Serum vascular markers and vascular imaging in assessment of rheumatoid arthritis disease activity and response to therapy

Nanomaterials in the treatment and diagnosis of rheumatoid arthritis: Advanced approaches

Rheumatoid arthritis (RA), a chronic inflammatory condition that affects persons between the ages of 20 and 40, causes synovium inflammation, cartilage loss, and joint discomfort as some of its symptoms. Diagnostic techniques for RA have traditionally been split into two main categories: imaging and serological tests. However, significant issues are associated with both of these methods. Imaging methods are costly and only helpful in people with obvious symptoms, while serological assays are time-consuming and require specialist knowledge. The drawbacks of these traditional techniques have led to the development of novel diagnostic approaches. The unique properties of nanomaterials make them well-suited as biosensors. Their compact dimensions are frequently cited for their outstanding performance, and their positive impact on the signal-to-noise ratio accounts for their capacity to detect biomarkers at low detection limits, with excellent repeatability and a robust dynamic range. In this review, we discuss the use of nanomaterials in RA theranostics. Scientists have recently synthesized, characterized, and modified nanomaterials and biomarkers commonly used to enhance RA diagnosis and therapy capabilities. We hope to provide scientists with the promising potential that nanomaterials hold for future theranostics and offer suggestions on further improving nanomaterials as biosensors, particularly for detecting autoimmune disorders.

The impact of exosomes derived from distinct sources on rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease that can induce joint deformities and functional impairment, significantly impacting the overall well-being of individuals. Exosomes, which are cellularly secreted vesicles, possess favorable biological traits such as biocompatibility, stability, and minimal toxicity. Additionally, they contain nucleic acids, lipids, proteins, amino acids, and metabolites, serving as mediators in cellular communication and information exchange. Recent studies have demonstrated the association between exosomes and the pathogenesis of RA. Exosomes derived from mesenchymal stem cells, dendritic cells, and neutrophils exert influence on the biological functions of immune cells and joint cells, however, the precise mechanism remains largely unclarified. This comprehensive review systematically analyzes and summarizes the biological characteristics and functionalities of exosomes derived from diverse cellular sources, thus establishing a scientific foundation for the utilization of exosomes as diagnostic targets and therapeutic modalities in the context of RA.

MMP-13, VEGF, and Disease Activity in a Cohort of Rheumatoid Arthritis Patients

Identifying certain serum biomarkers associated with the degree of rheumatoid arthritis (RA) activity can provide us with a more accurate view of the evolution, prognosis, and future quality of life for these patients. Our aim was to analyze the presence and clinical use of matrix metalloproteinase-13 (MMP-13), along with vascular endothelial growth factor (VEGF) and well-known cytokines such as tumor necrosis factor-alpha (TNF-α) and interleukin 6 (IL-6) for patients with RA. We also wanted to identify the possible correlations between MMP-13 and these serological markers, as well as their relationship with disease activity indices, quality of life, and ultrasonographic evaluation. For this purpose, we analyzed serum samples of 34 RA patients and 12 controls. In order to assess serum concentrations for MMP-13, VEGF, TNF-α, and IL-6, we used the enzyme-linked immunosorbent assay (ELISA) technique. Our results concluded that higher levels of MMP-13, VEGF, TNF-α, and IL-6 were present in the serum of RA patients compared to controls, with statistical significance. We furthermore identified moderately positive correlations between VEGF, MMP-13, and disease activity indices, as well as with the ultrasound findings. We also observed that VEGF had the best accuracy (97.80%), for differentiating patients with moderate disease activity. According to the data obtained in our study, that although MMP-13, TNF-α and C-reactive protein (CRP) have the same sensitivity (55.56%), MMP-13 has a better specificity (86.67%) in the diagnosis of patients with DAS28_(4v) CRP values corresponding to moderate disease activity. Thus, MMP-13 can be used as a biomarker that can differentiate patients with moderate or low disease activity. VEGF and MMP-13 can be used as additional parameters, along with TNF-α and IL-6, that can provide the clinician a better picture of the inflammatory process, disease activity, and structural damage in patients with RA. Our data can certainly constitute a start point for future research and extended studies with multicenter involvement, to support the selection of individualized and accurate therapeutic management strategies for our patients.

Intra-articular therapy with methotrexate or tumor necrosis factor inhibitors in rheumatoid arthritis: a systematic review

Background

Persistent monoarthritis in otherwise well-controlled rheumatoid arthritis presents a therapeutic challenge. Intra-articular (IA) steroids are a mainstay of treatment, though some have queried whether IA disease modifying anti-rheumatic drugs (DMARD) and biologics can be used in those who fail steroid injections.

Methods

A systematic literature review was conducted using four medical databases to identify randomized, controlled trials assessing IA therapies in RA patients. Included studies underwent Cochrane Risk of Bias 2 assessment for quality.

Results

Twelve studies were included, 6 of which examined intra-articular (IA) TNF inhibitors (TNFi), and 6 studies evaluating IA methotrexate. Of those evaluating IA TNFi, one study reported statistical improvement in TNFi therapy when compared with placebo. The remaining 5 studies compared IA TNFi therapy with steroid injections. IA TNFi had statistically improved symptom scores and clinical assessments comparable with IA steroid treatments.

In the 6 studies evaluating IA methotrexate, the addition of methotrexate to steroid intra-articular therapy was not found to be beneficial, and singular methotrexate injection was not superior to the control arms (saline or triamcinolone). Risk-of-bias (ROB) assessment with the Revised Cochrane ROB tool indicated that 2 of 6 TNFi studies were at some risk or high risk for bias, compared with 5 out of 6 methotrexate studies.

Conclusion

For persistent monoarthritis in rheumatoid arthritis, IA methotrexate was not found to have clinical utility. Intra-articular TNFi therapy appears to have equal efficacy to IA steroids, though the optimal dose and frequency of injections is yet unknown.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04651-5.

