Differential associations of inflammatory and endothelial biomarkers with disease activity in rheumatoid arthritis of short duration

Immunoregulatory Cells and Cytokines Discriminate Disease Activity Score 28-Remission Statuses and Ultrasound Grades in Rheumatoid Arthritis Patients with Non-High Disease Activity

It is not clear whether immunoregulatory cytokines and cells are associated with Disease Activity Score 28 (DAS28) scores and ultrasound grades/scores. Here, we investigated the relationships between immunoregulatory cytokines or cells and different DAS28 scores or ultrasound grades/scores in patients with rheumatoid arthritis (RA). This study enrolled 50 RA patients (with 147 visits) who had remission/low/moderate DAS28-ESR scores (92% in remission and low disease activity) at baseline. Blood was collected and an ultrasound was performed three times in a year. Percentages of regulatory B cells and T regulatory type 1 cells and M2 macrophage numbers in the blood were examined. Plasma levels of 10 immunoregulatory cytokines IL-4, IL-5, IL-9, IL-10, IL-13, IL-27, IL-35, TGF-β1, sTNF-R1, and sTNF-R2 and monocyte chemotactic protein-1 (MCP-1) were assessed using ELISA assay. The correlations of cytokines and cells with different DAS28 scores and ultrasound grades were investigated, and cytokines and cells were compared between different categories of DAS28 scores and ultrasound grades. Plasma TGF-β1 levels were higher in the DAS28-ESR < 2.6 (remission) subgroup than in the DAS28-ESR ≥ 2.6 (nonremission) subgroup (p = 0.037). However, plasma TGF-β1 levels were higher in the high ultrasound grade subgroup than those in the low ultrasound grade subgroup (p = 0.007). The number of M2 macrophages was lower in the DAS28-MCP-1 < 2.2 subgroup than in the DAS28-MCP-1 ≥ 2.2 subgroup (p = 0.036). The levels of TGF-β1, sTNF-R2, IL-10, and IL-27 were higher in patients with high ultrasound grades than in those with low ultrasound grades. IL-27 was also higher in the nonremission DAS28-ESR subgroup than the remission one (p = 0.025). Moreover, sTNF-R1 levels in the 2011 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) remission subgroup were significantly lower than in the 2011 ACR/EULAR nonremission subgroup (p = 0.007). This trend was reflected in that lower sTNF-R1 levels correlated with low DAS28-MCP-1 scores (rho = 0.222, p = 0.007). We conclude that high plasma TGF-β1 levels indicate the DAS28-ESR remission (<2.6) subgroup and the high ultrasound grade subgroup. IL-27 probably connects the nonremission DAS28-ESR to high ultrasound grades. Low sTNF-R1 levels probably link low DAS28-MCP-1 scores with the 2011 ACR/EULAR remission subgroup. It suggests that incongruent immuno-inflammatory abnormalities exist between DAS28 scores and ultrasound grades, and are also dissimilar among various DAS28-formula categories. Therefore, this study may provide a basis for further research into individual cytokines and immunoregulatory cells behind each DAS28 formula and ultrasound grades/scores.

Association between blood Pentraxin-3 concentrations and rheumatic diseases: A systematic review and meta-analysis

BACKGROUND

Among the Pentraxins, the long Pentraxin-3 (PTX-3) is associated with several processes, particularly in the earliest phases of the innate humoral response. Increased blood PTX-3 concentrations have been observed in a wide range of conditions, from infectious to cardiovascular disorders. Since its increase is more rapid than C-reactive protein (CRP), PTX-3 can be useful to detect and monitor early inflammation. To dissect its pathophysiological role in rheumatic diseases (RD), we conducted a systematic review and meta-analysis comparing blood PTX-3 concentrations in RD patients and healthy individuals and investigating possible associations with clinical, demographic, and study characteristics.

METHODS

We performed a search of published evidence until April 2024 in PubMed, Web of Science and Scopus, which led to the selection of 60 relevant manuscripts from a total of 1072 records.

RESULTS

Our synthesis revealed a statistically significant difference in PTX-3 concentrations between RD patients and controls (standard mean difference, SMD = 1.02, 95% CI 0.77-1.26, p < .001), that correlated with CRP concentrations. The effect size was associated with geographical region of study conduction, RD type, with a reduction of the observed heterogeneity in patients with low LDL-cholesterol and triglycerides concentrations.

CONCLUSIONS

Our study has shown a significant increase in blood PTX-3 concentrations in RD patients, which was associated with specific patient characteristics. Nevertheless, additional studies are needed to better define the utility of measuring PTX-3 in the early phase of RD. Our study was conducted in compliance with the PRISMA 2020 statement (study protocol available at PROSPERO CRD42024516600).

Predictors of Remission or Combined Remission and Low Disease Activity in Rheumatoid Arthritis Patients in Taiwan: A Prospective Cohort Study

Objectives: This study aimed to identify predictors of remission or low disease activity (LDA) in patients with rheumatoid arthritis (RA) and low-ultrasound inflammation. Methods: A total of 80 patients with RA who fulfilled the 1987 ACR criteria for RA with a disease activity score of 28 joints (DAS28) > 3.2 were recruited. Over 1 year of therapy, we conducted blood tests every 6 months to examine erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), monocyte chemotactic protein-1 (MCP-1), neuraminidase 3 (Neu3), and α-2,3-sialyltrasnferse I (ST3Gal-1) levels in B cells and monocytes. Additionally, we evaluated physical function by using the Health Assessment Questionnaire-Disability Index (HAQ-DI). Data on demographic and clinical parameters were collected, and musculoskeletal ultrasonography was performed twice a year on 12 specific joints to assess synovial changes. One year later, we compared all collected data and laboratory or ultrasound results between patients achieving remission or LDA and those who did not in order to determine the predictors. Results: Age, the presence or absence of rheumatoid factor, and the number of conventional disease-modifying anti-rheumatic drugs used were not correlated with remission or LDA for DAS28 or Simplified Disease Activity Index formulas. However, male sex, low CRP levels, low ESR levels, and low HAQ-DI scores were associated with a higher likelihood of achieving remission or LDA for DAS28-ESR. Negative anticyclic citrullinated peptide (CCP) and low HAQ-DI scores were predictors of remission or LDA for DAS28-MCP-1. Interestingly, having less than two comorbidities is a good predictor of a combined remission/low disease activity state for SDAI and DAS28-MCP-1. Furthermore, Neu3 and ST3Gal-1 levels and ST3Gal-1/Neu3 ratios in B cells and monocytes had no significant correlation with total ultrasound scores. Nevertheless, monocyte ST3Gal-1 and Neu3 correlated significantly with DAS28-ESR >5.1 and DAS-MCP-1 >4.8 (both categories belong to high disease activity), respectively (rho = 0.609 with p = 0.012, and rho = 0.727 with p = 0.011, respectively). Monocyte ST3Gal-1/Neu3 ratios connected with DAS28-ESR >5.1 and 3.3 < SDAI ≦ 11 (low disease activity), respectively (rho = 0.662 with p = 0.005, and rho = 0.342 with p = 0.048, respectively). Conclusions: In patients with RA in Taiwan, male sex, low CRP levels, low ESR levels, and low HAQ-DI scores are predictors of remission or LDA for DAS28-ESR, which differ from the predictors for DAS28-MCP-1. Moreover, monocyte ST3Gal-1, Neu3, and their ratios correlated with different disease activity categories of DAS28-ESR, DAS28-MCP-1, and SDAI scores.

Transsulfuration and folate pathways in rheumatoid arthritis: A systematic review and meta-analysis

BACKGROUND

Metabolomic assessment of the transsulfuration and folic acid biochemical pathways could lead to the identification of promising biomarkers of nitric oxide dysregulation and oxidative stress in rheumatoid arthritis (RA).

METHODS

We conducted a systematic review and meta-analysis of transsulfuration (methionine, homocysteine, and cysteine) and folic acid (folic acid, vitamin B6 , and vitamin B12 ) metabolites in RA patients in remission and healthy controls. Electronic databases were searched from inception to 15 July 2023 for relevant articles. We assessed the risk of bias using the JBI checklist and the certainty of evidence using GRADE.

