Serum level of oxidative stress marker is dramatically low in patients with rheumatoid arthritis treated with tocilizumab

Oxidative Imbalance in Psoriasis with an Emphasis on Psoriatic Arthritis: Therapeutic Antioxidant Targets

Psoriasis and psoriatic arthritis (PsA) are chronic autoimmune diseases characterized by persistent inflammation and oxidative imbalance. Oxidative stress, caused by excessive production of reactive oxygen species (ROS) and dysfunction in antioxidant mechanisms, plays a critical role in the pathogenesis of both conditions, leading to increased inflammatory processes and tissue damage. This study aims to review current antioxidant-based therapeutic options and analyze oxidative stress biomarkers in the context of psoriasis and PsA. Based on available literature, key biomarkers, such as malondialdehyde (MDA), advanced glycation end-products (AGEs), and advanced oxidation protein products (AOPP), were identified as being elevated in patients with psoriasis and PsA. Conversely, antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), showed reduced activity, correlating with symptom severity. The study also examines the efficacy of various antioxidant therapies, including curcumin, resveratrol, coenzyme Q10, and vitamins C and E, which may aid in reducing oxidative stress and alleviating inflammation. The findings indicated that antioxidants can play a significant role in alleviating symptoms and slowing the progression of psoriasis and PsA through modulation of redox mechanisms and reduction of ROS levels. Antioxidant-based therapies offer a promising direction in treating autoimmune diseases, highlighting the need for further research on their efficacy and potential clinical application.

Pyridostigmine ameliorates pristane-induced arthritis symptoms in Dark Agouti rats

OBJECTIVE

Rheumatoid arthritis (RA) is a chronic inflammatory disorder. Pyridostigmine (PYR), an acetylcholinesterase (AChE) inhibitor, has been shown to reduce inflammation and oxidative stress in several animal models for inflammation-associated conditions. The present study aimed to investigate the effects of PYR on pristane-induced (PIA) in Dark Agouti (DA) rats.

METHOD

DA rats were intradermally infused with pristane to establish the PIA model, which was treated with PYR (10 mg/kg/day) for 27 days. The effects of PYR on synovial inflammation, oxidative stress, and gut microbiota were evaluated by determining arthritis scores, H&E staining, quantitative polymerase chain reaction, and biochemical assays, as well as 16S rDNA sequencing.

RESULTS

Pristane induced arthritis, with swollen paws and body weight loss, increased arthritis scores, synovium hyperplasia, and bone or cartilage erosion. The expression of pro-inflammatory cytokines in synovium was higher in the PIA group than in the control group. PIA rats also displayed elevated levels of malondialdehyde, nitric oxide, superoxide dismutase, and catalase in plasma. Moreover, sequencing results showed that the richness, diversity, and composition of the gut microbiota dramatically changed in PIA rats. PYR abolished pristane-induced inflammation and oxidative stress, and corrected the gut microbiota dysbiosis.

CONCLUSION

The results of this study support the protective role of PYR in PIA in DA rats, associated with the attenuation of inflammation and correction of gut microbiota dysbiosis. These findings open new perspectives for pharmacological interventions in animal models of RA.

ROS-driven structural and functional fibrinogen modifications are reverted by interleukin-6 inhibition in Giant Cell Arteritis

BACKGROUND

Cranial and extra-cranial vascular events are among the major determinants of morbidity and mortality in Giant Cell Arteritis (GCA). Vascular events seem mostly of inflammatory nature, although the precise pathogenetic mechanisms are still unclear. We investigated the role of oxidation-induced structural and functional fibrinogen modifications in GCA. The effects of the anti-IL6R tocilizumab in counteracting these mechanisms were also assessed.

MATERIALS AND METHODS

A cross-sectional study was conducted on 65 GCA patients and 65 matched controls. Leucocyte reactive oxygen species (ROS) production, redox state, and fibrinogen structural and functional features were compared between patients and controls. In 19 patients receiving tocilizumab, pre vs post treatment variations were assessed.

RESULTS

GCA patients displayed enhanced blood lymphocyte, monocyte and neutrophil ROS production compared to controls, with an increased plasma lipid peroxidation and a reduced total antioxidant capacity. This oxidative impairment resulted in a sustained fibrinogen oxidation (i.e. dityrosine content 320 (204-410) vs 136 (120-176) Relative Fluorescence Units (RFU), p < 0.0001), with marked alterations in fibrinogen secondary and tertiary structure [intrinsic fluorescence: 134 (101-227) vs 400 (366-433) RFU, p < 0.001]. Structural alterations paralleled a remarkable fibrinogen functional impairment, with a reduced ability to polymerize into fibrin and a lower fibrin susceptibility to plasmin-induced lysis. In patients receiving tocilizumab, a significant improvement in redox status was observed, accompanied by a significant improvement in fibrinogen structural and functional features (p < 0.001).

