Identification of clinical parameters associated with serum oxidative stress in patients with rheumatoid arthritis

The efficacy of curcumin supplementation on serum total antioxidant capacity, malondialdehyde, and disease activity in women with rheumatoid arthritis: A randomized, double-blind, placebo-controlled clinical trial

Oxidative stress plays a crucial role in the physiopathology of rheumatoid arthritis (RA), which is associated with impaired antioxidant defenses. This study aimed to investigate the effects of curcumin supplementation on serum levels of total antioxidant capacity (TAC), malondialdehyde (MDA), and disease activity in women with RA. In this clinical trial, 48 women with RA were treated with one capsule of curcumin (500 mg daily) or placebo for 8 weeks. Anthropometric measurements and fasting blood samples were collected at baseline and end of the study. Finally, we assessed the Disease Activity Score in 28 joints (DAS-28), dietary intake, and physical activity levels. While curcumin supplementation for 8 weeks significantly increased the serum levels of TAC (p < 0.05), it decreased tender joint counts, swollen joint counts, visual analog scale (VAS) for pain, and DAS-28 compared to the placebo at the end of the study (p < 0.001 for all). MDA levels significantly decreased in the curcumin group (p < 0.05). However, changes in MDA concentration were not significant between groups at the end of the trial (p = 0.145). Curcumin supplementation had a beneficial effect on increasing the serum levels of TAC and decreased DAS-28 in women with RA.

High fat diet increases the severity of collagen-induced arthritis in mice by altering the gut microbial community

OBJECTIVES

Research has demonstrated that obesity may be associated with rheumatoid arthritis (RA). In addition, gut microbiota and its metabolites contribute to the occurrence and development of RA and obesity. However, the mechanism by which obesity affects RA remains unclear. In this study, we aimed to investigate whether gut microbiota and their metabolites alter the effects of high fat diet (HFD) on the severity of collagen-induced arthritis (CIA) in mice.

METHODS

Briefly, mice were divided into normal group (N), CIA model group (C), HFD group (T), and HFD CIA group (CT). Hematoxylin and Eosin staining(HE) and Safranin O-fast green staining were conducted, and levels of blood lipid and inflammatory cytokines were measured. 16S rDNA sequencing technique and liquid chromatography-mass spectrometry (LC-MS)-based metabolomics were performed to explore changes in the microbiota structure to further reveal the pathomechanism of HFD on CIA.

RESULTS

HFD aggravated the severity of CIA in mice. The CT group had the highest proportion of microbial abundance of Blautia, Oscillibacter, Ruminiclostridium-9, and Lachnospiraceae UCG 006 at the genus level, but had a lower proportion of Alistipes. Additionally, the fecal metabolic phenotype of the combined CT group shows significant changes, with differential metabolites enriched in 9 metabolic pathways, including primary bile acid biosynthesis, arginine biosynthesis, sphingolipid metabolism, purine metabolism, linoleic acid metabolism, oxytocin signaling pathway, aminoacyl-tRNA biosynthesis, the pentose phosphate pathway, and sphingolipid signaling pathway. Correlation analysis revealed that some of the altered gut microbiota genera were strongly correlated with changes in fecal metabolites, total cholesterol (TC), triglyceride (TG), and inflammatory cytokine levels.

CONCLUSIONS

This study shows that HFD may aggravate inflammatory reaction in CIA mice by altering the gut microbiota and metabolic pathways.

Serum Reactive Oxygen Metabolites as a Predictor of Clinical Disease Activity Index, Simplified Disease Activity Index, and Boolean Remissions in Rheumatoid Arthritis Patients Treated With Biologic Agents

Introduction

Reactive oxygen metabolites (ROMs) are metabolite hydroperoxides in the blood, and their serum levels were associated with the disease activity score 28 (DAS28) in patients with rheumatoid arthritis (RA). In this study, we aimed to investigate whether ROMs would be predictive of the clinical disease activity index (CDAI) remission, simplified disease activity index (SDAI) remission, or Boolean remission.

Materials and methods

Fifty-one biologic agents (BA)-naïve RA patients were included in this observational study. Associations between ROMs, C-reactive protein, matrix metalloproteinase-3, DAS28-erythrocyte sedimentation rate (ESR), CDAI, SDAI, and health assessment questionnaire (HAQ) at 12 weeks and the DAS28, CDAI, SDAI, and Boolean remission rates at 52 weeks were investigated.

Results

The DAS28, CDAI, SDAI, and Boolean remission rates at 52 weeks were 66.7, 52.9, 54.9, and 54.9%, respectively. A multivariate logistic regression analysis revealed that ROMs and HAQ at 12 weeks were associated with the CDAI, SDAI, and Boolean remission at 52 weeks. Receiver operating characteristic analyses demonstrated that the cut-off value for CDAI, SDAI, and Boolean remission was 389.5 U.Carr.

Conclusion

Reactive oxygen metabolites at 12 weeks of initial treatment with BAs was a predictor for CDAI, SDAI, and Boolean remission at 52 weeks. Serum levels of ROMs may be a useful biomarker in the current treatment strategy aiming at early remission of RA.

