[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.