CONCLUSIONS

An impaired redox status accounts for structural and functional fibrinogen modifications in GCA, suggesting a potential role of tocilizumab for cardiovascular prevention in GCA.

Oxidative stress and COVID-19-associated neuronal dysfunction: mechanisms and therapeutic implications

Severe acute respiratory syndrome (SARS)-CoV-2 virus causes novel coronavirus disease 2019 (COVID-19), and there is a possible role for oxidative stress in the pathophysiology of neurological diseases associated with COVID-19. Excessive oxidative stress could be responsible for the thrombosis and other neuronal dysfunctions observed in COVID-19. This review discusses the role of oxidative stress associated with SARS-CoV-2 and the mechanisms involved. Furthermore, the various therapeutics implicated in treating COVID-19 and the oxidative stress that contributes to the etiology and pathogenesis of COVID-19-induced neuronal dysfunction are discussed. Further mechanistic and clinical research to combat COVID-19 is warranted to understand the exact mechanisms, and its true clinical effects need to be investigated to minimize neurological complications from COVID-19.

Age-related mechanisms in the context of rheumatic disease

Ageing is characterized by a progressive loss of cellular function that leads to a decline in tissue homeostasis, increased vulnerability and adverse health outcomes. Important advances in ageing research have now identified a set of nine candidate hallmarks that are generally considered to contribute to the ageing process and that together determine the ageing phenotype, which is the clinical manifestation of age-related dysfunction in chronic diseases. Although most rheumatic diseases are not yet considered to be age related, available evidence increasingly emphasizes the prevalence of ageing hallmarks in these chronic diseases. On the basis of the current evidence relating to the molecular and cellular ageing pathways involved in rheumatic diseases, we propose that these diseases share a number of features that are observed in ageing, and that they can therefore be considered to be diseases of premature or accelerated ageing. Although more data are needed to clarify whether accelerated ageing drives the development of rheumatic diseases or whether it results from the chronic inflammatory environment, central components of age-related pathways are currently being targeted in clinical trials and may provide a new avenue of therapeutic intervention for patients with rheumatic diseases.

Mitochondrial Dysfunction and Oxidative Stress in Rheumatoid Arthritis

Control of excessive mitochondrial oxidative stress could provide new targets for both preventive and therapeutic interventions in the treatment of chronic inflammation or any pathology that develops under an inflammatory scenario, such as rheumatoid arthritis (RA). Increasing evidence has demonstrated the role of mitochondrial alterations in autoimmune diseases mainly due to the interplay between metabolism and innate immunity, but also in the modulation of inflammatory response of resident cells, such as synoviocytes. Thus, mitochondrial dysfunction derived from several danger signals could activate tricarboxylic acid (TCA) disruption, thereby favoring a vicious cycle of oxidative/mitochondrial stress. Mitochondrial dysfunction can act through modulating innate immunity via redox-sensitive inflammatory pathways or direct activation of the inflammasome. Besides, mitochondria also have a central role in regulating cell death, which is deeply altered in RA. Additionally, multiple evidence suggests that pathological processes in RA can be shaped by epigenetic mechanisms and that in turn, mitochondria are involved in epigenetic regulation. Finally, we will discuss about the involvement of some dietary components in the onset and progression of RA.

Potential roles of mitochondrial cofactors in the adjuvant mitigation of proinflammatory acute infections, as in the case of sepsis and COVID-19 pneumonia

BACKGROUND

The mitochondrial cofactors α-lipoic acid (ALA), coenzyme Q10 (CoQ10) and carnitine (CARN) play distinct and complementary roles in mitochondrial functioning, along with strong antioxidant actions. Also termed mitochondrial nutrients (MNs), these cofactors have demonstrated specific protective actions in a number of chronic disorders, as assessed in a well-established body of literature.

METHODS

Using PubMed, the authors searched for articles containing information on the utilization of MNs in inflammatory disorders as assessed from in vitro and animal studies, and in clinical trials, in terms of exerting anti-inflammatory actions.

RESULTS

The retrieved literature provided evidence relating acute pathologic conditions, such as sepsis and pneumonia, with a number of redox endpoints of biological and clinical relevance. Among these findings, both ALA and CARN were effective in counteracting inflammation-associated redox biomarkers, while CoQ10 showed decreased levels in proinflammatory conditions. MN-associated antioxidant actions were applied in a number of acute disorders, mostly using one MN. The body of literature assessing the safety and the complementary roles of MNs taken together suggests an adjuvant role of MN combinations in counteracting oxidative stress in sepsis and other acute disorders, including COVID-19-associated pneumonia.