RESULTS

In 28 eligible studies, compared to controls, RA patients had significantly higher concentrations of homocysteine (standardized mean difference, SMD = 0.74, 95% CI 0.54-0.93, p < 0.001; low certainty of evidence) and methionine (SMD = 1.00, 95% CI 0.57-1.44, p < 0.001; low certainty) and lower concentrations of vitamin B6 (SMD = -6.62, 95% CI -9.65 to -3.60, p < 0.001; low certainty). By contrast, there were non-significant between-group differences in vitamin B12 and folic acid. In meta-regression and subgroup analysis, there were no associations between the effect size and several study and patient characteristics except for homocysteine (year of publication, C-reactive protein, triglycerides, and analytical method) and folic acid (biological matrix).

CONCLUSIONS

The results of our study suggest that homocysteine, methionine, and vitamin B6 are promising biomarkers to assess nitric oxide dysregulation and oxidative stress in RA. (PROSPERO registration number: CRD42023461081).

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.

Relevance of circulating markers of endothelial activation for cardiovascular risk assessment in rheumatoid arthritis: a narrative review

Rheumatoid arthritis (RA) is associated with excessive cardiovascular mortality secondary to premature atherosclerosis, in which endothelial activation (EA) plays a central role. EA is characterized by loss of vascular integrity, expression of leucocyte adhesion molecules, transition from antithrombotic to prothrombotic phenotype, cytokines production, shedding of membrane microparticles and recruitment of endothelial progenitor cells. As EA is an early event in atherogenesis, circulating markers of EA are putative markers of vascular pathology and cardiovascular (CV) risk. After a presentation of biology of EA, the present review analyzed the available data regarding changes in EA markers in RA in link with the vascular pathology and CV events, discussed their relevance as biomarkers of CV risk and proposed future directions.

TNF-α Inhibitors in Combination with MTX Reduce Circulating Levels of Heparan Sulfate/Heparin and Endothelial Dysfunction Biomarkers (sVCAM-1, MCP-1, MMP-9 and ADMA) in Women with Rheumatoid Arthritis

Sulfated glycosaminoglycans (sGAGs) are likely to play an important role in the development and progression of rheumatoid arthritis (RA)-associated atherosclerosis. The present study investigated the effect of anti-tumor necrosis factor-α (anti-TNF-α) therapy in combination with methotrexate on plasma sGAG levels and serum markers of endothelial dysfunction. Among sGAG types, plasma chondroitin/dermatan sulfate (CS/DS) and heparan sulfate/heparin (HS/H) were characterized using electrophoretic fractionation. Serum levels of soluble vascular cell adhesion molecule-1 (sVCAM-1), monocyte chemoattractant protein-1 (MCP-1), matrix metalloproteinase-9 (MMP-9) and asymmetric dimethylarginine (ADMA) were measured by immunoassays. The measurements were carried out four times: at baseline and after 3, 9 and 15 months of anti-TNF-α therapy. All analyzed parameters, excluding ADMA, were significantly elevated in patients with RA before the implementation of biological therapy compared to healthy subjects. Performed anti-TNF-α treatment led to a successive decrease in HS/H levels toward normal values, without any effect on CS/DS levels in female RA patients. The treatment was also effective at lowering the serum levels of sVCAM-1, MCP-1, MMP-9 and ADMA. Moreover, a significant positive correlation was found between the circulating HS/H and the 28 joint disease activity score based on the erythrocyte sedimentation rate (DAS28-ESR, r = 0.408; p <0.05), MCP-1 (r = 0.398; p <0.05) and ADMA (r = 0.396; p <0.05) in patients before the first dose of TNF-α inhibitor. In conclusion, a beneficial effect of anti-TNF-α therapy on cell-surface heparan sulfate proteoglycans (HSPGs)/HS turnover and endothelial dysfunction was observed in this study. This was manifested by a decrease in blood HS/H levels and markers of endothelial activation, respectively. Moreover, the decrease in the concentration of HS/H in the blood of patients during treatment, progressing with the decline in disease activity, indicates that the plasma HS/H profile may be useful for monitoring the efficacy of anti-TNF-α treatment in patients with RA.

Increased Circulating Pentraxin 3 Levels in Patients with Rheumatoid Arthritis: a Meta-analysis

BACKGROUND

Pentraxin 3 (PTX3) as a soluble pattern recognition molecule not only acts as a promising indicator reflecting the disease activity of rheumatoid arthritis (RA) patients, but exerts essential pathogenic roles in the progression of RA and serves as a potential therapeutic target for RA patients. Our study intends to systematically evaluate the circulating PTX3 levels and their potential influencing factors in RA patients.

METHODS

Articles regarding the circulating PTX3 levels of RA patients were identified in Pubmed, Embase, China National Knowledge Infrastructure (CNKI), and Cochrane databases. Standardized mean difference (SMD) and corresponding 95% confidence intervals (95% CI) were calculated and further illustrated by the forest plot. Egger's regression test and sensitivity analysis were conducted to assess the publication bias and stability of the results, respectively.

RESULTS

Twenty articles with 21 individual studies were recruited in our meta-analysis. The overall results revealed that compared with healthy controls, RA patients had significantly higher circulating PTX3 levels (pooled SMD = 0.97, 95% CI: 0.48 to 1.45). Subgroup analyses further demonstrated that compared with healthy controls, RA patients of age ≤ 50 years, 2.6 < disease activity score in 28 joints (DAS28) ≤ 3.2, 3.2 < DAS28 ≤ 5.1, DAS28 > 5.1, C-reactive protein (CRP) levels > 10 mg/L, erythrocyte sedimentation rate (ESR) > 20 mm/h, and disease duration > 5 years had significantly higher circulating PTX3 levels, respectively; whereas RA patients of age > 50 years, DAS28 ≤ 2.6, CRP levels ≤ 10 mg/L, ESR ≤ 20 mm/h and disease duration ≤ 5 years had no significantly altered circulating PTX3 levels, respectively. Additionally, no matter the patients of Caucasian ethnicity or not, circulating PTX3 levels were significantly increased in RA patients.

CONCLUSION

Compared with healthy controls, circulating PTX3 levels are significantly increased in RA patients, which are influenced by the age, disease activity, CRP levels, ESR, and disease duration of the patients.

Leptin and Vascular Cell Adhesion Protein 1 as Physiological Biomarkers in Serum of Women Suffering from Rheumatoid Arthritis

BACKGROUND: Rheumatoid arthritis is defining as a common chronic and inflammatory disorder of systematic autoimmune disease. Leptin is a small peptide hormone involved in the inflammatory and immunomodulators processes of several diseases. AIM: The study aimed at evaluating the level of leptin and Vascular Cell Adhesion Protein 1 (VCAM-1) and proves that they act as vital markers in the serum of rheumatoid arthritis. MATERIALS AND METHODS: In this study, 80 serum samples from women were obtains (56 serum samples were distributing for women with rheumatoid arthritis and 24 serum samples for uninfected women who were considered a healthy group). RESULTS: There are no significant difference in the concentration of the leptin hormone in the serum of both patients and healthy women, and that age, period, and severity of the disease had no effect on the level of leptin hormone. However, the results confirmed that at the probability level p < 0.05 the VCAM-1 concentration increased significantly in patients’ serum when compared with the healthy group, and demonstrated that age groups only affected the VCAM-1 biomarker level. CONCLUSIONS: Our current study concludes that leptin levels in the serum were not impacts by the inflammatory state in patients with rheumatism, whereas VCAM-1 level in rheumatic patients may be associate with inflammatory reactions.

Comparative study evaluating antihistamine versus leukotriene receptor antagonist as adjuvant therapy for rheumatoid arthritis

PURPOSE

Investigating the efficacy and safety of rupatadine (RUP) versus montelukast (MON) as adjuvant therapy for patients with rheumatoid arthritis (RA).

METHODS

From December 2018 to December 2019, 75 patients with active RA were enrolled in this randomized double-blind placebo-controlled study. The patients were randomized into three groups (n = 25 in each group); methotrexate (MTX) group which received MTX 15-25 mg/week plus placebo tablet once daily; MTX/RUP group which received MTX plus RUP 10 mg once daily; and MTX/MON group which received MTX plus MON 10 mg once daily. The treatment duration was 3 months. At baseline and 3 months after treatment, blood samples were collected for the biochemical analysis of high-sensitivity C-reactive protein (hs-CRP), interleukins 8 and 17 (IL-8, IL-17), E-selectin, and clusterin (CLU) levels. Clinical and functional assessments using Disease Activity Score-CRP (DAS28-CRP) and Multidimensional Health Assessment Questionnaire (MDHAQ) were performed.

