To examine if there is any correlation between ankylosing spondylitis (AS) and TNF-a gene promoter single-nucleotide polymorphisms (SNP) and their associ- ated haplotypes. Using restriction fragment length poly- morphism—polymerase chain reaction method, the polymorphism of TNF-a-238, -308, -850, -857, -863 locus, and TNF-b ?252 were analyzed in patients with progres- sive AS, stable AS and control. (1) Neither the genotypes nor the allele frequencies of TNF-a (-308), (-238), (-863), and TNF-b ?252 showed differences in each group. TNF-a (-850) CC genotype and C allele frequency distribution was significantly higher in healthy controls group than in the stable and progressive groups. TNF-a (-857) CT, CC genotype, and C, T allele frequency showed differences in all groups. (2) Polymorphism linkage equilibrium test revealed that association of six TNF-a, b gene SNPs with haplotype GACTCG in progressive group is significantly higher than in the stable group and healthy control group (P 0.05). TNF-a (-857), (-850) gene polymorphism may increase the susceptibility to AS, but do not reflect the disease active state. The CC genotype and C allele may play a protective role in the pathogenesis of AS. TNF-a (-308) may be a weak indicator reflecting the active state of AS. Haplotype GACTCG may indicate both the suscepti- bility and the activity of AS.
