[Influence of steroid hormones on the production of two inflammatory markers, IL-12 and nitric oxide, in Behçet's disease]. / Influence des hormones stéroïdes sur la production de deux marqueurs inflammatoires, l'IL-12 et le monoxyde d'azote, au cours de la maladie de Behçet.

Uveitis is one of the major diagnostic criteria of Behçet's disease (BD), a chronic systemic inflammatory pathology with an uncertain etiology. Since uveitis is more frequent in male patients, we assessed the level and the effect of sex hormones on inflammatory responses during BD. Peripheral blood was taken from 19 patients with BD and 20 healthy subjects. Estradiol, testosterone and cortisol were measured in plasma by ELISA. Circulating mononuclear cells (PBMC) were obtained on gradient density and cultured with or without the three hormones for 24h at 37 ÌŠC. IL-12 and nitric oxide (NO) were measured in vivo and ex vivo by ELISA and a modified Griess method, respectively. We confirmed the significantly higher in vivo and in vitro levels of NO and IL-12 in BD in comparison to controls (P<0.05). We also found that circulating cortisol was lower in BD while sex hormones did not show any significant difference between the groups (P>0.05). In vitro, NO was reduced by estradiol and cortisol and increased by testosterone in both sexes. In contrast, while IL-12 production showed the same production profile as NO in women, estradiol and cortisol failed to reduce IL-12 levels in men. Our results may explain in part the differences observed between men and women in disease clinical expression. In fact, male patients seem to have defective IL-12 down-regulation by estradiol and cortisol that increases Th1 immune responses. This may be implicated in the severe expression of BD in men.

In vivo and in vitro IL-18 production during uveitis associated with Behçet disease: effect of glucocorticoid therapy.

Uveitis represents one of the major diagnostic criteria in Behçet's disease. It is most prevalent in the countries of the Mediterranean area, including Algeria, and along the Silk Road. Clinical features include oral and genital ulcers, ocular and skin lesions, as well as central nervous system, joint, vascular, gastrointestinal, or pulmonary manifestations. Many studies have reported that Th1 immune responses are involved in the physiopathology. We have previously studied the production of IL-12 and IFN-γ, cytokine markers in the Th1 pathway involved in Behçet's disease. In our study, we investigate in vivo and in vitro IL-18 production in Algerian patients with Behçet's disease with ocular manifestations in various stages of the disease. We examined the effect of glucocorticoids on IL-18 production during the active stage of the disease. Our results suggest that IL-18 could be a good biomarker for monitoring disease activity and its regression, demonstrating the effectiveness of treatment on the underlying immunopathologic process.

[Effects of peroxynitrite derived from nitric oxide on cultured bovine ocular explants]. / Effets du peroxynitrite dérivé du monoxyde d'azote sur des explants oculaires bovins en culture.

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.

Early involvement of nitric oxide in mechanisms of pathogenesis of experimental autoimmune uveitis induced by interphotoreceptor retinoid-binding protein (IRBP).

INTRODUCTION: Autoimmune uveitis is a group of HLA-associated inflammatory diseases of the eye, prevalent worldwide, that may cause blindness. It can be limited to the eye, or associated with a systemic syndrome. Furthermore, patients suffering from uveitis exhibit high serum and local nitric oxide (NO) levels as a consequence of cellular responses to immunologically privileged antigens within the eye such as interphotoreceptor retinoid binding protein (IRBP). To investigate NO production kinetics in autoimmune uveitis and its implication in mechanisms of ocular pathogenesis, we first attempted to develop an experimental model of autoimmune uveitis (EAU) on the Wistar rat, using the whole bovine retinal interphotoreceptor matrix extract (IPMe) and isolated IRBP. MATERIAL AND METHODS: Female Wistar rats (n=24) were divided into three experimental groups: "control rats" (n=3) consisting of non-immunized animals, "IRBP-immunized rats" (n=12) and "IPMe-immunized rats" (n=9), which received a subcutaneous injection, respectively, of 13 µg IRBP and 100 µg IPMe emulsified in complete Freund's adjuvant. On days 7, 14 and 21 post immunization, the rats were sacrificed. Nitrites were assessed in plasma and in homogenate of eyes using the Griess reaction. Meanwhile, eyes were collected for histological studies. RESULTS: Our results show the sensitivity of the Wistar strain to both IPMe and IRBP-induced EAU. In fact, we observed histological disorders affecting the retinal tissue in both models of EAU. On the other hand, a significantly increased production of NO in plasma and homogenate of eyes was also observed in comparison to the control group. Moreover, we noted with interest that maximal production of NO occurs prior to the alteration of retinal tissue. CONCLUSION: In summary, our results suggest the early involvement of NO in the mechanisms of pathogenesis of EAU. NO can be considered as a key bio-marker of poor prognosis in ocular autoimmune inflammation.

[Nitric oxide, biomarker of experimental autoimmune uveitis induced by S antigen]. / Le monoxyde d'azote, bio-marqueur de l'uvéite auto-immune expérimentale induite par l'antigène S.