RESULTS

Both RUP and MON produced clinical and functional improvements which were translated by significant improvements in DAS28-CRP score and MDHAQ. Rupatadine significantly reduced all measured parameters (P < 0.05) except for IL-17 and CLU. Montelukast significantly decreased all measured variables (P < 0.05) except for E-selectin. Interleukin-8 was positively correlated with IL-17 and CLU, while hs-CRP was positively correlated with E-selectin and body mass index (BMI). Both drugs were well tolerated; somnolence was the common side effect for RUP. No neuropsychiatric events were reported with MON.

CONCLUSION

Rupatadine or montelukast may serve as a potential adjuvant therapy for patients with rheumatoid arthritis secondary to the preliminary evidence of efficacy and safety. ClinicalTrials.gov identifier NCT03770923, December 10, 2018.

Circulating and Synovial Pentraxin-3 (PTX3) Expression Levels Correlate With Rheumatoid Arthritis Severity and Tissue Infiltration Independently of Conventional Treatments Response

Aims

To determine the relationship between PTX3 systemic and synovial levels and the clinical features of rheumatoid arthritis (RA) in a cohort of early, treatment naïve patients and to explore the relevance of PTX3 expression in predicting response to conventional-synthetic (cs) Disease-Modifying-Anti-Rheumatic-Drugs (DMARDs) treatment.

Methods

PTX3 expression was analyzed in 119 baseline serum samples from early naïve RA patients, 95 paired samples obtained 6-months following the initiation of cs-DMARDs treatment and 43 healthy donors. RNA-sequencing analysis and immunohistochemistry for PTX3 were performed on a subpopulation of 79 and 58 synovial samples, respectively, to assess PTX3 gene and protein expression. Immunofluorescence staining was performed to characterize PTX3 expressing cells within the synovium.

Results

Circulating levels of PTX3 were significantly higher in early RA compared to healthy donors and correlated with disease activity at baseline and with the degree of structural damages at 12-months. Six-months after commencing cs-DMARDs, a high level of PTX3, proportional to the baseline value, was still detectable in the serum of patients, regardless of their response status. RNA-seq analysis confirmed that synovial transcript levels of PTX3 correlated with disease activity and the presence of mediators of inflammation, tissue remodeling and bone destruction at baseline. PTX3 expression in the synovium was strongly linked to the degree of immune cell infiltration, the presence of ectopic lymphoid structures and seropositivity for autoantibodies. Accordingly, PTX3 was found to be expressed by numerous synovial cell types such as plasma cells, fibroblasts, vascular and lymphatic endothelial cells, macrophages, and neutrophils. The percentage of PTX3-positive synovial cells, although significantly reduced at 6-months post-treatment as a result of global decreased cellularity, was similar in cs-DMARDs responders and non-responders.

Conclusion

This study demonstrates that, early in the disease and prior to treatment modification, the level of circulating PTX3 is a reliable marker of RA activity and predicts a high degree of structural damages at 12-months. In the joint, PTX3 associates with immune cell infiltration and the presence of ectopic lymphoid structures. High synovial and peripheral blood levels of PTX3 are associated with chronic inflammation characteristic of RA. Additional studies to determine the mechanistic link are required.

A new laboratory surrogate (Monocyte Chemotactic Protein-1) for Disease Activity Score28: a favourable indicator for remission in rheumatoid arthritis

This prospective one-year follow-up study was conducted from 835 visits in 178 rheumatoid arthritis (RA) patients. Tender-/swollen-joint count, Health Assessment Questionnaire Disability Index (HAQ-DI), Disease Activity Score 28-ESR (DAS28-ESR), DAS28-CRP, Simplified Disease Activity Index (SDAI) and DAS28-monocyte chemotactic protein-1 (DAS28-MCP-1) scores were obtained every 3 months. Radiographs of hands and feet were acquired at baseline and one year. We evaluated the correlation and accuracy of activity scores in predicting remission, HAQ-DI changes and radiographic changes. DAS28-MCP-1 correlated strongly with DAS28-ESR, DAS28-CRP and SDAI scores (0.830, 0.899 and 0.931, respectively, with all P < 0.001). Score changes of DAS28-MCP-1 were comparable to those of DAS28-ESR, DAS28-CRP and SDAI in predicting changes in HAQ-DI and bone erosion. DAS28-MCP-1 (<2.2) was better than DAS28-ESR (<2.6) in indicating modified American Rheumatism Association remission and 2011 American College of Rheumatology/European League Against Rheumatism remission (75.61% vs. 36.99% and 81.71% vs. 49.13%, respectively) with odds ratios of 5.28 and 4.62 (both P < 0.001), respectively. We compared DAS28-MCP-1 with SDAI (≦3.3) in indicating remission with odds ratios of 2.63 (P = 0.002) and 0.98, respectively (and DAS28-MCP-1 with DAS28-CRP < 2.5: 1.33 and 0.92). Therefore, DAS28-MCP-1 is useful as an alternative in assessing RA activity.

Asymmetric and symmetric dimethylarginine concentration as an indicator of cardiovascular diseases in rheumatoid arthritis patients: a systematic review and meta-analysis of case-control studies

Rheumatoid arthritis (RA) is the most common type of inflammatory arthritis leading to joint damage and physical disability. Cardiovascular diseases (CVDs) are considered a common comorbidity in patients with RA. However, the mechanism underlying its pathogenesis is not definitively explained. Endothelial dysfunction caused by impaired nitric oxide synthesis is an early indicator of cardiovascular disease. Asymmetric and symmetric dimethylarginine (ADMA and SDMA, respectively) the inhibitors of endothelial nitric oxide synthase (NOS) have emerged as novel CVD risk factor determiners. Concerning the unmet need to identify a salutary biomarker for CVD prediction, the purpose of this meta-analysis was to assess the serum/plasma ADMA and SDMA levels in RA patients compared with the healthy controls. A thorough literature search was performed in PubMed, Scopus, Web of Science, and Google Scholar to identify all studies reporting ADMA and/or SDMA levels in RA patients compared with healthy controls. The quality of studies was evaluated using the Newcastle-Ottawa scale (NOS). Pooled standard mean difference (SMD) with 95% confidence interval (CI) was used as the effect size in this study. We also conducted stratified analysis based on assay methods and median age of the participants. Fourteen articles were included. The pooled serum/plasma levels of ADMA were higher in RA patients compared with those of healthy controls (SMD = 1.02, 95% CI = 0.49 to 1.55); However, no statistical differences between RA patients and healthy controls in serum/plasma SDMA levels was seen (SMD = 0.57, 95% CI = -0.21 to 1.36). Subgroup analyses suggested that participants aged > 50 years had higher levels of ADMA rather than controls and the measurement method was a source of heterogeneity for ADMA. According to the results of this meta-analysis, ADMA measurement but not SDMA, can be useful for assessment of endothelial dysfunction as a predictor of CVD risk in RA patients. Prospero registration number: CRD42019121126.

Serum RANKL, osteoprotegerin (OPG) and RANKL/OPG ratio in children with systemic lupus erythematosus

Background

Systemic lupus erythematosus (SLE) patients have lower bone mineral density (BMD) compared with healthy individuals because of general, genetic, disease and medication-related factors. The disturbance of the receptor activator of nuclear factor-κB ligand (RANKL)/osteoprotegerin (OPG) ratio has been reported to be associated with low BMD in many disorders in adults and children alike.

Objectives

The objectives of this study were (i) to assess serum OPG, RANKL and RANKL/OPG ratio levels in SLE children and controls, (ii) to determine whether the cumulative glucocorticoid (CGCS) dose had any effect on the concentration of serum RANKL, OPG and RANKL/OPG ratio, and (iii) to determine the relation of these parameters to BMD.

Methods

We evaluated 50 SLE children and 50 age- and sex-matched healthy controls. RANKL and OPG were assessed in serum and compared between patients and controls. For SLE patients, a univariate followed by multivariable analysis were carried out to detect the possible predictors of the changes in RANKL, OPG and RANKL/OPG ratio levels. Lumbar BMD for all patients was assessed by dual-energy X-ray absorptiometry (DXA) scan and then correlated to different probable correlated factors.

Results

RANKL, OPG and RANKL/OPG ratio were significantly higher in SLE patients ( p ≤ 0.001). Univariate analysis showed significant correlations of RANKL with CGCS ( p ≤ 0.001) and with DXA scan z-score ( p = 0.007): OPG was significantly correlated to Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) score ( p = 0.001) and anti-double-stranded DNA ( p = 0.001), whereas RANKL/OPG was significantly correlated to duration of illness and DXA z-score ( p = 0.002). The multivariable analysis showed that DXA z-score was an independent predictor of RANKL and RANKL/OPG ratio ( p = 0.019 and 0.008, respectively), whereas SLEDAI score was an independent predictor of OPG levels. BMD was negatively correlated to disease duration ( p = 0.008) and CGCS dose ( p = 0.015), but no significant correlation has been found between BMD and cumulative SLEDAI score ( p = 0.29).

