Lipid peroxidation and erythrocyte antioxidant enzymes in patients with Behçet's disease

Exploring the pharmacological mechanism of Tripterygium wilfordii hook for treatment of Behcet's disease using network pharmacology and molecular docking

Tripterygium wilfordii hook (TWH) has been used to treat Behcet's disease (BD) but its underlying mechanism remains unclear. This study aims to explore the mechanism of TWH on BD using network pharmacology and molecular docking. The bioactive constituents of TWH and their corresponding target genes were extracted from the Traditional Chinese Medicine systems pharmacology database and analysis platform. BD target genes were obtained by searching the DisGeNet and GeneCards databases. Gene ontology annotation and Kyoto encyclopedia of genes and genomes pathway enrichment analysis were conducted to elucidate the function of overlapping genes between TWH and BD target genes. A protein-protein interaction network was constructed using Cytoscape and STRING platforms, and the core target genes were identified from the overlapping genes. Finally, molecular docking was used to assess the binding affinity between the core targets and TWH bioactive constituents. We identified 25 intersection genes related to both TWH and BD and 27 bioactive ingredients of TWH. Through analysis of protein-protein interaction network, 6 core targets (TNF, IFNG, prostaglandin-endoperoxide synthase 2, NOS2, VCAM-1, and interleukin-2) were screened out. Enrichment analysis demonstrated that the antioxidant properties of TWH constituents might play a significant role in their therapeutic effects. Molecular docking revealed high binding affinity between the bioactive constituents of TWH, such as kaempferol, triptolide, 5, 8-Dihydroxy-7-(4-hydroxy-5-methyl-coumarin-3)-coumarin, and their corresponding target genes, suggesting the potential of TWH to treat BD. Our investigation clarified the active components, therapeutic targets of BD in the treatment of TWH and provided a theoretical foundation for further researches.

The association between vitamin D levels and oxidative stress markers in Egyptian Behcet's disease patients

BACKGROUND

Oxidative stress is postulated to have a major role in the pathophysiology of Bechet's Disease (BD). Growing evidence suggests that vitamin D has important roles in enhancing the expression of anti-inflammatory cytokines as well as certain antioxidants. However, there is little evidence currently about the antioxidant properties of vitamin D in BD.

OBJECTIVE

To study the relationship between vitamin D levels and the oxidative stress markers in patients with BD in addition to its association with disease activity and severity.

METHODS

Sixty BD patients (45 males, 15 females; mean age: 34.2 ± 9.6 years) were enrolled in this study and compared to a sex and age matched control group. Plasma 25-Hydroxy vitamin D (25-OH-D) was measured using Human (25-OH-D) ELISA assay. Plasma malondialdehyde (MDA), nitric oxide (NO), reduced glutathione (GSH), superoxide dismutase (SOD) activity, catalase (CAT) activity and total antioxidant capacity (TAC) were determined by spectrophotometric methods in both groups. Plasma calcium (Ca) was measured by ELISA assay.

RESULTS

When compared to controls vitamin D, GSH, CAT activity, TAC and Ca were significantly lower in BD patients, while MDA and NO levels were significantly increased in BD patients. Our Results Found that vitamin D was inversely correlated to BD current Activity form (BDCAF), disease severity score, ESR, CRP, MDA and NO, while vitamin D was significantly positively correlated to GSH, SOD, TAC and Ca.

CONCLUSION

Our study confirms that a lower level of vitamin D is associated with the oxidative stress state in BD patients as detected by MDA and NO elevation as well as decreased GSH, SOD activity, CAT activity and TAC. Hence, Vitamin D fortified foods and beverages or supplementation may improve disease severity and oxidative stress in BD patients.

Dry Bio-Decontamination Process in Reduced-Pressure O2 Plasma

The main objective of this work was to fully understand the bio-decontamination process in a reduced-pressure oxygen plasma. Gram-negative Escherichia coli species was chosen as the target microorganism in this test. The comparison of decontamination efficacy between plasma total and UV radiation individually under various treatment parameters and tests of DNA agarose electrophoresis were made to evaluate the inactivation effect of UV radiation. The quantity of protein leakage and the concentration of malondialdehyde (MDA), which are markers of the end products of lipid peroxidation, in bacterial suspension after treatment were determined to estimate the contribution of both charged particles and free radicals for bacterial death. In addition, a scanning electronic microscope was used to visualize the plasma effect on microorganisms. The results showed that the essential action of the oxygen plasma on Escherichia coli is believed to be attributed to the fast and intense etching on cell membrane by electrons and ions. Attacks on polyunsaturation fatty acid (PUFA) in the cell membrane by oxygen free radicals and the destruction of the DNA in the cell by UV radiation are accessorial during an effective decontamination process.

