Association between serum Toll-like receptor 4 and 8-hydroxy-2′-deoxyguanosine levels with disease activity in rheumatoid arthritis patients.

Considering the importance of toll-like receptor (TLR) 4 and oxidative stress in the pathogenesis of autoimmune disorders, present study was designed to assess serum TLR4, 8-hydroxy-2′-deoxyguanosine (8-OHdG) as a marker of oxidative DNA damage, and total antioxidant capacity (TAC) in rheumatoid arthritis (RA) patients and to study their relation with disease activity and their predictive potential. 44 RA patients and 44 matched controls were studied. Disease activity score (DAS-28) was assessed. Serum TLR4, 8-OHdG and TAC were measured. The mean age of patients was 44 ± 10.4 years, 33 females and 11 males with and disease duration 5.5 ± 3.8 months. The mean DAS-28 was 4.6 ± 0.6 (3.45–6.01). Rheumatoid factor (RF) and anti-cyclic citrullinated peptide (anti-CCP) were both positive in 20 patients. Compared to control, the mean ± SD of serum TLR4 (2.41 ± 4.50 vs. 1.20 ± 1.67 ng/ml), and 8-OHdG (67.67 ± 20.57 vs. 45.34 ± 30.61 ng/ml) were significantly higher in patients (p < 0.001); whilst serum TAC (1.3 ± 0.5 vs. 2.01 ± 0.55 µmol/L) was significantly lower (p < 0.001). TLR4, 8-OHdG were significantly increased and TAC decreased in patients with positive RF/anti-CCP compared to negative (p < 0.001, p = 0.005 and p = 0.036 respectively). TLR4 was significantly higher in patients with higher DAS-28 (p = 0.003) and both significantly correlated (p < 0.001). Areas under the ROC curve of TLR4 (0.87; 95%CI: 0.78–0.96) and 8-OHdG (0.88; 95%CI: 0.79–0.97) were greater than that of TAC (0.19, 95%CI: 0.09–0.29) (p < 0.001). The TLR4, 8-OHdG and TAC showed high predictive value in RA disease. TLR4 can be remarked as a sensitive and specific marker for determining disease activity in RA. [ABSTRACT FROM AUTHOR]