Oxidative stress: correlation with Behçet's disease duration, activity and severity

Neutrophil, NETs and Behçet's disease: A review

Behçet's disease (BD) is a chronic systemic vasculitis characterized by recurrent oral and genital ulcers, skin lesions, articular, neurological, vascular and sight-threatening ocular inflammation. BD is thought to share both autoimmune and autoinflammatory disease features. BD is triggered by environmental factors such as infectious agents in genetically predisposed subjects. Neutrophils seem to play an instrumental role in BD and recent works regarding the role of neutrophils extracellular traps (NETs) provides new insight in the pathophysiology of BD and the mechanisms involved in immune thrombosis. This review provides a recent overview on the role of neutrophils and NETs in the pathogenesis of BD.

Deregulated DNA damage response network in Behcet's disease

Behcet's disease (BD) is a chronic, relapsing systemic vasculitis of unknown etiology. Since the DNA repair enzyme NEIL1 has been identified as one of the two genetic risk factors for BD by whole exome study, we examined the potential involvement of the DNA damage response (DDR) network in BD. Peripheral blood mononuclear cells from 26 patients and 26 age-/sex-matched healthy controls were studied. Endogenous DNA damage levels were increased in active BD patients compared to controls or patients in remission. In parallel, BD patients had defective nucleotide excision repair capacity. RNA-sequencing revealed reduced expression of NEIL1 that negatively correlated with DNA damage accumulation. On the other hand, expression of genes involved in senescence and senescence-associated secretory phenotype positively correlated with individual endogenous DNA damage levels. We conclude that deregulated DDR contributes to the proinflammatory environment in BD.

Blood-retina barrier dysfunction in experimental autoimmune uveitis: the pathogenesis and therapeutic targets

Experimental autoimmune uveitis (EAU), an animal model of human uveitis, is characterized by infiltration of autoimmune T cells in the uvea as well as in the retina of susceptible animals. EAU is induced by the immunization of uveitogenic antigens, including either retinal soluble-antigen or interphotoreceptor retinoid-binding proteins, in Lewis rats. The pathogenesis of EAU in rats involves the proliferation of autoimmune T cells in peripheral lymphoid tissues and breakdown of the blood-retinal barrier, primarily in the uvea and retina, finally inducing visual dysfunction. In this review, we describe recent EAU studies to facilitate the design of a therapeutic strategy through the interruption of uveitogenic factors during the course of EAU, which will be helpful for controlling human uveitis.

Behcet's Disease: An In-Depth Review about Pathogenesis, Gastrointestinal Manifestations, and Management

Background

Behcet's disease (BD) is a complex inflammatory vascular disorder that follows a relapsing-remitting course with diverse clinical manifestations. The prevalence of the disease varies throughout the globe and targets different age-groups. There are many variations of BD; however, intestinal BD is not only more common but has many signs and symptoms.

Summary

BD is a relapsing-remitting inflammatory vascular disorder with multiple system involvement, affecting vessels of all types and sizes that targets young adults. The etiology of BD is unknown but many factors including genetic mechanisms, vascular changes, hypercoagulability, and dysregulation of immune function are believed to be responsible. BD usually presents with signs and symptoms of ulcerative disease of the small intestine; endoscopy being consistent with the clinical manifestations. The mainstay of treatment depends upon the severity of the disease. Corticosteroids are recommended for severe forms of the disease and aminosalicylic acids are used in maintaining remission in mild to moderate forms of the disease.

Key Messages

In this review, we have tried to summarize in the present review the clinical manifestations, differential diagnoses, and management of intestinal BD. Hopefully, this review will enable health policymakers to ponder over establishing clear endpoints for treatment, surveillance investigations, and creating robust algorithms.