Neutrophils and redox stress in the pathogenesis of autoimmune disease

Polymorphonuclear leukocytes, or neutrophils, are specialist phagocytic cells of the innate immune system. Their primary role is host defence against micro-organisms, which they kill via phagocytosis, followed by release of reactive oxygen species (ROS) and proteolytic enzymes within the phagosome. ROS are generated via the action of the NADPH oxidase (also known as NOX2), in a process termed the 'Respiratory Burst'. This process consumes large amounts of oxygen, which is converted into the highly-reactive superoxide radical O₂^- and H₂O₂. Subsequent activation of myeloperoxidase (MPO) generates secondary oxidants and chloroamines that are highly microbiocidal in nature, which together with proteases such as elastase and gelatinase provide a toxic intra-phagosomal environment able to kill a broad range of micro-organisms. However, under certain circumstances such as during an auto-immune response, neutrophils can be triggered to release ROS and proteases extracellularly causing damage to host tissues, modification of host proteins, lipids and DNA and dysregulation of oxidative homeostasis. This review describes the range of ROS species produced by human neutrophils with a focus on the implications of neutrophil redox products in autoimmune inflammation.

Serum Haptoglobin Levels in Ocular Behçet Disease and Acute Phase Proteins in the Course of Behçet Disease

Purpose

Changes in concentrations of acute phase proteins in the serum of patients might be significant in the pathogenesis of Behçet disease. This report investigates the association between ocular disease activity and serum haptoglobin levels in patients with Behçet disease, and summarizes the current understanding of the correlation between acute phase proteins and Behçet disease based on both personal studies and data from the literature.

Methods

Thirty patients with Behçet disease with ocular involvement and 15 healthy subjects were included in the study. Of the 30 patients, 14 had acute uveitis and 16 had inactive ocular involvement at the time of enrollment.

Results

There was a significant difference in haptoglobin levels between the patients with active ocular disease and controls (p=0.0005). There was also a significant difference in haptoglobin levels between the patients with inactive ocular disease and control subjects (p<0.0001). However, no significant difference was observed among patients with active versus inactive uveitis with regard to serum haptoglobin levels.

Conclusions

Higher serum haptoglobin levels in patients with Behçet disease compared to control subjects were obtained. However, elevated serum haptoglobin levels do not seem to be a risk factor for uveitis activity. Behçet disease is generally diagnosed by physical examinations and no laboratory marker has been widely accepted for follow-up of disease activity.

Paraoxonase and Arylesterase Levels in Behcet's Disease and Their Relations with the Disease Activity

The aim of this study was to determine the paraoxonase (PON) and arylesterase (ARE) enzyme activity levels in Behcet's disease (BD) and to investigate whether they are associated with the disease activity. Twenty-six patients (study group) with active BD and 28 healthy controls (control group) were included in this study. While the patients who had at least one of the symptoms related to genital ulcer, skin lesions, active uveitis, arthritis, thrombophlebitis, or central nervous system involvement in addition to oral ulcers were considered as the active group, the patients who did not show clinical symptoms in the last one month due to the medical treatment were considered as the inactive group in the clinical evaluation of patients with BD. The PON and ARE levels were found to be significantly lower in the study group than the control group (p < 0.05). The PON levels of the active and inactive groups were 96.23 ± 57.84 and 112.2 ± 65.14, respectively. The ARE levels of the active and inactive groups were 30.49 ± 5.81 and 30.85 ± 6.40, respectively. No significant correlations were found between clinical findings and the activity levels of PON and ARE in the active patient group (p > 0.05). The activities of the antioxidant PON and ARE enzymes are reduced in BD. Therefore, it may be useful to add antioxidant therapy to the conventional treatment of the disease.