CONCLUSIONS

The present state of art in the use of individual MNs in acute disorders suggests planning adjuvant therapy trials utilizing MN combinations aimed at counteracting proinflammatory conditions, as in the case of pneumonia and the COVID-19 pandemic.

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.

Relevance of Nrf2 and heme oxygenase-1 in articular diseases

Joint conditions pose an important public health problem as they are a leading cause of pain, functional limitation and physical disability. Oxidative stress is related to the pathogenesis of many chronic diseases affecting the joints such as rheumatoid arthritis and osteoarthritis. Cells have developed adaptive protection mechanisms to maintain homeostasis such as nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2) which regulates the transcription of many genes involved in redox balance, detoxification, metabolism and inflammation. Activation of Nrf2 results in the synthesis of heme oxygenase-1 (HO-1) leading to the formation of a number of bioactive metabolites, mainly CO, biliverdin and bilirubin. Ample evidence supports the notion that Nrf2 and HO-1 can confer protection against oxidative stress and inflammatory and immune responses in joint tissues. As a consequence, this pathway may control the activation and metabolism of articular cells to play a regulatory role in joint destruction thus offering new opportunities for better treatments. Further studies are necessary to identify improved strategies to regulate Nrf2 and HO-1 activation in order to enable the development of drugs with therapeutic applications in joint diseases.

Anti-atherogenic Modification of Serum Lipoprotein Function in Patients with Rheumatoid Arthritis after Tocilizumab Treatment, a Pilot Study

Lipid metabolism derangement contributes to increased cardiovascular risk in Rheumatoid Arthritis (RA). It is still debated whether and how tocilizumab, an interleukin-6 receptor inhibitor used in active RA, impacts cardiovascular risk. We studied the effect of tocilizumab on the regulation of macrophage cholesterol homeostasis, measuring patient serum ability to respectively load (cholesterol loading capacity, CLC) and discharge (cholesterol efflux capacity, CEC) cells with cholesterol. Patients with RA (n = 8) were studied before and after 4 and 12 weeks of tocilizumab treatment. CLC was measured by a fluorimetric assay of intracellular cholesterol content in human macrophages and CEC was measured for the three main pathways, mediated by the transporters Scavenger Receptor class B-type I (SR-BI), ATP binding cassette-G1 (ABCG1) and -A1 (ABCA1) in specific cell models. After 12 weeks of tocilizumab treatment, serum LDL cholesterol levels were increased, while CLC was reduced. HDL cholesterol levels were unchanged, but CEC was significantly ameliorated for the SR-BI and ABCG1 pathways with respect to baseline. Tocilizumab reduces LDL pro-atherogenic potential despite increasing their serum levels and increases HDL protective activity in RA. The data of our pilot study suggest that tocilizumab regulates lipoprotein function in selected patient populations and lay the groundwork for future larger studies.

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.

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.

Effects of a 15-month anti-TNF-α treatment on plasma levels of glycosaminoglycans in women with rheumatoid arthritis

Background

In this study, the effect of 15-month anti-tumor necrosis factor alpha (TNF-α) treatment on circulating levels of plasma sulfated glycosaminoglycans (GAGs) and the nonsulfated GAG hyaluronic acid (HA) in female rheumatoid arthritis (RA) patients was assessed.

Methods

Plasma was obtained from healthy subjects and RA women treated with TNF-α antagonists (etanercept or adalimumab or certolizumab pegol) in combination with methotrexate. GAGs were isolated from plasma samples using ion exchange low-pressure liquid chromatography. Total sulfated GAGs were quantified using a hexuronic acid assay. Plasma levels of keratan sulfate (KS) and HA were measured using immunoassay kits.

Results

Total sulfated GAGs and HA levels were higher in female RA patients before treatment in comparison to healthy subjects. KS levels did not differ between RA women and controls. Anti-TNF-α treatment resulted in normalization of plasma total GAG and HA levels in RA patients, without any effect on KS levels.

Conclusions

Our results suggest that anti-TNF-α therapy has a beneficial effect on extracellular matrix remodeling in the course of RA.

Hypoxia, oxidative stress and inflammation

Inflammatory Arthritis is characterized by synovial proliferation, neovascularization and leukocyte extravasation leading to joint destruction and functional disability. Efficiency of oxygen supply to the synovium is poor due to the highly dysregulated synovial microvasculature. This along with the increased energy demands of activated infiltrating immune cells and inflamed resident cells leads to an hypoxic microenvironment and mitochondrial dysfunction. This favors an increase of reactive oxygen species, leading to oxidative damage which further promotes inflammation. In this adverse microenvironment synovial cells adapt to generate energy and switch their cell metabolism from a resting regulatory state to a highly metabolically active state which allows them to produce essential building blocks to support their proliferation. This metabolic shift results in the accumulation of metabolic intermediates which act as signaling molecules that further dictate the inflammatory response. Understanding the complex interplay between hypoxia-induced signaling pathways, oxidative stress and mitochondrial function will provide better insight into the underlying mechanisms of disease pathogenesis.

