A systematic review and meta-analysis of circulating adhesion molecules in rheumatoid arthritis

BACKGROUND

The availability of robust biomarkers of endothelial activation might enhance the identification of subclinical atherosclerosis in rheumatoid arthritis (RA). We investigated this issue by conducting a systematic review and meta-analysis of cell adhesion molecules in RA patients.

METHODS

We searched electronic databases from inception to 31 July 2023 for case-control studies assessing the circulating concentrations of immunoglobulin-like adhesion molecules (vascular cell, VCAM-1, intercellular, ICAM-1, and platelet endothelial cell, PECAM-1, adhesion molecule-1) and selectins (E, L, and P selectin) in RA patients and healthy controls. Risk of bias and certainty of evidence were assessed using the JBI checklist and GRADE, respectively.

RESULTS

In 39 studies, compared to controls, RA patients had significantly higher concentrations of ICAM-1 (standard mean difference, SMD = 0.81, 95% CI 0.62-1.00, p < 0.001; I2 = 83.0%, p < 0.001), VCAM-1 (SMD = 1.17, 95% CI 0.73-1.61, p < 0.001; I2 = 95.8%, p < 0.001), PECAM-1 (SMD = 0.82, 95% CI 0.57-1.08, p < 0.001; I2 = 0.0%, p = 0.90), E-selectin (SMD = 0.64, 95% CI 0.42-0.86, p < 0.001; I2 = 75.0%, p < 0.001), and P-selectin (SMD = 1.06, 95% CI 0.50-1.60, p < 0.001; I2 = 84.8%, p < 0.001), but not L-selectin. In meta-regression and subgroup analysis, significant associations were observed between the effect size and use of glucocorticoids (ICAM-1), erythrocyte sedimentation rate (VCAM-1), study continent (VCAM-1, E-selectin, and P-selectin), and matrix assessed (P-selectin).

CONCLUSIONS

The results of our study support a significant role of cell adhesion molecules in mediating the interplay between RA and atherosclerosis. Further studies are warranted to determine whether the routine use of these biomarkers can facilitate the detection and management of early atherosclerosis in this patient group. PROSPERO Registration Number: CRD42023466662.

Humoral responses against HDL are linked to lipoprotein traits, atherosclerosis, inflammation and pathogenic pathways during early arthritis stages

OBJECTIVE

Chronic inflammation and immune dysregulation are crucial mechanisms for atherosclerosis in RA. Recent evidence suggests a link via humoral responses against high-density lipoproteins (HDL). This study aimed to characterize the specificity, clinical relevance and emergence of humoral responses against HDL along disease course, especially during the earliest phases of arthritis.

METHODS

IgG and IgM serum levels of antibodies against HDL (anti-HDL) and apolipoprotein A1 (anti-ApoA1) were measured in 82 early RA patients, 14 arthralgia individuals and 96 controls. Established RA patients (n = 42) were included for validation. Atherosclerosis and vascular stiffness were measured by Doppler ultrasound. Lipoprotein content, particle numbers and size were measured by H-NMR. Cytokines were measured by immunoassays. A cardiometabolic-related protein panel was evaluated using high-throughput targeted proteomics.

RESULTS

Anti-HDL and anti-ApoA1 responses were increased in early RA compared with controls (both P < 0.001) and were comparable to established disease. Only anti-ApoA1 antibodies were increased in arthralgia. IgG anti-HDL and anti-ApoA1 were associated with unfavourable lipoprotein traits in RA and arthralgia, respectively. A similar picture was observed for inflammatory mediators. No associations with clinical features or risk factors were found. IgG anti-HDL were independently associated with atherosclerosis occurrence in early RA, and outperformed patient stratification over conventional algorithms (mSCORE) and their anti-ApoA1 counterparts. Anti-HDL antibodies correlated with proteins involved in immune activation, remodelling and lipid metabolism pathways in early RA.

CONCLUSION

Humoral responses against HDL particles are an early event along the arthritis course, although quantitative and qualitative differences can be noticed among stages. These differences informed distinct capacities as biomarkers and underlying pathogenic circuits.

Diagnosis and management of cardiovascular risk in rheumatoid arthritis: main challenges and research agenda

INTRODUCTION

Rheumatoid arthritis (RA) exhibit a cardiovascular (CV) risk that is 1.5-2.0 times higher compared to the general population. This CV risk excess is likely caused by the involvement of chronic inflammation and immune dysregulation. Therefore, conventional algorithms and imaging techniques fail to fully account for this risk excess and provide a suboptimal risk stratification, hence limiting clinical management in this setting.

