TNF-a and TNF-β Polymorphisms are Associated with Susceptibility to Osteoarthritis in a Korean Population

Background: The tumor necrosis factor (TNF) is believed to play an important role in the pathophysiology of osteoarthritis (OA). Evidence shows that genetic polymorphisms make substantial contributions to the etiology of OA. Methods: We investigated the genotypes TNF-a and TNF-ß in 301 OA patients and 291 healthy subjects as controls. We employed a polymerase chain reaction- restriction fragment length polymorphism and a polymerase chain reaction-single strand conformation polymorphism assay to identify the genotypes TNFA -G308A and TNFB +G252A, respectively. Results: For TNFA -G308A, the percentages of genotypes GG, AG, and AA were 26.3% (79/301), 62.5% (188/301), and 11.3% (34/301) in OA patients and 88.7% (258/291), 11.3% (33/ 291), and 0% (0/291) in controls. For TNFB +G252A, the percentages of genotypes GG, AG, and AA were 15.3% (46/301), 41.9% (126/301), and 42.9% (129/301) in OA patients and 12% (35/291), 52.6% (153/291), and 35.4% (103/291) in controls. There were significant differences in genotypes and alleles of TNFA -308 between OA patients and controls (p<0.0001) and in alleles of TNFB +252 (p=0.0325). The risk of OA was significantly higher for carriers of the TNFA -308A alleleand the TNFB +252 AA homozygote (p=0.0224). Conclusions: The results suggest close relationships between TNFA -G308A and TNFB +G252A polymorphisms and individual susceptibility to OA in the Korean population.