Conclusions

Serum RANKL/OPG ratio is elevated in Egyptian children with SLE and is considered a risk factor for reduced bone mass in these children. Other risk factors for low BMD include high CGCS dose and disease duration, supporting that osteoporosis in SLE is multifactorial.

PTX3 Intercepts Vascular Inflammation in Systemic Immune-Mediated Diseases

PTX3 is a prototypic soluble pattern recognition receptor, expressed at sites of inflammation and involved in regulation of the tissue homeostasis. PTX3 systemic levels increase in many (but not all) immune-mediated inflammatory conditions. Research on PTX3 as a biomarker has so far focused on single diseases. Here, we performed a multi-group comparative study with the aim of identifying clinical and pathophysiological phenotypes associated with PTX3 release. PTX3 concentration was measured by ELISA in the plasma of 366 subjects, including 96 patients with giant cell arteritis (GCA), 42 with Takayasu's arteritis (TA), 10 with polymyalgia rheumatica (PMR), 63 with ANCA-associated systemic small vessel vasculitides (AAV), 55 with systemic lupus erythematosus (SLE), 21 with rheumatoid arthritis (RA) and 79 healthy controls (HC). Patients with SLE, AAV, TA and GCA, but not patients with RA and PMR, had higher PTX3 levels than HC. PTX3 concentration correlated with disease activity, acute phase reactants and prednisone dose. It was higher in females, in patients with recent-onset disease and in those with previous or current active vasculitis at univariate analysis. Active small- or large- vessel vasculitis were the main independent variables influencing PTX3 levels at multivariate analysis. High levels of PTX3 in the blood can contribute to identify an increased risk of vascular involvement in patients with systemic immune-mediated diseases.

[Endothelial damage and circadian blood pressure profile in rheumatoid arthritis]

AIM

To study the influence of the state of endothelium on the daily profile of arterial pressure (AP) in patients with rheumatoid arthritis (RA).

MATERIALS AND METHODS

In 70 RA pts carried out C-reactive protein (CRP), vascular endothelial adhesion molecule type 1 (sVCAM-1), antigen von Willebrand Factor (AG WF), interleukin-8 (Il-8), rheumatoid factor (RF), IgG, endotheline-1 (ET-1), number of desquamated endotheliocytes cells (DE), VS, activity of renin by immunoenzyme analysis. The dysfunction of endothelium was evaluated by calculation of DE. The functional methods included the daily monitoring of arterial pressure (AP).

RESULTS

Arterial hypertension (AH) occurred in 40 (57.1%) pts. RA pts are revealed the signs of endothelial dysfunction, about which significant differences among the indices of activation of endothelium in comparison with control group testify. ET-1, sVCAM-1, vWF AG, Il-8, CRP content was higher in RA pts. Reliably above there was a number of DE. Reliable differences according to these indices depending of RA activity were discovered. With conducting of correlation analysis it is revealed, that markers of the activation of endothelium: sVCAM-1, vWF AG positively correlated with increasing RF IgG and indices of the immune inflammation: CRP, and DE number. In patients suffering from RA, showed signs of endothelial dysfunction. The positive correlation between endothelial damage and daily profile of AP show the relationship of these processes.

CONCLUSION

Positive correlations between the damage of endothelium and disturbance of AP daily profile testify about the interrelation of these processes.

Genetic regulation of dimethylarginines and endothelial dysfunction in rheumatoid arthritis

Rheumatoid Arthritis (RA) confers an increased cardiovascular disease (CVD) risk which accounts for much of the premature morbidity and mortality observed in this population. Alterations in vascular function and morphology leading to increased atherosclerotic burden are considered the main drivers of CVD in RA individuals with systemic inflammation playing a key role in the dysregulation of endothelial homeostasis and initiation of vascular injury. Dimethylarginines are endogenous inhibitors of nitric oxide (NO) synthase and have emerged as novel, independent biomarkers of CVD in a wide range of conditions associated with vascular pathology. In RA several reports have demonstrated abnormal dimethylarginine metabolism attributable to various factors such as systemic inflammation, decreased degradation or upregulated synthesis. Although a causal relationship between dimethylarginines and vascular damage in RA has not been established, the tight interrelations between inflammation, dimethylarginines and endothelial dysfunction suggest that determination of dimethylarginine regulators may shed more light in the pathophysiology of the atherosclerotic process in RA and may also provide new therapeutic targets. The Alanine-Glyoxylate Aminotransferase 2 (AGTX2)-dependent pathway is a relatively recently discovered alternative pathway of dimethylarginine catabolism and its role on RA-related atherosclerotic disease is yet to be established. As factors affecting dimethylarginine concentrations linked to CVD risk and endothelial dysfunction are of prominent clinical relevance in RA, we present preliminary evidence that gene variants of AGTX-2 may influence dimethylarginine levels in RA patients and provide the rationale for larger studies in this field.

Meta-Analysis of Asymmetric Dimethylarginine Concentrations in Rheumatic Diseases

Raised circulating concentrations of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase (NOS), have been reported in several rheumatic diseases (RDs). However, the strength of this relationship is unclear. Therefore, the aim of this systematic review and meta-analysis was to evaluate the magnitude and the robustness of the association between ADMA concentrations and RDs. We calculated standardized mean differences (SMD, with 95% confidence intervals, CI). Study heterogeneity was evaluated by meta-regressions and sensitivity analyses according to type of RDs, conventional cardiovascular risk factors, inflammatory markers, and type of ADMA assessment methodology. Thirty-seven studies with a total of 2,982 subjects (1,860 RDs patients and 1,122 healthy controls) were included in our meta-analysis. Pooled results showed that ADMA concentrations were significantly higher in patients with RDs than in healthy controls (SMD = 1.27 µmol/L, 95% CI 0.94–1.60 µmol/L; p < 0.001). However, the between-studies heterogeneity was high. Differences in ADMA concentrations between controls and RDs patients were not significantly associated with inflammatory markers, increasing age, lipid concentrations, body mass index, blood pressure, or methodology used to assess ADMA. Furthermore, subgroup analysis showed no difference across RDs. This meta-analysis showed that, in the context of significant between-study heterogeneity, circulating concentrations of ADMA are positively related to RDs.

α-2,3-Sialyltransferase 1 and neuraminidase-3 from monocytes in patients with rheumatoid arthritis correlate with disease activity measures: A pilot study

BACKGROUND

We decided to study the association of monocyte α-2,3-sialyltransferase 1 (ST3Gal-1), neuraminidase-3 (Neu3), α-2,6-sialyltransferase 1 (ST6Gal-1), and neuraminidase-1 (Neu1) levels with disease activity score 28 (DAS28) in human rheumatoid arthritis (RA), considering that mouse monocytes' sialic acid (SIA) levels relate to their phagocytosis and IgG binding ability.

METHODS

ST3Gal-1, Neu3, ST6Gal-1, Neu1, α-2,3-SIA, and α-2,6-SIA levels on RA peripheral blood monocytes, T cells, and polymorphonuclear cells were determined by using fluorochrome-conjugated anti-cell-specific marker antibodies and fluorochrome-conjugated anti-enzyme antibodies. Simple correlation and linear regression were used to correlate enzyme levels with DAS28.

RESULTS

RA monocyte ST3Gal-1 and Neu3 levels correlated with DAS28 in patients having DAS28 >5.1 (r = 0.469, p = 0.002; r = 0.410, p = 0.006, respectively). When multivariable analysis was performed for erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and SIA-related enzyme levels in different cell types as independent variables with DAS28 as a dependent variable, monocyte ST3Gal-1 levels correlated with DAS28 (p = 0.009) but not ESR and CRP in patients having DAS28 >5.1 (both p ≥ 0.292). RA monocyte ST3Gal-1 levels correlated with DAS28 (p = 0.010) and with ESR (p < 0.001) at month 0 when applied to all RA patients including both remission and nonremission groups in multivariable analysis. The latter findings persisted longitudinally at month 3.

CONCLUSION

Monocyte ST3Gal-1 and Neu3 levels correlated longitudinally with DAS28 by two different methods suggest that monocyte ST3Gal-1 and Neu3 levels may be used as biomarkers to monitor RA disease activity.