Oxidative stress impairs energy metabolism in primary cells and synovial tissue of patients with rheumatoid arthritis

Background

In this study, we examined the effect of oxidative stress on cellular energy metabolism and pro-angiogenic/pro-inflammatory mechanisms of primary rheumatoid arthritis synovial fibroblast cells (RASFC) and human umbilical vein endothelial cells (HUVEC).

Methods

Primary RASFC and HUVEC were cultured with the oxidative stress inducer 4-hydroxy-2-nonenal (4-HNE), and extracellular acidification rate, oxygen consumption rate, mitochondrial function and pro-angiogenic/pro-inflammatory mechanisms were assessed using the Seahorse analyser, complex I–V activity assays, random mutation mitochondrial capture assays, enzyme-linked immunosorbent assays and functional assays, including angiogenic tube formation, migration and invasion. Expression of angiogenic growth factors in synovial tissue (ST) was assessed by IHC in patients with rheumatoid arthritis (RA) undergoing arthroscopy before and after administration of tumour necrosis factor inhibitors (TNFi).

Results

In RASFC and HUVEC, 4-HNE-induced oxidative stress reprogrammed energy metabolism by inhibiting mitochondrial basal, maximal and adenosine triphosphate-linked respiration and reserve capacity, coupled with the reduced enzymatic activity of oxidative phosphorylation complexes III and IV. In contrast, 4-HNE elevated basal glycolysis, glycolytic capacity and glycolytic reserve, paralleled by an increase in mitochondrial DNA mutations and reactive oxygen species. 4-HNE activated pro-angiogenic responses of RASFC, which subsequently altered HUVEC invasion and migration, angiogenic tube formation and the release of pro-angiogenic mediators. In vivo markers of angiogenesis (vascular endothelial growth factor, angiopoietin 2 [Ang2], tyrosine kinase receptor [Tie2]) were significantly associated with oxidative damage and oxygen metabolism in the inflamed synovium. Significant reduction in ST vascularity and Ang2/Tie2 expression was demonstrated in patients with RA before and after administration of TNFi.

Conclusions

Oxidative stress promotes metabolism in favour of glycolysis, an effect that may contribute to acceleration of inflammatory mechanisms and subsequent dysfunctional angiogenesis in RA.

Electronic supplementary material

The online version of this article (10.1186/s13075-018-1592-1) contains supplementary material, which is available to authorized users.

Effect of Drug Therapy on Net Cholesterol Efflux Capacity of High-Density Lipoprotein-Enriched Serum in Rheumatoid Arthritis

OBJECTIVE

Patients with rheumatoid arthritis (RA) have an increased risk of coronary heart disease (CHD). Some RA therapies may modify this risk, but the underlying mechanisms are unclear. The cholesterol efflux capacity of high-density lipoprotein (HDL) is associated with a reduced CHD risk in non-RA populations; however, inflammation may impair the function of HDL. The aim of this study was to evaluate whether reduced inflammation resulting from treatment with methotrexate (MTX), adalimumab (ADA), or tocilizumab (TCZ) would increase the net cholesterol efflux capacity of HDL in patients with RA.

METHODS

A longitudinal multicenter study repository (Treatment Efficacy and Toxicity in Rheumatoid Arthritis Database and Repository) provided clinical information for and serum samples from 70 patients with RA before and 6 months after starting treatment with a new drug (MTX [n = 23], ADA [n = 22], or TCZ [n = 25]). Disease activity was measured using the Disease Activity Score in 28 joints using the erythrocyte sedimentation rate (DAS28-ESR). The net cholesterol efflux capacity was measured in paired serum samples using THP-1 macrophages, and total cellular cholesterol was measured by fluorometric assay.

RESULTS

The DAS28-ESR decreased with all treatments (P < 0.001). Net cholesterol efflux capacity was not significantly changed after 6 months of new RA therapy (mean ± SD 36.9 ± 17.3% units at baseline versus 38.0% ± 16.9% units at 6 months [P = 0.58]). However, change in net cholesterol efflux capacity was associated with change in the DAS28-ESR (ρ = -0.25, P = 0.04). In a post hoc analysis of patients with impaired net cholesterol efflux capacity at baseline, treatment with TCZ resulted in significant improvement in net cholesterol efflux capacity (21.9 ± 14.7% units at baseline versus 31.3% ± 12.8% units at 6 months [P < 0.02]), but this was not observed with MTX or ADA.

