Association of anti-citrullinated protein or peptide antibodies with left ventricular structure and function in rheumatoid arthritis

Rheumatoid arthritis increases the risk of heart failure: results from the cross-sectional study in the US population and mendelian randomization analysis in the European population

Objective

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease. Among its various complications, heart failure (HF) has been recognized as the second leading cause of cardiovascular death in RA patients. The objective of this study was to investigate the relationship between RA and HF using epidemiological and genetic approaches.

Methods

The study included 37,736 participants from the 1999-2020 National Health and Nutrition Examination Survey. Associations between RA and HF in the US population were assessed with weighted multivariate logistic regression analysis. A two-sample Mendelian randomization (MR) analysis was employed to establish the causal relationship between the two variables. The primary analysis method utilized was inverse variance weighting (IVW). Additionally, horizontal pleiotropy and heterogeneity were assessed to account for potential confounding factors. In cases where multiple independent datasets were accessible during MR analysis, we combined the findings through a meta-analytical approach.

Results

In observational studies, the prevalence of HF in combination with RA reached 7.11% (95%CI 5.83 to 8.39). RA was positively associated with an increased prevalence of HF in the US population [odds ratio (OR):1.93, 95% confidence interval (CI):1.47-2.54, P < 0.0001]. In a MR analysis utilizing a meta-analytical approach to amalgamate the results of the IVW method, we identified a significant causal link between genetically predicted RA and a heightened risk of HF (OR = 1.083, 95% CI: 1.028-1.141; P = 0.003). However, this association was not deemed significant for seronegative RA (SRA) (OR = 1.028, 95% CI: 0.992-1.065; P = 0.126). These findings were consistent across sensitivity analyses and did not indicate any horizontal pleiotropy.

Conclusion

RA correlates with an elevated prevalence of HF within the US population. Furthermore, genetic evidence derived from European populations underscores a causal link between RA and the risk of HF. However this association was not significant in SRA.

Cardiovascular Disease in Rheumatoid Arthritis: Risk Factors, Autoantibodies, and the Effect of Antirheumatic Therapies

Objective:

To scope the current published evidence on cardiovascular risk factors in rheumatoid arthritis (RA) focusing on the role of autoantibodies and the effect of antirheumatic agents.

Methods:

Two reviews were conducted in parallel: A targeted literature review (TLR) describing the risk factors associated with cardiovascular disease (CVD) in RA patients; and a systematic literature review (SLR) identifying and characterizing the association between autoantibody status and CVD risk in RA. A narrative synthesis of the evidence was carried out.

Results:

A total of 69 publications (49 in the TLR and 20 in the SLR) were included in the qualitative evidence synthesis. The most prevalent topic related to CVD risks in RA was inflammation as a shared mechanism behind both RA morbidity and atherosclerotic processes. Published evidence indicated that most of RA patients already had significant CV pathologies at the time of diagnosis, suggesting subclinical CVD may be developing before patients become symptomatic. Four types of autoantibodies (rheumatoid factor, anti-citrullinated peptide antibodies, anti-phospholipid autoantibodies, anti-lipoprotein autoantibodies) showed increased risk of specific cardiovascular events, such as higher risk of cardiovascular death in rheumatoid factor positive patients and higher risk of thrombosis in anti-phospholipid autoantibody positive patients.

Conclusion:

Autoantibodies appear to increase CVD risk; however, the magnitude of the increase and the types of CVD outcomes affected are still unclear. Prospective studies with larger populations are required to further understand and quantify the association, including the causal pathway, between specific risk factors and CVD outcomes in RA patients.

NETosis as a Pathogenic Factor for Heart Failure

Heart failure threatens the lives of patients and reduces their quality of life. Heart failure, especially heart failure with preserved ejection fraction, is closely related to systemic and local cardiac persistent chronic low-grade aseptic inflammation, microvascular damage characterized by endothelial dysfunction, oxidative stress, myocardial remodeling, and fibrosis. However, the initiation and development of persistent chronic low-grade aseptic inflammation is unexplored. Oxidative stress-mediated neutrophil extracellular traps (NETs) are the main immune defense mechanism against external bacterial infections. Furthermore, NETs play important roles in noninfectious diseases. After the onset of myocardial infarction, atrial fibrillation, or myocarditis, neutrophils infiltrate the damaged tissue and aggravate inflammation. In tissue injury, damage-related molecular patterns (DAMPs) may induce pattern recognition receptors (PRRs) to cause NETs, but whether NETs are directly involved in the pathogenesis and development of heart failure and the mechanism is still unclear. In this review, we analyzed the markers of heart failure and heart failure-related diseases and comorbidities, such as mitochondrial DNA, high mobility box group box 1, fibronectin extra domain A, and galectin-3, to explore their role in inducing NETs and to investigate the mechanism of PRRs, such as Toll-like receptors, receptor for advanced glycation end products, cGAS-STING, and C-X-C motif chemokine receptor 2, in activating NETosis. Furthermore, we discussed oxidative stress, especially the possibility that imbalance of thiol redox and MPO-derived HOCl promotes the production of 2-chlorofatty acid and induces NETosis, and analyzed the possibility of NETs triggering coronary microvascular thrombosis. In some heart diseases, the deletion or blocking of neutrophil-specific myeloperoxidase and peptidylarginine deiminase 4 has shown effectiveness. According to the results of current pharmacological studies, MPO and PAD4 inhibitors are effective at least for myocardial infarction, atherosclerosis, and certain autoimmune diseases, whose deterioration can lead to heart failure. This is essential for understanding NETosis as a therapeutic factor of heart failure and the related new pathophysiology and therapeutics of heart failure.

