IkappaBalpha promoter polymorphisms in patients with primary Sjögren's syndrome

To investigate the association of IkBalpha promoter polymorphisms with the development of primary Sjögren's syndrome in Taiwan, 98 patients with primary Sjögren's syndrome and 110 unrelated healthy controls were enrolled in this study.

The IkappaBalpha -881 A/G, IkappaBalpha -826 C/T, IkappaBalpha -550 A/T, IkappaBalpha -519 C/T, and IkappaBalpha -297 C/T polymorphisms were determined by the methods of polymerase chain reaction/restriction fragment length polymorphism.

This study demonstrated that the genotype frequencies of IkappaBalpha -826 C/T and IkappaBalpha -826 T/T, in comparison with that of IkappaBalpha -826 C/C, were significantly higher in the patients with primary Sjögren's syndrome than in the controls. The allele frequency of IkappaBalpha -881 G was significantly decreased in the patients with primary Sjögren's syndrome compared with that of the controls. In contrast, the allele frequency of IkappaBalpha -826 T was significantly higher in the patients with primary Sjögren's syndrome than in the controls. The similar findings could also be found in the allele carriage frequencies. The patients with primary Sjögren's syndrome had lower allele carriage frequencies of IkappaBalpha -881 G and IkappaBalpha -826 C, and a higher allele carriage frequency of IkappaBalpha -826 T. We also found that the estimated haplotype frequency of IkappaBalpha -881A-826T-550A-519C-297C was significantly increased in the patients with primary Sjögren's syndrome in comparison with that of the controls.

This study demonstrated that the IkBalpha -826T allele and IkBalpha -881A-826T-550A-519C-297C haplotype were associated with susceptibility to primary Sjögren's syndrome in Taiwan. However, these findings may not be disease-specific but may be related to inflammatory responses.