CONCLUSION

Net cholesterol efflux capacity of HDL cholesterol did not change significantly after 6 months of new RA therapy, except in patients with impaired baseline cholesterol efflux capacity who were receiving TCZ. Change in disease activity was associated with change in the net cholesterol efflux capacity.

Tocilizumab improves the proatherothrombotic profile of rheumatoid arthritis patients modulating endothelial dysfunction, NETosis, and inflammation

Tocilizumab (TCZ) is an effective treatment for rheumatoid arthritis (RA). However, the changes that occurred after TCZ therapy on endothelial dysfunction, monocyte activity, NETosis, and oxidative stress, the principal effectors of atherosclerosis and cardiovascular disease, have not been analyzed yet. A total of 20 RA patients received 162 mg per week subcutaneous TCZ for 6 months. Endothelial function was measured through postocclusive hyperemia using Laser Doppler. Oxidative stress markers in monocytes and neutrophils were analyzed by flow cytometry. NETosis was measured through SYTOX staining of DNA fibers and the expression of myeloperoxidase and neutrophil elastase. Percentage of low-density granulocytes was analyzed through flow cytometry. Gene expression and phosphorylation of intracellular pathways was analyzed in monocytes. TCZ improved endothelial function and decreased oxidative stress in RA leukocytes. Percentage of low-density granulocytes and NETosis generation were reduced. The proinflammatory and prothrombotic status of RA monocytes was also reversed through a modulation of specific intracellular pathways. All these results were recapitulated after in vitro treatment with TCZ of monocytes and neutrophils purified from RA patients and cocultured with endothelial cells. TCZ might reduce the proatherothrombotic profile in RA patients through the restoration of the endothelial function, oxidative stress reduction, inhibition of monocytes' prothrombotic and inflammatory profile, and abridged NETosis generation.

Effect of spa therapy with saline balneotherapy on oxidant/antioxidant status in patients with rheumatoid arthritis: a single-blind randomized controlled trial

Oxidative stress has been shown to play a contributory role in the pathogenesis of rheumatoid arthritis (RA). Recent studies have provided evidence for antioxidant properties of spa therapy. The purpose of this study is to investigate whether spa therapy with saline balneotherapy has any influence on the oxidant/antioxidant status in patients with RA and to assess clinical effects of spa therapy. In this investigator-blind randomized controlled trial, we randomly assigned 50 patients in a 1:1 ratio to spa therapy plus standard drug treatment (spa group) or standard drug treatment alone (control group). Spa group followed a 2-week course of spa therapy regimen consisting of a total of 12 balneotherapy sessions in a thermal mineral water pool at 36-37 °C for 20 min every day except Sunday. All clinical and biochemical parameters were assessed at baseline and after spa therapy (2 weeks). The clinical parameters were pain intensity, patient global assessment, physician global assessment, Health Assessment Questionnaire disability index (HAQ-DI), Disease Activity Score for 28-joints based on erythrocyte sedimentation rate (DAS28-4[ESR]). Oxidative status parameters were malondialdehyde (MDA), nonenzymatic superoxide radical scavenger activity (NSSA), antioxidant potential (AOP), and superoxide dismutase (SOD). The NSSA levels were increased significantly in the spa group (p = 0.003) but not in the control group (p = 0.509); and there was a trend in favor of spa therapy for improvements in NSSA levels compared to control (p = 0.091). Significant clinical improvement was found in the spa group compared to the control in terms of patient global assessment (p = 0.011), physician global assessment (p = 0.043), function (HAQ-DI) (p = 0.037), disease activity (DAS28-4[ESR]) (0.044) and swollen joint count (0.009), and a trend toward improvement in pain scores (0.057). Spa therapy with saline balneotherapy exerts antioxidant effect in patients with RA as reflected by the increase in NSSA levels after spa therapy; whether this antioxidant effect contributes to the clinical improvements observed remains to be verified.

Infliximab equivalently suppresses oxidative stress compared to tocilizumab among well-controlled patients with rheumatoid arthritis

AIM

This study was designed to investigate which biological agent, infliximab or tocilizumab, would more intensively keep suppressing oxidative stress among well-controlled patients as C-reactive protein (CRP) levels normalized in rheumatoid arthritis (RA). In addition, it was intended to clarify indicative factors of oxidative stress among well-controlled patients with RA.

METHODS

We recruited 61 well-controlled (CRP < 0.3 mg/dL within normal ranges) patients with RA using biological agents (infliximab n = 33; tocilizumab n = 28), active RA patients with CRP > 1.0 mg/dL (n = 10) and healthy subjects (n = 10) and examined the fraction of oxidized albumin (oxidized-albumin [%]) as a marker of oxidative stress in addition to inflammatory measures and disease activity scores such as CRP, erythrocyte sedimentation rate (ESR), matrix metalloproteinase 3 (MMP-3), serum amyloid A (SAA), Clinical Disease Activity Index, Simplified Disease Activity Index, visual analog scale (VAS), Disease Activity Index of 28 joints (DAS28)-CRP, DAS28-ESR and renal function (creatinine clearance [CCr]).