Effects of betulinic acid on synovial inflammation in rats with collagen-induced arthritis

Betulinic acid (BA) inhibits the migration, invasion, and cytoskeletal reorganization of fibroblast-like synoviocytes (RA-FLS) in patients with rheumatoid arthritis. Here, to further explore the mechanism of action of BA in collagen-induced arthritis (CIA) rats, we investigated the pharmacodynamic effects of BA on synovial inflammation in a rat model of type II CIA. After inducing hind paw swelling, the rats were divided into four groups: healthy controls (normal), and rats that underwent CIA and received methotrexate treatment (MTX), BA treatment (BA), or no treatment (CIA). Body weight and hind paw swelling were determined regularly, and arthritis scores were calculated weekly. On day 35, rats were sacrificed and their hind ankle joints sectioned and stained with hematoxylin and eosin for histopathological evaluation. BA significantly reduced CIA-induced hind paw swelling, synovial tissue proliferation, cartilage destruction, and vasospasm. BA treatment also decreased serum interleukin (IL)-1β, IL-6, and tumor necrosis factor-alpha (TNF-α) levels in rats with CIA. The CCK-8 assay was used to detect the proliferation of isolated vimentin⁺CD68^- RA-FLS; RA-FLS were stimulated with TNF-α in vitro. BA significantly inhibited TNF-α-stimulated RA-FLS proliferation, as well as IL-1β and IL-6 secretion. BA also downregulated the transcription of vascular endothelial growth factor (VEGF) and transforming growth factor β (TGF-β) and decreased the expression of the NF-кB pathway proteins (NF-kB-P65, IkBα, and IKKα/β) in the TNF-α-stimulated RA-FLS. These results indicate that BA alleviated the symptoms of CIA by inhibiting synoviocyte proliferation, modifying TNF-α- and NF-кB-related inflammatory pathways, and downregulating inflammatory mediators and growth factors including IL-1β, IL-6, VEGF, and TGF-β.

The Relationship Between Serum Angiogenic Factor Levels and Disease Activity in Rheumatoid Arthritis

Objectives

This study aims to evaluate the relationship between serum angiogenic factor levels and disease activity in patients with rheumatoid arthritis (RA) using both clinical and dynamic wrist magnetic resonance imaging (MRI) data.

Patients and methods

Simultaneous serum angiogenesis markers [vascular endothelial growth factor (VEGF), angiopoietin-1 (ANG1), ANG2, and tyrosine-protein kinase receptor for angiopoietin (Tie-2)] were studied in 40 patients with RA (13 males, 27 females; mean age 51.1±10.8 years; range, 23 to 69 years) and 20 healthy controls (11 males, 9 females; mean age 47.3±12.8 years; range, 29 to 69 years) and dynamic contrast-enhanced wrist MRI was performed in 40 RA patients and seven controls. Rate of early in 55th second (REE) and Relative enhancement (REt) values were calculated from the signal time curve values obtained from the analysis of images. In clinical assessment, duration of morning stiffness, patient pain assessment [visual analog scale (VAS)], physician and patient global assessments (VAS) were recorded. The number of tender joints and swollen joints were determined. Disease activity score 28 and Ritchie scores were calculated. Health assessment questionnaire was used for functional evaluation. Anti-cyclic citrullinated peptide, rheumatoid factor, erythrocyte sedimentation rate and high sensitive C-reactive protein analyses were performed.

Results

Serum VEGF, REE and REt values were significantly higher in RA patients than healthy controls (p=0.002, p=0.00, p=0.00, respectively). There was no significant correlation between serum angiogenesis markers and clinical parameters or REE and REt (p>0.05). VEGF value correlated positively with disease duration (p=0.024).

Conclusion

Serum VEGF was higher in RA patients. While its level was associated with disease duration, no significant correlation was found with disease activity. As a diagnostic test, dynamic contrast-enhanced MRI was a valuable method for showing disease activity.

A fresh look at angiogenesis in juvenile idiopathic arthritis

Angiogenesis is the complex process of creating new capillaries from preexisting blood vessels due to hypoxemia, injury or inflammation of the tissues. Numerous cytokines and cell mediators have been identified to induce and stimulate angiogenesis, but vascular endothelial growth factor (VEGF) is a key regulator. The role of proangiogenic factors in the pathogenesis of chronic arthritis is currently a subject of intensive investigations in adult patients with rheumatoid arthritis (RA) and, to a limited extent, in children with juvenile idiopathic arthritis (JIA). Recent studies has shown a significant correlation between proangiogenic marker concentrations and the severity of inflammation in either RA or JIA patients. The serum neovascularization markers correlate with the power Doppler ultrasound image of the inflamed joint and hypertrophic synovium, which may be connected with the disease activity.

The aim of this paper is to describe the state of the art on the important role of angiogenesis in adult and childhood rheumatoid arthritis.

Raised VEGF: High sensitivity and specificity in the diagnosis of POEMS syndrome

Objective

To investigate the sensitivity and the specificity of serum vascular endothelial growth factor (sVEGF) for the diagnosis of polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes (POEMS) syndrome in patients with a neuropathy (NP) and to identify confounding causes of raised vascular endothelial growth factor (VEGF) in this context to improve accuracy.

Methods

We studied the specificity and sensitivity of sVEGF for the diagnosis of POEMS syndrome in a cohort of 195 consecutive patients with an NP in serum samples from June 2009 to November 2013, including 27 untreated patients with POEMS syndrome. We then studied VEGF in other neuropathies and analyzed causes of elevated VEGF in a multiple logistic regression analysis in a larger cohort of 236 patients including 168 with a non-POEMS NP and 68 without NP.

Results

The sensitivity of elevated sVEGF for the diagnosis of POEMS was 100%. Its specificity was 91% in patients with an NP and 92% in patients with an NP and a paraproteinemia. sVEGF was much higher in POEMS before treatment. sVEGF was not significantly elevated in any non-POEMS NP or hematologic disease group. Multiple logistic regression showed that anemia with low iron was a significant predictor for elevated sVEGF and that chronic obstructive pulmonary disease (COPD) and obstructive sleep apnoea-hypopnoea syndrome were significant predictors for very elevated sVEGF.

Interpretation

We confirmed the high sensitivity and specificity of an elevated VEGF for the diagnosis of POEMS. However, VEGF testing should be repeated, particularly after acute illnesses. Raised sVEGF should be interpreted with caution unless anemias with low iron, sleep apnea, COPD, cancers, vasculitis, and chronic inflammatory diseases are excluded.