Getting to the <em>heart</em> of the matter: diagnostic tools and therapeutic approach to cardiac involvement in Behçet syndrome A Tunisian case series

The aim was to investigate the frequency and spectrum of cardiac involvement (CI) in patients with Behçet syndrome (BS) in the Tunisian context, and to assess the clinical and imaging features, treatment, and outcomes. We retrospectively retrieved the medical records of patients with CI among 220 BS patients admitted to the hospital internal medicine department between February 2006 and April 2019, who fulfilled the International Study Group diagnostic criteria for BS. Ten patients (8 men, 2 women) were eligible for the study. Mean age was 37.3 years. Three patients had 2 isolated episodes of cardiac BS. The different types of CI were coronary artery disease (5/10), intracardiac thrombus (4/10), pericarditis (1/10), myocarditis (1/10), and myocardial fibrosis (1/10). Five patients had associated vascular involvement (50%). Medical treatment was based on corticosteroids and colchicine in all patients (100%), anticoagulants in 8 (80%), and cyclophosphamide followed by azathioprine in 9 (90%). The clinical course was favorable in 9 patients; 1 patient died. CI remains an important feature of BS because of its association with increased risk of mortality and morbidity. Therefore, early screening and detection with imaging methods are paramount. Also, better cooperation between rheumatologists and cardiologists could improve outcomes.

Thiol/disulfide homeostasis in patients with ocular-active and ocular-inactive Behçet disease

PURPOSE

To evaluate thiol/disulfide homeostasis in ocular-active (OA) and ocular-inactive (OI) Behçet disease (BD) patients and compare the data with healthy subjects.

METHODS

Twenty OABD patients, 20 OIBD patients and 20 healthy control subjects were included into the study. The BD ocular attack score 24 (BOS24) scoring system was used to assess the activity of disease in ocular BD patients. Systemic activity was also evaluated using BD current activity form (BDCAF). The native thiol (NT), total thiol (TT) and disulfide levels and NT/TT, disulfide/NT and disulfide/TT ratios were measured via using an innovative and automated method.

RESULTS

BOS24 and BDCAF scores were 13.25 ± 2.32 and 4.18 ± 2.06 in OABD patients and 0.31 ± 0.47 and 2.14 ± 1.98 in OIBD patients, respectively. The NT, TT levels and NT/TT ratio were significantly reduced; in contrast, the disulfide levels, disulfide/NT and disulfide/TT ratios were significantly increased in OABD and OIBD patients compared to the healthy control subjects (p < 0.05). Moreover, while the levels of NT and TT were significantly reduced, the disulfide levels as well as disulfide/NT and disulfide/TT ratios were significantly elevated between OABD and OIBD patients (p < 0.05). However, the ratio of NT/TT did not significantly differ between OABD and OIBD patients (p = 0.449). The multiple regression model including BOS24 and BDCAF score statistically significantly predicted NT level, TT level and disulfide level (p < 0.001 for all).

CONCLUSION

Thiol oxidation in BD patients resulted in a change of the thiol/disulfide balance. Therefore, thiol/disulfide homeostasis in BD patients can be used an innovative oxidative stress marker.

Oxidative Stress Indexes for Diagnosis of Health or Disease in Humans

Oxidative stress (OS) is the imbalance between oxidant and antioxidant molecules, in favor of oxidants, that causes aging and disease. Many studies have been published that demonstrate the relationship between OS and human health and disease; however, the following questions arise: (i) how are we sure that the OS is present in a biological process? (ii) Is the OS reported in the different investigations equivalent? (iii) What are the best oxidant and antioxidant markers for OS diagnosis? (iv) Can we establish the types and the intensity of the OS? (v) Does OS index could be useful for research and/or application in clinical medicine? In this regard, several indexes have been proposed to measure OS in humans relative to the state of health and disease, among which the following can be highlighted: Oxidative Stress Index (OSI), Tiol Ratios (-SH/TT, -SS/-SH, and-SS/TT), Glutathione Ratio (GSSG/GSH), Oxidative Stress Score (OSS), and OXY-index. Therefore, the aim of this review is to present the state of the art of knowledge about OS indexes for diagnosis of health or disease in humans. We searched for articles in English or Spanish in the PubMed/MEDLINE and Scopus electronic databases published up until May 2019. The keywords used were “oxidative stress,” “index,” and “oxidative stress index.” It was identified 11479 records in both databases, and 490 articles were analyzed. Our review suggests that all indexes analyzed allow diagnose and differentiate the OS related to human health and disease. Also, the studies on OSI, Oxy-score, and OSS indexes have proven to be reliable, practical, and with clinical utility. However, it is necessary to continue with longitudinal studies, especially assess the usefulness of the indexes in the clinical prognosis, and make comparative studies between the different indexes.

