheumatoid arthritis

INTRODUCTION

Patients with rheumatoid arthritis (RA) develop early changes in left ventricular (LV) geometry and experience cardiovascular events in excess than in the general population. This study was designed to assess prevalence, predictors and prognostic role of LV hypertrophy (LVH) in a selected group of RA patients with normal blood pressure and glycemia who should be at low risk for LVH.

METHODS

We prospectively analyzed 241 normotensive normoglycemic RA patients (mean age 53 ± 12 years, 61% women) involved in a primary prevention program for cardiovascular diseases who were followed-up for 40 (24-56) months. LVH was detected by echocardiography and defined as LV mass ≥49.2 g/m^2.7 for men and ≥46.7 g/m^2.7 for women. Primary outcome was a composite of cardiovascular death/hospitalization.

RESULTS

LVH was detected in 39 patients (16%). Older age (>53 years), greater body mass index (BMI > 25 kg/m² ), longer duration of RA disease, anti-cyclic citrullinated peptide antibody (ACPA) positivity and concentric LV geometry were the variables associated with LVH. During the follow-up, a cardiovascular event occurred in 12 of 39 (31%) patients with LVH and in 22 of 202 (11%; P < .001) patients without LVH. LVH independently predicted cardiovascular events (hazards ratio 3.28 [95% CI 1.03-9.20], P = .03) at Cox regression analysis together with C-reactive protein and ACPA positivity.

CONCLUSIONS

Nearly one-sixth of normotensive normoglycemic RA patients analyzed in a primary prevention program for cardiovascular diseases has LVH which is associated with obesity and older age, and strongly predicts cardiovascular event in these subjects.

Citrullinated and homocitrullinated low- density lipoprotein in rheumatoid arthritis

Objective: Antibodies to citrullinated and homocitrullinated (also known as carbamylated) proteins, specific for rheumatoid arthritis (RA), are associated with cardiovascular disease (CVD). Immune complexes containing these proteins have been identified in the atherosclerotic plaque of CVD patients. In mice, homocitrullinated low-density lipoprotein (HomoCitLDL) promotes foam cell formation, which is critical in the pathogenesis of atherosclerosis. We aimed to investigate the atherogenic potential of HomoCitLDL and citrullinated low-density lipoprotein (CitLDL) in RA.Method: Human LDL was homocitrullinated in potassium cyanate and citrullinated by rabbit skeletal muscle peptidyl arginine deiminase-2. The modifications were confirmed by mass spectrometry. Primary human monoctyes from healthy subjects (N = 8) were differentiated to macrophages using macrophage colony-stimulating factor and incubated with modified LDL. Foam cells were visualized using Oil Red O staining. Serum from RA patients (N = 101) and controls (N = 32) was tested for immunoglobulin G antibodies to modified LDL using enzyme-linked immunosorbent assay.Results: HomoCitLDL and CitLDL strongly induced foam cell production (> 90%) versus unmodified LDL (11%) (p < 0.0001). The characteristics of the RA subjects were: 73% females, median age 60 [interquartile range (IQR) 17] years and disease duration 7.5 (IQR 13) years; 11% had a prior major cardiovascular event, 66% were ever smokers, 32% had hypertension, 33% dyslipidaemia, and 14% diabetes. Antibodies to HomoCitLDL were detected in 18% of RA patients; they were significantly associated with dyslipidaemia [odds ratio (OR) 3.86; 95% confidence interval (CI) 1.22, 12.17] and antibodies to other homocitrullinated antigens (OR 10.61; 95% CI 1.31, 86.11).Conclusions: HomoCitLDL and CitLDL have atherogenic properties in vitro. Antibody responses to HomoCitLDL, but not CitLDL, were detected in RA patients.

Cardiovascular Risk in Rheumatoid Arthritis and Mechanistic Links: From Pathophysiology to Treatment

Rheumatoid arthritis (RA) is an autoimmune inflammatory arthritis. Inflammation, however, can spread beyond the joints to involve other organs. During the past few years, it has been well recognized that RA associates with increased risk for cardiovascular (CV) disease (CVD) compared with the general population. This seems to be due not only to the increased occurrence in RA of classical CVD risk factors and comorbidities like smoking, obesity, hypertension, diabetes, metabolic syndrome, and others but also to the inflammatory burden that RA itself carries. This is not unexpected given the strong links between inflammation and atherosclerosis and CVD. It has been shown that inflammatory cytokines which are present in abundance in RA play a significant role in every step of plaque formation and rupture. Most of the therapeutic regimes used in RA treatment seem to offer significant benefits to that end. However, more studies are needed to clarify the effect of these drugs on various parameters, including the lipid profile. Of note, although pharmacological intervention significantly helps reduce the inflammatory burden and therefore the CVD risk, control of the so-called classical risk factors is equally important. Herein, we review the current evidence for the underlying pathogenic mechanisms linking inflammation with CVD in the context of RA and reflect on the possible impact of treatments used in RA.