Cell adhesion molecules and plasminogen activator inhibitor type-1 (PAI-1) in patients with rheumatoid arthritis: influence of metabolic syndrome

Rheumatoid arthritis (RA) is a chronic inflammatory and systemic disease characterized by endothelial activation. The main objective of this study was to verify the profile of cell adhesion molecules (CAM) in RA patients, and the influence of metabolic syndrome (MetS) and drugs used in the treatment of RA in this profile. A second objective was to propose models of prediction of activity in RA using these biomarkers. A total of 115 healthy individuals and 144 RA patients were enrolled. Disease activity was determined by DAS28 (disease activity score 28) based on erythrocyte sedimentation rate (DAS28-ESR) or C-reactive protein (DAS28-CRP). Serum CAM and plasminogen activator inhibitor type-1 (PAI-1), anthropometric and immunological parameters were measured. Vascular cell adhesion molecule-1 (VCAM-1) was significantly decreased, and PAI-1 was significantly higher in RA patients as compared to controls. Binary logistic regression analysis showed that VCAM-1, CRP, and tumor necrosis factor-α (TNF-α) predicted RA with a sensitivity of 95.9% and a specificity of 89.5%. 42.9% of the variance in DAS28-ESR and 49.2% of the variance in DAS28-CRP are explained by increased PAI-1, TNF-α, body mass index (BMI) and decreased platelet endothelial cell adhesion molecule 1 (PECAM-1). Our data show that lower levels of VCAM-1 are associated with RA independently of MetS, while increased PAI-1 levels were associated with both RA and MetS and increased selectins (E-selectin and P-selectin) were exclusively associated with MetS and not with RA. A model to predict disease activity based on PECAM-1, PAI-1, TNF-α, age and BMI is proposed.

The Long Pentraxin 3 Plays a Role in Bone Turnover and Repair

Pentraxin 3 (PTX3) is an inflammatory mediator acting as a fluid-phase pattern recognition molecule and playing an essential role in innate immunity and matrix remodeling. Inflammatory mediators also contribute to skeletal homeostasis, operating at multiple levels in physiological and pathological conditions. This study was designed to investigate the role of PTX3 in physiological skeletal remodeling and bone healing. Micro-computed tomography (μCT) and bone histomorphometry of distal femur showed that PTX3 gene-targeted female and male mice (ptx3^−/−) had lower trabecular bone volume than their wild-type (ptx3^+/+) littermates (BV/TV by μCT: 3.50 ± 1.31 vs 6.09 ± 1.17 for females, p < 0.0001; BV/TV 9.06 ± 1.89 vs 10.47 ± 1.97 for males, p = 0.0435). In addition, μCT revealed lower trabecular bone volume in second lumbar vertebra of ptx3^−/− mice. PTX3 was increasingly expressed during osteoblast maturation in vitro and was able to reverse the negative effect of fibroblast growth factor 2 (FGF2) on osteoblast differentiation. This effect was specific for the N-terminal domain of PTX3 that contains the FGF2-binding site. By using the closed transversal tibial fracture model, we found that ptx3^−/− female mice formed significantly less mineralized callus during the anabolic phase following fracture injury compared to ptx3^+/+ mice (BV/TV 17.05 ± 4.59 vs 20.47 ± 3.32, p = 0.0195). Non-hematopoietic periosteal cells highly upregulated PTX3 expression during the initial phase of fracture healing, particularly CD51⁺ and αSma⁺ osteoprogenitor subsets, and callus tissue exhibited concomitant expression of PTX3 and FGF2 around the fracture site. Thus, PTX3 supports maintenance of the bone mass possibly by inhibiting FGF2 and its negative impact on bone formation. Moreover, PTX3 enables timely occurring sequence of callus mineralization after bone fracture injury. These results indicate that PTX3 plays an important role in bone homeostasis and in proper matrix mineralization during fracture repair, a reflection of the function of this molecule in tissue homeostasis and repair.

Acute phase reactant, Pentraxin 3, as a novel marker for the diagnosis of rheumatoid arthritis

INTRODUCTION

Pentraxins are a group of highly conserved acute-phase reactant proteins and play crucial role as modulators of inflammatory processes. Pentraxin 3 (PTX3) is primarily produced and released by vascular cell wall, hence, we attempt to establish the role of PTX3 as a biomarker for Rheumatoid Arthritis (RA) compared to CRP.

METHODS

Thirty patients having active RA as cases and 30 osteoarthritis (OA) patients as controls were recruited. Paired serum and synovial fluid samples were analysed for concentrations of both PTX3 and CRP by using high sensitivity ELISA kit and ROC curve was plotted.

RESULTS

Concentrations of PTX3 and CRP were significantly higher in RA patient serum (p < 0.0001) as well as in synovial fluid (p < 0.0001) and correlated with disease severity. Upon correlation analysis, positive correlation was found between serum and synovial fluid concentrations of PTX3 and CRP. The diagnostic potential of PTX3 was observed in synovial fluid while combination of PTX3 and CRP showed better sensitivity in serum.

CONCLUSION

PTX3 found to be sensitive non-invasive indicator of clinical arthritic activity in RA patients when compared to traditional markers like CRP. Combination of PTX3 and CRP could serve as better differential diagnostic markers for RA after validation in larger patient cohort.

Circulating osteoprotegerin levels are elevated in rheumatoid arthritis: a systematic review and meta-analysis

This study aimed to systemically review the evidence regarding the relationship between the circulating blood osteoprotegerin (OPG) level and rheumatoid arthritis (RA), as well as the potential influential factors. Research related to plasma/serum OPG levels in RA patients and healthy controls were gathered using PubMed, EMBASE, and The Cochrane Library database (up to Jan. 1, 2017). Pooled standard mean difference (SMD) with 95% confidence interval (CI) was calculated by fixed-effects or random-effect model analysis. Heterogeneity test was performed by the Q statistic and quantified using I ², and publication bias was evaluated using a funnel plot and Egger's linear regression test. After searching databases, 443 articles were obtained, and 11 studies with 710 RA patients and 561 controls were finally included. Meta-analysis revealed that, compared with the control group, the OPG level was significantly higher in the RA group (P < 0.001), with the SMD of 1.02 and 95%CI (0.20, 1.84). Subgroup analyses showed that race, disease duration, body mass index (BMI), and disease activity score based on the assessment of 28 joints (DAS28) were positively associated with OPG level in RA patients. Our meta-analysis revealed a significantly higher circulating OPG level in RA patients, and it was influenced by race, disease duration, BMI, and DAS28.

Glucocorticoids improve endothelial function in rheumatoid arthritis: a study in rats with adjuvant-induced arthritis

To determine the effect of glucocorticoids (GCs) on endothelial dysfunction (ED) and on traditional cardiovascular (CV) risk factors in the adjuvant-induced arthritis (AIA) rat model. At the first signs of AIA, a high dose (HD) [10 mg/kg/day, intraperitoneally (i.p.), GC-HD] or low dose (LD) (1 mg/kg/day, i.p., GC-LD) of prednisolone was administered for 3 weeks. Endothelial function was studied in aortic rings relaxed with acetylcholine (Ach) with or without inhibitors of nitric oxide synthase (NOS), cyclooxygenase 2 (COX-2), arginase, endothelium derived hyperpolarizing factor (EDHF) and superoxide anions ( O2-°) production. Aortic expression of endothelial NOS (eNOS), Ser1177-phospho-eNOS, COX-2, arginase-2, p22^phox and p47^phox was evaluated by Western blotting analysis. Arthritis scores, blood pressure, heart rate and blood levels of cytokines, triglycerides, cholesterol and glucose were measured. GC-HD but not GC-LD reduced arthritis score significantly and improved Ach-induced relaxation (P < 0·05). The positive effect of GC-HD resulted from increased NOS activity and EDHF production and decreased COX-2/arginase activities and O2-° production. These functional effects relied upon increased phospho-eNOS expression and decreased COX-2, arginase-2 and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase expression. Despite the lack of effect of GC-LD on ED, it increased NOS and EDHF and down-regulated O2-° pathways but did not change arginase and COX-2 pathways. GC-HD increased triglycerides levels and blood pressure significantly (P < 0·05). Both doses of GCs decreased to the same extent as plasma interleukin (IL)-1β and tumour necrosis factor (TNF)-α levels (P < 0·05). Our data demonstrated that subchronic treatment with prednisolone improved endothelial function in AIA via pleiotropic effects on endothelial pathways. These effects occurred independently of the deleterious cardiometabolic effects and the impact of prednisolone on systemic inflammation.

