Aim: This study aimed to investigate genotype and allele frequencies of -174 (rs1800795) and -572 (rs1800796) IL-6 promoter gene polymorphisms in Egyptian patients with rheumatoid arthritis (RA) in comparison to control group.
Methods: The study was conducted on 198 Egyptian subjects (99 RA patients and 99 healthy control). The promoter region of the IL-6 gene was amplified by PCR using DNAs from patients and the controls, and their PCR products were digested by suitable enzymes.
Results: No statistical differences were found in -572G/C genotype (P = 0.177) or allele (P = 0.147) frequencies between RA patients and controls. Significant differences were observed in -174G/C genotype (P < 0.001) and allele (P < 0.001) frequencies between RA patients and controls.
Conclusion: A significant association of IL-6 -174G/C gene polymorphism and RA in Egyptian population was found with significantly higher frequencies of GC and CC genotypes and C allele in RA patients compared to controls. No association was found between IL-6 -572G/C gene polymorphism and RA.
Keywords: IL6–174G/C; IL6–572G/C; Interleukin 6; Rheumatoid arthritis; gene polymorphism.