Overlooked Management and Risk Factors for Anemia in Patients with Intestinal Behçet's Disease in Actual Clinical Practice

Background/Aims

Anemia in patients with inflammatory bowel disease significantly affects the quality of life. The aim of this study was to investigate the frequency of and risk factors for anemia and to describe the management of anemia in patients with intestinal Behçet’s disease (BD) in actual clinical practice.

Methods

We included 64 patients with intestinal BD who visited the outpatient clinic of a tertiary referral center in June 2011 and had available laboratory data for the subsequent 6 months.

Results

Anemia was detected in 26 patients (40.6%). After 6 months, anemia was still present in 14 of these patients (53.8%). The cause of anemia was investigated in eight patients (30.8%), and oral iron supplementation was prescribed to four patients (15.4%). Of these four patients, two (50%) recovered completely within 6 months. Anemia was associated with a high Disease Activity Index for Intestinal Behçet’s Disease (DAIBD, p=0.024), erythrocyte sedimentation rate (p=0.003), and C-reactive protein (p=0.049) in univariate analysis. In multivariate analysis, the factor predictive for anemia in patients with intestinal BD was a higher DAIBD (≥40; odds ratio, 4.08; 95% confidence interval, 1.21 to 13.71; p=0.023).

Conclusions

Although anemia is common in intestinal BD patients, its clinical importance is overlooked in daily practice. Moderate to severe disease activity is predictive of anemia.

Thiol/disulfide homeostasis in patients with ankylosing spondylitis

Ankylosing spondylitis (AS) is a chronic inflammatory disease. In many inflammatory diseases, increased production of pro-inflammatory cytokines is associated with an increase in oxidative stress mediators. Thiol/disulfide homeostasis is a marker for oxidative stress. The aim of this study was to examine the dynamic thiol/disulfide homeostasis in AS. Sixty-nine patients with AS and 60 age- and sex-matched controls were included in the study. The Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and visual analogue scale (VAS) were used to determine the disease activity. Native thiol, total thiol, and disulfide levels were measured with a novel automated method recently described by Erel and Neselioglu. The aforementioned method is also optionally manual spectrophotometric assay. The total thiol levels were significantly lower in the AS group compared with the control group (p = 0.03). When the patients were divided into active (n = 35) and inactive (n = 34) subgroups using BASDAI scores, the native plasma thiol and total thiol levels were significantly lower in the active AS patients compared to the inactive AS patients (p = 0.02, p = 0.03 respectively). There was a negative correlation between the plasma native thiol levels and VAS, BASDAI scores. Thiol/disulfide homeostasis may be used for elucidating the effects of oxidative stress in AS. Understanding the role of thiol/disulfide homeostasis in AS might provide new therapeutic intervention strategies for patients.

Trace element levels in patients with familial mediterranean Fever

OBJECTIVE

Although the genetic etiology of familial Mediterranean fever (FMF) is known, limited information is available regarding the regulation of inflammation during attack-free periods. The aim of this study was to determine the alterations in serum copper (Cu), zinc (Zn) and selenium (Se) levels that may be associated with inflammation during attack-free periods in FMF patients.

MATERIALS AND METHODS

This study included 33 patients with FMF and 30 healthy volunteers. Erythrocyte sedimentation rate (ESR), the serum C-reactive protein (CRP) level and serum levels of Cu, Zn and Se in FMF patients and healthy volunteers were assessed by the atomic absorption spectrophotometry method.

RESULTS

ESR and serum CRP levels and serum Cu and Zn levels were similar between patients with FMF during an attack-free period and healthy controls (p>0.05). Serum Se levels in the patient group were significantly higher than in the control group (p<0.05).

CONCLUSION

Our study shows that levels of trace elements in serum are variable in patients with FMF during attack-free periods. Serum Se concentrations may at least in part contribute to the subclinical inflammation in FMF patients during attack-free periods. However, further studies are necessary to confirm this result.