Acute Coronary Syndrome in a Male with Elevated Anti-Cyclic Citrullinated Peptide and no Evidence of Longstanding Rheumatoid Arthritis

A 55-year-old male, previously known to be healthy, presented to the emergency department with a 30-minute history of chest pain radiating to the upper extremities. Vital signs were within normal limits. Four days prior to this presentation, the patient presented for acute onset of polyarthritis and morning stiffness. Significantly elevated titres of anti-cyclic citrullinated peptides (anti-CCP) were found. In the emergency department, electrocardiography showed ST segment elevations in leads V1 to V5 and aVL. Cardiac enzymes were elevated. The patient underwent cardiac catheterization. A coronary angiography revealed an ectatic proximal left anterior descending (LAD) coronary artery with critical (90–99%) stenosis at the mid segment. A drug-eluting stent was successfully inserted in the LAD without any residual stenosis. Although it is known that anti-CCP positivity is a key element in the pathogenesis of atherosclerosis in RA patients, this case report adds to the existing body of literature which demonstrates that anti-CCP positivity is an independent risk factor for development of cardiovascular events.

Efferocytic Defects in Early Atherosclerosis Are Driven by GATA2 Overexpression in Macrophages

The loss of efferocytosis-the phagocytic clearance of apoptotic cells-is an initiating event in atherosclerotic plaque formation. While the loss of macrophage efferocytosis is a prerequisite for advanced plaque formation, the transcriptional and cellular events in the pre-lesion site that drive these defects are poorly defined. Transcriptomic analysis of macrophages recovered from early-stage human atherosclerotic lesions identified a 50-fold increase in the expression of GATA2, a transcription factor whose expression is normally restricted to the hematopoietic compartment. GATA2 overexpression in vitro recapitulated many of the functional defects reported in patient macrophages, including deficits at multiple stages in the efferocytic process. These findings included defects in the uptake of apoptotic cells, efferosome maturation, and in phagolysosome function. These efferocytic defects were a product of GATA2-driven alterations in the expression of key regulatory proteins, including Src-family kinases, Rab7 and components of both the vacuolar ATPase and NADPH oxidase complexes. In summary, these data identify a mechanism by which efferocytic capacity is lost in the early stages of plaque formation, thus setting the stage for the accumulation of uncleared apoptotic cells that comprise the bulk of atherosclerotic plaques.

Atherosclerosis in Rheumatoid Arthritis: Promoters and Opponents

Substantial epidemiological data identified cardiovascular (CV) diseases as a main cause of mortality in patients with rheumatoid arthritis (RA). In light of this, RA patients may benefit from additional CV risk screening and more intensive prevention strategies. Nevertheless, current algorithms for CV risk stratification still remain tailored on general population and are burdened by a significant underestimation of CV risk in RA patients. Acute CV events in patients with RA are largely related to an accelerated atherosclerosis. As pathophysiological features of atherosclerosis overlap those occurring in the inflamed RA synovium, the understanding of those common pathways represents an urgent need and a leading challenge for CV prevention in patients with RA. Genetic background, metabolic status, gut microbiome, and systemic inflammation have been also suggested as additional key pro-atherosclerotic factors. The aim of this narrative review is to update the current knowledge about pathophysiology of atherogenesis in RA patients and potential anti-atherosclerotic effects of disease-modifying anti-rheumatic drugs.

Calcium-sensing receptor-mediated NLRP3 inflammasome response to calciprotein particles drives inflammation in rheumatoid arthritis

Increased extracellular Ca2+ concentrations ([Ca2+]ex) trigger activation of the NLRP3 inflammasome in monocytes through calcium-sensing receptor (CaSR). To prevent extraosseous calcification in vivo, the serum protein fetuin-A stabilizes calcium and phosphate into 70-100 nm-sized colloidal calciprotein particles (CPPs). Here we show that monocytes engulf CPPs via macropinocytosis, and this process is strictly dependent on CaSR signaling triggered by increases in [Ca2+]ex. Enhanced macropinocytosis of CPPs results in increased lysosomal activity, NLRP3 inflammasome activation, and IL-1β release. Monocytes in the context of rheumatoid arthritis (RA) exhibit increased CPP uptake and IL-1β release in response to CaSR signaling. CaSR expression in these monocytes and local [Ca2+] in afflicted joints are increased, probably contributing to this enhanced response. We propose that CaSR-mediated NLRP3 inflammasome activation contributes to inflammatory arthritis and systemic inflammation not only in RA, but possibly also in other inflammatory conditions. Inhibition of CaSR-mediated CPP uptake might be a therapeutic approach to treating RA.

Cardiovascular risk in persons at risk of developing rheumatoid arthritis

Background

Rheumatoid arthritis (RA) is associated with an increased cardiovascular disease (CVD) risk which may start even before diagnosis. To explore this CVD risk prior to RA, we determined multiple risk factors and two 10-year clinical risk scores in a cohort of individuals at-risk of RA. We also analyzed associations with arthritis development and autoantibody status and compared a subset of at-risk individuals to an age and sex matched seronegative control group.