Clinical significance of CCN2/connective tissue growth factor in Behçet's disease patients

AIM

Behçet's disease (BD) is a chronic autoimmune vasculitic disorder of unclear pathogenesis. CCN2/CTGF (connective tissue growth factor) is one of the CCN family members which carry out pro-angiogenic biological functions and play an important role in inflammatory and autoimmune diseases. The aim of the present study was to assess CCN2 plasma concentrations in BD patients and to analyze their association with clinical features of the disease, activity and laboratory parameters.

METHODS

We included 87 BD patients and 60 healthy control subjects matched for age and gender. Demographic, clinical, disease activity and severity data were recorded. Plasma CCN2 concentrations were measured using enzyme-linked immunosorbent assay.

RESULTS

The plasma concentrations of CCN2 in BD patients were significantly elevated compared to healthy controls. The mean plasma CCN2 levels in patients with major organ involvement were significantly higher than those without. Patients who received steroids or cyclophosphamide showed a significant reduction in CCN2 levels. This was confirmed by the results of multivariate analysis. Patients with active ocular disease had a significant increase in CCN2 compared to the inactive group. On the other hand, CCN2 levels were not significantly correlated with overall disease activity and severity scores.

CONCLUSION

Behçet's disease patients showed a significant increase of CCN2 levels, especially in the group of patients with major organ involvement. A significant reduction of these levels was found in patients who received steroids or cyclophosphamide. Larger studies with further investigations of the precise role of CCN2 in BD pathogenesis might lead to novel therapies for the clinical management of this disease.

Parameters of arterial stiffness in patients with Behçet's disease and their relationship with disease duration

The results of investigations of arterial stiffness in Behçet's disease (BD) are contradictory and the reason for this contradictory situation is not clear. The lack of studies in homogenous groups according to the duration of the disease may be the cause of conflicting results. To compare arterial stiffness by assessing pulse wave velocity (PWV) and augmentation index (AIx) measurements in healthy controls (HC) and patients diagnosed with BD with short and long disease duration. This cross-sectional study was conducted between August-November 2017 and 54 patients with BD and 34 HC were included. Patients with BD who were diagnosed within 12 months were included in the group with short disease duration (SDD) and the others in the group with long disease duration (LDD). Parameters of cardiovascular risk of all participants were recorded and PWV and AIx values were measured from the brachial artery. AIx was significantly higher in all patients with BD, patients with BD with SDD and patients with BD with LDD, than in HC (p = 0.005, p = 0.011, p = 0.004, respectively). Pulse wave velocity values were not different from HC in patients with BD. When patients with BD with SDD and LDD were compared with each other, PWV was significantly higher in patients with BD with LDD (p = 0.030). There was a moderate correlation between PWV and disease duration (Rho = 0.414, p = 0.002). Augmentation index is higher in patients with BD than HC regardless of disease duration.

Pitfalls in the analysis of the physiological antioxidant glutathione (GSH) and its disulfide (GSSG) in biological samples: An elephant in the room

Glutathione (GSH) is the most abundant low-molecular-mass thiol within cells and one of the major antioxidant compounds in body fluids. Under pro-oxidant conditions, two GSH molecules donate one electron each and are converted into glutathione disulfide (GSSG). The GSH/GSSG molar ratio is considered a powerful index of oxidative stress and disease risk. Despite high interest in GSH/GSSG titration as measures of thiol redox balance, no broad agreement has yet been reached as to the best pre-analytical and analytical methods for the quantitation of these molecules in biological samples. Consequently, measured concentrations of GSH and GSSG and calculated GSH/GSSG molar ratios vary widely among laboratories. Here, we describe in detail the main analytical and pre-analytical problems related to the artificial oxidation of the sulfhydryl (SH) group of GSH that occur during sample manipulation. We underline how this aspect has been neglected for long time after its first description more than fifty years ago. Finally, selected reliable procedures and methods to measure GSH and GSSG in biological samples are discussed.