The Significance of Serum Nitric Oxide Levels in Behçet's Disease and Recurrent Aphthous Stomatitis

Behçet's disease (BD) is an inflammatory multisystem disorder characterized by recurrent oral and genital aphthous ulcers, arthritis, uveitis, and thrombophlebitis; it can involve several organs. However, recurrent aphthous stomatitis (RAS) can be seen without a confirmed diagnosis of BD. Moreover, there is no way of predicting whether a patient with RAS will develop BD. Nitric oxide (NO) is a free radical synthesized from L-arginine by one of the family of nitric oxide synthase (NOS) enzymes. Increased production of NO during several inflammatory and infectious processes has been recently postulated. Our aim was to investigate the serum NO levels in patients with active and inactive BD and RAS. Forty-six patients with BD, 30 patients with RAS and 30 healthy controls were enrolled in the study. The patients with BD were separated into two groups: clinically active (n = 24) and inactive (n = 22). A blood sample was collected from all subjects in order to determine their serum NO levels. In patients with active BD, higher serum levels of NO metabolite were found in comparison with patients with inactive BD, in patients with RAS, or healthy controls (p < 0.05). We also found higher serum NO metabolite levels in patients with RAS than in healthy controls (p < 0.05). In patients with inactive BD, statistically significant higher levels of serum NO levels were found in comparison with the control group (p < 0.05). However, we found no statistically significant difference between the patients with inactive BD and RAS, which indicated that inactive BD cannot be distinguished from RAS by serum NO levels. We conclude that serum NO levels may be an important marker for estimating the severity of BD. However, further studies are needed to confirm our findings.

Serum Lipid, Lipoprotein and Oxidatively Modified Low Density Lipoprotein Levels in Active or Inactive Patients with Behçet's Disease

Aim:

To determine serum lipid, lipoproteins and oxidized low density lipoprotein (oxLDL) levels in Behçet's disease (BD) and to evaluate the relationship of these parameters with the clinical activity of the disease.

Materials and Methods:

Sixty-two patients (25 active, 37 inactive) and —26 healthy controls were included in the study. We measured serum oxLDL levels using the enzyme-linked immunosorbent assay method, and serum total cholesterol (TC), triglyceride (TG) and high density lipoprotein-cholesterol (HDL-C) levels by spectrophotometric method.

Results:

Serum TG (108±70 mg/dL and 79±40 mg/dL, respectively; P<0.05), LDL-C (124±35 mg/dL and 108±26 mg/dL, respectively; P<0.05) and oxLDL (65±19 U/L and 53±10 U/L, respectively; P<0.01) levels were significantly higher in patients than in controls, but HDL-C levels were significantly lower in patients than in controls (39±11 mg/dL and 50±13 mg/dL, respectively; P<0.05). The levels of oxLDL in patients were found to correlate with those of TC and LDL-C. Neither the lipid parameters nor the oxLDL levels in the patients with active disease (n=25) were different than those in the patients who were in inactive stage (n=37). Serum levels of oxLDL in the patients with active and inactive disease were significantly higher than those in controls (66±19 U/L, 65±19 U/L, and 53±10 U/L, respectively; P<0.05).

Conclusions:

We conclude that the increase of TG, LDL-C and oxLDL levels and the decrease of HDL-levels may indicate that there is a tendency to atherothrombotic process in patients with BD. Inflammation and immunologic reactions in BD may be caused by a response to elevated oxLDL. TG, LDL-C and oxLDL are not useful markers for the severity of the disease activity.

Ocular Behçet disease: current therapeutic approaches

PURPOSE OF REVIEW

To alert physician to timely recognition and current treatment of recurrent hypopyon iridocyclitis or panuveitis in ocular Behçet disease (OBD).

RECENT FINDINGS

Interferon-α, rituximab, intravitreal triamcinolone, and biological response modifiers by tumor necrosis factor inhibitors such as infliximab and adalimumab are being used increasingly for the treatment of severe sight-threatening ocular inflammation including retinal vasculitis and cystoid macular edema (CME).

SUMMARY

Biological agents offer tremendous potential in the treatment of OBD. Given that OBD predominantly afflicts the younger adults in their most productive years, dermatologist, rheumatologist, internist, or general practitioners supervising patients with oculo-articulo-oromucocutaneous syndromes should be aware of systemic Behçet disease. Early recognition of ocular involvement is important and such patients should strongly be instructed to visit immediately an ophthalmologist, as uveitis management differs from extraocular involvements with high ocular morbidity from sight-threatening complications due to relapsing inflammatory attacks in the posterior segment of the eye. A single infliximab infusion should be considered for the control of acute panuveitis, whereas repeated long-term infliximab infusions were proved to be more effective in reducing the number of episodes in refractory uveoretinitis with faster regression and complete remission of CME.