Methods

In a cohort of 555 consecutive arthralgia patients positive for rheumatoid factor (RF) and / or anti-citrullinated protein antibody (ACPA) we retrospectively identified patients with preclinical arthritis (i.e. those who developed arthritis), and non-arthritis patients (those without arthritis development during maximum 5 years follow up). Demographics, CVD risk factors and the 10-year cardiovascular risk according to the SCORE and QRISK3 system were determined at baseline.

Results

Preclinical arthritis patients (n = 188) had a higher heart rate (68 vs 63 bpm, p = 0.048) and lower cholesterol (5.2 mmol/l vs 5.5, p = 0.006), HDL (1.0 mmol/l vs 1.1, p0.003) and ApoB (0.85 g/l vs 0.91, p = 0.011) compared to non-arthritis patients (n = 367). Lipid levels were associated with ACPA status in both the preclinical arthritis and non-arthritis group. Ten-year CVD risk scores did not differ between preclinical arthritis and non-arthritis patients, in total, 7% (SCORE) and 8% (QRISK3) of seropositive arthralgia patients were classified as high risk. Seropositive at-risk patients (n = 71) had higher total cholesterol (5.4 vs 4.9, p<0.001), TC/HDL ratio (4.0 vs 3.0, p<0.001), triglycerides (1.4 vs 1.0, p = 0.001), ApoB (1.0 vs 0.9, p = 0.019) and 10-year risk scores (median SCORE 1.0 vs 0.0, p = 0.030 and median QRISK3 4.4 vs 3.1, p<0.001) compared to seronegative controls.

Conclusion

Our results suggest that lipid changes commence prior to RA diagnosis and that ACPAs might play a role.

Subclinical and clinical atherosclerosis in rheumatoid arthritis: results from the 3-year, multicentre, prospective, observational GIRRCS (Gruppo Italiano di Ricerca in Reumatologia Clinica e Sperimentale) study

Background

Rheumatoid arthritis (RA) is associated with an increased risk of morbidity and mortality, when compared with general population, largely due to enhanced atherosclerotic disease. In this work, we aimed at assessing both occurrence and predictive factors of subclinical and clinical atherosclerosis in RA.

Methods

From January 1, 2015, to December 31, 2015, consecutive participants with RA, admitted to Italian Rheumatology Units, were assessed in the GIRRCS (Gruppo Italiano di Ricerca in Reumatologia Clinica e Sperimentale) cohort. After that, those participants were followed up in a 3-year, prospective, observational study, assessing the occurrence of subclinical and clinical atherosclerosis and possible predictive factors. McNemar test was employed to assess the changes in subclinical and clinical atherosclerosis, and regression analyses exploited the ORs for the occurrence of those comorbidities.

Results

We analysed 841 participants, mostly female (82.2%) and with median age of 60 years (range 21–90). The remission was achieved and maintained by 41.8% of participants during the follow-up. We observed an increased rate of subclinical atherosclerosis at the end of follow-up (139 vs 203 participants, p < 0.0001), particularly in participants with a disease duration less than 5 years at baseline (70 participants vs 133 participants, p < 0.0001). Type 2 diabetes (T2D) (OR 4.50, 95%CI 1.74–11.62, p = 0.002), high blood pressure (OR 2.03, 95%CI 1.04–4.14, p = 0.042), ACPA (OR 2.36, 95%CI 1.19–4.69, p = 0.014) and mean values of CRP during the follow-up (OR 1.07, 95%CI 1.03–1.14, p = 0.040) were significantly associated with higher risk of subclinical atherosclerosis. We observed an increased rate of clinical atherosclerosis at the end of follow-up (48 vs 76 participants, p < 0.0001). T2D (OR 6.21, 95%CI 2.19–17.71, p = 0.001) was associated with a significant risk of clinical atherosclerosis. The achievement and the maintenance of remission reduced the risk of subclinical (OR 0.25, 95%CI 0.11–0.56, p = 0.001) and clinical atherosclerosis (OR 0.20, 95%CI 0.09–0.95, p = 0.041).

Conclusions

We reported an increased prevalence and incidence of both subclinical and clinical atherosclerosis in 3-year prospectively followed participants, mainly in the subset with a duration of disease less than 5 years. The achievement and the maintenance of remission are associated with a reduction of the risk of subclinical and clinical atherosclerosis. Among “traditional” cardiovascular risk factors, participants with T2D showed a higher risk of clinical and subclinical atherosclerosis.

Electronic supplementary material

The online version of this article (10.1186/s13075-019-1975-y) contains supplementary material, which is available to authorized users.

