Association of IL-8-251T/A (rs4073) gene polymorphism with Systemic lupus erythematosus in a cohort of Egyptian patients

Systemic lupus erythematosus (SLE) susceptibility was found to be correlated with genetic polymorphisms. Therefore, the current study aimed to investigate the association of the IL-8-251 T/A polymorphism with the risk of SLE.A total of 135 SLE patients and 75 controls were enrolled in our study. The IL-8-251 T/A polymorphism was analysed by PCR-RFLP. Also, the serum concentration of IL-8 was measured using ELISA. Finally, investigate possible IL-8 pathways in SLE pathogenesis by using the STRING database.Our results revealed that the risk of having SLE in AA genotype carriers was significantly increased (OR = 1.92, 95 % CI = 1.23-3.10, p = 0.006) when compared with TT genotype carriers. Patients with SLE had a significantly higher frequency of the A allele (OR = 1.37, 95 % CI = 1.09-1.7; P = 0.01) than controls. Serum IL-8 levels were significantly increased in SLE patients (77.81 ± 21.27; p < 0.001) when compared to healthy controls (48.85 ± 7.89). Also, it was found that the serum IL-8 level had significant positive correlations with proteinuria, ESR, ANA, urea and SELADI, and significant negative correlations with RBCs count, C3 and hemoglobin. According to ROC curve analysis, serum IL-8 levels are a good biomarker for the detection of SLE disease, with 87.5 % sensitivity and 85 % specificity. STRING analysis revealed that IL-8 interacts with key SLE signaling pathway members such as TNF-α, IL-1β, IL-6, and IL-10.There was a correlation between the IL-8-251 T/A polymorphism and the risk of SLE. Our findings also suggest that the IL8-251 A allele may be an important risk factor for the development of SLE.