Pathophysiology of the Behçet's Disease

Behçet's disease (BD) is a multisystemic disease of unknown etiology characterized by chronic relapsing oral-genital ulcers and uveitis. Multiple systemic associations including articular, gastrointestinal, cardiopulmonary, neurologic, and vascular involvement are also observed in BD. Although the etiopathogenesis of the disease remains unknown, increased neutrophil functions such as chemotaxis, phagocytosis, and excessive production of reactive oxygen species (ROS), including superoxide anion, which may be responsible for oxidative tissue damage seen in BD, and also immunological alterations, T lymphocyte abnormalities in both subpopulation and function have been considered to be correlated with the etiopathogenesis of BD. There is some clinical evidence suggesting that emotional stress and hormonal alterations can influence the course and disease activity of BD.

Increased oxidative stress in patients with familial Mediterranean fever during attack period

OBJECTIVES

We aimed to investigate the status of oxidant and antioxidants during attack period (AP) and attack free periods (AFP) in Familial Mediterranean fever (FMF) patients.

METHODS

Measured the levels of malondialdehyde (MDA), protein carbonyl (PC), glutathione (GSH) and antioxidant vitamins (A,C and E) as well as the activities of catalase (CAT) and glutathione peroxidase (GSH-Px) in serum and whole blood of FMF patients in FMF-AP and FMF-AFP.

RESULTS

Levels of MDA and PC were found significantly higher (p <0.05) both in serum and whole blood of FMF-AP group compared with other groups. The CAT and GSH-Px activities in FMF-AP group were found markedly lower (p <0.05) comparing to HC group. However, there were no statistically significant differences between the groups in terms of antioxidant vitamin levels.

CONCLUSIONS

Our study demonstrated increased oxidative stress in patients with FMF during AP. Investigations are needed to establish the effect of antioxidant supplementation on FMF attack frequency and severity. We also suggest that these increased MDA and PC levels and decreased antioxidants may be used as supportive markers to differentiate AP from AFP. These conclusions need to be validated in further multicenter studies with high number of FMF patients.

Erythrocyte malondialdehyde and glutathione levels in vitiligo patients

BACKGROUND

Vitiligo is an acquired and progressive hypomelanotic disease that manifests as circumscribed depigmented patches on the skin. Although the precise mechanism remains to be elucidated, an imbalance of the oxidant/antioxidant system has been proposed as an important etiologic mechanism.

OBJECTIVE

The objective of this study was to evaluate the oxidant/antioxidant status of vitiligo patients at the erythrocyte level.

METHODS

Fifty-three vitiligo patients and 65 phototype-, age-, and sex-matched healthy controls were included in this study. Blood samples were collected from all subjects, and all patients were instructed to answer a questionnaire.

RESULTS

Erythrocyte levels of malondialdehyde (MDA) and glutathione (GSH) were measured. All patients were told to answer a questionnaire regarding their habitual behavior, including frequency of smoking and type of diet. We observed significantly lower levels of GSH in vitiligo patients, but the levels of MDA did not differ between patients and controls. Vitiligo patients who smoked showed significantly lower GSH levels compared to non-smoking patients, but the levels of MDA were unchanged between the 2 groups.

CONCLUSION

From our results, we conclude that reduced erythrocytic or systemic GSH levels constitute a distinctive feature in vitiligo patients regardless of disease activity.

Role of the membrane in the formation of heme degradation products in red blood cells

AIMS

Red blood cells (RBCs) have an extensive antioxidant system designed to eliminate the formation of reactive oxygen species (ROS). Nevertheless, RBC oxidant stress has been demonstrated by the formation of a fluorescent heme degradation product (excitation (ex) 321 nm, emission (em) 465 nm) both in vitro and in vivo. We investigated the possibility that the observed heme degradation results from ROS generated on the membrane surface that are relatively inaccessible to the cellular antioxidants.

MAIN METHODS

Membrane and cytosol were separated by centrifugation and the fluorescence intensity and emission maximum were measured. The effect on the maximum emission of adding oxidized and reduced hemoglobin to the fluorescent product formed when hemin is degraded by hydrogen peroxide (H(2)O(2)) was studied.