Classification of evidence

This study provides class IV evidence that elevated sVEGF levels accurately identifies patients with POEMS syndrome.

Serum Angiogenesis Markers and Their Correlation with Ultrasound-Detected Synovitis in Juvenile Idiopathic Arthritis

Synovial angiogenesis is considered to be an important early step in the pathogenesis of juvenile idiopathic arthritis (JIA). In this study we assessed levels of angiogenic markers in serum or synovial fluid and their possible relevance to disease activity or degree of ultrasound signs of synovial inflammation and angiogenesis in early JIA. The concentration of vascular endothelial growth factor (VEGF), its soluble receptors 1 and 2 (sVEGF-R1, sVEGF-R2), and angiopoietins 1 and 2 (ANG-1, ANG-2) were evaluated in 43 JIA patients and 23 healthy controls. Synovial angiogenesis was assessed by means of Power-Doppler Ultrasonography (PDUS), according to the fourth-grade vascularity scale. VEGF and its receptors' (sVEGF-R1, sVEGF-R2) serum levels were significantly higher in JIA patients (p = 0.002). We found large variation in serum ANG-1 and ANG-2 levels. The PDUS imaging identified increased synovial microvascular blood flow in 15 (35.7%) examined JIA children. Intensity of joint vascularization correlated with higher serum VEGF and its levels was lowest in grade 0 and highest in grade 3 (p < 0.007 and p < 0.001, resp.). In conclusion, the high correlation between synovial microvascular blood flow, serum angiogenic proteins, and symptoms of synovitis may indicate its important role in pathogenesis of JIA.

Association between VEGF -634G/C polymorphism and susceptibility to autoimmune diseases: a meta-analysis

The role of VEGF -634G/C polymorphism has been involved in the investigations of susceptibility to autoimmune diseases, but the conclusion remains controversial. Here, we have performed a meta-analysis to clarify the relationship between them. All relevant articles updating to August 2013 were searched in PubMed and EMBASE. Crude odds ratios (ORs) with 95% confidence intervals (CIs) based on the available articles were calculated. A total of 24 independent studies associated with autoimmune disease were analyzed in our research. The results show that VEGF -634G/C polymorphism was associated with susceptibility to autoimmune disease in Asian population (C vs. G: OR=0.88, 95% CI: 0.80-0.96, P=0.543; CC vs. GG: OR=0.77, 95% CI: 0.63-0.93, P=0.787; CC+GC vs. GG: OR=0.80, 95% CI: 0.67-0.96, P=0.080 by random effects model). Nevertheless, no significant associations were found in total population or in other stratified groups. In the current meta-analysis, we reveal a significant association between VEGF -634G/C polymorphism and susceptibility to autoimmune diseases in Asian population.

Myelosuppressive and hepatotoxic potential of leflunomide and methotrexate combination in a rat model of rheumatoid arthritis

BACKGROUND

Safety of the combination of leflunomide and methotrexate was examined in several studies with inconclusive results. The present study was designed to compare the efficacy and safety of the combination of leflunomide and methotrexate in adjuvant-induced arthritis (AIA) in rats focusing on immunosuppressive and hepatotoxic effects.

METHODS

Eighty four rats were divided into seven groups. Group 1: Sham control, group 2: the vehicle control, group 3: methotrexate group, group 4-5: leflunomide (5 and 10mg/kg/day) groups, group 6-7: combination 1 and 2 [methotrexate+leflunomide (5 and 10mg/kg/day)] groups, respectively.

RESULTS

The current results indicated that combination therapies improved the ankle circumference and clinical scores compared to monotherapies; histopathological examination confirmed these findings. The myelosuppressive effect of leflunomide (10mg/kg/day) was comparable to that produced by methotrexate as indicated by the complete blood count and bone marrow cellularity; however their combination resulted in greater toxicity. Furthermore, methotrexate greatly affected the splenic histopathology compared to leflunomide and the combination therapy produced a greater effect compared to leflunomide not methotrexate. Differently, assessment of the hepatotoxic potential of the two drugs highlighted that leflunomide induced a dose-dependent increase in the fibrosis score which was higher in their magnitude than that induced by methotrexate. Leflunomide (10mg/kg/day) and combination 2 groups showed the greatest degree of liver fibrosis.

CONCLUSIONS

In rats with AIA, current drug combinations provided higher therapeutic benefit compared to monotherapies, however, greater toxicities were observed. Therefore, continuous monitoring of hematologic parameters and liver function will be recommended in clinical settings.

Neovascularization is prominent in the chronic inflammatory lesions of Sjögren's syndrome

Angiogenesis is a common finding in chronic inflammatory diseases; however, its role in Sjögren's syndrome (SS) remains to be elucidated. Previous SS studies have demonstrated an increase in VEGF-A/VEGFR-2 system expression in minor salivary gland (MSG) biopsies from patients with SS, but differences in the new blood vessel formation between the different grades of disease severity have not been reported. Therefore, experiments were performed to demonstrate angiogenesis during different phases of primary SS (pSS) and to define the relationship between the microvessel density (MVD), macrophage infiltration and histiocyte distribution in SS MSG inflammatory lesions. In this series of experiments, immunohistochemistry was used to examine angiogenesis in serial sections of pSS MSG. Patients with pSS were classified accordingly with the grade of inflammatory lesions as I = low-grade (low focus score of 1 or 2), II = intermediate-grade (focus score of 3–6) and III = extensive inflammation in the MSG (high focus score of 12). Histological examination demonstrated that the MVD increased with the severity of the inflammatory lesions, and in addition, we found an increased infiltration of inflammatory and pro-angiogenic cells.These findings reveal that angiogenesis is intimately involved in the progression of pSS, may be central to the propagation of the chronic immune response observed in pSS and could represent a novel potential biomarker of pSS disease activity.

The potential role of angiogenic factors in rheumatoid arthritis

Angiogenesis is an important phenomenon in the pathogenesis of some diseases, such as numerous types of tumors and autoimmunity, and also a number of soluble and cell-bound factors may stimulate neovascularization in inflammatory reaction processes. Here, by highlighting the significance of angiogenesis reaction in rheumatoid arthritis (RA), we will mainly focus on the role of various growth factors, cytokines, enzymes, cells, hypoxic conditions and transcription factors in the angiogenic process and we will then explain some therapeutic strategies based on blockage of angiogenesis and modification of the vascular pathology in RA.

