IL-2, IFN-γ, and IL-12 Gene Polymorphisms and Susceptibility to Multiple Sclerosis

Multiple sclerosis (MS) is a multifactorial disease. Positive genetic background could predispose individuals to this chronic disabling disease. In order to investigate the role of some proinflammatory cytokines (interleukin (IL)-2, IL-12, and interferon-gamma (IFN-gamma)) as a risk factor for MS, this study was performed. Two hundred and eleven patients with relapsing-remitting form of MS were enrolled in this study and compared with 359 healthy individuals. Using polymerase chain reaction based on sequence-specific primer method, the cytokine genes were amplified, and alleles and genotypes were detected on gel electrophoresis. Significant increases for IFN-gamma AT (+874) genotype (54.5% vs. 37.8%, p = 0.0002) and IL-12 AA (-1188) genotype (60.8% vs. 49.7%, p = 0.014) were found in MS patients in comparison with healthy controls. A significant decrease in IFN-gamma TT (+874) genotype (17.7% vs. 27.5%, p = 0.01) and IL-12 CA (-1188) genotype (30.9% vs. 45%, p = 0.001) in MS patients was also detected. No significant differences of IL-2 G/T (-330) and IL-2 G/T (+166) in alleles and genotypes were observed between MS patients and normal subjects. It could be suggested that the genetic variation in IL-12 A/C (-1188) and IFN-gamma A/T (+874) cytokine genes could be risk factors for MS patients.