KEY FINDINGS

90% of the fluorescent heme degradation products in hemolysates are found on the membrane. Furthermore, these products are not transferred from the cytosol to the membrane and must, therefore, be formed on the membrane. We also showed that the elevated level of heme degradation in HbCC cells that is attributed to increased oxidative stress was found on the membrane.

SIGNIFICANCE

These results suggest that, although ROS generated in the cytosol are neutralized by antioxidant enzymes, H(2)O(2) generated by the membrane bound hemoglobin is not accessible to the cytosolic antioxidants and reacts to generate fluorescent heme degradation products. The formation of H(2)O(2) on the membrane surface can explain the release of ROS from the RBC to other tissues and ROS damage to the membrane that can alter red cell function and lead to the removal of RBCs from circulation by macrophages.

Evaluation of allantoin levels as a new marker of oxidative stress in Behçet's disease

The increased production of reactive oxygen species (ROS) from activated neutrophils in Behçet's disease (BD) and recurrent aphthous stomatitis (RAS) may result in increased oxidative stress. Uric acid can react rapidly with neutrophil-derived ROS to form allantoin. The purpose of the study was to evaluate the serum levels of allantoin as a new marker of oxidative stress in BD compared with malondialdehyde (MDA) levels as a well-known marker. Blood samples were obtained from 23 BD patients, 22 RAS patients as positive controls, and 21 healthy controls. When compared to the healthy controls, we found higher allantoin and MDA levels in the BD patients and higher MDA levels in the RAS patients. Serum ascorbic acid levels in the BD patients were significantly lower than in the controls. Increased allantoin and MDA levels suggest the possible involvement of free radicals in BD. As allantoin is only a product of uric acid oxidation by reactive oxygen and nitrogen species, it may also be used as a marker of oxidative stress in BD.

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

OBJECTIVE

To study the oxidant/antioxidant status in Behçet's disease (BD) patients and the potential link between antioxidant enzymatic defences impairment and the disease duration, activity and severity.

METHODS

40 BD patients (27 males, 13 females; mean age: 38.8 years) were prospectively enrolled in the study and compared to a sex and age matched control group. Plasma malondialdehyde (MDA), the reduced glutathione (GSH)/oxidised glutathione (GSSG) ratio, erythrocyte superoxide dismutase, catalase and glutathione peroxidase (GSH-PX) were analysed in both groups. A correlation analysis was performed between these parameters and disease duration, activity and severity. Activity and severity of BD were assessed meaning two respective clinical scores.

RESULTS

When compared to controls MDA was increased and GSH/GSSG reduced in BD patients (respectively p<0.005). Superoxide dismutase (SOD) was significantly lower while catalase was significantly higher in BD than in controls. Correlation analysis showed that SOD activity was significantly and negatively correlated to disease duration and activity but not to severity. Other oxidant/antioxidant markers were not significantly linked to neither disease duration nor activity and severity.

CONCLUSION

Our study confirm the existence of an oxidative stress (OS) state in BD as shown by the increase of MDA and the diminution of GSH/GSSG ratio which can be used as another index of OS. Despite this OS state, the activity of antioxidant enzymes and especially of SOD is impaired and negatively correlated to the disease duration and activity. We think that a rational strengthening of antioxidant defences should be part of an optimal treatment strategy.

Cytochrome P450 polymorphisms in patients with Behcet's disease

OBJECTIVES

Although the etiopathogenesis of Behcet's disease (BD) remains unknown, increased neutrophil functions such as chemotaxis, phagocytosis and excessive production of reactive oxygen species, including superoxide anion, may be responsible for the oxidative tissue damage observed in BD. Cytochrome P-450 are a multigene family of enzymes involved in the detoxification and occasional activation of a wide variety of chemicals. Our aim was to investigate CYP2C9 and CYP2C19 polymorphisms in patients with BD.

METHODS

Sixty-two subjects with BD and 107 healthy control subjects were enrolled in the study. Polymorphisms of CYP2C9 and CYP2C19 were performed by real-time PCR with a LightCycler instrument. We researched associations between CYP polymorphisms and BD.