RESULTS

Oxidized-albumin (%) was significantly elevated among active RA patients (33.83 ± 5.31%) as compared with healthy subjects (23.00 ± 2.56%). Although oxidized-albumin (%) among well-controlled RA patients also increased, there was no difference with oxidized-albumin (%) between infliximab and tocilizumab groups (26.40 ± 5.44% in infliximab; 26.62 ± 4.53% in tocilizumab). In Pearson's correlation, oxidized-albumin (%) had significant correlations with CRP, MMP-3, ESR, SAA, age, CCr, VAS, DAS28-CRP and DAS28-ESR. With those variables, multiple stepwise forward regression analysis was conducted and revealed that CCr, DAS28-ESR and CRP are the statistically significant explanatory variables on oxidized-albumin (%) among well-controlled RA patients.

CONCLUSIONS

We demonstrated that there was no difference with infliximab and tocilizumab on oxidative stress and we clarified that CCr, DAS28-ESR and CRP become indicative factors of oxidative stress among well-controlled RA patients.

Activity of Glutathione Antioxidant System and NADPH-Generating Enzymes in Rats with Experimental Rheumatoid Arthritis

Induction of rheumatoid arthritis in rats was accompanied by an increase in diene conjugate content and glutathione reductase and glutathione peroxidase activities in muscles and blood serum. These changes can be related to mobilization of the glutathione reductase/glutathione peroxidase system coupled with intensification of free radical oxidation. In addition, activity of glucose-6-phosphodehydrogenase and NADP-dependent isocitrate dehydrogenase increased, which can be related to increased demand of NADPH for the glutathione reductase/glutathione peroxidase system. The content of reduced glutathione in muscles and blood serum decreased, probably, due to its utilization for ROS neutralization. Glutathione transferase activity decreased in rheumatoid arthritis, which can be related to shortness of reduced glutathione developing during oxidative stress. The observed shifts in parameters of free radical homeostasis in rheumatoid arthritis are probably associated with intensification of free radical oxidation.

Fcγ and Complement Receptors and Complement Proteins in Neutrophil Activation in Rheumatoid Arthritis: Contribution to Pathogenesis and Progression and Modulation by Natural Products

Rheumatoid arthritis (RA) is a highly disabling disease that affects all structures of the joint and significantly impacts on morbidity and mortality in RA patients. RA is characterized by persistent inflammation of the synovial membrane lining the joint associated with infiltration of immune cells. Eighty to 90% of the leukocytes infiltrating the synovia are neutrophils. The specific role that neutrophils play in the onset of RA is not clear, but recent studies have evidenced that they have an important participation in joint damage and disease progression through the release of proteolytic enzymes, reactive oxygen species (ROS), cytokines, and neutrophil extracellular traps, in particular during frustrated phagocytosis of immune complexes (ICs). In addition, the local and systemic activation of the complement system contributes to the pathogenesis of RA and other IC-mediated diseases. This review discusses (i) the participation of Fcγ and complement receptors in mediating the effector functions of neutrophils in RA; (ii) the contribution of the complement system and ROS-dependent and ROS-independent mechanisms to joint damage in RA; and (iii) the use of plant extracts, dietary compounds, and isolated natural compounds in the treatment of RA, focusing on modulation of the effector functions of neutrophils and the complement system activity and/or activation.

Intravenous tocilizumab: a review of its use in adults with rheumatoid arthritis

Tocilizumab (Actemra®, RoActemra®) is a humanized monoclonal antibody that acts as an interleukin-6 receptor antagonist. Intravenous tocilizumab as monotherapy or in combination with disease-modifying anti-rheumatic drugs (DMARDs) is indicated for the treatment of adult patients with moderate to severe active rheumatoid arthritis (RA) who had an inadequate response to one or more DMARDs or tumor necrosis factor (TNF) α antagonists (the specific indication varies between countries); it may also be used as monotherapy in patients for whom continued methotrexate use is inappropriate. This article reviews the efficacy and tolerability of tocilizumab in these patients and briefly summarizes its pharmacology. Several large well-designed clinical trials and routine clinical practice studies showed that tocilizumab was an effective and generally well tolerated biologic for the treatment of adults with RA, including those with an inadequate response to DMARDs or TNFα antagonists. In these studies, tocilizumab as monotherapy or in combination with DMARDs (including methotrexate) had beneficial effects on the signs and symptoms of disease, health-related quality of life/physical function, and/or radiologic disease progression. In addition, tocilizumab monotherapy was more effective than adalimumab monotherapy in improving the signs and symptoms of disease in patients for whom continued methotrexate use was inappropriate. As with other biologic DMARDS, infections were the most common adverse event associated with tocilizumab therapy. Pooled and meta-analyses demonstrated that the efficacy and tolerability profile of tocilizumab was sustained during long-term (up to 9 years) therapy. Although additional comparative data are needed to position tocilizumab more definitively with respect to other biologic DMARDs, current evidence indicates that tocilizumab is effective as a first- or subsequent-line biologic in patients with moderate to severe RA.