AREAS COVERED

Compelling evidence has suggested a role for adaptations of conventional algorithms (Framingham, SCORE, AHA, etc) or the development of RA-specific algorithms, as well as the use of a number of several, noninvasive imaging techniques to improve CV risk assessment in RA populations. Similarly, in-depth analyses of atherosclerosis pathogenesis in RA patients have shed new light into a plethora of soluble biomarkers (such as inflammatory cytokines, vascular remodeling mediators or autoantibodies) that may provide incremental value for CV risk stratification.

EXPERT OPINION

Extensive research has demonstrated a lack of performance of chart adaptations in capturing real CV risk in RA population, as well as for RA-specific algorithms. Similarly, limitations have been detected in the use of soluble mediators. The development of a novel, RA-specific algorithm including classical and non-traditional risk factors may be advisable.

Association of Circulating Vascular Endothelial Growth Factor Levels With Autoimmune Diseases: A Systematic Review and Meta-Analysis

Background

Autoimmune diseases (ADs) are characterized by immune-mediated tissue damage, in which angiogenesis is a prominent pathogenic mechanism. Vascular endothelial growth factor (VEGF), an angiogenesis modulator, is significantly elevated in several ADs including rheumatoid arthritis (RA), systemic sclerosis (SSc), and systemic lupus erythematosus (SLE). We determined whether circulating VEGF levels were associated with ADs based on pooled evidence.

Methods

The analyses included 165 studies from the PubMed, EMBASE, Cochrane Library, and Web of Science databases and fulfilled the study criteria. Comparisons of circulating VEGF levels between patients with ADs and healthy controls were performed by determining pooled standard mean differences (SMDs) with 95% confidence intervals (CIs) in a random-effect model using STATA 16.0. Subgroup, sensitivity, and meta-regression analyses were performed to determine heterogeneity and to test robustness.

Results

Compared with healthy subjects, circulating VEGF levels were significantly higher in patients with SLE (SMD 0.84, 95% CI 0.25-1.44, P = 0.0056), RA (SMD 1.48, 95% CI 0.82-2.15, P <0.0001), SSc (SMD 0.56, 95% CI 0.36-0.75, P <0.0001), Behcet's disease (SMD 1.65, 95% CI 0.88-2.41, P <0.0001), Kawasaki disease (SMD 2.41, 95% CI 0.10-4.72, P = 0.0406), ankylosing spondylitis (SMD 0.78, 95% CI 0.23-1.33, P = 0.0052), inflammatory bowel disease (SMD 0.57, 95% CI 0.43-0.71, P <0.0001), psoriasis (SMD 0.98, 95% CI 0.62-1.34, P <0.0001), and Graves' disease (SMD 0.69, 95% CI 0.20-1.19, P = 0.0056). Circulating VEGF levels correlated with disease activity and hematological parameters in ADs.

Conclusion

Circulating VEGF levels were associated with ADs and could predict disease manifestations, severity and activity in patients with ADs.

Systematic Review Registration

PROSPERO, identifier CRD42021227843.

The role of high-density lipoprotein cholesterol, apolipoprotein A and paraoxonase-1 in the pathophysiology of neuroprogressive disorders

Lowered high-density lipoprotein (HDL) cholesterol has been reported in major depressive disorder, bipolar disorder, first episode of psychosis, and schizophrenia. HDL, its major apolipoprotein component, ApoA1, and the antioxidant enzyme paraoxonase (PON)1 (which is normally bound to ApoA1) all have anti-atherogenic, antioxidant, anti-inflammatory, and immunomodulatory roles, which are discussed in this paper. The paper details the pathways mediating the anti-inflammatory effects of HDL, ApoA1 and PON1 and describes the mechanisms leading to compromised HDL and PON1 levels and function in an environment of chronic inflammation. The molecular mechanisms by which changes in HDL, ApoA1 and PON1 might contribute to the pathophysiology of the neuroprogressive disorders are explained. Moreover, the anti-inflammatory actions of ApoM-mediated sphingosine 1-phosphate (S1P) signalling are reviewed as well as the deleterious effects of chronic inflammation and oxidative stress on ApoM/S1P signalling. Finally, therapeutic interventions specifically aimed at improving the levels and function of HDL and PON1 while reducing levels of inflammation and oxidative stress are considered. These include the so-called Mediterranean diet, extra virgin olive oil, polyphenols, flavonoids, isoflavones, pomegranate juice, melatonin and the Mediterranean diet combined with the ketogenic diet.