Comparative Study for Carrot Juice and Selenium Supplement in Many Physiological and Biochemical Parameters in Patients with Rheumatoid Arthritis in Kirkuk City

Carrot juice is a critical source of vitamins, selenium, and β-carotene, which is suggested to protect from Rheumatoid Arthritis (RA). The present study aimed to show the effect of carrot juice supplementation compared to selenium tablet supplementation, so our study includes (44) blood samples belonging to young men with RA. All patients aged (20-45) years, 44 blood samples were obtained before treatment at week (0), twenty-four men with RA were supplied with fresh carrot juice. The other group of 20 patients was given an artificial selenium supplement for 21 days as well, and the results were analyzed.The samples were collected from Kirkuk hospital, and external specialized clinical from October/2019 to September /2020; experimental groups were divided into three groups: Group 1 : (44) men Rheumatoid arthritis (RA) before treatment, Group 2: (24) men with RA+ Carrot juice, Group 3: (20) men with RA +Selenium Tab, We reach to following results: the patients who have RA consumption Carrot juice and patients take up Se tab. show significant decrease respectively in RBCs, WBCs, ERS, and RF compared with the Rheumatoid arthritis group, so as the results show a significant decrease in Leptin, IL-6, C-Reactive Protein, and TNF-α concentrations in comparison with the Rheumatoid arthritis group. In contrast, we found a significant increase in GSH, Selenium concentrations, and VD3 in men with RA administration carrot juice and patients' consumption Se tab. Respectively compared with the RA group and, finally, our finding shows no difference in Ceruloplasmin in experimental groups.

The Efficacy of Antioxidative Stress Therapy on Oxidative Stress Levels in Rheumatoid Arthritis: A Systematic Review and Meta-analysis of Randomized Controlled Trials

Objective

To explore the efficacy of antioxidative stress therapy on oxidative stress levels in rheumatoid arthritis (RA) by a systematic review and meta-analysis of randomized controlled trials.

Methods

Chinese and English databases such as PubMed, Embase, China National Knowledge Infrastructure (CNKI), and China Biomedical Literature were searched, mainly searching for clinical randomized controlled trials of antioxidant therapy for rheumatoid arthritis. The search time is from the establishment of the database to July 2021. Two researchers independently carried out literature search, screening, and data extraction. The bias risk tool provided by the Cochrane Collaboration was used to evaluate the bias risk of all the included literature, and the RevMan 5.3 software was used for meta-analysis.

Results

A total of 24 RCTs (28 records) and 1277 participants were included. The time span of randomized controlled trials (RCTs) is from 1986 to 2020. These RCTs involve 14 types of antioxidants or antioxidant therapies, and these therapies have varying degrees of improvement on oxidative stress in RA patients. The summary results showed that the MDA in the experiment group is lower (SMD -0.82, 95% CI -1.35 to -0.28, P = 0.003). The difference of TAC, SOD, NO, GPx, CAT, and GSH between two groups was of no statistical significance (TAC (SMD 0.27, 95% CI -0.21 to 0.75, P = 0.27), SOD (SMD 0.12, 95% CI -0.16 to 0.40, P = 0.41), NO (SMD -2.03, 95% CI -4.22 to 0.16, P = 0.07), GPx (SMD 0.24, 95% CI -0.07 to 0.54, P = 0.13), CAT (SMD 2.95, 95% CI -2.6 to 8.51, P = 0.30), and GSH (SMD 2.46, 95% CI -0.06 to 4.98, P = 0.06)). For adverse events, the summary results showed that the difference was of no statistical significance (RR 1.16, 95% CI 0.79 to 1.71, P = 0.45). In addition, antioxidant therapy has also shown improvement in clinical efficacy indexes (number of tender joints, number of swollen joints, DAS28, VAS, and HAQ) and inflammation indexes (ESR, CRP, TNF-α, and IL6) for RA patients.

Conclusion

The existing evidence shows potential benefits, mainly in reducing MDA and increasing TAC and GSH in some subgroups. However, more large samples and higher quality RCTs are needed to provide high-quality evidence, so as to provide more clinical reference information for the antioxidant treatment of RA.

Oxidative Stress and Abnormal Tendon Sonographic Features in Elite Soccer Players (A Pilot Study)

Objective  Sound experimental data suggest that oxidative stress plays an important role in the pathogenesis of tendinopathies. However, this hypothesis in humans remains speculative given that clinical data are lacking to confirm it. Recently, a new methodology has allowed to quantify the oxidative stress in vivo by measuring the concentration of hydroperoxides of organic compounds, which have been utilized as an oxidative stress-related marker in several pathologic and physiologic conditions. Given the reliability of this test and the lack of information in subjects with tendinopathies, the aim of the present study was to assess the oxidative stress status in elite professional soccer players with and without ultrasonographic features of tendon damage.

Methods  In 73 elite players, blood metabolic parameters were evaluated and oxidative stress was measured by means of a specific test (expressed as U-Carr units). Therefore, an ultrasonographic evaluation of the Achilles and patellar tendons was performed.

Results  No significant relationships were observed between metabolic parameters and oxidative stress biomarkers. The Achilles and patellar tendons showed a normal echographic pattern in 58 athletes, and sonographic abnormalities in 15. The athletes with ultrasonographic alterations, compared to those with normal US picture, showed significantly higher U-Carr levels ( p  = 0.000), body mass index (BMI) values ( p  = 0.03) and were older ( p  = 0.005). The difference in U-Carr values among the subjects remained significant also after adjustment for age and BMI.