Fatigue in rheumatic diseases

Fatigue is a common and important problem in many diseases including rheumatologic illnesses, and it has a negative impact on health-related quality of life. Fatigue is described as having an impact on multiple aspects of a patient's life. There is a need for knowledge about causes of and treatments for fatigue to ensure that patient outcomes are improved. There are several effective treatment strategies available for fatigue including pharmacological and non-pharmacological therapies. We aim to provide an overview of fatigue in rheumatologic disorders and some recommendations on its optimal management.

Assessment of genotoxicity associated with Behcet's disease using sister-chromatid exchange assay: vitamin E versus mitomycin C

Behcet's disease (BD) is a multisystemic chronic inflammatory disorder that presents throughout the world with high frequency in Turkey and Middle East. BD has been shown to be associated with genotoxicity as patients with the disease have demonstrated high rates of sister chromatid exchange (SCE) and oxidative DNA damage. In this study, we examined the effect of vitamin E, which is known for its strong antioxidant activity, on the rate of SCE in cultured lymphocytes obtained from BD patients. In addition, the susceptibility of patient lymphocytes to the mutagenic agent mitomycin C (MMC) was also investigated. The results showed significant elevation in the rate of SCE in lymphocytes obtained from patients compared to those from healthy subjects (P < 0.01). Treatment with vitamin E normalized the elevated rate of SCE to a comparable level observed in the control group (P < 0.01). Finally, treatment of cultures with MMC significantly increased the rate of SCE in the lymphocytes of both patients and controls (P < 0.001). The magnitude of change in the rate of SCE induced by MMC was equivalent in both groups. This result suggests similar sensitivity of BD lymphocytes and control ones to MMC. In conclusion, genotoxicity associated with BD can be overcome by treatment with vitamin E. Lymphocytes of BD have normal sensitivity to the mutagenic agent MMC.

Outcome measures used in clinical trials for Behçet syndrome: a systematic review

Behçet syndrome (BS) is a multisystem vasculitis that is most active during young adulthood, causing serious disability and significant impairment in quality of life. Differences in the disease course, severity, and organ involvement between patients, depending on the age at presentation and sex, makes it impossible to determine a single management strategy. The diversity and variability in the outcome measures used in clinical trials in BS makes it difficult to compare the results or inform physicians about the best management strategy for individual patients. There is a large unmet need to determine or develop validated outcome measures for use in clinical trials in BS that are acceptable to researchers and regulatory agencies. We conducted a systematic review to describe the outcomes and outcome measures that have been used in clinical trials in BS. This review revealed the diversity and variability in the outcomes and outcome measures and the lack of standard definitions for most outcomes and rarity of validated outcome tools for disease assessment in BS. This systematic literature review will identify domains and candidate instruments for use in a Delphi exercise, the next step in the development of a core set of outcome measures that are properly validated and widely accepted by the collaboration of researchers from many different regions of the world and from different specialties, including rheumatology, ophthalmology, dermatology, gastroenterology, and neurology.

Serum prolidase enzyme activity and oxidative status in patients with Behçet's disease

OBJECTIVES

To assess serum prolidase enzyme activity and oxidative stress in patients with Behçet's disease (BD).

METHODS

The study population consisted of BD patients (n = 42) and healthy participants (n = 29). BD patients were classified as active (n = 18) or inactive (n = 24) according to disease activity. Serum prolidase enzyme activity, total antioxidant status (TAS), total oxidative status (TOS), oxidative stress index (OSI), and malondialdehyde (MDA) levels were measured.

RESULTS

In BD patients with active disease, serum prolidase activity was significantly higher compared with the inactive and control participants. Serum prolidase activity was also significantly higher in all BD patients in comparison with controls. Serum prolidase activity was also positively correlated with OSI, C-reactive protein, and active BD. MDA, TOS, and OSI levels were all significantly higher in the BD group when compared with the healthy control participants. Serum TAS levels were significantly lower in BD patients in comparison with healthy controls.