Inhibitory role of long non-coding RNA OIP5-AS1 in rheumatoid arthritis progression through the microRNA-448-paraoxonase 1-toll-like receptor 3-nuclear factor κB axis

NEW FINDINGS

What is the central question of this study? What are the functions of long non-coding (lnc) RNA OIP5-AS1 in development of rheumatoid arthritis inflammation and what is the molecular mechanism? What is the main finding and its importance? LncRNA OIP5-AS1 mitigates rheumatoid arthritis progression through the competitive endogenous RNA network involving the miR-448-paraoxonase 1 axis and through the inactivation of the toll-like receptor 3-nuclear factor κB signalling pathway. This study may offer new ideas for molecularly based control of rheumatoid arthritis.

ABSTRACT

Rheumatoid arthritis (RA) is an autoimmune disorder with dysregulation of long non-coding RNAs (lncRNAs) possibly involved. This study aimed to inquire into the roles of lncRNA OIP5-AS1 in RA progression. A rat model of RA was induced. Overexpression of OIP5-AS1 was introduced in the model rats, and the changes in paw swelling, RA severity and the inflammatory factors interleukin (IL)-1β, IL-10, IL-6 and tumour necrosis factor α were measured. Fibroblast-like synoviocytes (FLSs) from RA patients were collected for in vitro experiments. A gain- and loss-of function study of OIP5-AS1, miR-448 and paraoxonase 1 (PON1) was performed to explore their roles in RA-FLS growth, apoptosis and inflammation. A toll-like receptor 3 (TLR3)-specific agonist, polyinosine-polycytidylic acid, or a nuclear factor κB (NF-κB)-specific antagonist, QNZ, was administrated in RA-FLSs. Consequently, overexpression of OIP5-AS1 reduced the symptom severity and the levels of inflammatory factors in RA rats. OIP5-AS1 could bind to miR-448 to up-regulate PON1 expression. Further overexpression of miR-448 reversed the effects of OIP5-AS1, while overexpression of PON1 inhibited RA-FLS growth and inflammation. In addition, TLR3 activation promoted RA progression. To conclude, this study evidenced that lncRNA OIP5-AS1 may mitigate RA progression through the miR-448-PON1 axis and through the inactivation of the TLR3-NF-κB signalling pathway.

Humoral Immunity Against HDL Particle: A New Perspective in Cardiovascular Diseases?

BACKGROUND

Autoimmune diseases are closely associated with cardiovascular diseases (CVD). Over the last decades, the comprehension of atherosclerosis, the principal initiator of CVD, evolved from a lipidcentered disease to a predominant inflammatory and immune response-driven disease displaying features of autoimmunity against a broad range of auto-antigens, including lipoproteins. Among them, high density lipoproteins (HDL) are important actors of cholesterol transport and bear several anti-atherogenic properties, raising a growing interest as therapeutic targets to decrease atherosclerosis and CVD burden, with nevertheless rather disappointing results so far. Reflecting HDL composition complexity, autoimmune responses and autoantibodies against various HDL components have been reported.

RESULTS

In this review, we addressed the important complexity of humoral autoimmunity towards HDL and particularly how this autoimmune response could help improving our understanding of HDL biological implication in atherosclerosis and CVD. We also discussed several issues related to specific HDL autoantibody subclasses characteristics, including etiology, prognosis and pathological mechanisms according to Rose criteria.

CONCLUSION

Finally, we addressed the possible clinical value of using these antibodies not only as potential biomarkers of atherogenesis and CVD, but also as a factor potentially mitigating the benefit of HDL-raising therapies.

IgG Anti-High Density Lipoprotein Antibodies Are Elevated in Abdominal Aortic Aneurysm and Associated with Lipid Profile and Clinical Features

High-density lipoproteins cholesterol (HDLc) levels are decreased in abdominal aortic aneurysm (AAA), which is hallmarked by autoimmunity and lipid aortic deposits. To investigate whether IgG anti-HDL antibodies were present in AAA and their potential association with clinical features, IgG anti-HDL and total IgG along with HDLc plasma levels were measured in 488 AAA patients and 184 controls from the Viborg Vascular (VIVA) study, and in tissue-conditioned media from AAA intraluminal thrombus and media layer samples compared to control aortas. Higher IgG anti-HDL levels were found in AAA compared to controls, even after correcting for total IgG, and after adjusting for potential confounders. IgG anti-HDL levels were correlated with aortic diameter in univariate and adjusted multivariate analyses. IgG anti-HDL antibodies were negatively associated with HDLc levels before and after correcting for potential confounders. Increased anti-HDL antibodies were identified in tissue-conditioned media from AAA samples compared to healthy aortas, with higher levels being observed in the media layer. In conclusion, increased IgG anti-HDL levels (both in plasma and in tissue) are linked to AAA, associated with aortic diameter and HDLc levels. These data suggest a potential immune response against HDL in AAA and support an emerging role of anti-HDL antibodies in AAA.