Conclusion  The results of the present study support the hypothesis that oxidative substances, also increased at systemic and not only at local level, may favor tendon damage.

Level of Evidence  IV (pilot study).

Inflammation and ROS in arthritis: management by Ayurvedic medicinal plants

Chronic joint inflammatory disorders like osteoarthritis and rheumatoid arthritis, which are manifested by joint dysfunction, show an upsurge in inflammation and oxidative stress. Although conventional anti-arthritic drugs are being used to relieve pain from arthritic symptoms, they usually cause severe side effects. Traditionally used Ayurvedic medicinal plants are a promising alternative for the management of arthritic symptoms, as they are safe and effective. Ayurvedic medicinal plants improve arthritic symptoms by reducing joint tenderness, joint pain, swelling, bone and cartilage damage, and increasing knee flexion, walking distance and sports activities. These beneficial effects of Ayurvedic medicinal plants on arthritis are mediated through various cellular mechanisms including inhibition of the inflammatory markers NF-κB, cytokines, adipokines, PGE2, NO, iNOS, COX-2, and MMPs and induction of antioxidant status by decreasing free radicals, lipid peroxidation, and myeloperoxidase, and increasing antioxidant enzymes, Nrf2, and HO-1. Thus, a strategy requires using these Ayurvedic medicinal plants to treat arthritis. This article describes the status of inflammation and oxidative stress in arthritic conditions. We also provide evidence that Ayurvedic medicinal plants and their bioactive components are highly effective in improving arthritic symptoms.

Effects of Biological Therapies on Molecular Features of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune and chronic inflammatory disease primarily affecting the joints, and closely related to specific autoantibodies that mostly target modified self-epitopes. Relevant findings in the field of RA pathogenesis have been described. In particular, new insights come from studies on synovial fibroblasts and cells belonging to the innate and adaptive immune system, which documented the aberrant production of inflammatory mediators, oxidative stress and NETosis, along with relevant alterations of the genome and on the regulatory epigenetic mechanisms. In recent years, the advances in the understanding of RA pathogenesis by identifying key cells and cytokines allowed the development of new targeted disease-modifying antirheumatic drugs (DMARDs). These drugs considerably improved treatment outcomes for the majority of patients. Moreover, numerous studies demonstrated that the pharmacological therapy with biologic DMARDs (bDMARDs) promotes, in parallel to their clinical efficacy, significant improvement in all these altered molecular mechanisms. Thus, continuous updating of the knowledge of molecular processes associated with the pathogenesis of RA, and on the specific effects of bDMARDs in the correction of their dysregulation, are essential in the early and correct approach to the treatment of this complex autoimmune disorder. The present review details basic mechanisms related to the physiopathology of RA, along with the core mechanisms of response to bDMARDs.

The Relevance of Selenium Status in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune and inflammatory disease that can cause joint damage. Among the environmental risk factors, diet plays an important role because it can aggravate or attenuate inflammation. Selenium (Se) is considered an essential trace element since it is a structural component of antioxidant enzymes; however, its concentration can be affected by diet, drugs and genetic polymorphisms. Studies have reported that RA patients have a deficient diet in some food groups that is associated with parameters of disease activity. Furthermore, it has been shown that there is an alteration in serum Se levels in this population. Although some clinical trials have been conducted in the past to analyze the effect of Se supplementation in RA, no significant results were obtained. Contrastingly, experimental studies that have evaluated the effect of novel Se nanoparticles in RA-induced models have shown promising results on the restoration of antioxidant enzyme levels. In particular, glutathione peroxidase (GPx) is an important selenoprotein that could have a modulating effect on inflammation in RA. Considering that RA patients present an inflammatory and oxidative state, the aim of this review is to give an overview of the current knowledge about the relevance of Se status in RA.

Assessment of oxidative stress in autism spectrum disorder using reactive oxygen metabolites and biological antioxidant potential

There are several studies on oxidative stress of Autism Spectrum Disorder (ASD), but in these cases there is no study to measure oxidative stress and antioxidant capacity at the same time or studies considering childhood development. Therefore, this study comprehensively assessed the level of oxidative stress in ASD children by simultaneously measuring reactive oxygen metabolites (d-ROMs) and biological antioxidant potential (BAP). The subjects were Japanese, 77 typical development (TD) children, 98 ASD children, samples were plasma. The subjects were divided into age groups: toddlers/preschool age (2–6 years) and school age (7–15 years), to compare the relationships among the d-ROMs levels and BAP/d-ROMs ratios. Furthermore, the correlations between the Parent-interview ASD Rating Scales (PARS) scores and the measured values were analyzed. The levels of d-ROMs were significantly higher in the ASD (7–15 years) than in TD (7–15 years). The PARS scores were significantly higher in the ASD and were significantly correlated with d-ROMs levels. These results suggested that d-ROMs and BAP/d-ROMs ratios could be objective, measured indicators that could be used in clinical practice to assess stress in ASD children.

Serum levels of reactive oxygen metabolites at 12 weeks during tocilizumab therapy are predictive of 52 weeks-disease activity score-remission in patients with rheumatoid arthritis

Background

To verify whether serum levels of reactive oxygen metabolites (ROM) are predictive of future clinical remission in patients with rheumatoid arthritis (RA) receiving tocilizumab (TCZ) therapy.

