Tumor necrosis factor alpha gene polymorphisms in ankylosing spondylitis: associations with clinical disease progression and disease susceptibility / 中国组织工程研究

ABSTRACT

BACKGROUND: The association of tumor necrosis factor alpha (TNF-α) gene polymorphisms with the onset and development of ankylosing spondylitis (AS) has been the focus of studies on AS in the field of genetics.OBJECTIVE: To explore the association of the polymophisms of TNF-α promoter gene at positions-308 and -238 with AS susceptibility and clinical pathological changes.DESIGN: A case-control study.SETTING:The Rheumatic Immunology Department of Changhai Hospital of the Second Military Medical University of Chinese PLA.PARTICIPANTS: Totally, 108 AS patients were recruited from Rheumatic Immunology Department of Changhai Hospital, Second Military Medical University of Chinese PLA from January 1999 to December 2003 ,they had no kinship. The ratio of men to women was 5.3 1. They aged from 13 to 71 (30-± 12) years old, and AS was divided into Ⅰ- Ⅳ radiographic stages according to the sacro-iliac joint damage. A total of 100 healthy controls were randomly selected from the blood donators(Shanghai Hospital) who were aged from 19 -56 (33 ±9) years old, and the ratio of men to women was 4.9 1. Informed consent was obtained from all the subjects.ti-coagulated with EDTA. Polymerase chain reaction amplification and purification of the TNF-α promoter region was made and the sequence of polymerase chain reaction products was examined and displayed by Chromas 1.62 softcorresponding radiographic stage of sacro-iliac joint damage was assessed to investigate the influence of gene polymorphisms on AS.MAIN OUTCOME MEASURES: DNA direct sequencing method was used to detect -238 and -308 allele phenotypes for investigating the association with clinical presentations.G and -238G/A allele was 98.1% (106 cases) and1. 9% (2 cases) respectively in AS group and 95.0% (95 cases) and 5.0% (5 cases) respecquency of TNF-α promoter gene at positions -308. 1.1(G/G) and - 308.1.2(G/A) alleles was 82.4% (89 cases) and 17.6% (192 cases) respectively in AS group, which was not significantly different compared respectively with 85.0% (85 cases) and 14.0% (14 cases) of the control of sacro-iliac joint damage and the frequency of TNF-α promoter gene at the position of - 308 (G/G) and (G/A) AS patients with(G/G) phenotype who were confirmed of radiographic stage Ⅰ, Ⅱ, Ⅲ, and Ⅳ were observed in 3/35/40/11cases,compared with (G/A) phenotype of 1/12/6/0 cases.The difference was statistically significant (χ2GMH = 4.77, P ＜ 0.05 ).CONCLUSION: Our data suggest that the polymorphisms of TNF-α promoter gene at positions of - 238 and - 308 allele has no association with AS susceptibility, but the polymorphisms of TNF - α promoter gene at the position of -308 might exert great influence on AS according to the radiographic stage of sacro-iliac joint damage.