Emerging avenues linking inflammation, angiogenesis and Sjögren's syndrome

Sjögren's syndrome (SS) is an autoimmune disease characterized by an inflammatory mononuclear infiltration and the destruction of epithelial cells of the lachrymal and salivary glands. The aetiology is unknown. The expression "autoimmune epithelitis" has been proposed as an alternative to SS, in view of the emerging central role of the epithelial cells in the disease pathogenesis. At the biomolecular level, the epithelial cells play an important role in triggering the autoimmune condition via antigen presentation, apoptosis, and chemokine and cytokines release. Inflammation and angiogenesis are frequently coupled in the pathological conditions associated to autoimmune diseases, and an angiogenic imbalance contributes to the pathogenesis of a number of inflammatory disorders. This work reviews the current knowledge of the molecular and cellular mechanisms underlying the pathogenesis of the inflammatory reactions that characterize SS. The literature and our data on the role of angiogenesis in the pathophysiology of the disease are discussed.

Linking systemic angiogenic factors (VEGF, angiogenin, TIMP-2) and Doppler ultrasound to anti-inflammatory treatment in rheumatoid arthritis

OBJECTIVE

To evaluate an association between synovial Doppler flow and serum levels of vascular endothelial growth factor (VEGF), angiogenin and TIMP-2 in patients with rheumatoid arthritis during anti-inflammatory treatment with glucocorticoids and TNF-α inhibitors.

METHODS

Inflamed wrists of 15 patients with rheumatoid arthritis (RA) were examined by two independent ultrasound investigators prior to and at days 3, 7, 14 and 42 after the initiation of treatment with glucocorticoids in therapy-naïve patients or after the beginning of a therapy with a TNF-α inhibitor in patients with DMARD failure. Quantitative three-dimensional power Doppler ultrasonographic assessment of synovial vascularization was compared at each visit with serum levels of VEGF, angiogenin and TIMP-2.

RESULTS

In the glucocorticoid group, synovial Doppler signals decreased significantly at day 3 (-44%; P=0.003) in comparison to a delayed decrease in the TNF-α inhibitor group after 6 weeks (-46%; P=0.001). A significant reduction of serum VEGF levels could be determined with a delay of 1 week after the decrease of Doppler activity but no correlation was found between both parameters (rho: P=0.7; r=-0.03). Angiogenin concentrations decreased in the TNF group and increased in the GC group. Levels of TIMP-2 did not change significantly in both groups.

CONCLUSION

The decrease of serum VEGF levels under treatment with glucocorticoids or TNF-α inhibitors followed the reduction of the intra-articular synovial Doppler flow. This result supports the idea that the reduction of synovial perfusion due to anti-inflammatory treatment is not regulated by systemic VEGF, but that the inflamed joints are the source for circulating VEGF.

Relationship of ultrasonographic findings with synovial angiogenesis modulators in different forms of knee arthritides

Angiogenesis is controlled by a variety of angiogenesis stimulators and inhibitors. The increased power Doppler (PD) signals determined by ultrasonography is an indirect marker of synovial vascularity in arthritis. We aimed to investigate relationship between ultrasonographic findings and synovial angiogenesis modulators. Thirteen Behcet's disease (BD), 15 spondyloarthropathy, 21 rheumatoid arthritis (RA), and 15 osteoarthritis (OA) patients with knee arthritis were included. Cumulative effusion, synovial hypertrophy, and PD signal scores were calculated in arthritic joints. In synovial fluid samples, angiogenesis inhibitors (angiostatin, thrombospondin-1, and endostatin) and stimulators [bFGF (basic fibroblast growth factor), angiopoietin-1] were studied. The comparisons between groups were made by Kruskal-Wallis test, and correlation analysis was calculated with Pearson and Spearman tests. Effusion scores were significantly higher in inflammatory arthritis than in OA. Synovial hypertrophy scores were higher in RA and spondylarthritis than in OA and BD. PD scores were not different between the groups. Synovial angiostatin and bFGF levels were significantly higher in patients with inflammatory arthritis than in OA. Cumulative effusion scores were positively correlated with angiopoietin-1, angiostatin, and bFGF and negatively correlated with thrombospondin-1 levels. Synovial hypertrophy scores were positively correlated with angiostatin and bFGF levels and negatively correlated with thrombospondin-1. No correlation was found between PD scores and modulators of angiogenesis. In large joints like knee, detecting PD signals alone was not sufficient to assess the angiogenesis. However, cumulative activity scores were positively correlated with angiogenesis stimulators. Therefore, when investigating the angiogenesis, PD technique should be added to gray-scale examinations.

Vascular endothelial growth factor polymorphisms increase the risk of developing Graves' disease

BACKGROUND

Graves' disease (GD) is a consequence of genetic and environmental factors. Vascular endothelial growth factor (VEGF) is a strong angiogenic and mitogenic factor, which plays a key role in lymphocyte infiltration, and hypervascularization in the thyroid gland of patients with GD.

AIM

The aim of this study is to investigate the relationship between GD and A-2578C, T-460C and G+405C single nucleotide polymorphisms (SNPs) of VEGF gene, as well as to evaluate whether there are any relationships between genotypes and some clinical/laboratory parameters of GD.

METHODS

We analyzed the genotype and allele distributions of the above mentioned SNPs in 167 patients with established GD diagnosis and 203 healthy controls by real-time PCR combined with melting curve analysis using fluorescence-labeled hybridization probes.

RESULTS

The distribution of VEGF A-2578C and T-460C genotypes and allele frequencies in control and GD groups were not significantly different. With regard to the +405 polymorphism, the frequency of C allele was 1.8-fold increased in GD patients compared to controls, and the CC genotype was associated with a 4.6-fold increased disease risk. There was no relationship between some clinical/laboratory parameters with G+405C polymorphism. However, in -2578C allele carrying GD patients the anti-thyroid antibody levels were increased according to wild homozygous. Additionally, -2578C and -460T alleles were related with early (at age before 40) disease onset.