Degenerative protein modifications in the aging vasculature and central nervous system: A problem shared is not always halved

Aging influences the pathogenesis and progression of several major diseases affecting both the cardiovascular system (CVS) and central nervous system (CNS). Defining the common molecular features that underpin these disorders in these crucial body systems will likely lead to increased quality of life and improved 'health-span' in the global aging population. Degenerative protein modifications (DPMs) have been strongly implicated in the molecular pathogenesis of several age-related diseases affecting the CVS and CNS, including atherosclerosis, heart disease, dementia syndromes, and stroke. However, these isolated findings have yet to be integrated into a wider framework, which considers the possibility that, despite their distinct features, CVS and CNS disorders may in fact be closely related phenomena. In this work, we review the current literature describing molecular roles of the major age-associated DPMs thought to significantly impact on human health, including carbamylation, citrullination and deamidation. In particular, we focus on data indicating that specific DPMs are shared between multiple age-related diseases in both CVS and CNS settings. By contextualizing these data, we aim to assist future studies in defining the universal mechanisms that underpin both vascular and neurological manifestations of age-related protein degeneration.

Common mechanisms and holistic care in atherosclerosis and osteoporosis

Cardiovascular (CV) disease and osteoporosis (OP) have become increasing challenges in the aging population and even more in patients with inflammatory rheumatic diseases, such as rheumatoid arthritis, spondyloarthropathies, and systemic lupus erythematosus. In this review, we discuss how the epidemiology and pathogenesis of CV events and OP are overlapping. Smoking, diabetes mellitus, physical inactivity as conventional risk factors as well as systemic inflammation are among the modifiable risk factors for both CV events and bone loss. In rheumatic patients, systemic “high-grade” inflammation may be the primary driver of accelerated atherogenesis and bone resorption. In the general population, in which some individuals might have low-grade systemic inflammation, a holistic approach to drug treatment and lifestyle modifications may have beneficial effects on the bone as well as the vasculature. In rheumatic patients with accelerated inflammatory atherosclerosis and bone loss, the rapid and effective suppression of inflammation in a treat-to-target regime, aiming at clinical remission, is necessary to effectively control comorbidities.

The Clinical Value of Autoantibodies in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a highly heterogeneous syndrome in terms of clinical presentation, progression, and response to therapy. In such a complicated context, the identification of disease-related biomarkers would be undoubtedly helpful in assisting tailored approaches for every patient. Despite remarkable efforts, however, progress in new biomarker development and validation is dramatically slow. At present, none of the candidate genetic, cellular, or molecular biomarker has yet surpassed the clinical value of RA-specific autoantibodies, including rheumatoid factor (RF) and anti-citrullinated protein autoantibodies (ACPA). Rather, recent years have witnessed significant advancements in our understanding of the multiple roles that RF and ACPA play in RA pathophysiology. This has helped clarifying the mechanistic basis of the clinical associations of autoantibodies in RA. In this short review, we will briefly summarize the effector functions of RF and ACPA, and analyse how autoantibodies may help subclassifying RA patients in terms of clinical presentation and response to therapy.

Citrullination as a plausible link to periodontitis, rheumatoid arthritis, atherosclerosis and Alzheimer's disease

Periodontitis, rheumatoid arthritis (RA), atherosclerosis (AS), and Alzheimer’s disease (AD) are examples of complex human diseases with chronic inflammatory components in their etiologies. The initial trigger of inflammation that progresses to these diseases remains unresolved. Porphyromonas gingivalis is unique in its ability to secrete the P. gingivalis-derived peptidyl arginine deiminase (PPAD) and consequently offers a plausible and exclusive link to these diseases through enzymatic conversion of arginine to citrulline. Citrullination is a post-translational enzymatic modification of arginine residues in proteins formed as part of normal physiological processes. However, PPAD has the potential to modify self (bacterial) and host proteins by deimination of arginine amino acid residues, preferentially at the C-terminus. Migration of P. gingivalis and/or its secreted PPAD into the bloodstream opens up the possibility that this enzyme will citrullinate proteins at disparate body sites. Citrullination is associated with the pathogenesis of multifactorial diseases such as RA and AD, which have an elusive external perpetrator as they show epidemiological associations with periodontitis. Therefore, PPAD deserves some prominence as an external antigen, in at least, a subset of RA and AD cases, with as yet unidentified, immune/genetic vulnerabilities.

Increased cardiovascular risk in rheumatoid arthritis: mechanisms and implications

Rheumatoid arthritis is a systemic autoimmune disease characterized by excess morbidity and mortality from cardiovascular disease. Mechanisms linking rheumatoid arthritis and cardiovascular disease include shared inflammatory mediators, post-translational modifications of peptides/proteins and subsequent immune responses, alterations in the composition and function of lipoproteins, increased oxidative stress, and endothelial dysfunction. Despite a growing understanding of these mechanisms and their complex interplay with conventional cardiovascular risk factors, optimal approaches of risk stratification, prevention, and treatment in the context of rheumatoid arthritis remain unknown. A multifaceted approach to reduce the burden posed by cardiovascular disease requires optimal management of traditional risk factors in addition to those intrinsic to rheumatoid arthritis such as increased disease activity. Treatments for rheumatoid arthritis seem to exert differential effects on cardiovascular risk as well as the mechanisms linking these conditions. More research is needed to establish whether preferential rheumatoid arthritis therapies exist in terms of prevention of cardiovascular disease. Ultimately, understanding the unique mechanisms for cardiovascular disease in rheumatoid arthritis will aid in risk stratification and the identification of novel targets for meaningful reduction of cardiovascular risk in this patient population.