CONCLUSION

High prolidase activity may indicate critical biological activities relevant to pathological events in BD, and this activity may be a biological indicator of disease. Further studies are needed to verify these findings.

[Effects of peroxynitrite derived from nitric oxide on cultured bovine ocular explants]

INTRODUCTION

Several studies have reported a significant production of nitric oxide (NO) with peroxynitrite formation in the setting of intraocular inflammation. In a previous study, we showed the cytotoxic effect of nitrites and nitrates, stable metabolites of NO, on the various tissues forming the layers of the eye, with variable degrees of tissue sensitivity. This study aims to investigate the effect of peroxynitrite on whole ocular bovine explants in culture.

METHODS

Healthy ocular bovine eyes, obtained immediately upon enucleation, were dissected and samples were taken from the anterior and posterior segments, and then cultured in DMEM supplemented with 10% fetal bovine serum, 2mM L-glutamine and antibiotics. Cultures were treated with 3-morpholino-sydonimin N-ethyl-carbamide (SIN-1) (molecule which produces NO and superoxide anion O(2)(.-)) at varying concentrations (100 to 500 μM) over 24 hours. After incubation, the explants were fixed in 10% buffered formalin, and histological study was performed.

RESULTS

Most of the structures showed changes on tissue and cellular levels after incubation with the peroxynitrite donor and various responses depending on the concentration used. These observations reflect variable concentration-dependent tissue sensitivity. The epithelia (cornea, iris and ciliary process) showed high sensitivity in comparison with sclera, which developed greater resistance.

CONCLUSION

In all, our results indicate a deleterious effect of peroxynitrite on bovine ocular structures in vitro. This effect is proportional to the concentration used. These results corroborate those reported by other teams and suggest the role of peroxynitrite derived from NO in the ocular lesions observed in the setting of uveitis.

Protective effect of pristane on experimental autoimmune uveitis

This study evaluates the effects of pristane and phytol, two mineral oils with pro-oxidative effects, on the course of experimental autoimmune uveitis. C57BL6 mice were immunized with IRBP1-20 peptide emulsified in CFA and treated five days prior to immunization with phytol or with pristane or with PBS as control. Administration of pristane reduces the incidence and severity of IRBP-induced uveitis as demonstrated by the decrease in vasculitis and inflammatory foci in fundus and by a reduction in histological damages and leukocyte infiltration compared to untreated or phytol-treated mice. The protective effect observed is associated with a decreased activation of peripheral CD4+ and CD8+ T lymphocytes and a decrease in the intensity of the Th1 and Th17 autoimmune response to IRBP in pristane-treated mice compared to control mice, as evidenced by the decreased production of IFNγ and IL17 by IRBP-specific lymphocytes from lymph nodes draining the site of immunization and by the increased production of anti-IRBP IgG1 over IgG2a. In addition, HUVEC and ARPE-19 cells incubated with the sera of mice treated with pristane presented a reduced production of H(2)O(2). The benefit of lowering the systemic oxidative stress by pristane in the course of EAU was confirmed by injecting the antioxidant NAC in IRBP-immunized mice. As pristane, NAC decreased clinical and histological inflammation of the retina and preserved the integrity of the hemato-retinal barrier. Finally, the protective effect of pristane on the development of EAU suggests that some mineral oils may represent a new therapeutic strategy in human uveitis.

Oxidative stress impairs endothelial nitric oxide levels in Behçets' disease

BACKGROUND

Behçet's disease (BD) is an inflammatory vasculitis. Endogenous nitric oxide (NO), produced by endothelial cells, has pleiotropic effects such as vasodilatator, antiplatelet, antiproliferative. Reactive oxygen species (ROS) are produced at sites of endothelial inflammation. ROS target polyunsaturated lipids, which results in malondialdehyde (MDA) production.

OBJECTIVE

The aim was to investigate the oxidative stress in BD patients by measuring MDA and total antioxidant status (TAS) levels and to establish a possible relationship with respect to NO levels regarding disease activity.