Disease Activity and Anticitrullinated Peptide Antibody Positivity Predict the Worsening of Ventricular Function in Rheumatoid Arthritis

Objective

This prospective study was designed to analyze the incidence and the factors associated with impairment in left ventricular systolic function (LVSF) overtime in patients with rheumatoid arthritis (RA) without overt cardiac disease. In particular, we verified the hypothesis that a relationship between worsening of LVSF and markers of RA disease activity exists.

Methods

One hundred forty outpatients with RA without overt heart disease underwent clinical, laboratory, and echocardiographic evaluation at baseline and after 35 (interquartile range [IQR] 23‐47) months of follow‐up. A clinical Disease Activity Index (CDAI) score greater than 10 indicated the presence of moderate‐high RA disease activity; data on anticitrullinated peptide antibody (ACPA) positivity were recorded at baseline. Stress‐corrected midwall fractional shortening (sc‐MFS) was used as a measure of LVSF and was considered impaired if less than 86.5%.

Results

At 36 (IQR 23‐47) months follow‐up, impaired sc‐MFS was detected in 60 of 140 (43%) patients, compared with 80 patients with normal sc‐MFS. Disease duration and activity, ACPA positivity, inflammatory markers, cardiovascular and antirheumatic therapies, and sc‐MFS were similar between the two groups at baseline. A multiple logistic regression analysis showed ACPA positivity, moderate‐high disease activity (CDAI greater than 10), and disease duration as independent predictors of impaired sc‐MFS at follow‐up. Finally, a simple clinical score to predict worsening of LVSF at midterm was built (area under the curve of 0.80, with a sensibility and specificity of 78% and 82%, respectively).

Conclusion

Disease duration, ACPA positivity, and moderate‐high disease activity are independent prognosticators of LVSF impairment in RA. Adverse changes in heart function could be prevented by good control of inflammation and modulation of autoimmunity.

Autoimmunity and Inflammation Link to Cardiovascular Disease Risk in Rheumatoid Arthritis

Rheumatoid arthritis (RA) patients have a 50% increased risk of cardiovascular (CV)-related morbidity and mortality. This excess CV risk is closely linked to RA disease severity and chronic inflammation, hence is largely underestimated by traditional risk calculators such as the Framingham Risk Score. Epidemiological studies have shown that patients with RA are more likely to have silent ischemic heart disease, develop heart failure, and experience sudden death compared with controls. Elevations in pro-inflammatory cytokines, circulating autoantibodies, and specific T cell subsets, are believed to drive these findings by promoting atherosclerotic plaque formation and cardiac remodeling. Current European League Against Rheumatism (EULAR) guidelines state that rheumatologists are responsible for the assessment and coordination of CV disease (CVD) risk management in patients with RA, yet the optimal means to do so remain unclear. While these guidelines focus on disease activity control to mitigate excess CV risk, rather than providing a precise algorithm for choice of therapy, studies suggest a differential impact on CV risk of non-biologic disease-modifying anti-rheumatic drugs (DMARDs), biologic DMARDs, and small molecule-based therapy. In this review, we explore the mechanisms linking the pathophysiologic intrinsic features of RA with the increased CVD risk in this population, and the impact of different RA therapies on CV outcomes.

Precision Profiling of the Cardiovascular Post-Translationally Modified Proteome: Where There Is a Will, There Is a Way

There is an exponential increase in biological complexity as initial gene transcripts are spliced, translated into amino acid sequence, and post-translationally modified. Each protein can exist as multiple chemical or sequence-specific proteoforms, and each has the potential to be a critical mediator of a physiological or pathophysiological signaling cascade. Here, we provide an overview of how different proteoforms come about in biological systems and how they are most commonly measured using mass spectrometry-based proteomics and bioinformatics. Our goal is to present this information at a level accessible to every scientist interested in mass spectrometry and its application to proteome profiling. We will specifically discuss recent data linking various protein post-translational modifications to cardiovascular disease and conclude with a discussion for enablement and democratization of proteomics across the cardiovascular and scientific community. The aim is to inform and inspire the readership to explore a larger breadth of proteoform, particularity post-translational modifications, related to their particular areas of expertise in cardiovascular physiology.