Relationship between redox status and cell fate in immunity and autoimmunity

SIGNIFICANCE

The signaling function of redox molecules is essential for an efficient and proper execution of a large number of cellular processes, contributing to the maintenance of cell homeostasis. Excessive oxidative stress is considered as playing an important role in the pathogenesis of autoimmune diseases by enhancing inflammation and breaking down the immunological tolerance through protein structural modifications that induce the appearance of neo/cryptic epitopes.

RECENT ADVANCES

There is a complex reciprocal relationship between oxidative stress and both apoptosis and autophagy, which is essential to determine cell fate. This is especially relevant in the context of autoimmune disorders in which apoptosis and autophagy play a crucial pathogenic role.

CRITICAL ISSUES

In this review, we describe the latest developments with regard to the involvement of redox molecules in the initiation and progression of autoimmune disorders, focusing on their role in cell fate regulation. We also discuss new therapeutic approaches that target oxidative stress in the treatment of these disorders. The administration of antioxidants is scarcely studied in autoimmunity, and future analyses are needed to assess its beneficial effects in preventing or ameliorating these diseases.

FUTURE DIRECTIONS

Deciphering the intricate relationships between oxidative stress and both apoptosis and autophagy in the context of autoimmunity could be critical in elucidating key pathogenic mechanisms and could lead to novel interventions for the clinical management of autoimmune diseases.

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

OBJECTIVES

Reactive oxygen species (ROS) are considered to be involved in the pathobiology of rheumatoid arthritis (RA); however, their association with disease activity has not been elucidated. In this study, we measured reactive oxygen metabolites (ROM) in patients with RA using a new Free Radical Analytical System and determined clinical parameters associated with ROM.

METHODS

One hundred and fifty-two patients with RA and 80 patients with diabetes mellitus (DM) were included in this observational study. To measure ROM, the d-ROM test was performed on blood samples drawn from all subjects. The correlation between ROM and biomarkers, disease activity, doses of methotrexate (MTX), and prednisolone (PSL) were investigated.

RESULTS

There were significant, positive correlations between ROM and CRP, matrix metalloproteinase 3 (MMP3), Disease Activity Score 28-erythrocyte sedimentation rate (DAS28-ESR), Clinical Disease Activity Index (CDAI), and the Simplified Disease Activity Index (SDAI). Multiple regression analysis revealed that CRP and DAS28-ESR were correlated with ROM.

CONCLUSIONS

The serum level of ROM was associated with CRP and DAS28-ESR, suggesting that ROM, in conjunction with CRP and MMP3, may be able to be used as a new biological disease marker to evaluate the disease activity of RA.

Reactive oxygen species and serum antioxidant defense in juvenile idiopathic arthritis

In autoimmune inflammatory diseases, including juvenile idiopathic arthritis (JIA), which leads to joint destruction, there is an imbalance between production of reactive oxygen species (ROS) and their neutralization which, as a consequence, leads to “oxidative stress.” The aim of the study was to assess the concentration of oxidative stress markers: nitric oxide (NO), a degree of lipid membrane damage, and total antioxidant plasma capacity in children with JIA. Thirty-four children with JIA were included into the study. A degree of lipid membrane damage (lipid peroxidation products) was estimated as thiobarbituric acid-reactive substances (TBARs), NO concentration as NO end-products: nitrite/nitrate (NO₂⁻/NO₃⁻) and total antioxidant plasma capacity as ferric reducing ability of plasma (FRAP). NO₂⁻/NO₃⁻ serum concentration in children with JIA was statistically significantly higher than that in healthy children (p = 0.00069). There was no significant difference in TBAR levels between children with JIA and the control group. FRAP in sera of children with JIA was lower than that in healthy children, but the difference was not statistically significant. A statistically significant positive correlation was observed between NO end products and the 27-joint juvenile arthritis disease activity score (JADAS-27) and ESR, and a negative correlation was observed between FRAP and C-reactive protein (CRP) and white blood cell count (WBC). Our results confirm the increased oxidative stress in children with JIA. Overproduction of NO and decrease in the antioxidant plasma capacity may be involved in JIA pathogenesis.

Targeting classical IL-6 signalling or IL-6 trans-signalling in depression?