Methods

A total of 46 patients with RA receiving TCZ therapy were enrolled in this study. Patients were divided into remission and non-remission groups based on disease activity score 28 (DAS28)-erythrocyte sedimentation rate (ESR) or clinical disease activity index (CDAI) at 52 weeks. Associations between serum levels of ROM, C-reactive protein (CRP), and matrix metalloproteinase-3 (MMP-3) at 4 and 12 weeks and the remission by DAS28-ESR and CDAI at 52 weeks were investigated.

Results

There were no significant differences in CRP and MMP-3 between DAS- or CDAI-remission and non-remission groups at 12 weeks. However, ROM in DAS-remission group were significantly lower than those in the non-remission group. For ROM, the area under the curve of the receiver operating characteristic curve was 0.735 and the cut-off value that distinguished DAS-remission group from non-remission group was 305.5 U. Carr (sensitivity: 70.0%, specificity: 72.2%). A multivariate logistic regression analysis revealed that ROM at 12 weeks was associated with DAS-remission at 52 weeks (odds ratio: 6.067, 95% confidence interval: 1.305–28.203).

Conclusion

Serum levels of ROM at 12 weeks during TCZ therapy may be predictive of DAS-remission at 52 weeks in patients with RA.

Oxidative Stress in Rheumatoid Arthritis: What the Future Might Hold regarding Novel Biomarkers and Add-On Therapies

Numerous rheumatologic autoimmune diseases, among which rheumatoid arthritis, are chronic inflammatory diseases capable of inducing multiple cumulative articular and extra-articular damage, if not properly treated. Nevertheless, benign conditions may, similarly, exhibit arthritis as their major clinical finding, but with short-term duration instead, and evolve to spontaneous resolution in a few days to weeks, without permanent articular damage. Such distinction—self-limited arthritis with no need of immunosuppressive treatment or chronic arthritis at early stages?—represents one of the greatest challenges in clinical practice, once many metabolic, endocrine, neoplastic, granulomatous, infectious diseases and other autoimmune conditions may mimic rheumatoid arthritis. Indeed, the diagnosis of rheumatoid arthritis at early stages is a crucial step to a more effective mitigation of the disease-related damage. As a prototype of chronic inflammatory autoimmune disease, rheumatoid arthritis has been linked to oxidative stress, a condition in which the pool of reactive oxygen species increases over time, either by their augmented production, the reduction in antioxidant defenses, or the combination of both, ultimately implying compromise in the redox signaling. The exact mechanisms through which oxidative stress may contribute to the initiation and perpetuation of local (in the articular milieu) and systemic inflammation in rheumatoid arthritis, particularly at early stages, still remain to be determined. Furthermore, the role of antioxidants as therapeutic adjuvants in the control of disease activity seems to be overlooked, as a little number of short studies addressing this issue is currently found. Thus, the present review focuses on the binomial rheumatoid arthritis-oxidative stress, bringing insights into their pathophysiological relationships, as well as the implications of potential diagnostic oxidative stress biomarkers and therapeutic interventions directed to the oxidative status in patients with rheumatoid arthritis.

Serum oxidative stress influences neurological recovery after surgery to treat acutely worsening symptoms of compression myelopathy: a cross-sectional human study

Background

Recent reports indicate that oxidative stress induced by reactive oxygen species is associated with the pathobiology of neurodegenerative disorders that involve neuronal cell apoptosis. Here we conducted a cross-sectional study to evaluate serum levels of oxidative stress in cervical compression myelopathy.

Methods

Thirty-six serum samples were collected preoperatively from patients treated for acutely worsening compression myelopathy (AM) and chronic compression myelopathy (CM). Serum levels of oxidative stress markers were evaluated by measuring derivatives of reactive oxygen metabolites (ROM), which reflect concentrations of hydroperoxides. ROM in healthy individuals range from 250 to 300 (U. CARR), whereas ROM >340–400 and > 400 define moderate and severe levels of oxidative stress, respectively. Difference of ROM by the cause of disorders whether cervical spondylotic myelopathy (CSM) or cervical ossification of longitudinal ligament (OPLL), correlations between ROM and patient age, body mass index (BMI), history of smoking, existence of diabetes were examined. Neurological evaluations according to Japanese Orthopaedic Association (JOA) scores were performed and correlated with ROM.

Results

ROM increased to 349.5 ± 54.8, representing a moderate oxidative stress, in CM samples. ROM increased to 409.2 ± 77.9 in AM samples, reflecting severe oxidative stress which were significantly higher than for CM samples (p < 0.05). There was no significant difference by the cause of disorders (CSM or OPLL). ROM were significantly increased in AM serum samples from female patients versus AM male and CM patients (p < 0.05). There were no correlations between ROM and age, BMI, history of smoking, and existence of diabetes. A negative correlation between ROM and recovery rate of JOA score (R² = 0.454, p = 0.047) was observed in the AM group.

Conclusions

Although moderate oxidative stress was present in patients with CM, levels of oxidative stress increased in severity in patients with AM. These results suggest that postsurgical neurological recovery is influenced by severe oxidative stress in AM.