CONCLUSION

VEGF +405 polymorphism may be a risk factor for GD, while the -2578 SNP is related with increased autoantibody production.

Citrullination of autoantigens: upstream of TNFα in the pathogenesis of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterised by synovial inflammation and destruction of joints. Over 20 years ago, tumour necrosis factor alpha (TNFα) was identified as a key player in a cytokine network, whose multifunctional effects could account for both the inflammation and destruction in RA. The remarkable efficacy of TNF inhibitors in the treatment of RA has resulted in extensive research addressing the regulation of TNFα production responsible for this excessive production. The discovery of autoimmunity to citrullinated protein/peptide antigens (ACPA) has led the concept that ACPA may be the essential link between disease susceptibility factors and the production of TNFα, which ultimately accounts for the disease phenotype. In this review we will consider (1) the mechanisms of citrullination, both physiological and pathological, (2) how known genetic and environmental factors could drive this peculiar form of autoimmunity and (3) how the immune response could lead to excessive production of TNFα by the synovial cells and ultimately to the disease phenotype (Fig. 1).

Circulating cytokine profiles and their relationships with autoantibodies, acute phase reactants, and disease activity in patients with rheumatoid arthritis

Our objective was to analyse the relationship between circulating cytokines, autoantibodies, acute phase reactants, and disease activity in DMARDs-naïve rheumatoid arthritis (RA) patients (n = 140). All cytokines were significantly higher in the RA cohort than in healthy controls. Moderate-to-strong positive intercorrelations were observed between Th1/Th2/macrophage/fibroblast-derived cytokines. RF correlated significantly with IL-1β, IL-2, IL-4, IL-10, IL-12, G-CSF, GM-CSF, IFN-γ, and TNF (P < .0001), and aCCP and aMCV with IL-1β, IL-2, IL-4, and IL-10 (P < .0002), while IL-6 correlated best with the acute phase reactants, CRP, and SAA (P < .0001). In patients with a DAS28 score of ≥5.1, IFN-γ, IL-1β, IL-1Ra, TNF, GM-CSF, and VEGF were significantly correlated (P < .04–.001) with high disease activity (HDA). Circulating cytokines in RA reflect a multifaceted increase in immune reactivity encompassing Th1 and Th2 cells, monocytes/macrophages, and synovial fibroblasts, underscored by strong correlations between these cytokines, as well as their relationships with RF, aCCP, and aMCV, with some cytokines showing promise as biomarkers of HDA.

Noninvasive quantitative assessment of synovial pannus angiogenesis by contrast-enhanced gray-scale sonography in antigen-induced arthritis in rabbits

RATIONALE AND OBJECTIVES

The aim of this study was to evaluate the value of contrast-enhanced gray-scale sonography in quantitative assessment of synovial pannus angiogenesis in antigen-induced arthritis in rabbits.

MATERIALS AND METHODS

Twenty-four adult New Zealand White rabbits were divided into two groups. Inflammatory arthritis was induced by intra-articular injection of ovalbumin into right knee joints with 4 mg in low-dose group (LD, n = 12) and 8 mg in high-dose group (HD, n = 12). The left side of the knee on each rabbit was used as normal control. Contrast-enhanced gray-scale sonography with time intensity curve (TIC) was performed on the synovia of suprapatellar bursa and posterior capsules 4 weeks after the injection. Immunohistochemical examinations of synovia were applied to assess the microvessel density and the expression of vascular endothelial growth factor. Correlation analysis between sonographic and immunohistochemical findings was performed.

RESULTS

Contrast-enhanced gray-scale sonography of all right knees demonstrated intra-articular hypoechoic lesions with enhanced blood flow and no abnormal findings on all left knees. Parameters of TIC, including ascending curve (A), derived peak intensity (DPI), and area under curve (AUC) on arthritis joints were significantly higher in HD group compared to LD group (P < .05). Positive correlation was found between immunohistochemical findings and parameters of A, DPI, and AUC (P < .05). However, no correlation was found between other parameters (slope of descending rate, time to peak, time to rise, and initial intensity) and immunohistochemical findings.

CONCLUSIONS

Contrast-enhanced gray-scale sonography with TIC measurement could provide reliable method for noninvasive quantitative assessment of synovial pannus angiogenesis of arthritis in clinical settings.

Immature blood vessels in rheumatoid synovium are selectively depleted in response to anti-TNF therapy

Background

Angiogenesis is considered an important factor in the pathogenesis of Rheumatoid Arthritis (RA) where it has been proposed as a therapeutic target. In other settings, active angiogenesis is characterized by pathologic, immature vessels that lack periendothelial cells. We searched for the presence of immature vessels in RA synovium and analyzed the dynamics of synovial vasculature along the course of the disease, particularly after therapeutic response to TNF antagonists.

Methodology/Principal Findings

Synovial arthroscopic biopsies from RA, osteoarthritis (OA) and normal controls were analyzed by double labeling of endothelium and pericytes/smooth muscle mural cells to identify and quantify mature/immature blood vessels. To analyze clinicopathological correlations, a cross-sectional study on 82 synovial biopsies from RA patients with variable disease duration and severity was performed. A longitudinal analysis was performed in 25 patients with active disease rebiopsied after anti-TNF-α therapy. We found that most RA synovial tissues contained a significant fraction of immature blood vessels lacking periendothelial coverage, whereas they were rare in OA, and inexistent in normal synovial tissues. Immature vessels were observed from the earliest phases of the disease but their presence or density was significantly increased in patients with longer disease duration, higher activity and severity, and stronger inflammatory cell infiltration. In patients that responded to anti-TNF-α therapy, immature vessels were selectively depleted. The mature vasculature was similarly expanded in early or late disease and unchanged by therapy.

Conclusion/Significance

RA synovium contains a significant fraction of neoangiogenic, immature blood vessels. Progression of the disease increases the presence and density of immature but not mature vessels and only immature vessels are depleted in response to anti-TNFα therapy. The different dynamics of the mature and immature vascular fractions has important implications for the development of anti-angiogenic interventions in RA.

