TIM‐1 rs41297579 G>A (−1454) and TIM‐4 rs7700944 gene polymorphisms as possible risk factor for rheumatoid arthritis: relation to activity and severity

T his study was aimed to evaluate the impact of both TIM‐1 rs41297579 G>A (?1454) and TIM‐4 rs7700944 polymorphisms on susceptibility to rheumatoid arthritis (RA) in a cohort of Egyptian population and to evaluate for the first time their relation to activity, severity, disease‐related disability and erosion. TIM‐1 rs41297579 G>A (?1454) and TIM‐4 rs7700944 gene polymorphisms were typed by RFLP for 128 patients with RA and 125 healthy controls. The A allele, A‐containing genotypes (GA and AA) of the TIM‐4 and GA haplotype were present with significant higher frequency in patients with RA than healthy controls (P_c < 0.001). These findings suggest that the A allele, A‐containing genotypes (GA and AA) and GA haplotype may be a susceptibility risk factor for RA OR = 5.83 (3.6–9.4), OR = 9.41 (5.0–17.6) and OR = 4.21 (1.07–19.2), respectively]. No associations were found between TIM genotypes and disease activity, severity or presence of erosion. However, the RA patients with GA genotype of TIM‐4 have higher grade of rheumatoid factor (RF) positivity (P = 0.018), and have worse disease‐related disability (P = 0.007) and worse pain (0.025). TIM‐4 rs7700944 and not TIM‐1 rs41297579 G>A (?1454) is associated with RA in the present cohort of Egyptian and may be a risk factor for development of RA in Egyptian. Both SNPs have no effect on disease activity, severity or erosion. However, TIM‐4 GA genotype is associated with higher grade of RF positivity and worse disease‐related disability and pain.