Endothelial injury in rheumatoid arthritis: a crosstalk between dimethylarginines and systemic inflammation

Background

Symmetric (SDMA) and asymmetric (ADMA) dimethylarginines have emerged as novel biomarkers of cardiovascular disease (CVD) in several disease settings associated with atherosclerosis. Rheumatoid arthritis (RA) is a chronic systemic inflammatory disease characterized by high CVD mortality and morbidity. ADMA and SDMA levels are abnormal in RA patients, but their correlation with assessments of endothelial function and structure remains unknown. We aimed to investigate whether SDMA and ADMA are associated with carotid intima media thickness (cIMT) and arterial stiffness as well as non-invasive assessments of in vivo micro- and macrovascular endothelial function in RA patients with high systemic inflammatory load.

Method

ADMA and SDMA levels were measured using immunoassays in 197 RA individuals. Twenty-six of these [23 (86.4%) females, median age 70, quartiles (60, 73)] were identified as having high inflammatory markers [erythrocyte sedimentation rate (ESR) >25 mm/hr and C-reactive protein (CRP) > 5 mg/L], and were compared to the remainder of the cohort. Patients underwent assessments of microvascular endothelium-dependent and endothelium-independent function [laser Doppler imaging with iontophoresis of acetylcholine (Ach) and sodium-nitroprusside (SNP) respectively], macrovascular endothelium-dependent and endothelium-independent function (flow-mediated dilatation and glyceryl-trinitrate-mediated dilation respectively), and vascular morphology [pulse wave analysis, and carotid intima media thickness (cIMT)].

Results

Significant interactions with inflammation were detected in the associations between ACh and both SDMA (p = 0.014) and ADMA:SDMA ratio (p = 0.027), as well as between SNP and SDMA (p = 0.042) and between arterial stiffness and ADMA:SDMA (p = 0.036), with the associations being stronger in the patients with high inflammatory markers in each case.

Conclusions

Besides their emerging role as markers of endothelial dysfunction SDMA and ADMA may promote endothelial injury in RA as mediators of the adverse effects of systemic inflammation on micro- and macrovasculature respectively in patients with active disease.

Pentraxin 3 in serum and synovial fluid of patients with rheumatoid arthritis with and without autoantibodies

OBJECTIVES

Pentraxin 3 (PTX3) is a locally produced multifunctional protein involved in inflammation, matrix deposition, and immunity. As patients with seropositive rheumatoid arthritis (RA) have a more severe disease course and higher risk of joint destruction than seronegative patients, the aim of the present study was to examine differences in PTX3 in synovial fluid (SF) (and serum) in seropositive compared to seronegative RA, and other local markers of inflammation and destruction.

METHOD

Ninety-seven RA patients with knee effusion were included. Serum and SF levels of PTX3, as well as serum levels of anti-citrullinated protein antibody and rheumatoid factor of immunoglobulin A and M subclasses, and markers of inflammation and potential destruction in SF: white blood cell counts, tumour necrosis factor, interleukin-6, vascular endothelial growth factor, metalloproteinase 3, and cartilage oligomeric matrix protein, were analysed. In addition, a radiographic knee examination was performed.

RESULTS

Seropositive patients had significantly higher PTX3 levels in SF than seronegative patients, whereas there was no difference for serum levels. SF-PTX3 levels correlated with disease activity and with local inflammatory markers, especially polymorphonuclear cells, and with autoantibody levels. There was no correlation between PTX3 levels in serum and SF.

CONCLUSION

The correlation of disease activity and autoantibody levels with SF-PTX3 levels in antibody-positive patients suggests a role for PTX3 in the inflammatory process specifically in seropositive RA joints, and supports the hypothesis that seropositive and seronegative RA are different disease entities. Polymorphonuclear granulocytes may be an important source of PTX3 in RA SF.

A New Explanation of Inflammation in Rheumatoid Arthritis Patients With Respect to Claudin-5, Matrix Metalloproteinase-9, and Neuroserpin

Objectives

This study aims to investigate the relationship between neuroserpin (NSP) and claudin-5, as well as matrix metalloproteinase-9 (MMP-9), with respect to clinical activity of disease in patients with rheumatoid arthritis.

Patients and methods

The study included a total of 75 patients (18 males, 57 females; mean age 48.12±11.23 years; range 20 to 60 years) who were admitted to the rheumatology outpatient facility at the Medical Faculty Hospital, Sakarya University, in October 2014. Patients were divided into four groups based on their Disease Activity Score 28 (DAS28) scores as remission group (n=16, DAS28 <2.6), low disease activity group (n=16, DAS28 between 2.6-3.2), moderate disease activity group (n=28, DAS28 between 3.2-5.1), and high disease activity group (n=15, DAS28 >5.1). Ten healthy subjects (HS) served as controls.

Results

Claudin-5, MMP-9, and NSP levels were significantly different in rheumatoid arthritis patients compared to HS (p=0.035, 0.026, and 0.014, respectively). Additionally, there were no differences between claudin-5 levels and disease activity among all RA groups. However, compared to HS, patient groups showed a significant difference (p=0.035) in terms of claudin-5 levels. Serum levels of MMP-9 were significantly different in moderate disease activity group compared to HS (p=0.013). Levels of NSP were significantly different in moderate disease activity and high disease activity groups compared to HS (p=0.008 and 0.031, respectively).

Conclusion

Our study demonstrated the differential associations of endothelial function/dysfunction biomarkers and disease activity in rheumatoid arthritis. How and why this impairment occurs is not fully understood and more data regarding NSP, MMP, and claudin expression in plasma are warranted.

Osteoimmunology: from mice to humans

The immune system has been recognized as one of the most important regulators of bone turnover and its deregulation is implicated in several bone diseases such as postmenopausal osteoporosis and inflammatory bone loss; recently it has been suggested that the gut microbiota may influence bone turnover by modulation of the immune system. The study of the relationship between the immune system and bone metabolism is generally indicated under the term 'osteoimmunology'. The vast majority of these studies have been performed in animal models; however, several data have been confirmed in humans as well: this review summarizes recent data on the relationship between the immune system and bone with particular regard to the data confirmed in humans.

In vivo microvascular and macrovascular endothelial function is not associated with circulating dimethylarginines in patients with rheumatoid arthritis: a prospective analysis of the DRACCO cohort

OBJECTIVES

To examine associations between asymmetric (ADMA), symmetric dimethylarginine (SDMA) and ADMA:SDMA ratio with assessments of endothelial function and coronary artery perfusion in RA patients.

METHODS

ADMA and SDMA levels were measured in 197 RA individuals [144 (77.4%) females, median age: 66 years (quartiles: 59-73)]. Patients underwent assessments of microvascular endothelium-dependent and endothelium-independent function, macrovascular endothelium-dependent and endothelium-independent function and vascular morphology (pulse wave analysis, carotid intima-media thickness (cIMT), and carotid plaque). Coronary perfusion was assessed by subendocardial viability ratio (SEVR).

RESULTS

SEVR correlated with SDMA (r = 0.172, p = 0.026) and ADMA:SDMA (r = -0.160, p = 0.041) in univariable analysis, but not in multivariable analysis accounting for confounding factors. Neither ADMA:SDMA ratio nor SDMA were significantly correlated with microvascular or macrovascular endothelial function, or with arterial stiffness and cIMT. Within subgroup of patients (n = 26) with high inflammatory markers, a post-hoc analysis showed that SDMA and the ADMA:SDMA ratio were significantly associated with endothelium-dependent microvascular function in univariable analysis, with Pearson's r correlation coefficients of -0.440 (p = 0.031) and 0.511 (p = 0.011), respectively. Similar finding were established between ADMA:SDMA ratio and arterial stiffness in univariable analysis, with Pearson's r of 0.493, (p = 0.024).

CONCLUSION

Dimethylarginines were not found to be significantly associated with several assessments of vascular function and morphology in patients with RA, however, post-hoc analysis indicates that there may be associations in patients with raised inflammatory markers. Our results suggest that dysregulated NO metabolism may not be the sole mechanism for the development of preclinical atherosclerosis in RA.

Sialyltransferase and Neuraminidase Levels/Ratios and Sialic Acid Levels in Peripheral Blood B Cells Correlate with Measures of Disease Activity in Patients with Systemic Lupus Erythematosus and Rheumatoid Arthritis: A Pilot Study

Objective

We attempted to determine whether the level of enzymes sialyltransferase (ST) and neuraminidase (Neu) and sialic acid (SIA) in patients with systemic lupus erythematosus (SLE) correlates with the SLE Disease Activity Index (SLEDAI) and in patients with rheumatoid arthritis (RA) correlates with the Disease Activity Score28 (DAS28).