Scopolin isolated from Erycibe obtusifolia Benth stems suppresses adjuvant-induced rat arthritis by inhibiting inflammation and angiogenesis

Despite scopolin is a main coumarin constituent in the stems of Erycibe obtusifolia Benth, a herb drug that has long been utilized in traditional Chinese medicine for the treatment of rheumatoid arthritis, little information is available about the pharmacological activities of this compound. The present study was performed to investigate the anti-rheumatic effects of scopolin in adjuvant-induced arthritis (AIA) in rats, and explore the underlying mechanisms of action in views of anti-inflammatory and anti-angiogenic properties in the synovial tissues. Scopolin (50, 100 mg/kg), injected intraperitoneally for 10 days from the onset of secondary response, significantly inhibited both inoculated and non-inoculated paw swelling as well as articular index scores in AIA. Meanwhile, the mean body weight of rats treated with scopolin was higher than that of model group. Rats treated with high dose of scopolin (100 mg/kg) preserved a nearly normal histological architecture of the joints and showed a significant reduction of the new blood vessels in the synovial tissues. Additionally, scopolin could reduce IL-6, VEGF and FGF-2 expressions in rat synovial tissues. In conclusion, scopolin can reduce the clinical symptoms of rat AIA by inhibiting inflammation and angiogenesis, and this compound may be a potent agent for angiogenesis related diseases and can serve as a structural base for screening more potent synthetic analogs.

Plasma indices of angiogenesis in rheumatoid disease: relationship to cardiovascular risk factors and cardiac function

INTRODUCTION

Rheumatoid Disease (RD) is associated with increased rates of cardiovascular disease (CVD). Angiogenesis is central to RD, and well-recognized in CVD. We hypothesised that plasma levels of two indices associated with angiogenesis, vascular endothelial growth factor (VEGF) and angiogenin, would be higher among RD patients compared to healthy controls (HC), would relate to CVD risk factors, calculated 10-year coronary heart disease (CHD) and stroke risk scores.

METHODS

144 clinic patients with established RD and 63 HC were recruited in a cross-sectional study. RD patients were grouped according to the presence (RD-CVD, n=73 or absence (non-CVD RD; n=71) of CVD risk factors. Angiogenin and VEGF levels were quantified by ELISA.

RESULTS

There were no significant differences for VEGF or angiogenin, between RD-CVD, non-CVD RD and HC groups (p=NS). Calculated risks for both CHD (p=0.017) and stroke (p=0.016) were higher when RD-CVD was compared to non-CVD RD and HC. Upon multivariate analysis, methotrexate use (p=0.006) and prior mycocardial infarction (MI) (p=0.034) were associated with higher angiogenin levels; body mass index (BMI) (p=0.034) and presence of RD (p=0.029) itself predicted lower levels. For RD patients, serum creatinine (p<0.001) and CRP levels, VEGF levels, and NSAID/COX2 inhibitor use (all p<0.05) were independently associated with CHD risk; plasma VEGF and serum creatinine levels were independently associated with stroke risk (p<0.05).

CONCLUSIONS

Although levels of angiogenin were not significantly different between HC and RD patients, RD may have some influence on their variation. Methotrexate use and prior MI predicted higher angiogenin levels, whilst levels of VEGF were negatively associated with 10-year CHD and stroke risk.

Circulating vascular endothelial growth factor and systemic inflammatory markers in patients with stable and exacerbated chronic obstructive pulmonary disease

The aim of the present study was to assess circulating levels of VEGF (vascular endothelial growth factor), a biomarker with prognostic significance in cardiovascular disease, and markers of systemic inflammation in patients with stable and exacerbated COPD (chronic obstructive pulmonary disease). Lung function parameters, arterial blood gas analysis and circulating levels of VEGF, IL-6 (interleukin-6), TNF-alpha (tumour necrosis factor-alpha), CRP (C-reactive protein), fibrinogen and the peripheral blood neutrophil cell count were assessed in 30 patients on admission to the hospital for acute exacerbation of COPD, in 30 age-, gender- and BMI (body mass index)-matched patients with stable COPD, and 30 matched controls with normal lung function. Patients with acute exacerbated COPD had higher circulating concentrations of VEGF (P<0.001), IL-6 (P<0.05) and CRP (P<0.01) and an increased blood neutrophil cell count (P<0.05) compared with patients with stable COPD and healthy controls. VEGF levels in exacerbated COPD correlated with systemic inflammatory markers, such as CRP (r=0.61, P<0.005), IL-6 (r=0.46; P<0.01) and fibrinogen (r=0.39, P<0.05). In patients with stable COPD, there was a significant relationship between circulating VEGF levels and the percentage of the predicted FEV(1) (forced expiratory volume in 1 s) (r=0.47, P<0.01). Recovery from the exacerbation resulted in a significant decrease in both circulating VEGF levels and markers of systemic inflammation. In conclusion, circulating levels of VEGF and markers of systemic inflammation are up-regulated in patients with acute exacerbated COPD and decrease after recovery from the exacerbation.

The need for prognosticators in rheumatoid arthritis. Biological and clinical markers: where are we now?

Rheumatoid arthritis is a heterogeneous disease with respect to clinical manifestations, serologic abnormalities, joint damage and functional impairment. Predicting outcome in a reliable way to allow for strategic therapeutic decision-making as well as for prediction of the response to the various therapeutic modalities available today, especially biological agents, would provide means for optimization of care. In the present article, the current information on biological and clinical markers related to disease activity and joint damage as well as for predictive purposes is reviewed. It will be shown that the relationship of many biomarkers with disease characteristics is confounded by factors unrelated to the disease, and that only few biomarkers exist with some predictive value. Moreover, clinical markers appear of equal value as biomarkers for this purpose, although they likewise have limited capacity in these regards. The analysis suggests the search for better markers to predict outcomes and therapeutic responsiveness in rheumatoid arthritis needs to be intensified.

Three-dimensional ultrasonographic application for analyzing synovial hypertrophy of the knee in patients with osteoarthritis

OBJECTIVE

The purpose of this study was to evaluate 3-dimensional (3D) ultrasonography for the visualization of intra-articular synovial hypertrophy in patients with osteoarthritis.