Anti-High-Density Lipoprotein Antibodies and Antioxidant Dysfunction in Immune-Driven Diseases

Introduction

Impaired high-density lipoprotein (HDL) levels and antioxidant functionality of HDL, mainly attributed to a decreased paraoxonase-1 (PON1) functionality, have been described in autoimmune conditions. In this setting, a role for humoral response in cardiovascular disease is emerging. This study evaluates the role of immunoglobulin G (IgG) antibodies against HDL and disease-related autoantibodies on HDL dysfunction in immune-driven diseases.

Methods

Serum IgG anti-HDL antibodies, PON1 activity, and total antioxidant capacity (TAC) were quantified in 381 patients with different immune-driven diseases [18 mixed connective tissue disease (MCTD), 35 primary Sjögren syndrome (pSS), 38 systemic sclerosis (SSc), 33 ANCA-associated vasculitis (AAV), 60 diabetes mellitus 1, 29 autoimmune B12 deficiency/pernicious anemia, 29 primary biliary cirrhosis, 46 IBD/Crohn, 54 IBD/UC, and 39 celiac disease (CD)] and 138 healthy controls.

Results

IgG anti-HDL antibodies were increased in MCTD, pSS, AAV, and inflammatory bowel disease (IBD) [Crohn and ulcerative colitis (UC)], even after correcting for total IgG levels, but not in organ-specific autoimmune diseases. Anti-HDL antibodies were negatively associated with PON1 activity in MCTD (r = −0.767, p < 0.001) and AAV (r = −0.478, p = 0.005), whereas both anti-HDL and anti-neutrophil cytoplasm antibod levels were related to an impaired PON1 activity and TAC in IBD/UC. In SSc, anti-centromere antibodies correlated PON1 activity. anti-Saccharomyces cerevisiae antibodies levels were negatively associated with PON1 activity (r = −0.257, p = 0.012) and PON1/TAC ratio (r = −0.261, p = 0.009) in IBD/Crohn. HDL dysfunction in CD was only related to anti-transglutaminase levels.

Conclusion

IgG anti-HDL antibodies and HDL dysfunction are common hallmarks of systemic autoimmunity. Anti-HDL and disease-related autoantibodies account for the HDL antioxidant dysfunction in immune-driven conditions, mainly in systemic autoimmune disorders.

Is ACPA positivity the main driver for rheumatoid arthritis treatment? Pros and cons

Rheumatoid Arthritis (RA) is an autoimmune chronic disease that is characterized by the positivity of various antibodies, the most specific being autoantibodies against citrullinated antigens (ACPA). Despite ACPA are not arthritogenic by themselves, ACPA positive individuals have high risk of RA development and ACPA positivity is associated with severe erosive phenotype and higher mortality rate compared to seronegative RA. Moreover, ACPA status is associated with favorable response to biologics targeting pathways involving autoantibody producing cells as B lymphocytes. In the current review we have discussed the pros and cons on the available scientific evidences, regarding the diagnostic, prognostic and management implications of ACPAs in RA.

[Long-term glucocorticoid therapy : Is there a safe dosage?]

Glucocorticoids have been successfully used for a long time to treat a wide range of chronic inflammatory diseases. Despite the well-accepted efficacy, possible adverse effects still provoke discussions among patients and physicians. In particular, the long-term use of glucocorticoids at higher dosages may cause unwanted adverse effects; therefore, the question arises if conditions for a safe long-term treatment regimen with these drugs can be defined. Studies specifically and comprehensively addressing this question are missing; therefore, a multidisciplinary task force comprised of medical experts and patients was formed to analyze and discuss the existing literature in order to identify conditions where long-term glucocorticoid treatment has an acceptably low level of harm. The group agreed that the actual level of harm of long-term glucocorticoid therapy depends on both drug (dose and duration) and patient-specific characteristics. The patient-specific parameters (some of which can be modified by patients and/or physicians) should always be monitored before and during treatment with glucocorticoids and optimized if necessary. A positive benefit-risk ratio can be achieved when current knowledge and existing recommendations are kept in mind and implemented in clinical practice.

Practical Management of Cardiovascular Comorbidities in Rheumatoid Arthritis

Cardiovascular (CV) comorbidities are a frequent extra-articular manifestation of rheumatoid arthritis (RA). Cardiovascular disease (CVD) with accelerated atherosclerosis is a major cause of morbidity and mortality in patients with RA. Subclinical CVD may be present since the early phase of RA. Not only traditional but also non-traditional CV risk factors are involved in the pathogenesis of RA-related CVD. Due to the lack of specifically designed randomized clinical trials, it is still unclear which tools to use to perform CV risk assessment, how to interpret the results and which interventions are appropriate in RA patients both to prevent and to manage CVD. Based on the available evidence, we propose a practical approach.