MATERIALS AND METHODS

55 BD patients (30 active/25 inactive) and 20 healthy volunteers were included in the study. Blood samples were drawn following an overnight fasting. TAS and MDA levels were determined spectrophotometrically. Serum nitrite (NO(2-)) and nitrate (NO(3-)) levels were measured to estimate NO production. Data were expressed as mean ± SD.

RESULTS

TAS levels were significantly lower in BD patients than the controls (1.19 ± 0.34 vs. 3.29 ± 0.89 mmol/L). In the active BD group, MDA levels (0.36 ± 0.19 nmol/mL) were significantly higher than both the inactive BD group (0.25 ± 0.18 nmol/mL) and controls (0.18 ± 0.41 nmol/mL). NO levels were significantly lower in the active group compared to the inactive group (18.0 ± 2.80 vs. 19.40 ± 2.70 µmol/L). MDA levels correlated negatively with NO levels in the active group.

CONCLUSION

Decreased NO levels mediated by increased oxidative stress significantly contribute to endothelial dysfunction observed in BD.

Elevated Oxidative Stress Markers and its Relationship With Endothelial Dysfunction in Behçet Disease

Behçet’s disease (BD) is a multisystemic disorder characterized by endothelial dysfunction. However, the relationship between oxidative stress and endothelial function has not been clearly shown. We investigated the relationship between oxidative stress markers and endothelial function in patients with BD. Patients with BD (n = 40) having active disease and sex- and age-matched 40 controls were included. Endothelial function was assessed by flow-mediated dilatation (FMD) technique. Serum gamma-glutamyltransferase (GGT) and high-sensitive C-reactive protein levels (hsCRP) were measured in all participants. Brachial artery FMD was significantly lower in patients with BD than in controls. Gamma-glutamyltransferase and hsCRP levels were higher in patients with BD than in controls. Also, GGT and hsCRP levels were inversely correlated with endothelial function. Oxidative stress markers are elevated in patients with BD having active disease. This may be one of the reasons behind the vasculitis in active BD.

Behçet's Disease as a Model of Venous Thrombosis

Behçet's disease (BD) is a chronic inflammatory disease of unknown aetiology characterized by recurrent oral, genital aphthous ulcerations, uveitis, skin lesions and other multisystem affections associated with vasculitis. Different types of vessels, predominantly veins, can be affected in BD. The frequency of vascular lesions in BD, such as superficial and deep venous thromboses, arterial aneurysms and occlusions, ranges between 7-29%. In this review, various factors of thrombogenesis in BD, particularly pro- and antithrombotic endothelial and non-endothelial factors, factors of coagulation, platelet activation and rheological changes are presented and discussed from positions of Virchow's triad of venous thrombosis. Despite advances in understanding of thrombogenesis in BD, still many issues of diagnosis and targeted preventive and therapeutic measures remain unresolved. Further studies are needed to clarify the pathobiology of BD-related thrombosis and to provide the clinicians with recommendations over the utility, safety and effectiveness of the antithrombotic therapy in BD.

Behçet’s Disease as a Model of Venous Thrombosis

Behçet’s disease (BD) is a chronic inflammatory disease of unknown aetiology characterized by recurrent oral, genital aphthous ulcerations, uveitis, skin lesions and other multisystem affections associated with vasculitis. Different types of vessels, predominantly veins, can be affected in BD. The frequency of vascular lesions in BD, such as superficial and deep venous thromboses, arterial aneurysms and occlusions, ranges between 7-29%.

In this review, various factors of thrombogenesis in BD, particularly pro- and antithrombotic endothelial and non-endothelial factors, factors of coagulation, platelet activation and rheological changes are presented and discussed from positions of Virchow’s triad of venous thrombosis.

Despite advances in understanding of thrombogenesis in BD, still many issues of diagnosis and targeted preventive and therapeutic measures remain unresolved. Further studies are needed to clarify the pathobiology of BD-related thrombosis and to provide the clinicians with recommendations over the utility, safety and effectiveness of the antithrombotic therapy in BD.