METHODS

Knee joints of 22 patients with osteoarthritis were examined by 3D ultrasonography, and their synovial fluids were analyzed. Ultrasonographic image patterns, vascular endothelial growth factor and transforming growth factor beta concentrations in synovial fluid, and serum inflammatory markers were analyzed.

RESULTS

It was possible to visualize the intra-articular structure by 3D ultrasonography. Three-dimensional ultrasonography revealed various interesting stereoscopic views of the synovial structures, and the patterns of synovial proliferation ranged from simple proliferations to complex shrubby structures. Patients with a more complex and proliferative pattern in the synovium tended to have higher C-reactive protein concentrations, but this difference was not significant (P = .09). The concentrations of vascular endothelial growth factor and transforming growth factor beta in synovial fluid were significantly higher in patients with complex hypertrophy (P < .05).

CONCLUSIONS

Three-dimensional technology was useful in delineating the shape of the synovium. It may have a possible impact on future imaging in rheumatology.

Ultrasound of the small joints of the hands and feet: current status

The aim of this article was to review the current status of ultrasound imaging of patients with rheumatological disorders of the hands and feet. Ultrasound machines with high-resolution surface probes are readily available in most radiology departments and can be used to address important clinical questions posed by the rheumatologist and sports and rehabilitation physician. There is increasing evidence that ultrasound detects synovitis that is silent to clinical examination. Detection and classification of synovitis and the early detection of bone erosions are important in clinical decision making. Ultrasound has many advantages over other imaging techniques with which it is compared, particularly magnetic resonance. The ability to carry out a rapid assessment of many widely spaced joints, coupled with clinical correlation, the ability to move and stress musculoskeletal structures and the use of ultrasound to guide therapy accurately are principal amongst these. The use of colour flow Doppler studies provides a measure of neovascularisation within the synovial lining of joints and tendons, and within tendons themselves, that is not available with other imaging techniques. Disadvantages compared to MRI include small field of view, poor image presentation, and difficulty in demonstrating cartilage and deep joints in their entirety. Contrast-enhanced magnetic resonance provides a better measure of capillary permeability and extracellular fluid than does ultrasound. The ability to image simultaneously multiple small joints in the hands and feet and their enhancement characteristics cannot be matched with ultrasound, though future developments in 3-D ultrasound may narrow this gap. Magnetic resonance provides a more uniform and reproducible image for long-term follow-up studies.

Value of contrast-enhanced ultrasound in rheumatoid arthritis

The purpose of this review is to describe the spectrum of sonographic findings in rheumatic diseases with respect to the diagnostic potential using US contrast media which prove activity or inactivity in synovial tissue where new treatment regimes target. Synovial activity can be found in non-erosive and erosive forms of primary and secondary osteoarthritis, and in inflammatory forms of joint diseases like rheumatoid arthritis and peripheral manifestations of spondyloarthritis including, ankylosing spondylitis, Reiter's syndrome, psoriatic arthritis and enteropathic arthritis. It can also be present in metabolic and endocrine forms of arthritis, in connective tissue arthropathies like systemic lupus erythematosus or scleroderma and in infectious arthritis. Ultrasound should be used as first-line imaging modality in suspected early cases of RA and other forms of arthritis, whereas contrast-enhanced ultrasound (CEUS) can further enable for sensitive assessment of vascularity which correlates with disease activity.

Advanced imaging in rheumatoid arthritis. Part 1: synovitis

Rheumatoid arthritis (RA) is a chronic and progressive inflammatory disorder primarily affecting the synovium. We now recognise that conventional radiographic images show changes of rheumatoid arthritis long after irreversible joint damage has occured. With the advent of powerful disease-modifying drugs, there is a need for early demonstration of rheumatoid arthritis and a need to monitor progress of the disease and response to therapy. Advanced imaging techniques such as ultrasound and MRI have focussed on the demonstration and quantification of synovitis and erosions and allow early diagnosis of RA. The technology to quantify synovitis and erosions is developing rapidly and now allows change in disease activity to be assessed. However, problems undoubtedly exist in quantification techniques, and this review serves to highlight them. Much of the literature on advanced imaging in RA appears in rheumatological journals and may not be familiar to radiologists. This review article aims to increase the awareness of radiologists about this field and to encourage them to participate and contribute to the ongoing development of these modalities. Without this collaboration, it is unlikely that these modalities will reach their full potential in the field of rheumatological imaging. This review is in two parts. The first part addresses synovitis imaging. The second part will look at advanced imaging of erosions in RA.

Vascular Endothelial Growth Factor (VEGF) in Autoimmune Diseases

Vascular endothelial growth factor (VEGF) is a potent stimulating factor for angiogenesis and vascular permeability. There are eight isoforms with different and sometimes overlapping functions. The mechanisms of action are under investigation with emerging insights into overlapping pathways and cross-talk between other receptors such as the neuropilins, which were not previously associated to angiogenesis. VEGF has important physiological actions on embryonic development, healing, and menstrual cycle. It also has a great role in pathological conditions that are associated to autoimmune diseases. There is considerable evidence in various autoimmune diseases such as in systemic lupus erythematosus, rheumatoid arthritis, and multiple sclerosis of an interrelationship between the VEGF system and theses disorders. Serum levels of VEGF correlate with disease activity in a large number of autoimmune diseases and fall with the use of standard therapy. We raised the possible future therapeutic strategies in autoimmune diseases with the anti-VEGF or anti-VEGFR (receptor). So far, this therapy has been used in cancer and macular ocular degeneration in diabetes. This review outlines the evidence for VEGF participation in various autoimmune diseases and proposes lines for future research in this field.

Three-dimensional Doppler sonographic vascular imaging in regions with increased MR enhancement in inflamed wrists of patients with rheumatoid arthritis

OBJECTIVE

To compare three-dimensional (3D) power Doppler ultrasonography (PDUS) with contrast enhanced magnetic resonance imaging (MRI) in their capability to visualize synovial vascularity in inflamed wrists of patients with rheumatoid arthritis (RA).

