Oxidant/Antioxidant Status of the Erythrocytes from Patients with Rheumatoid Arthritis

Abstract

It has been suggested that enzymatic and/or non-enzymatic antioxidant systems are impaired in rheumatoid arthritis (RA) and hence patients are exposed to oxidant stress. This study aimed to establish whether this is really the case. Fasting blood samples were obtained from 24 patients with rheumatoid arthritis and 20 controls. The activities of erythrocyte superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and xanthine oxidase (XO) enzymes and malondialdehyde (MDA), oxidant resistant (OR) and non-enzymatic superoxide radical scavenger activity (NSSA) values were measured in both groups. Patients with RA had higher SOD and XO activities and MDA levels than did the controls. However, NSSA and OR levels were found to be decreased, and CAT and GSH-Px activities unchanged in the study group. Results suggest that excessive free radical production through the xanthine-xanthine oxidase system is the primary factor in rheumatoid arthritis, rather than an impaired antioxidant system. The therapeutic use of XO enzyme inhibitors and some antioxidants can be beneficial in this regard.

Relationship of Cellular Oxidant and Antioxidant Status with Disease Activity in Patients with Rheumatoid Arthritis

“…In our study, pMDA and eMDA levels were found to be significantly elevated in the patients with RA compared to controls (Table 1). This is in agreement with other studies in which higher MDA levels have been reported in patients with RA (9,23,24). When we look at this finding with respect to disease activity levels, a significant increase was found in plasma levels of severe RA and erythrocyte levels of moderate and severe RA.…”

“…However, the relationship of disease activity of RA with erythrocyte activity of SOD and levels of MDA and XO is not clear. Our findings suggested that the levels of eMDA and the activity of eSOD were increased in RA patients, consistent with most of the previous studies (23,32). On the other hand, Banford et al (33) reported a significant decrease in eSOD activity in RA patients.…”

Antioxidant Enzymes in Rheumatoid Arthritis

“…But possibly increased activity of SOD [35,36] may be attributed to increased O 2 -production by hyperactive cells leading to SOD induction [37,38]. Another possibility may be excessive free radical production through the xanthine-xanthine oxidase system is the primary factors in RA, rather than an impaired antioxidant system [36].…”

“…Another possibility may be excessive free radical production through the xanthine-xanthine oxidase system is the primary factors in RA, rather than an impaired antioxidant system [36]. Else higher SOD levels may be a change to nullify excessive free radical production.…”

Lack of role of endothelial nitric oxide synthase gene Glu298Asp polymorphism in rheumatoid arthritis among Asian Indians

“…This may be due to higher oxidative stress associated with RA. [16][17][18][19][20] Under the conditions of high levels of oxidants like oxygen free radicals, NO gets converted to injurious peroxynitrite radical (ONOOˉ), which further may get isomerized to NO 3 or get converted to nitrotyrosine [21,22,23]. The low level of NO in RA patients might explain for the relatively high prevalence of vascular pathology such as vasculitis among RA patients.…”