Oxidative hotspots on actin promote skeletal muscle weakness in rheumatoid arthritis

Skeletal muscle weakness in patients suffering from rheumatoid arthritis (RA) adds to their impaired working abilities and reduced quality of life. However, little molecular insight is available on muscle weakness associated with RA. Oxidative stress has been implicated in the disease pathogenesis of RA. Here we show that oxidative post-translational modifications of the contractile machinery targeted to actin result in impaired actin polymerization and reduced force production. Using mass spectrometry, we identified the actin residues targeted by oxidative 3-nitrotyrosine (3-NT) or malondialdehyde adduct (MDA) modifications in weakened skeletal muscle from mice with arthritis and patients afflicted by RA. The residues were primarily located to three distinct regions positioned at matching surface areas of the skeletal muscle actin molecule from arthritis mice and RA patients. Moreover, molecular dynamic simulations revealed that these areas, here coined "hotspots", are important for the stability of the actin molecule and its capacity to generate filaments and interact with myosin. Together, these data demonstrate how oxidative modifications on actin promote muscle weakness in RA patients and provide novel leads for targeted therapeutic treatment to improve muscle function.

Thiol/Disulfide homeostasis in patients with rheumatoid arthritis

BACKGROUND

Oxidative stress may play an important role in rheumatoid arthritis (RA) etiopathogenesis. The thiol group is a very strong antioxidant. In this study, we aimed to investigate the presence of oxidative stress in patients with RA by evaluating thiol/disulfide homeostasis.

MATERIAL AND METHODS

A total of 50 female RA patients and 50 healthy female controls were included in this study. Thiol and disulfide values were calculated utilizing novel methods.

RESULTS

Native thiol (p < 0.001) and total thiol (p < 0.001) levels of RA patients were significantly lower compared to values in the control group. However, the disulfide (p < 0.001) levels of RA patients were strongly higher than in healthy individuals. A negative correlation was found between thiol and disease activity score-28 among the patients, whereas a positive correlation was found between disulfide and disease activity score-28 among the patients.

CONCLUSION

We found that the thiol-disulfide rate deteriorated in RA patients, with the proportion of disulfide increasing. There is a strong correlation between the decrease in thiol levels, increase in disulfide levels and the disease activity scores.

Bezafibrate Ameliorates Arterial Stiffness Assessed by Cardio-Ankle Vascular Index in Hypertriglyceridemic Patients with Type 2 Diabetes Mellitus

AIM

Cardio-ankle vascular index (CAVI) reflects arterial stiffness and has been established as a useful surrogate marker of atherosclerosis. Contrary to the abundant data indicating slower progression of atherosclerosis with statins, studies on fibrates remain scarce. The aim of this study was thus to clarify the effect of bezafibrate on CAVI as well as on oxidative stress.

METHODS

A randomized, open-label, controlled study was performed. 66 hypertriglyceridemic patients with type 2 diabetes were assigned to two groups: bezafibrate (400 mg/day) group and eicosapentaenoic acid (EPA 1.8 g/day) group. Patients were administered the respective treatment for 12 weeks. CAVI, glycolipid metabolic parameters, and diacron-reactive oxygen metabolites (d-ROMs) were evaluated before and after the study period.

RESULTS

Serum triglycerides (TG), remnant-like particle cholesterol (RLP-C), fasting plasma glucose, HbA1c and d-ROMs decreased, while HDL-cholesterol increased significantly in the bezafibrate group but did not change in the EPA group. The decreases in TG, RLP-C, HbA1c and d-ROMs were significantly greater in the bezafibrate group than in the EPA group. CAVI decreased significantly only in the bezafibrate group and the decrease was significantly greater in bezafibrate group than in EPA group. Simple regression analysis showed no significant relationship between the change in CAVI and changes in other variables. Multivariate logistic regression analysis identified high baseline CAVI, low HDL-cholesterol level, and bezafibrate administration as significant independent predictors of CAVI decrease.

CONCLUSION

Bezafibrate treatment ameliorates arterial stiffness accompanied by improvement of glycolipid metabolism and oxidative stress. These effects potentially have important beneficial health consequences in hypertriglyceridemic patients with type 2 diabetes.

Integrated Serum and Fecal Metabolomics Study of Collagen-Induced Arthritis Rats and the Therapeutic Effects of the Zushima Tablet

The Zushima tablet (ZT) has been used for decades in the clinical treatment of rheumatoid arthritis (RA) in China. However, its therapeutic mechanism is unclear. In this study, we aimed to explore the distinctive metabolic patterns in collagen-induced arthritis (CIA) rats and evaluate the therapeutic effects of ZT on RA using untargeted serum and fecal metabolomics approaches based on gas chromatography coupled with mass spectrometry. Body weight, hind paw swelling, TNF-α and IL-1β levels, arthritis scores, and histopathological parameters were assessed. In the metabolomics study, 31 altered metabolites in the serum and 30 in the feces were identified by comparing the model with the control group using statistical processing. These altered metabolites revealed that the tricarboxylic acid cycle, glycolysis metabolism, fatty acid metabolism, and purine metabolism were disturbed in CIA rats, and most of these altered metabolites including l-isoleucine, l-aspartic acid, pyruvic acid, cholic acid, and hypoxanthine, were rectified by ZT. Furthermore, short-chain fatty acids in feces were quantitatively determined, and the results showed that ZT could regulate the levels of propionate, butyrate, and valerate in CIA rats. Then, gut microbiota were analyzed by 16S rRNA analysis. Our results showed that Firmicutes and Bacteroidetes were the most abundant bacteria in rats. The levels of 19 types of bacteria at the family level were altered in RA rats, and most of them could be regulated by ZT. This study demonstrated that metabolomics analysis is a powerful tool for providing novel insight into RA and for elucidating the potential mechanism of ZT.