METHODS

Nine patients with RA showing clinically active arthritis of the wrist as determined by tenderness and swelling were examined by contrast enhanced MRI and 3D PDUS. Vascularity close to and inside the joint capsule was visualized by conventional power Doppler mode. In a region with high Doppler signal intensity (=region of interest/ROI) a 3D blood vessel tree was obtained by a free-hand sweep. 3D images were evaluated with regard to the number of blood vessels in the intra- and peri-articular region. MRI examinations were performed using a 1.5 T Scanner. In MRI, time resolved coronal contrast enhanced T1-weighted sequences with fat suppression were acquired during an 8 min period to assess tissue enhancement. Relative enhancement was calculated and compared to 3D PDUS findings.

RESULTS

A 3D vascular tree consisting of peri- and intra-articular blood vessels could be demonstrated in the same anatomical ROI in which an increased gadolinium enhancement was measured by MRI in all examined RA patients. The number of penetrating vessels into the joint capsule, the number of intra-articular vessels and a semiquantitative estimation of the strength of blood flow were used to generate a 3D score for the intensity of synovial vascularity.

CONCLUSION

When compared with clinical symptoms and the gold standard dynamic MRI, 3D PDUS is a reliable imaging technique for assessing synovial vascularity in inflamed wrists of RA patients.

Power Doppler Ultrasound in Musculoskeletal Disease: A Systematic Review

OBJECTIVE

To evaluate the performance characteristics of power Doppler ultrasound as a diagnostic and monitoring tool in the assessment of musculoskeletal disease through a systematic review of the literature.

METHODS

SEARCH STRATEGY

We performed a literature search of PUBMED (1966 to June 2005).

SELECTION CRITERIA

Only original research reports written in English involving musculoskeletal disease and power Doppler ultrasound were included. Reviews were noted but not included. Data Extraction/Reporting: The design, subjects, methods, imaging protocols, and performance characteristics studied in the research papers were reported.

RESULTS

Of 3568 identified reports, 139 involved power Doppler ultrasound of the musculoskeletal system. Fifty-three of these reports met the inclusion criteria. Ultrasound machine settings were specified in 63% of reports. Rheumatoid arthritis was the most commonly studied musculoskeletal disease (64% of papers). Validity was the most studied performance characteristic (94% of reports), while reliability and responsiveness were studied in 17 and 34%, respectively.

CONCLUSIONS

Although the majority of research reports of power Doppler ultrasound assessment of the musculoskeletal system evaluated validity, less than half reported reliability and responsiveness. Further work is needed to evaluate power Doppler ultrasound assessment of the musculoskeletal system before it can be used to guide clinical decisions or be used as an endpoint in clinical trials.

The role of vascular endothelial growth factor (VEGF) in inflammatory bowel disease

BACKGROUND

Vascular endothelial growth factor (VEGF) is a candidate susceptibility gene to inflammatory bowel disease (IBD), both from a functional as well as genetic perspective. Moreover, serum VEGF (sVEGF) levels are increased in IBD and correlate with disease activity. Both VEGF expression and sVEGF levels may be influenced by VEGF gene polymorphisms.

AIMS

To study VEGF polymorphisms in IBD susceptibility and their impact on sVEGF levels.

METHODS

Four functional VEGF polymorphisms (-C2578A, -G1154A, -G634C, and C936T) were genotyped in two independent cohorts (cohort 1: 372 IBD trios; cohort 2: 452 unrelated IBD patients, 271 healthy controls [HC]; and 93 patients with non-IBD gastrointestinal inflammation [non-IBD GI]), using polymerase chain reaction with restriction fragment length polymorphism and TaqMan minor groove binding. Phenotypical data on all patients as well as sVEGF levels were correlated with the genetic data.

RESULTS

Both the VEGF genotype and haplotype frequencies did not differ between IBD patients and controls, and no distortion of transmission was observed. sVEGF levels were increased in IBD but also in non-IBD GI patients, compared with HC, and were only influenced by VEGF polymorphisms in patients with Crohn's disease (-G1154A genotype and -2578/-1154/-634 AAG promoter haplotype).

CONCLUSIONS

The VEGF polymorphisms studied are not implicated in susceptibility to IBD and do not predict sVEGF levels. Although increased sVEGF and angiogenesis are important features of IBD, they do not appear genetically determined.

Sonographie synovialer und erosiver entzündlicher Veränderungen

High-frequency sonography enables excellent detection of early erosions and synovial proliferations. Power Doppler sonography (PDUS) allows for an improved characterization of articular and peritendinous augmented volume, because detection of hypervascularity correlates with inflammatory activity and further is helpful in differentiation from effusion and inactive pannus. The use of contrast media improves the sensitivity of vascularity detection, because they allow for a delineation of vessels at the microvascular level. This is of increased interest, as the development of new therapeutic options targeting the microvascular level calls for earlier diagnosis and optimal assessment of disease activity. Because of good availability, cost effectiveness, and patient acceptance, sonography facilitates early diagnosis of synovial proliferations and erosions as well as therapy follow-up.

Copper chelation with tetrathiomolybdate suppresses adjuvant-induced arthritis and inflammation-associated cachexia in rats

Tetrathiomolybdate (TM), a drug developed for Wilson's disease, produces an anti-angiogenic and anti-inflammatory effect by reducing systemic copper levels. TM therapy has proved effective in inhibiting the growth of tumors in animal tumor models and in cancer patients. We have hypothesized that TM may be used for the therapy of rheumatoid arthritis and have examined the efficacy of TM on adjuvant-induced arthritis in the rat, which is a model of acute inflammatory arthritis and inflammatory cachexia. TM delayed the onset of and suppressed the severity of clinical arthritis on both paw volume and the arthritis score. Histological examination demonstrated that TM significantly reduces the synovial hyperplasia and inflammatory cell invasion in joint tissues. Interestingly, TM can inhibit the expression of vascular endothelial growth factor in serum synovial tissues, especially in endothelial cells and macrophages. Moreover, the extent of pannus formation, which leads to bone destruction, is correlated with the content of vascular endothelial growth factor in the serum. There was no mortality in TM-treated rat abnormalities. TM also suppressed inflammatory cachexia. We suggest that copper deficiency induced by TM is a potent approach both to inhibit the progression of rheumatoid arthritis with minimal adverse effects and to improve the well-being of rheumatoid arthritis patients.