Anticyclic Citrullinated Peptide Antibodies and Rheumatoid Factor as Risk Factors for 10-year Cardiovascular Morbidity in Patients with Rheumatoid Arthritis: A Large Inception Cohort Study

Objective.

To determine whether anticyclic citrullinated peptide antibodies (anti-CCP) and rheumatoid factor (RF) are risk factors for 10-year cardiovascular disease (CVD) in patients with rheumatoid arthritis (RA).

Methods.

Analyses were performed using data from the Nijmegen early RA inception cohort, in which patients with newly diagnosed RA, consecutively included since 1985, were regularly followed up. Anti-CCP and RF were determined at baseline (diagnosis). Outcome was the first cardiovascular disease (CVD) event [ischemic heart disease, nonhemorrhagic cerebrovascular accident (CVA), or peripheral artery disease (PAD)] after baseline as retrieved from physician diagnosis. Fatality was checked against death certificates. Cox regression including correction for baseline confounders was performed to estimate the effect of anti-CCP, RF, and their interaction on 10-year CVD-free survival.

Results.

Of 929 patients included, 628 were anti-CCP–positive and 697 were RF-positive. During followup, with a median of 7.5 years, 162 CV events were observed (101 ischemic heart disease, 45 CVA, and 16 PAD), of which 15 were fatal. The HRadjusted for anti-CCP was 1.17 (95% CI 0.82–1.67) and the HRadjusted for RF was 1.52 (95% CI 1.00–2.30). The association of RF positivity with CVD was even stronger in the anti-CCP–negative patients: HRadjusted 2.09 (95% CI 1.18–3.71). There was no significant interaction (p = 0.098) between anti-CCP and RF.

Conclusion.

Rather than anti-CCP, presence of RF was associated with CVD in this cohort of patients with RA.

Association between antibodies to carbamylated proteins and subclinical atherosclerosis in rheumatoid arthritis patients

BACKGROUND

Rheumatoid arthritis (RA) patients carry a high risk of cardiovascular morbidity and mortality. The excess of cardiovascular disease cannot be entirely explained by traditional risk factors and the immune system contributes to the development of atherosclerosis. Moreover, post-translational modifications such as citrullination and carbamylation have been linked to inflammation and atherosclerosis. Anti-carbamylated proteins antibodies (anti-CarP) are a new subset of autoantibodies identified in RA patients. This study aimed to investigate a possible association between anti-CarP and subclinical atherosclerosis in RA patients.

METHODS

We enrolled RA patients and normal healthy controls (NHS) without known cardiovascular risk factors or heart disease. Cardiovascular risk was assessed using the Modified Systemic Coronary Risk Evaluation (mSCORE). Anti-CarP were investigated by a solid phase "home-made" ELISA. Anti-citrullinated protein antibodies (ACPA) and Rheumatoid Factor (RF) were investigated by ELISA assays. Subclinical atherosclerosis was evaluated by brachial artery Flow-Mediated Dilatation (FMD) and Carotid Intima-Media Thickness (c-IMT) while arterial stiffness by Ankle-Brachial Index (ABI) and Cardio-Ankle Vascular Index (CAVI).

RESULTS

We enrolled 50 RA patients (34 F and 16 M, mean age 58.4 ± 13.1 years, mean disease duration 127 ± 96.7 months) and 30 age and sex matched NHS. According to the mSCORE, 58% of patients had a low risk, 32% a moderate and 8% a high risk for cardiovascular disease. FMD was significantly lower in RA patients than in NHS (5.6 ± 3.2 vs 10.7 ± 8.1%; p < 0.004) and CAVIs significantly higher in a RA patients compared to NHS (left CAVI 8.9 ± 1.7 vs 8.1 ± 1.5; p < 0.04 for and right CAVI 8.8 ± 1.6 vs 8.0 ± 1.4; p < 0.04 for the). ABI and c-IMT did not differ between the two populations. The multivariate regression analysis showed a significant association of anti-CarP antibodies with FMD, left and right CAVI and both c-IMT (r = 1.6 and p = 0.05; r = 1.7 and p = 0.04; r = 2.9 and p = 0.05; r = 1.5 and p = 0.03; r = 1.1 and p = 0.03 respectively).

CONCLUSIONS

This study confirms that RA patients, without evidence of cardiovascular disease or traditional risk factors, have an impaired endothelial function. Moreover, we found an association with anti-CarP antibodies suggesting a possible contribution of these autoantibodies to endothelial dysfunction, the earliest stage of atherosclerosis. Besides ultrasound assessment, anti-CarP should be assessed in RA patients and considered an additional cardiovascular risk factor.