Metabolic syndrome and the decreased levels of uric acid by leflunomide favor redox imbalance in patients with rheumatoid arthritis

Oxidative stress plays a role in the pathophysiology of rheumatoid arthritis (RA). The aim of the present study was to verify the influence of metabolic syndrome (MetS) and disease-modifying antirheumatic drugs on nitrosative and oxidative biomarkers in patients with RA. A total of 177 patients with RA and 150 healthy volunteers participated in this study, which measured lipid hydroperoxides, advanced oxidation protein products (AOPP), nitric oxide metabolites (NOx), carbonyl protein, total radical-trapping antioxidant parameter (TRAP), uric acid (UA), and C-reactive protein (CRP). NOx and the NOx/TRAP ratio were significantly increased in RA, while no significant differences in lipid hydroperoxides, AOPP, UA, and TRAP levels were found between both groups. Treatment with leflunomide was associated with increased levels of carbonyl protein, and lowered levels in TRAP and UA, while the NOx/TRAP ratio further increased. NOx and the NOx/TRAP ratio were significantly higher in women than in men, while TRAP and UA were significantly lower in women. MetS was accompanied by increased AOPP and UA levels. RA was best predicted by increased NOx/TRAP ratio, CRP, and BMI. In conclusion, our data demonstrated that NOx and NOx/TRAP are strongly associated with RA physiopathology. Our findings suggest that inhibition of iNOS may become an interesting therapeutic approach for the treatment of RA. In addition, the presence of MetS and a decrease in levels of UA by leflunomide favor redox imbalance in RA patients. More studies are needed to evaluate the impact of antioxidant capacity reduction on RA progression.

Autoimmune reactivity to malondialdehyde adducts in systemic lupus erythematosus is associated with disease activity and nephritis

BACKGROUND

Immunoglobulin M (IgM) autoreactivity to malondialdehyde (MDA) protein modifications is part of the natural antibody repertoire in health and may have beneficial functions. In contrast, IgG anti-MDA are increased in chronic inflammation and autoimmunity and may instead have pathogenic properties.

METHODS

Herein, we investigated serum IgG anti-MDA levels by enzyme-linked immunosorbent assay (ELISA) in 398 systemic lupus erythematosus (SLE) patients in the Swedish Karolinska SLE cohort and compared these to findings in 225 US SLE patients from New York University and Johns Hopkins University.

RESULTS

In two independent cohorts, IgG anti-MDA levels correlated positively with disease activity by the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI; p < 0.0001, Spearman R = 0.3). Meta-analysis found an odds ratio of 2.7 (confidence interval (CI) 1.9-3.9; p < 0.0001) for high anti-MDA IgG levels with active disease (SLEDAI ≥ 6). Furthermore, IgG anti-MDA correlated directly with erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), soluble tumor necrosis factor receptors (sTNFR-1, sTNFR-2), and vascular cell adhesion molecule 1 (VCAM-1) measurements, and inversely with complement factors (C1q, C2, C3, C4). Importantly, IgG anti-MDA levels were significantly elevated in SLE patients with active nephritis (p = 0.0005) and correlated with cystatin C estimated glomerular filtration rate and albuminuria.

CONCLUSIONS

Elevated IgG anti-MDA in SLE patients was associated with high disease activity, with active lupus nephritis, and with biomarkers of systemic inflammation. This natural antibody reactivity may have potential prognostic utility, and may also actively contribute to pathogenesis.

Association of oxidative stress with clinical characteristics in patients with rheumatoid arthritis

BACKGROUND

Few studies examining the association between oxidative stress and clinical parameters or disease activity in patients with rheumatoid arthritis (RA) are available. Therefore, the objective of this study was to test whether oxidative stress has any association with clinical parameters and disease activity in patients with RA.

MATERIALS AND METHODS

In this post hoc cross-sectional study, 45 patients with RA treated with traditional disease-modifying antirheumatic drugs (DMARDs) ± low-dose glucocorticoids ± nonsteroidal analgesics for at least 3 months were analysed. Oxidative stress parameters were malondialdehyde (MDA), superoxide dismutase (SOD), antioxidant potential (AOP) and nonenzymatic superoxide radical scavenger activity (NSSA). Clinical parameters were pain, patient global assessment, physician global assessment, Health Assessment Questionnaire (HAQ), and disease activity score (DAS28).

RESULTS

Plasma NSSA levels were significantly inversely correlated with tender joints count (r = -.304; P = .042), swollen joints count (r = -.342; P = .021) and DAS28 (r = -.396; P = .009). There were no significant correlations between MDA/SOD/AOP and any of clinical parameters or DAS28 (P > .05 for all). Multiple regression analysis revealed that NSSA was an independent variable of DAS28 (β=-.243, P = .016).

CONCLUSION

The preliminary results demonstrate that plasma NSSA levels were inversely correlated with tender and swollen joints count and DAS28 and that NSSA was independently associated with DAS28, in patients with RA treated with traditional DMARDs; and provide initial support that NSSA may be used as a biomarker of disease activity in patients with RA.

