Tumour necrosis factor alpha -308G/A gene polymorphism: lack of association with knee osteoarthritis in a Turkish population

OBJECTIVE

To study the association between TNFalpha-308 G/A polymorphism and susceptibility to and severity of knee osteoarthritis in a Turkish population.

METHODS

Genomic DNA was obtained from 151 patients with knee osteoarthritis and 84 ethnically matched healthy controls. Polymerase chain reaction-restriction fragment length analysis was used to identify G/A polymorphism at position -308 in the promoter region. Genotype distributions and allelic frequencies of TNFalpha-308 G/A polymorphism were compared between osteoarthritis patients and controls. Thereafter, this association was investigated between patients and controls of the same sex. In addition, the standard Kellgren-Lawrence grading score and the Turkish version of the Western Ontario and McMaster Universities Osteoarthritis Index were used to assess the radiological and functional severity of the disease and their relationship with the TNFalpha-308 gene polymorphism was investigated.

RESULTS

Genotype distribution and allelic frequencies of -308 G/A polymorphism in the TNFalpha gene did not differ significantly between patients with knee osteoarthritis and controls (p>0.05). Moreover, there were no significant differences between patients and controls of the same sex (p>0.05). In addition, no association was observed between the radiological and functional severity of the disease and TNFalpha-308 G/A polymorphism (p>0.05).

CONCLUSION

These findings suggest that the examined polymorphism in the TNFalpha gene does not contribute to susceptibility to or severity of knee osteoarthritis in the Turkish population.