Chronic Heart Failure in Rheumatoid Arthritis Patients (Part II): Difficulties of Diagnosis

Rheumatoid arthritis (RA) is characterized by a twofold increase in morbidity and mortality due to chronic heart failure (CHF). At the same time, the prevalence of CHF among RA patients is significantly underestimated. The aim of the review was to analyze the results of the main studies on the features of the clinical presentation of heart failure (HF) in RA patients, the role of visualization techniques and biomarkers in the diagnosis of HF and preclinical dysfunction of the myocardium. HF in patients with RA is characterized by a predominance of HF with a preserved left ventricular ejection fraction (LVEF). The use of clinical diagnostic criteria in RA patients can lead to both over- or underdiagnosis of CHF. Systolic dysfunction estimated by LVEF is rare in RA and does not reflect the real frequency of myocardial dysfunction. Echocardiography (ECHO-CG) with tissue Doppler echocardiography (TDE) and visualization of myocardial deformation, magnetic resonance imaging (MRI) of the heart in RA patients revealed a high frequency of HF with preserved ejection fraction, left ventricular remodeling and hypertrophy, pre-clinical systolic and diastolic dysfunction. Determination of natriuretic peptides is useful for verifying the diagnosis of HF and estimating the prognosis in this cohort, despite the possible decrease in the sensitivity and specificity of these indicators in RA patients. The review discusses the advantages of MRI of the heart, including quantitative T1 and T2 regimens, in the diagnosis of myocarditis, myocardial fibrosis, and myocardial perfusion disorders in RA patients. In order to verify the diagnosis of heart failure and detect pre-clinical myocardial dysfunction in RA patients, the determination of natriuretic peptides concentration should become part of the routine examination, beginning with the debut of the disease, along with the collection of a cardiological history, physical examination, ECHO-CT with TDE, and visualization of myocardial deformation. Evaluation of the quantitative characteristics of tissue according to MRI of the heart could improve the diagnosis of myocardial damage.

Progress on Identifying and Characterizing the Human Proteome: 2018 Metrics from the HUPO Human Proteome Project

The Human Proteome Project (HPP) annually reports on progress throughout the field in credibly identifying and characterizing the human protein parts list and making proteomics an integral part of multiomics studies in medicine and the life sciences. NeXtProt release 2018-01-17, the baseline for this sixth annual HPP special issue of the Journal of Proteome Research, contains 17 470 PE1 proteins, 89% of all neXtProt predicted PE1-4 proteins, up from 17 008 in release 2017-01-23 and 13 975 in release 2012-02-24. Conversely, the number of neXtProt PE2,3,4 missing proteins has been reduced from 2949 to 2579 to 2186 over the past two years. Of the PE1 proteins, 16 092 are based on mass spectrometry results, and 1378 on other kinds of protein studies, notably protein-protein interaction findings. PeptideAtlas has 15 798 canonical proteins, up 625 over the past year, including 269 from SUMOylation studies. The largest reason for missing proteins is low abundance. Meanwhile, the Human Protein Atlas has released its Cell Atlas, Pathology Atlas, and updated Tissue Atlas, and is applying recommendations from the International Working Group on Antibody Validation. Finally, there is progress using the quantitative multiplex organ-specific popular proteins targeted proteomics approach in various disease categories.

Potential Impact of Oral Inflammations on Cardiac Functions and Atrial Fibrillation

Inflammation may be a risk factor for atrial fibrillation (AF). Oral infections frequently lead to chronic inflammation, such as gingivitis, periodontitis, and endodontic lesions. In this narrative review, we consider five basic pathogenic mechanisms that involve oral infections and inflammations in the pathogenesis of AF: (1) low level bacteremia by which oral bacteria enter the blood stream at inflamed sites of the oral cavity and invade the heart; (2) Systemic inflammation induced by inflammatory mediators, which are released from the sites of oral inflammation into the blood stream, affecting cardiac remodeling; (3) autoimmunity against molecular structures expressed in the heart caused by the host immune response to specific components of oral pathogens; (4) potentially arrhythmic effects mediated by activation of the autonomous nervous system triggered by oral inflammations; and (5) arrhythmic effects resulting from specific bacterial toxins that are produced by oral pathogenic bacteria. A number of studies support the involvement of all five mechanisms, suggesting a potentially complex contribution of oral inflammations to the pathogenesis of AF.

Roles of Oral Infections in the Pathomechanism of Atherosclerosis

Oral infections occur frequently in humans and often lead to chronic inflammations affecting the teeth (i.e., caries), the gingival tissues surrounding the teeth (i.e., gingivitis and endodontic lesions), and the tooth-supporting structures (i.e., periodontitis). At least four basic pathogenic mechanisms have been proposed that involve oral inflammations in the pathogenesis of atherosclerosis: (1) low level bacteremia by which oral bacteria enter the blood stream and invade the arterial wall; (2) systemic inflammation induced by inflammatory mediators released from the sites of the oral inflammation into the blood stream; (3) autoimmunity to host proteins caused by the host immune response to specific components of oral pathogens; (4) pro-atherogenic effects resulting from specific bacterial toxins that are produced by oral pathogenic bacteria. In this narrative review, we summarize published experimental evidence related to these four mechanisms and discuss their impact on the pathogenesis of atherosclerosis.

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.