Resveratrol Ameliorates Arterial Stiffness Assessed by Cardio-Ankle Vascular Index in Patients With Type 2 Diabetes Mellitus

Resveratrol has been reported to have potent anti-atherosclerotic effects in animal studies. However, there are few interventional studies in human patients with atherosclerogenic diseases. The cardio-ankle vascular index (CAVI) reflects arterial stiffness and is a clinical surrogate marker of atherosclerosis. The aim of the present study was to investigate the effect of resveratrol on arterial stiffness assessed by CAVI in patients with type 2 diabetes mellitus (T2DM).In this double-blind, randomized, placebo-controlled study, 50 patients with T2DM received supplement of a 100mg resveratrol tablet (total resveratrol: oligo-stilbene 27.97 mg/100 mg/day) or placebo daily for 12 weeks. CAVI was assessed at baseline and the end of study. Body weight (BW), blood pressure (BP), glucose and lipid metabolic parameters, and diacron-reactive oxygen metabolites (d-ROMs; an oxidative stress marker) were also measured.Resveratrol supplementation decreased systolic BP (-5.5 ± 13.0 mmHg), d-ROMs (-25.6 ± 41.8 U.CARR), and CAVI (-0.4 ± 0.7) significantly (P < 0.05) and decreased BW (-0.8 ± 2.1 kg, P = 0.083) and body mass index (-0.5 ± 0.8 kg/m², P = 0.092) slightly compared to baseline, while there were no significant changes in the placebo group. Decreases in CAVI and d-ROMs were significantly greater in the resveratrol group than in the placebo group. Multivariate logistic regression analysis identified resveratrol supplementation as an independent predictor for a CAVI decrease of more than 0.5.In conclusion, 12-week resveratrol supplementation may improve arterial stiffness and reduce oxidative stress in patients with T2DM. Resveratrol may be beneficial in preventing the development of atherosclerosis induced by diabetes. However, a large-scale cohort study is required to validate the present findings.

Autoreactivity to malondialdehyde-modifications in rheumatoid arthritis is linked to disease activity and synovial pathogenesis

Oxidation-associated malondialdehyde (MDA) modification of proteins can generate immunogenic neo-epitopes that are recognized by autoantibodies. In health, IgM antibodies to MDA-adducts are part of the natural antibody pool, while elevated levels of IgG anti-MDA antibodies are associated with inflammatory and autoimmune conditions. Yet, in human autoimmune disease IgG anti-MDA responses have not been well characterized and their potential contribution to disease pathogenesis is not known. Here, we investigate MDA-modifications and anti-MDA-modified protein autoreactivity in rheumatoid arthritis (RA). While RA is primarily associated with autoreactivity to citrullinated antigens, we also observed increases in serum IgG anti-MDA in RA patients compared to controls. IgG anti-MDA levels significantly correlated with disease activity by DAS28-ESR and serum TNF-alpha, IL-6, and CRP. Mass spectrometry analysis of RA synovial tissue identified MDA-modified proteins and revealed shared peptides between MDA-modified and citrullinated actin and vimentin. Furthermore, anti-MDA autoreactivity among synovial B cells was discovered when investigating recombinant monoclonal antibodies (mAbs) cloned from single B cells, and 3.5% of memory B cells and 2.3% of plasma cells were found to be anti-MDA positive. Several clones were highly specific for MDA-modification with no cross-reactivity to other antigen modifications such as citrullination, carbamylation or 4-HNE-carbonylation. The mAbs recognized MDA-adducts in a variety of proteins including albumin, histone 2B, fibrinogen and vimentin. Interestingly, the most reactive clone, originated from an IgG1-bearing memory B cell, was encoded by near germline variable genes, and showed similarity to previously reported natural IgM. Other anti-MDA clones display somatic hypermutations and lower reactivity. Importantly, these anti-MDA antibodies had significant in vitro functional properties and induced enhanced osteoclastogenesis, while the natural antibody related high-reactivity clone did not. We postulate that these may represent distinctly different facets of anti-MDA autoreactive responses.

Synbiotic supplementation and the effects on clinical and metabolic responses in patients with rheumatoid arthritis: a randomised, double-blind, placebo-controlled trial