RESULTS

The frequencies of wild-type and heterozygous CYP2C19*2 genotypes were 66.1% and 33.9% in the patients and 83.2% and 16.8% in the controls, respectively. There was a 2.53-fold increased risk of Behcet's disease in individuals with the CYP2C19*2 heterozygous genotype (OR = 2.53; 95% CI, 1.22-5.25) when compared with the control group. But the CYP2C9*2, CYP2C9*3 and CYP2C19*3 gene polymorphisms were not related to an increased risk of developing BD.

CONCLUSIONS

We observed that patients with BD presented with a higher prevalence of the heterozygous CYP2C19*2 genotype. Hereditary deficiencies of this enzyme activity may lead to an imbalance between pro- and antioxidant systems, resulting in the formation of excessive reactive oxygen species.

Oxidant/antioxidant status in men with Behçet’s disease

Behçet's disease (BD) is a chronic, progressive disorder that affects many systems of the body including the eye. The aim of this study was to assess whether the increase in oxidative stress in the affected tissues is reflected by lipid peroxidation and to check for alterations in antioxidants and antioxidant enzyme activities in patients with BD. Erythrocyte antioxidant potential (AOP), glutathione (GSH) and GSH-dependent enzymes (glutathione peroxidase (GSH-Px), glutathione reductase (GRD) and glutathione-S-transferase (GST), catalase (CAT), Cu-Zn superoxide dismutase (Cu-Zn SOD) activities, malondialdehyde (MDA) and some trace elements (zinc, Zn; copper, Cu; manganese, Mn) levels in men with BD. Erythrocyte CAT, GSH-Px activities, MDA, GSH, AOP and serum Zn values were significantly lower in patients with BD than in the control group. However, erythrocyte Cu-Zn SOD, GRD activities, erythrocyte sedimentation rate (ESR), serum C-reactive protein (CRP) and Cu values were significantly higher in patients with BD than in the control group, but GST activity and serum Mn values were unchanged. In conclusion, our results confirm the presence of oxidative stress in patients with BD and suggest that the severity of BD may arise from impaired antioxidant mechanisms. Therapy with antioxidants may lead to the increase in the antioxidant defense system and thus improvement in clinical symptoms.

Serum and erythrocyte adenosine deaminase activities in patients with Behçet's disease

OBJECTIVES

Adenosine deaminase (ADA) is a non-specific marker of the activation of the T cell, which has an important role in the etiology of Behçet's disease (BD). The purpose of this study was to investigate the determination of ADA activity as an index of T-lymphocyte function in BD, which is known to have an T-cell-mediated immune response.

MATERIALS AND METHODS

Adenosine deaminase activities in both serum and erythrocytes were measured in 23 untreated patients with BD and in 20 healthy controls. The patients with BD were divided into two groups: active (n = 10) and inactive (n = 13).

RESULTS

When compared with the control group, serum ADA activity was high (P < 0.01) and erythrocyte ADA activity was significantly low (P < 0.01) in BD. Serum ADA activity of active BD was higher than that of inactive BD (P < 0.01), but erythrocyte ADA activity was found to be lower in active BD than inactive BD (P < 0.01).

COMMENT

These findings may provide an additional benefit for the diagnosis of BD and sub-typing of active and inactive BD.

Nitric oxide, lipid peroxidation and antioxidant defence system in patients with active or inactive Behçet's disease

BACKGROUND

One of the prominent features of Behçet's disease (BD) is vasculitis and thrombosis as a result of endothelial dysfunction. Nitric oxide (NO) is responsible for endothelial vasorelaxation and inhibition of platelet adhesion.

OBJECTIVES

To assess serum total NO, erythrocyte superoxide dismutase (SOD), whole blood glutathione peroxidase (GSH-Px), plasma total antioxidant status (TAS) and plasma malondialdehyde (MDA) in patients with BD and to correlate their levels with disease activity.

METHODS

The study group consisted of 49 patients with BD and 26 healthy control subjects. None of the subjects was given a standardized diet. Patients with any systemic disease were excluded. Patients with BD were randomized to two groups according to their disease activity (active/inactive, 26/23). We measured serum total NO levels using the enzyme-linked immunosorbent assay method, and SOD, GSH-Px, TAS and MDA levels by spectrophotometric methods.