Methods

We examined cell-surface levels of ST6Gal-1, Neu1, ST3Gal-1, Neu3, α-2,6-SIA, and α-2,3-SIA by using fluorescent anti-enzyme antibodies, fluorescent-conjugated Sambucus nigra lectin, and fluorescent-conjugated Maackia amurensis lectin on blood cells in SLE and RA patients and assessed correlations of these levels with SLEDAI and with DAS28. Areas under the curve (AUC) were calculated for different variables against SLEDAI.

Results

The B-cell ST3Gal-1/Neu3 ratio positively correlated with SLEDAI scores (ρ = 0.409 and P = 0.002, statistically significant after Bonferroni’ correction for multiple analyses.). It was supported by the inverse correlation of B-cell Neu3 levels with SLEDAI scores (ρ = −0.264, P = 0.048). The B-cell ST3Gal-1/Neu3 ratio against SLEDAI yielded an AUC of 0.689, which was comparable to that of anti-dsDNA levels at 0.635. In contrast, both ST3Gal-1 and Neu3 levels of RA B cells (r = 0.376, P = 0.013; r = 0.425, P = 0.005, respectively) correlated positively with high disease-activity DAS28 scores.

Conclusion

B-cell ST3Gal-1/Neu3 ratios in SLE and B-cell ST3Gal-1 and Neu3 levels in RA with high disease-activity DAS28 scores correlated with disease activity measures and may be useful in monitoring disease activities.

Urinary osteoprotegerin: a potential biomarker of lupus nephritis disease activity

OBJECTIVES

Urinary biomarkers may help in identification, treatment and assessment of response in patients with lupus nephritis (LN). Osteoprotegerin (OPG) is produced by the kidneys and lymphoid cells and may reflect renal disease activity better. The data on its utility are sparse.

METHODS

Fifty-eight patients with active LN (AN), 24 with active non-renal disease (ANR) and 39 with inactive disease (ID) were included. Median disease duration was 32 (1-204) months and median age was 27 (12-50) years. AN patients were followed up every three months for one year. Urine and serum samples were collected for OPG measurement by ELISA (pg/ml) and urinary values were normalised for creatinine excretion (pg/mg). Urine samples from 24 healthy individuals (HCs) and 20 patients each of rheumatoid arthritis (RA) and diabetic nephropathy (DM) served as controls. Variables were expressed as median (range).

RESULTS

At baseline, normalised urinary OPG (uOPG) was significantly higher (p < 0.001) in AN (1229 (0-8577)) than ANR (236 (0-14713)), ID (463 (7-4253)), HCs (366 (120-2849)) and DM (350 (127-1577)) but it was not different from RA (1511 (122-8849)). uOPG correlated modestly with rSLEDAI (r = 0.4, p < 0.001) and SLEDAI (r = 0.31, p < 0.001) but not with serum OPG (sOPG). uOPG but not sOPG could differentiate between AN and ANR groups. In the longitudinal study, uOPG and sOPG decreased significantly with treatment at all follow-up visits but the trend of fall in sOPG was erratic. uOPG values at baseline, 3, 6, 9 and 12 months were 1229 (0-8577), 466 (3-4874), 104 (0-1598), 325 (0-4025) and 555 (6-6771) pg/mg, respectively. uOPG but not sOPG rose before conventional markers in three patients who had a relapse of LN. In two patients who developed chronic kidney disease, uOPG remained persistently high. For differentiating AN from ANR patients, uOPG performed the best on receiver operator characteristics analysis (AUC = 0.72) when compared with anti-dsDNA antibodies, C3, C4 and sOPG.

CONCLUSION

uOPG is derived from kidneys and helps differentiate active SLE patients with and without LN. It shows modest correlation with disease activity and has a potential to predict poor response to therapy and relapse of LN.

Endothelial Dysfunction in Rheumatoid Arthritis: Mechanistic Insights and Correlation with Circulating Markers of Systemic Inflammation

Objectives

To determine mechanisms involved in endothelial dysfunction (ED) during the course of arthritis and to investigate the link between cytokines, chemokines and osteoprotegerin.

Approach and Results

Experiments were conducted on aortic rings at day 4 (preclinical), day 11 (onset of disease), day 33 (acute disease) and day 90 (chronic disease) after adjuvant-induced arthritis (AIA) in Lewis rats. At day 4, the unique vascular abnormality was a reduced norepinephrine-induced constriction. At day 11, endothelial function assessed by the relaxation to acetylcholine was normal despite increased cyclo-oxygenase-2 activity (COX-2) and overproduction of superoxide anions that was compensated by increased nitric oxide synthase (NOS) activity. At day 33, ED apparition coincides with the normalization of NOS activity. At day 90, ED was only observed in rats with a persisting imbalance between endothelial NOS and COX-2 pathways and higher plasma levels of IL-1β and TNFα. Plasma levels of IL-1β, TNFα and MIP-1α negatively correlated with Ach-induced relaxation throughout the course of AIA.

Conclusions

Our data identified increased endothelial NOS activity as an important compensatory response that opposes the ED in the early arthritis. Thereafter, a cross-talk between endothelial COX-2/NOS pathways appears as an important element for the occurrence of ED. Our results encourage determining the clinical value of IL-1β, TNFα and MIP-1α as biomarkers of ED in RA.

Associations between asymmetric dimethylarginine, homocysteine, and the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism (rs1801133) in rheumatoid arthritis

OBJECTIVES

The aim of our study was to determine whether asymmetric dimethylarginine (ADMA) levels are associated with homocysteine (Hcy) and methylenetetrahydrofolate reductase (MTHFR) C677T (rs1801133) gene variants in patients with rheumatoid arthritis (RA).

METHOD

Serum ADMA and Hcy levels were measured in 201 RA individuals [155 (77.1%) females, median age 67 years (interquartile range 59-73)]. The MTHFR C677T polymorphism was assessed by using the LightCyclerTM System. Initially, ADMA was compared across the categories of MTHFR using a one-way analysis of variance (ANOVA), followed by a multivariate model, which accounted for Hcy, age, erythrocyte sedimentation rate (ESR), and homeostatic model assessment (HOMA).

RESULTS

In univariable analysis, ADMA differed significantly across the categories of MTHFR (p = 0.037). Patients with the MTHFR 677TT genotype had the highest ADMA levels, with a mean of 0.62 (SE = 0.03), significantly higher than either those patients carrying the MTHFR 677CT (0.55, SE = 0.01) or the MTHFR 677CC (0.55, SE = 0.01) genotype (p = 0.042) in both cases. In the multivariable model, Hcy (p = 0.022) and ESR (p < 0.001) were found to have significant positive associations with ADMA but the relationship between MTHFR gene variants and ADMA was found to be non-significant (p = 0.102).

CONCLUSIONS

Hcy and ADMA are significantly associated in RA. It is plausible that abnormal Hcy metabolism plays an important role in premature atherosclerosis in RA by promoting ADMA accumulation and leading to the derangement of vascular haemostasis.

Inhibition of each module of connective tissue growth factor as a potential therapeutic target for rheumatoid arthritis

We previously reported the importance of connective tissue growth factor (CTGF) in rheumatoid arthritis (RA). CTGF contains four distinct modules connected in tandem, namely insulin-like growth factor-binding protein (IGFBP)-like, von Willebrand factor (vWF) type C repeat, thrombospondin type 1 (TSP-1) repeat, and carboxyl-terminal (CT) modules. The relationships between each of these modules of CTGF and RA remain unknown. Here, we analyzed how inhibition of each CTGF module affects the pathophysiology of RA. We conducted stimulation and suppression experiments on synovial cells (MH7A) obtained from patients with RA. Moreover, we examined angiogenesis by means of a tube-formation assay performed using human umbilical vein endothelial cells (HUVECs), and we used tartrate-resistant acid phosphatase (TRAP) staining to analyze osteoclastogenesis. Our results showed that M-CSF/RANKL-mediated osteoclastogenesis was enhanced when CTGF was added, but the effect of CTGF was neutralized by mAbs against CTGF modules 1-4. Furthermore, CTGF treatment of HUVECs induced formation of tubular networks, which resulted in acceleration of the angiogenesis of RA synoviocytes, and quantification showed that this tubular-network formation was also disrupted by anti-CTGF module 1-4 mAbs. Lastly, TNF-α enhanced the expression of CTGF and matrix metalloproteinase-3 (MMP3) in MH7A cells, and this enhancement was potently neutralized by mAbs against CTGF modules 1, 3 and 4. Thus, our results indicate that not only a mAb against CTGF but also mAbs against each specific module of CTGF might serve as potential therapeutic agents in the treatment of RA.