INTRODUCTION

Increased IL-6 and soluble IL-6 receptor (sIL-6R) levels in depressed patients was first shown over 20 years ago. The pro-inflammatory effects of IL-6 are predominantly mediated by IL-6 trans-signalling via the sIL-6R, whereas IL-6R membrane signalling has anti-inflammatory effects.

AREAS COVERED

We review data on IL-6 and sIL-6R in inflammation, depression, animal models of depression and the effects of different classes of antidepressants. The biological context for IL-6 trans-signalling as a pathogenic factor in depression involves its role in the acute phase response, disorders in zinc and the erythron, hypothalamic-pituitary-adrenal axis activation, induction of the tryptophan catabolite pathway, oxidative stress, bacterial translocation, transition towards sensitisation, autoimmune processes and neuroprogression and the multicausal aetiology of depression, considering that psychosocial stressors and comorbid immune-inflammatory diseases are associated with the onset of depression.

EXPERT OPINION

The homeostatic functions of IL-6 imply that ubiquitous IL-6 inhibitors, for example, tocilizumab, may not be the optimal treatment target in depression. A more promising target may be to increase soluble glycoprotein 130 (sgp130) inhibition of IL-6 trans-signalling, while allowing the maintenance of IL-6R membrane signalling. Future research should delineate the effects of treatments with sgp130Fc in combination with antidepressants in various animal models of chronic depression.

Tocilizumab: An Updated Review of Its Use in the Treatment of Rheumatoid Arthritis and Its Application for Other Immune-Mediated Diseases

Interleukin-6 (IL-6), produced by a variety of cells, is a typical cytokine featuring redundancy and pleiotropic activity. IL-6 is promptly and transiently synthesized in response to infections or injuries, and participates in host defense by inducing immune responses, hematopoiesis, and acute-phase reactions. However, since its abnormal persistent production of mostly unknown etiology plays an important pathological role in the development of various immune-mediated diseases, a humanized anti-IL-6 receptor monoclonal antibody, tocilizumab, was developed and is now used as an innovative biologic for rheumatoid arthritis in more than 90 countries. Several factors strongly suggest that a IL-6 blockade strategy may have a broad application for the treatment of various immune-mediated diseases. These factors include favorable results of pilot or case studies with off-label use of tocilizumab, pathological analyses of the contribution of IL-6 to the development of immune-mediated diseases, and the potential capability of tocilizumab to both repair an imbalance of effector T cell subsets and to suppress pathologic autoantibody production. However, clinical trials to evaluate the efficacy and safety of tocilizumab for these diseases are essential. Furthermore, clarification of the cell source of IL-6 production and of the mechanisms through which dysregulated continuous IL-6 synthesis is induced constitutes an important issue for future studies into the pathogenesis of diseases.

Targeting interleukin-6: all the way to treat autoimmune and inflammatory diseases

Interleukin (IL)-6, a cytokine featuring redundancy and pleiotropic activity, contributes to host defense against acute environmental stress, while dysregulated persistent IL-6 production has been demonstrated to play a pathological role in various autoimmune and chronic inflammatory diseases. Targeting IL-6 is thus a rational approach to the treatment of these diseases. Indeed, clinical trials of tocilizumab, a humanized anti-IL-6 receptor antibody have verified its efficacy and tolerable safety for patients with rheumatoid arthritis, Castleman's disease and systemic juvenile idiopathic arthritis, resulting in approval of this innovative biologic for treatment of these diseases. Moreover, a considerable number of case reports and pilot studies of off-label use of tocilizumab point to the beneficial effects of tocilizumab for a variety of other phenotypically different autoimmune and chronic inflammatory diseases. Elucidation of the source of IL-6 and of mechanisms through which IL-6 production is dysregulated can thus be expected to lead to clarification of the pathogenesis of various diseases.

Safety and efficacy of tocilizumab for the treatment of rheumatoid arthritis

Because of the pathological role of IL-6 in rheumatoid arthritis (RA), tocilizumab (TCZ), a humanized anti-IL-6 receptor monoclonal antibody, was expected to improve inflammation and joint destruction of RA. Indeed, randomized clinical trials demonstrated the clinical efficacy of TCZ as monotherapy or combined with methotrexate (MTX) for RA patients with inadequate responses to disease-modifying antirheumatic drugs, MTX or tumor necrosis factor (TNF) inhibitors. Although long-term tolerability for TCZ is superior to that for TNF inhibitors, information regarding the potency of drug free remission of TCZ is limited at present. In terms of its safety profile, the general risk of infection when using TCZ is comparable to that of TNF inhibitors. TCZ has some advantage in RA patients who can not use MTX and are non-responders to TNF inhibitors. In conclusion, TCZ is one of the most prospective next generation biologics for the treatment of RA.