8-Hydroxy-2'-Deoxiguanosine (8-OHdG) as a reliable biomarker for rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic, autoimmune, destructive inflammatory synovitis that ultimately affects metabolic function, the vascular system, and systemic bone. Many researchers have demonstrated that free radicals induce oxidative stress and are involved in several disease conditions. It was observed that a physiological equilibrium between oxidants and antioxidants is being disrupted by oxidative stress. Free radicals are molecules, ions, or atoms with unpaired electrons. These elements tend to be stabilized. For stabilization, they attack other molecules to get electrons. In the cells, this behavior can cause mutations or even cellular death. This study aimed to evaluate the oxidative stress marker 8-Hydroxy-2-Deoxiguanosine (8-OHdG) as a biomarker for Iraqi RA patients.

The estimation of the plasma level of this marker was achieved in human RA patients using ELISA. The current study included 132 adult individuals who were diagnosed as RA patients with joint complications, while the remaining 66 were healthy and served as controls. Blood plasma levels of 8-OHdG were estimated using a commercial ELISA kit. The resultant solution was washed after being incubated, and then a conjugate enzyme was added; finally, the results were read using an ELISA reader at 450nm.

A significant increase in plasma concentration of 8- OHdG was detected in the disease group. The most significant increase in this biomarker (p = 0.001) appeared in RA patients in comparison with the healthy subjects. The significant increase of inflammatory and oxidative biomarkers highlighted in this study might point to a relationship between these biomarkers and the pathogenesis and progression of rheumatoid arthritis in adult subjects.

This study suggests the role of 8-OHdG as an early diagnostic marker of RA. Because 8-OHdG is a strong indicator of oxidative stress-related DNA damage, this result may have significant clinical implications.