Symmetric Dimethylarginine Is Not Associated with Cumulative Inflammatory Load or Classical Cardiovascular Risk Factors in Rheumatoid Arthritis: A 6-Year Follow-Up Study

Symmetric dimethylarginine (SDMA) indirectly inhibits nitric oxide (NO) synthesis and predicts cardiovascular and all-cause mortality in high-risk patients. The aim of our study was to investigate the associations of cumulative inflammatory burden (assessed by serial measurements of inflammatory markers) and classical cardiovascular (CV) disease risk factors with SDMA in RA patients. 201 RA patients (155 females, median age 67 (59–73)) were assessed at baseline (2006). Classical CV disease risk factors were recorded and systemic inflammation was determined by the measurement of C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). At follow-up (2012) SDMA levels were measured by enzyme-linked immunosorbent assay. Mean SDMA levels in RA population were 0.40 (0.40–0.53) μmol/L. No significant association between SDMA and cumulative inflammatory load was established in the analysis. SDMA levels were not found to be significantly related to CV disease risk factors. We explored the potential relationship between SDMA and cumulative inflammatory burden in patients with RA and obtained negative results. SDMA did not relate to CV disease risk factors in our population and its clinical significance as a surrogate marker of endothelial dysfunction in patients with RA remains to be determined.

Serum Adenosine Deaminase as Inflammatory Marker in Rheumatoid Arthritis

BACKGROUND

Rheumatoid arthritis (RA) is a prototypical inflammatory joint disease. The degree of inflammation is reflected in the extent of joint damage, which further has influence on the quality of life of patients with RA, including risk of atherosclerosis. Hence, besides clinical indices, estimation of degree of inflammation using biochemical markers helps in effecting optimum treatment strategies. C-reactive protein (CRP) is established as an inflammatory marker in patients with RA. Adenosine deaminase (ADA), an enzyme of purine metabolism is considered as a marker of cell mediated immunity and has also been suggested as a marker of inflammatory process in RA. The present study attempts to study the efficacy of serum ADA activity as an inflammatory marker in RA.

MATERIALS AND METHODS

Forty six RA patients and forty six age and sex matched healthy controls were included in the study. ADA activity and high sensitivity C-reactive protein (hsCRP) levels in serum were measured in all the subjects. Statistical analyses were done using Medcalc statistical software version 12.2.2.

RESULTS

ADA activity and hsCRP levels were increased in RA patients compared to controls (p<0.0001 and 0.0001 respectively). Significant positive correlation was obtained between hsCRP and ADA in patients (r=0.316, p=0.033). Receiver operating characteristic (ROC) curve analysis revealed statistically significant area under curve (AUC) for ADA that is comparable to that obtained for hsCRP (0.776, p<0.0001 for ADA, 0.726, p<0.0001 for hsCRP). Similar diagnostic utility was obtained with ROC generated cut-off value of 25.3 IU/L (82.6% sensitivity and 65.2% specificity) and with control mean value of 23.48 IU/L (86.96% sensitivity and 54.35% specificity) for ADA.

CONCLUSION

Findings of the present study indicate the importance of ADA as a marker of inflammation. Considering the higher sensitivity obtained, we propose control mean (23.48 IU/L) as a cut-off for serum ADA activity as an inflammatory marker. Owing to the simplicity and also the cost effectiveness of ADA assay, ADA may be recommended as a marker of inflammation in patients with RA. However, further larger and well controlled studies are needed to establish its role as inflammatory marker.

Symmetric dimethylarginine (SDMA) serum levels in rheumatoid arthritis: correlations with insulin resistance and disease activity scores

Vascular abnormalities predisposing to atherosclerosis are present in patients with rheumatoid arthritis (RA) and associate with excess cardiovascular risk. Symmetric dimethylarginine (SDMA), an endogenous inhibitor of nitric oxide (NO) synthase activity, has been recognised as novel risk factor for endothelial dysfunction and cardiovascular disease. We aimed to compare SDMA levels in RA patients and controls and to investigate whether they are influenced by demographic, inflammatory or metabolic factors. Serum SDMA levels were measured in 197 RA individuals [median age: 67 years (quartiles: 59-3), 153 (78 %) females] and 82 controls [median age: 44 years [quartiles: 33-55, 50 (61 %) females]. Routine biochemistry tests, lipid profile, glycemic profile [glucose, insulin, homeostasis model assessment (HOMA-IR), quantitative insulin sensitivity check index (QUICKI)], as well as inflammatory markers were measured in all patients. Paired analysis was employed for the comparison of SDMA in two groups and multivariable regression models were performed to identify predictors of SDMA in the RA cohort. SDMA was significantly lower in RA than control patients in both unpaired and paired analyses (P < 0.001 and P = 0.005, respectively), with the magnitude of the difference being similar in both models. QUICKI (P = 0.005) and disease activity score-28 (P = 0.007) were positively related to SDMA in the RA cohort, whilst a negative correlation with renal function (eGFR) was detected (P = 0.005). The molecular explanation of lower serum SDMA is unclear, but the established relationships with indices of disease activity and insulin resistance, may underline the pathogenetic role of the L-arginine/NO pathway dysregulation in the development of atherosclerosis in RA. The biological and clinical importance of SDMA in RA remains to be evaluated in clinical and experimental studies.

Roles of claudin-5 and von Willebrand factor in patients with rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disorder that affects approximately 1% of the world's population. The pathogenesis of RA is not understood fully. It is assumed that endothelial function is associated with the proinflammatory state of RA. Endothelial dysfunction/activation reflects the increased level of von Willebrand factor (vWF) and a shift toward prothrombotic activity of the endothelium. The present study was performed to investigate the possible relationships between vWF and claudin-5 and the level of disease activity in patients with RA. The study population was divided into four groups according to the disease activity score in 28 joints (DAS28): remission group (RG), 18 patients (DAS28 < 2.6); low disease activity group (LDAG), 23 patients (DAS28 > 2.6-3.2); moderate disease activity (MDAG), 23 patients (DAS28 > 3.2-5.1); high disease activity group (HDAG), 14 patients (DAS28 > 5.1); and control group (CG), 10 healthy subjects. Claudin-5 and vWF assessment were derived from serum samples gathered from the patients known to have RF and anti-CCP titers in the normal ranges. A high positive association of claudin-5 and vWF with the MDAG was observed (P < 0.001). The results of our study indicated that the relationship between vWF and claudin-5, which are indicators of endothelial cell dysfunction and tight junction activity, may be a predictor of disease activity. Further studies are required to investigate these pathways to shed light on the roles of claudin-5 and vWF in the progression of inflammation and other vascular conditions.

Blood monocyte subsets and selected cardiovascular risk markers in rheumatoid arthritis of short duration in relation to disease activity

OBJECTIVES

To evaluate blood monocyte subsets and functional monocyte properties in patients with rheumatoid arthritis (RA) of short duration in the context of cardiovascular (CV) risk and disease activity.

METHODS

We studied conventional markers of CV risk, intima media thickness (IMT), and blood monocyte subsets in 27 patients aged 41 ± 10 years with RA of short duration (median 12 months) and 22 healthy controls. The RA subjects were divided into low (DAS28: 2.6-5.1) and high (DAS28 > 5.1) disease activity.

RESULTS

RA patients exhibited increased levels of intermediate (CD14(++)CD16(+)) monocytes with decreased CD45RA expression compared to controls, increased counts of classical (CD14(++)CD16(-)) monocytes, and decreased percentages of nonclassical (CD14(+)CD16(++)) monocytes. Patients with high disease activity had lower HLA DR expression on classical monocytes compared to low disease activity patients. There were no differences in monocyte subsets between subjects with DAS > 5.1 and DAS ≤ 5.1. There were no significant intergroup differences in IMT and the majority of classical CV risk factors.

CONCLUSIONS

Patients with RA of short duration show alteration in peripheral blood monocyte subsets despite the fact that there is no evidence of subclinical atherosclerosis. Disease activity assessed with DAS28 was associated with impaired functional properties but not with a shift in monocyte subpopulations.