Toll-like receptor (TLR9) -1486 T/C (rs187084) gene polymorphism in Egyptian patients with rheumatoid arthritis

Aim of the work The aim of the study was to assess the role of Toll-like receptor-9 (TLR9) gene polymorphism in rheumatoid arthritis (RA) and to evaluate its association with disease activity and severity in Egyptian patients. Patients and methods The study included 100 RA patients and 100 matched controls. Genotyping of TLR9 -1486 T/C (rs187084) gene polymorphism for all participants was performed. Medical Records-Based Index of Severity (RARBIS), modified Health Assessment Questionnaire (mHAQ), disease activity score (DAS28) and clinical and laboratory parameters of disease activity were assesses in RA patients. Anti-cyclic citrullinated peptide antibodies (anti-CCP) and rheumatoid factor (RF) were also determined. Results The patients mean age was 43.7 ± 8.9 years and were 73 females and 27 males with mean disease duration of 13.3 ± 6.2 years. The mean DAS28 was 3.5 ± 1.1, RARBIS was 6.6 ± 2.8 and the mHAQ 1.4 ± 0.8. The frequency of the TLR9 TT genotype carriers were significantly higher in RA patients than in controls (27% and 9% respectively). Similarly, the T allele was significantly more frequent in RA patients in comparison to the controls (56.5% and 42% respectively). No significant association was found between the TLR9 genotypes with the gender or the age at disease onset. The clinical and laboratory parameters reflecting disease activity showed no association with the TLR9 genotype. No significant association was found between the TRL9 genotyping with the RARBIS or presence of RF or anti-CCP antibodies. Conclusion TLR9 gene polymorphism -1486 T/C is associated with the increased RA susceptibility in Egyptian patients.