Post-translational modifications in rheumatoid arthritis and atherosclerosis: Focus on citrullination and carbamylation

Coronary heart disease is the main cause of mortality in patients with rheumatoid arthritis (RA), a disease known to be associated with accelerated atherosclerosis. The role of inflammation and immunity in atherosclerotic process offers possible explanations for the increased cardiovascular risk in patients with RA. The immune response to citrullinated peptides has been extensively studied in RA; antibodies directed to citrullinated peptides are now a cornerstone for RA diagnosis. However, few studies have investigated the response to citrullinated peptides and the development of atherosclerotic plaque. Antibodies to carbamylated proteins can be detected before the clinical onset of RA, suggesting a potential predictive role for these antibodies; on the other hand, carbamylation of lipoproteins has been described in patients with cardiovascular disease. This review examines the role of citrullination and carbamylation, two post-translational protein modifications that appear to be involved in the pathogenesis of both RA and atherosclerosis, expanding the similarities between these two diseases. Further investigation on the role of the immune response to modified proteins may contribute to a better comprehension of cardiovascular disease in patients with RA.

Defining conditions where long-term glucocorticoid treatment has an acceptably low level of harm to facilitate implementation of existing recommendations: viewpoints from an EULAR task force

There is convincing evidence for the known and unambiguously accepted beneficial effects of glucocorticoids at low dosages. However, the implementation of existing recommendations and guidelines on the management of glucocorticoid therapy in rheumatic diseases is lagging behind. As a first step to improve implementation, we aimed at defining conditions under which long-term glucocorticoid therapy may have an acceptably low level of harm. A multidisciplinary European League Against Rheumatism task force group of experts including patients with rheumatic diseases was assembled. After a systematic literature search, breakout groups critically reviewed the evidence on the four most worrisome adverse effects of glucocorticoid therapy (osteoporosis, hyperglycaemia/diabetes mellitus, cardiovascular diseases and infections) and presented their results to the other group members following a structured questionnaire for final discussion and consensus finding. Robust evidence on the risk of harm of long-term glucocorticoid therapy was often lacking since relevant study results were often either missing, contradictory or carried a high risk of bias. The group agreed that the risk of harm is low for the majority of patients at long-term dosages of ≤5 mg prednisone equivalent per day, whereas at dosages of >10 mg/day the risk of harm is elevated. At dosages between >5 and ≤10 mg/day, patient-specific characteristics (protective and risk factors) determine the risk of harm. The level of harm of glucocorticoids depends on both dose and patient-specific parameters. General and glucocorticoid-associated risk factors and protective factors such as a healthy lifestyle should be taken into account when evaluating the actual and future risk.

Anticitrullinated protein antibodies and rheumatoid factor are associated with increased mortality but with different causes of death in patients with rheumatoid arthritis: a longitudinal study in three European cohorts

OBJECTIVE

Patients with rheumatoid arthritis (RA)-related autoantibodies have an increased mortality rate. Different autoantibodies are frequently co-occurring and it is unclear which autoantibodies associate with increased mortality. In addition, association with different causes of death is thus far unexplored. Both questions were addressed in three early RA populations.

METHODS

2331 patients with early RA included in Better Anti-Rheumatic Farmaco-Therapy cohort (BARFOT) (n=805), Norfolk Arthritis Register (NOAR) (n=678) and Leiden Early Arthritis Clinic cohort (EAC) (n=848) were studied. The presence of anticitrullinated protein antibodies (ACPA), rheumatoid factor (RF) and anticarbamylated protein (anti-CarP) antibodies was studied in relation to all-cause and cause-specific mortality, obtained from national death registers. Cox proportional hazards regression models (adjusted for age, sex, smoking and inclusion year) were constructed per cohort; data were combined in inverse-weighted meta-analyses.

RESULTS

During 26 300 person-years of observation, 29% of BARFOT patients, 30% of NOAR and 18% of EAC patients died, corresponding to mortality rates of 24.9, 21.0 and 20.8 per 1000 person-years. The HR for all-cause mortality (95% CI) was 1.48 (1.22 to 1.79) for ACPA, 1.47 (1.22 to 1.78) for RF and 1.33 (1.11 to 1.60) for anti-CarP. When including all three antibodies in one model, RF was associated with all-cause mortality independent of other autoantibodies, HR 1.30 (1.04 to 1.63). When subsequently stratifying for death cause, ACPA positivity associated with increased cardiovascular death, HR 1.52 (1.04 to 2.21), and RF with increased neoplasm-related death, HR 1.64 (1.02 to 2.62), and respiratory disease-related death, HR 1.71 (1.01 to 2.88).

CONCLUSIONS

The presence of RF in patients with RA associates with an increased overall mortality rate. Cause-specific mortality rates differed between autoantibodies: ACPA associates with increased cardiovascular death and RF with death related to neoplasm and respiratory disease.

Anti-citrullinated protein antibodies contribute to platelet activation in rheumatoid arthritis

Introduction

Although the role of platelets in rheumatoid arthritis (RA) is relatively unexplored, recent studies point towards a contribution of platelets in arthritis. We set out to determine platelet phenotype in RA and studied whether this could be influenced by the presence of anti-citrullinated protein antibodies (ACPA).

Methods

Platelets from healthy controls were incubated in the presence of plasma of patients with RA or age- and sex-matched healthy controls and plasma from ACPA^neg or ACPA^pos patients or in the presence of plate-bound ACPA. Characteristics of platelets isolated from patients with RA were correlated to disease activity.