Mutual Influences between Nitric Oxide and Paraoxonase 1

One of the best consolidated paradigms in vascular pharmacology is that an uncontrolled excess of oxidizing chemical species causes tissue damage and loss of function in the endothelial and subendothelial layers. The fact that high-density lipoproteins play an important role in preventing such an imbalance is integrated into that concept, for which the expression and activity of paraoxonases is certainly crucial. The term paraoxonase (aryldialkyl phosphatase, EC 3.1.8.1) encompasses at least three distinct isoforms, with a wide variation in substrate affinity, cell and fluid localization, and biased expression of polymorphism. The purpose of this review is to determine the interactions that paraoxonase 1 has with nitric oxide synthase, its reaction product, nitric oxide (nitrogen monoxide, NO), and its derived reactive species generated in an oxidative medium, with a special focus on its pathological implications.

Antibodies towards high-density lipoprotein components in patients with psoriasis

Psoriasis is a chronic inflammatory immune disorder associated with an increased risk of atherosclerosis. This increased risk is not fully understood. High-density lipoproteins (HDL) play an important role in the prevention of atherosclerosis and any factors that may hamper HDL function such as anti-HDL antibodies (aHDL) might be associated with an increased cardiovascular risk. We aimed to determine whether anti-HDL antibodies (aHDL) are present in patients with psoriasis. Sixty-seven patients with psoriasis were compared with a healthy control group. Epidemiologic and clinical data were recorded. IgG and IgM aHDL, IgG anti-apolipoprotein A-I (aApoA-I), anti-apolipoprotein E (aApoE), and anti-paraoxonase 1 (aPON1) antibodies, as well as VCAM-1, IL-6, and TNF-α were assessed by ELISA. Apolipoprotein A-I (ApoA-I) and Apolipoprotein E (ApoE) were measured by immunoturbidimetric immunoassay. Patients with psoriasis had higher titers of IgG aHDL (p < 0.001), IgG aApoA-I (p = 0.001) and aApoE antibodies (p < 0.001). IgG aHDL and aApoE titers were higher in patients with severe psoriasis (p = 0.010 and p = 0.018, respectively). Multiple regression analysis, considering all clinical and biological variables, showed that aApoE, IL-6, and aPON1 are the biological variables that best explain aHDL variability. This is the first report showing the presence of aHDL, aApoA-I, and aApoE antibodies in patients with psoriasis. These antibodies were associated with increased disease severity and may contribute to the pathogenesis of atherosclerosis in psoriasis. They may fulfill the clinical need for biomarkers of cardiovascular risk associated with psoriasis that would help to stratify patients for prevention and therapeutic approaches.

Correlation of PON1 polymorphisms with ankylosing spondylitis susceptibility: A case-control study in Chinese Han population

Paraoxonase 1 (PON1) modulates the oxidative stress and inflammatory response, thus, it might relate to the risk of ankylosing spondylitis (AS). The aim of present study was to discover the correlation of PON1 polymorphisms (rs662 and rs854560) with PON1 activity and AS risk.Around 128 AS patients and 146 healthy controls were recruited in this case-control study. PON1 polymorphisms were genotyped by direct sequencing. Serum PON1 activity was detected and compared by nonparametric test in different genotypes of PON1 polymorphisms. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to present the relative risk for AS.GG genotype and G allele of rs662 polymorphism were closely correlated with enhanced AS risk (P = .034, OR = 2.318, 95%CI = 1.051-5.113; P = .032, OR = 1.485, 95%CI = 1.033-2.135). PON1 activity was obviously higher in controls than that in AS patients. Significant difference of PON1 activity has been discovered in the different rs662 genotypes (P < .01). rs662 GG genotype carriers had the lowest PON1 activity, followed by AG carriers and the AA carriers. Besides, no significant relationship existed between rs854560 genotypes and AS risk.PON1 rs662 polymorphism is significantly correlated with increased AS risk via inhibiting PON1 activity.