RESULTS

In patients with active disease (n = 26), serum total NO levels were found to be significantly decreased when compared with the inactive (n = 23) and control (n = 26) groups. Levels were also significantly lower in patients with inactive disease and in total BD patients (n = 49) than in the controls. GSH-Px activities and TAS levels were significantly lower in total BD patients than those in the controls. Patients with active disease and total BD patients exhibited markedly higher MDA levels than the control subjects. MDA levels in the patients with active disease were also found to be elevated compared with the patients with inactive disease.

CONCLUSIONS

We conclude that changes in parameters associated with oxidative stress such as NO-related processes, activities of antioxidant enzymes in the bloodstream and erythrocytes and total plasma antioxidant capacity are involved in the aetiopathogenesis of the vasculitis seen in BD.

Increased advanced oxidation protein products in Behçet's disease: a new activity marker?

BACKGROUND

Behçet's disease (BD) is a chronic inflammatory disease with unknown pathogenesis. As various functions of neutrophils in peripheral blood, such as chemotaxis, phagocytosis and generation of reactive oxygen species (ROS) increase in BD, ROS-mediated oxidative stress related to neutrophil activation may have an important role in the pathogenesis of BD.

OBJECTIVES

To investigate the importance of neutrophil activation as the main source of oxidative stress through protein oxidation in the pathogenesis of BD, and also to investigate whether one of the products of protein oxidation, advanced oxidation protein products (AOPP), may be used as an activity marker for BD.

METHODS

Patients with BD (n = 49), at active and inactive stages, with or without evidence of uveitis, and healthy volunteers (n = 40) were entered into the study. A full blood count, peripheral blood smears, routine biochemical analyses, C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) measurements were performed in all patients preceding the study. Plasma myeloperoxidase (MPO) activity, representing neutrophil activation, and biomarkers of oxidative stress reflecting protein oxidation, such as levels of AOPP and thiol, were measured spectrophotometrically. Statistical comparisons were made using Mann-Whitney U-tests, Student's t-tests, anova/post-anova tests and correlation analyses.

RESULTS

In all patients, the results of full blood count, peripheral blood smears and routine biochemical analyses were in the normal range, but mean values of CRP and ESR were higher than laboratory reference values. Plasma MPO activity and AOPP levels were found to be higher and thiol values lower in the total patient group and individual subgroups than in controls. Patients with active BD had significantly higher MPO and AOPP levels and lower thiol levels than patients with inactive BD. There was no difference between uveitis-positive and uveitis-negative subgroups in MPO and thiol levels, but AOPP levels were lower in the latter group. Patients with active BD +/- uveitis were shown to have increased MPO and AOPP but decreased thiol levels in comparison with the inactive BD, uveitis-negative subgroup. There were strong positive correlations between ESR and CRP, ESR and MPO, ESR and thiol, ESR and AOPP, CRP and MPO, CRP and AOPP, MPO and AOPP, and thiol and AOPP levels in patients with BD.

CONCLUSIONS

Based on this first study, in which MPO-mediated AOPP formation has been demonstrated, it may be suggested that activated neutrophils may play an important role in the pathogenesis of BD and that chlorinated oxidants of neutrophil origin may lead to oxidative stress, notably protein oxidation. Therefore, AOPP may be a useful marker for monitoring the progress and the severity of the disease activity.

Erythrocyte superoxide dismutase, catalase activities and plasma nitrite and nitrate levels in patients with Behcet disease and recurrent aphthous stomatitis

Behçet disease (BD) and recurrent aphthous stomatitis (RAS) are two distinct diseases of unknown aetiology which are both characterized by oral aphthae. The aim of this study was to determine the possible association of both diseases with antioxidant status and nitric oxide levels. Twenty-six patients (17 female, nine male) with RAS, 28 patients (17 female, 11 male) with BD and 31 (22 female, nine male) healthy control subjects were included in the study. Blood samples were studied for erythrocyte superoxide dismutase (SOD) and catalase (CAT) activities and plasma nitric oxide (NO) levels. Erythrocyte SOD activity in BD patients was significantly higher than in RAS patients and controls. Although SOD activity in RAS patients was higher than in controls, the difference was not statistically significant. No significant differences in CAT activities or NO levels were found between the three groups. In conclusion, changes in SOD activity may be important in the inflammatory reactions observed in BD and RAS, but NO does not seem to play a primary role in the aetiopathogenesis.