Synbiotic intake may be associated with reduced inflammation in patients with rheumatoid arthritis (RA) due to optimised inflammatory markers, oxidative stress and insulin resistance. This research was conducted to assess the effects of synbiotic supplementation on the clinical and metabolic parameters of patients with RA. A total of fifty-four patients with RA were allocated into two groups to receive either a synbiotic capsule (n 27) or a placebo (n 27) for 8 weeks in this randomised, double-blind, placebo-controlled trial. Fasting blood samples were taken at baseline and week 8 of the study to quantify related markers. After the 8-week intervention, compared with the placebo, synbiotic supplementation resulted in a significant reduction in serum high-sensitivity C-reactive protein (hs-CRP) levels (–1427·8 (sd 3267·2) v. +2833·4 (sd 5639·7) ng/ml, P=0·001). In addition, compared with the placebo, synbiotic supplementation improved disease activity score-28 joints (DAS-28) (–1·6 (sd 0·8) v. –0·3 (sd 0·5), P<0·001) and visual analogue scales (VAS) pain (–30·4 (sd 18·7) v. –11·5 (sd 15·9), P<0·001). In addition, a significant elevation in plasma nitric oxide (NO) (+0·8 (sd 4·4) v. –2·6 (sd 4·5) µmol/l, P=0·008), and significant reductions in insulin values (–13·8 (sd 26·4) v. +4·2 (sd 28·2) pmol/l, P=0·01), homoeostasis model of assessment-estimated insulin resistance (HOMA-IR) (–0·5 (sd 1·0) v.+0·1 (sd 1·1), P=0·03) and homoeostatic model assessment-β-cell function (HOMA-B) (–9·4 (sd 17·9) v. +3·3 (sd 18·9), P=0·01) following supplementation with the synbiotic compared with the placebo. Compared with the placebo, synbiotic supplementation also resulted in a significant increase in plasma GSH (+36·6 (sd 63·5) v. –58·5 (sd 154·4) µmol/l, P=0·005). Overall, our study demonstrated that synbiotic supplementation for 8 weeks among patients with RA had beneficial effects on hs-CRP, DAS-28, VAS, NO, insulin levels, HOMA-IR, HOMA-B and GSH levels.

Serum level of reactive oxygen metabolites (ROM) at 12 weeks of treatment with biologic agents for rheumatoid arthritis is a novel predictor for 52-week remission

We have shown that serum levels of reactive oxygen metabolites (ROM) were associated with C-reactive protein (CRP) and disease activity score based on the examination of 28 joints (DAS28) in patients with rheumatoid arthritis (RA); however, their clinical significance as biomarkers has not been elucidated. Forty-eight biologic agent (BA)-naïve RA patients were included in this study. Associations between serum levels of ROM, CRP, matrix metalloproteinase-3 (MMP-3), DAS28-erythrocyte sedimentation rate (ESR), and Health Assessment Questionnaire (HAQ) at 12 weeks of treatment and DAS28 (ESR) remission at 52 weeks (52-week remission) were investigated. The ROM serum level at baseline in the remission group (n = 34) was 527 ± 132 Carratelli units (U.Carr) (normal range <300), decreased to 335 ± 79.1 at 4 weeks, and remained low thereafter. In the non-remission group (n = 14), the ROM serum level at baseline was 592 ± 113 U.Carr, decreased to 450 ± 152 at 4 weeks, but gradually increased thereafter. Among significantly different factors at 12 weeks between the remission and non-remission groups, ROM and DAS28 (ESR) were identified as predictors of 52-week remission (p = 0.045, odds ratio 0.985, 95% confidence interval 0.97-1.000 for ROM). The cutoff value of ROM was determined to be 381.5 U.Carr (sensitivity 0.833, specificity 0.871). These results show that serum ROM levels can predict remission with high accuracy and could be a useful biomarker for achieving remission in the current treat-to-target strategy for RA.

Influence of Insulin Resistance and TNF-α on the Inflammatory Process, Oxidative Stress, and Disease Activity in Patients with Rheumatoid Arthritis

The aim of this study was to evaluate the involvement of TNF-α and insulin resistance (IR) in the inflammatory process, oxidative stress, and disease activity in patients with rheumatoid arthritis (RA). This cross-sectional study included 270 subjects (control group, n = 97) and RA patients (n = 173). RA patients were divided into four groups: the first group without IR and not using antitumor necrosis factor-α (TNF−) (G1, IR− TNF−); the second group without IR and using anti-TNF-α (G2, IR− TNF+); the third group with IR and not using anti-TNF-α (G3, IR+ TNF−); and the fourth group with IR and using anti-TNF-α (G4, IR+ TNF+). G3 and G4 had higher (p < 0.05) advanced oxidation protein products (AOPPs) and oxidative stress index (OSI) compared to G1. G4 group presented higher (p < 0.05) AOPPs and OSI than G2. TRAP was significantly lower in G3 compared to G1. Plasma TNF-α levels were significantly higher in G4 and G2 compared to G1 (p < 0.0001) and G3 (p < 0.0001 and p < 0.01, resp.). The presence of insulin resistance was robustly associated with both oxidative stress and TNF-α levels. More studies are warranted to verify if IR can be involved in therapeutic failure with TNF-α inhibitors. This trial is registered with Brazilian Clinical Trials Registry Register number RBR-2jvj92.

Oxidative Stress Relevance in the Pathogenesis of the Rheumatoid Arthritis: A Systematic Review

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease whose pathogenic mechanisms remain to be elucidated. The oxidative stress and antioxidants play an important role in the disease process of RA. The study of oxidants and antioxidants biomarkers in RA patients could improve our understanding of disease pathogenesis; likely determining the oxidative stress levels in these patients could prove helpful in assessing disease activity and might also have prognostic implications. To date, the usefulness of oxidative stress biomarkers in RA patients is unclear and the evidence supporting them is heterogeneous. In order to resume and update the information in the status of oxidants and antioxidants and their connection as biomarkers in RA, we performed a systematic literature search in the PubMed database, including clinical trials published in the last five years using the word combination "rheumatoid arthritis oxidative stress". In conclusion, this review supports the fact that the oxidative stress is an active process in RA pathogenesis interrelated to other better known pathogenic elements. However, some controversial results preclude a definite conclusion.