INTRODUCTION: uveitis is an intraocular inflammation and one of the most severe and frequent manifestations of Behçet disease. S antigen (S Ag) is a highly conserved retinal protein implicated in the mechanism of the physiopathology in Behçet disease. This autoantigen is used in different animal models for experimental autoimmune uveitis (EAU) development, particularly in Behçet uveitis. Nitric oxide (NO) production has been reported in this disease by several groups and mainly by our team. MATERIALS AND METHODS: in this study, we investigated the development of Behçet uveitis in an experimental model using the Wistar rat after treatment with S antigen. This antigen was isolated and purified from bovine retina by gel filtration chromatography using Sephadex G-200. The rats were immunized with 10µg of S Ag. We evaluated the changes in nitric oxide metabolite production in plasma using the Griess reaction, during the 7th, 14th, and 21st days post-immunization. Furthermore, deleterious effects by S antigen on retinal tissue were assessed in a histological study. RESULTS: the results showed a significant increase in NO production in Wistar rats treated with S Ag in comparison with controls. We noted with interest that the clinical stages of EAU correlated with NO production. Furthermore, S Ag had several deleterious effects on Wistar rat retina. CONCLUSION: this study indicated in vivo elevation of NO levels, which was observed before retinal tissue damage. Nitric oxide appears to be a good marker for a poor prognosis in this experimental model. Moreover, oxidative stress can be considered the primary step in pathogenesis inducing the destruction of retinal photoreceptors. Collectively, our data could be helpful in the development of strategies for diagnosing patients with Behçet uveitis.

[Deleterious effects of stable nitric oxide derivatives, a uveitis inflammatory marker, on cultured bovine ocular layers]. / Effets délétères des dérivés stables du monoxyde d'azote, marqueur inflammatoire des uvéites, sur les différentes tuniques de l'oeil de boeuf en culture.

INTRODUCTION: Uveitis is an intraocular inflammation affecting various eye segments. This disease is characterized by a high level of nitric oxide production. It is estimated via the quantification of its end products: nitrites and nitrates. In a previous study, we showed the cytotoxic effect of these molecules on bovine retina in vitro. In this study, we investigated the effect of these two molecules on cultured ocular explants in vitro. METHODS: After clinical examination, healthy bovine eyes were obtained immediately after enucleation and were transported to the laboratory at +4 degrees C. After dissection, ocular explants from anterior and posterior segments were cultured in DMEM supplemented with 10% of FBS, 2mM glutamine, 100UI penicillin, and 100UI/ml streptomycin. Cultures were treated with either nitrites or nitrates at different concentrations (300-500 microM). After culture incubation (24-48h), ocular explants were fixed in buffered formalin and the histological study was performed. RESULTS: All structures showed structural alterations in relation with culture duration and molecule concentrations. The different structures showed different degrees of sensitivity depending on the type and concentration of the metabolite used. Sclerotic analysis showed very little response to the two molecules, whereas the cornea and ciliary process epithelia showed the highest sensitivity. CONCLUSION: Our results showed a cytotoxic effect of nitrites and nitrates on ocular structures in vitro. This effect was correlated with molecule concentration and duration of exposure. The structural alterations observed suggest that nitric oxide, via its products, is implicated in the ocular lesions observed during uveitis.

[Production of Th1/Th2 cytokines and nitric oxide in Behçet's uveitis and idiopathic uveitis]. / Production des cytokines Th1/Th2 et du monoxyde d'azote au cours de l'uvéite "Behçet" et de l'uvéite "idiopathique".

INTRODUCTION: The aim of this study was to investigate the role of Th1 (IFN-gamma and IL-12), Th2 (IL-10) cytokines and nitric oxide (NO) in the immunopathologic mechanisms of uveitis related to Behçet's disease and isolated idiopathic uveitis. PATIENTS AND METHOD: This study was conducted on 24 patients with Behçet's syndrome who had active uveitis, ten of whom showed isolated uveitis classified as idiopathic uveitis, and 13 healthy controls. The levels of IFN-gamma, IL-12 and IL-10 in sera and supernatants of PBMC cultures stimulated by PHA were estimated using immunoenzymatic dosage (ELISA sandwich according to the methods recommended by Immunotech France). The production of NO was measured in vivo and in vitro for the same patients using the modified Griess method. RESULTS: The induction of IFN-gamma and IL-12 was higher in the two groups of patients than in the controls (P<0.001). Significant IL-10 levels were recorded in 56.5% of patients with Behçet's disease presenting uveitis versus 30% of patients with idiopathic uveitis. NO production was more pronounced in idiopathic uveitis than in Behçet's syndrome (P<0.02). CONCLUSION: The predominance of the Th1 profile was associated with high production of NO in idiopathic uveitis. A Th1/Th2 profile with a moderated increase in NO production was observed in Behçet's disease. Our data have a clinical impact. The observation of combined Th1/Th2 cytokines and NO elevation in both in vivo an in vitro experiments could have a predictive value in characterizing uveitis associated with Behçet's disease.

[Pseudo-exfoliative glaucoma in eastern Algeria. Clinical study]. / Le glaucome pseudo-exfoliatif dans l'Est Algérien. Etude clinique.

The authors present the results of a study concerning 656 patients, over 40 years old, presenting a glaucoma, or a Capsular pseudoexfoliation, or both. These patients have been admitted at the Annaba Ophthalmology Clinic between September 1st, 1984 and September 1st, 1987. Frequency, age, sex, glaucoma-CPE association, opening and pigmentation of the iris-cornea angle, as well as the level of intraocular pressure, are studied. It turns out that the pseudoexfoliative glaucoma represents 53% of all glaucoma, that it is a particular form of primitive glaucoma, generally with open angle, of severe evolution, but that it can be controlled with an adequate treatment, often surgical.