Exploring the relationship between oxidative stress status and inflammatory markers during primary Sjögren's syndrome: A new approach for patient monitoring.

INTRODUCTION: Primary Sjögren's syndrome (pSS) is a chronic inflammatory disease primarily affects exocrine glands dysfunction. Oxidative stress (OS) is a phenomenon occurring as a result of an imbalance between the generation of free radicals and antioxidant defense system. Hence, we aimed to establish the status of OS and inflammatory response according to the pSS disease activity index. In this context, we investigated malondialdehyde (MDA), and antioxidant enzymes during pSS. The possible association between MDA and nitric oxide (NO) levels and between MDA and some pro-inflammatory cytokines (IL-1ß, IL-6, TNF-α, and IL-33). METHODS: The study has been conducted on 53 pSS patients. The antioxidant enzymes, represented by glutathione peroxidase (GSH-Px), catalase (CAT) and superoxide dismutase (SOD), were estimated by a colorimetric activity kit. Whereas, MDA value was assessed by measuring thiobarbituric acid reactive substances. Moreover, pro-inflammatory cytokines (IL-1ß, IL-6, TNF-α, and IL-33) and NO were respectively quantified by enzyme-linked immunosorbent assays (ELISA) and the modified Griess. RESULTS: Interestingly, we report a notable reduction in our pSS patients' antioxidant enzyme activity, while NO, MDA and proinflammatory cytokines values were significantly increased. pSS patients with higher disease activity had much stronger increases in NO and MDA levels. No significant difference was assessed in CRP level. Additionally, substantial significant correlations between plasmatic NO and MDA levels and between MDA, NO and IL-1ß, IL-6, TNF-α cytokines were reported. However, no significant association was found between NO, MDA and IL-33 concentrations. CONCLUSION: Collectively, our data showed altered oxidant-antioxidant balance in pSS patients. MDA, NO, IL-1ß, IL-6, TNF-α seem to be good indicators in monitoring disease activity. Oxidative stress was closely related to inflammation in pSS. Exploiting this relationship might provide valuable indicators in the follow-up and prognosis of pSS with a potential therapeutic value.

Association between Increased Bcl-2, Fas and FasL Levels and Inflammation Extent in Labial Salivary Glands During Primary Sjögren's Syndrome.

BACKGROUND: Primary Sjögren Syndrome (pSS) is a chronic autoimmune disease characterized by epithelial atrophy, mononuclear infiltration in exocrine glands resulting in the defective function of these glands. In pSS, atrophy of the epithelium is caused by an increased amount of apoptosis. OBJECTIVE: The main aim of this study is to investigate the role of the apoptosis-related factors by studying Bcl-2, Fas and FasL expression in relation to the extent of inflammation as well as the effect of therapy on the expression of these mediators. METHODS: In pSS patients (n=62) documented for their serological and clinical features, Fas, FasL and Bcl-2 plasma levels were assessed using enzyme-linked immunosorbent assays. In the same context, we investigated their expression by immunohistochemistry analysis in the labial salivary glands samples in association with the extent of inflammation. RESULTS: Interestingly, our results indicated that in pSS patients, the plasmatic Bcl-2, Fas and FasL levels, which appeared to be associated with the severity of inflammation and were significantly elevated in comparison to the healthy controls. Moreover, a significant decrease in all these factors was observed in patients after combined corticosteroids-hydroxychloroquine therapy. Importantly, we report a strong positive correlation between Bcl-2 and NO levels. The immunohistochemical staining reveals a strong Bcl-2 expression in infiltrating mononuclear cells and a total absence in the acinar cells. The Bcl-2 level varies according to the severity of pathology. However, the expression of Fas and FasL was less important and predominantly localized in infiltrating mononuclear cells. CONCLUSION: Our current study highlights the involvement of Bcl-2, Fas and FasL in pSS glands injury. These factors may act as useful predictor markers of a clinical course in pSS, suggesting a novel approach in the pSS patients monitoring.