Results

Platelets isolated from healthy controls displayed markers of platelet activation in the presence of plasma derived from RA patients, as determined by P-selectin expression, formation of aggregates and secretion of soluble CD40 ligand (sCD40L). Furthermore, levels of P-selectin expression and sCD40L release correlated with high ACPA titres. In accordance with these findings, enhanced platelet activation was observed after incubation with ACPA^pos plasma versus ACPA^neg plasma. Pre-incubation of platelets with blocking antibodies directed against low-affinity immunoglobulin G receptor (FcγRIIa) completely inhibited the ACPA-mediated activation. In addition, expression of P-selectin measured as number of platelets correlated with Disease Activity Score in 44 joints, C-reactive protein level, ACPA status and ACPA level.

Conclusions

We show for the first time that ACPA can mediate an FcγRIIa-dependent activation of platelets. As ACPA can be detected several years before RA disease onset and activated platelets contribute to vascular permeability, these data implicate a possible role for ACPA-mediated activation of platelets in arthritis onset.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0665-7) contains supplementary material, which is available to authorized users.

Atherosclerosis in rheumatoid arthritis: is it all about inflammation?

Rheumatoid arthritis (RA) has long been associated with increased cardiovascular risk, but despite substantial improvements in disease management, mortality remains high. Atherosclerosis is more prevalent in RA than in the general population, and atherosclerotic lesions progress at a faster rate and might be more prone to rupture, causing clinical events. Cells and cytokines implicated in RA pathogenesis are also involved in the development and progression of atherosclerosis, which is generally recognized as an inflammatory condition. The two diseases also share genetic and environmental risk factors, which suggests that patients who develop RA might also be predisposed to developing cardiovascular disease. In RA, inflammation and atherosclerosis are closely linked. Inflammation mediates its effects on atherosclerosis both through modulation of traditional risk factors and by directly affecting the vessel wall. Treatments such as TNF inhibitors might have a beneficial effect on cardiovascular risk. However, whether this benefit is attributable to effective control of inflammation or whether targeting specific cytokines, implicated in atherosclerosis, provides additional risk reduction is unclear. Further knowledge of the predictors of cardiovascular risk, the effects of early control of inflammation and of drug-specific effects are likely to improve the recognition and management of cardiovascular risk in patients with RA.

Is preclinical autoimmunity benign?: The case of cardiovascular disease

Although there are many examples of autoantibodies in disease-free individuals, they can be a preclinical phenomenon heralding future autoimmune rheumatic disease. They may be a marker for autoreactive B-cell activation and other inflammatory autoimmune processes. The increased prevalence of cardiovascular disease (CVD) in autoimmune rheumatic diseases such as rheumatoid arthritis and systemic lupus erythematosus, and the increased risk of CVD in patients with rheumatic disease with autoantibodies, suggest that CVD may have autoimmune features. Autoantibodies might be risk markers for subclinical and clinical CVD development not only in patients with rheumatic diseases but in the general population as well.

Prevalence of anti-citrullinated protein antibodies (ACPA) in patients with diffuse large B-cell lymphoma (DLBCL): a case-control study

Background

Antibodies against citrullinated proteins (ACPA) have been recognised as the most specific serum marker for rheumatoid arthritis. However, serum autoantibodies such as anti-nuclear antibodies have also been detected in the sera of different lymphatic malignancies without accompanying rheumatologic disease. Therefore, we conducted a study to evaluate the prevalence of ACPA in diffuse large B-cell non-Hodgkin lymphoma (DLBCL).

Methods

Sera of 395 DLBCL patients and 258 age-matched healthy controls were investigated to evaluate the prevalence of ACPA and RF. ACPA-positive data were stratified into subgroups of RF positivity and established prognostic parameters for DLBCL, including overall survival. In addition, the ACPA serum concentrations levels were compared to an ACPA-positive RA cohort (n = 175). The statistics were performed with χ2 test and Mann- Whitney-U test; Kaplan-Meyer curves (log rank test) were used to analyse the overall survival. P-value <0.05 was statistically significant.

Results

ACPA, but not RF, occurred significantly more frequently in the sera of DLBCL patients than in healthy controls (3.5% versus 0.8%, p = 0.030). However, the ACPA serum concentration levels were significantly lower than in RA patients (median 10.4 versus 124.1 U/ml, p = 0.0001). After subgroup stratification, ACPA positivity in DLBCL was significantly associated with male gender (4.4% versus 0%, p = 0.022; odds ratio 1.046, CI 1.014–1.079) and with RF-IgM seropositivity (1.77% versus 0%, p = 0.043), but not with prognostic parameters for DLBCL.

Conclusions

DLBCL is associated with a significantly higher prevalence of ACPA, with an increased prevalence in male patients, and simultaneous RF-IgM positivity. However, ACPA is not prognostic for DLBCL. The prevalence of RF-IgM, -IgA, or -IgG did not differ from healthy controls.