TNF-alpha and TNF-beta gene polymorphisms in systemic sclerosis.
Tumor necrosis factor (TNF)-alpha and TNF-beta, mediators of inflammatory responses, have been implicated in the pathogenesis of autoimmune diseases. The aim of this investigation was to determine whether two promoter region polymorphisms of the TNF-alpha gene (TNF-alpha -308 and TNF-alpha -238) and a determinant in the first intron of the TNF-beta gene (TNF-beta +252) affect susceptibility to systemic sclerosis (scleroderma) (SSc). Fifty patients and 60 healthy blood donors from Japan were genotyped for these markers by polymerase chain reaction-based methods. Fisher's exact test was used to test for significant associations. Because of very limited variation at the TNF-alpha -308 and TNF-alpha -238 loci in the Japanese people, statistical analyses with sufficient power could not be done for these genotypes. However, the two homozygous genotypes of the TNF-beta +252 locus were found to be significantly associated with SSc. Compared to controls, the frequency of the TNF-1 genotype was decreased, whereas that of TNF-2 was increased in SSc patients. The former implies an association with resistance, while the latter suggests an association with susceptibility to the disease. These results show that the TNF-beta +252 locus plays an important role in the etiopathogenesis of SSc.
Pandey
J P
JP
Department of Microbiology and Immunology, Medical University of South Carolina, Charleston 29425-2230, USA.
Takeuchi
F
F
D016022:Case-Control Studies; D005787:Gene Frequency; D005838:Genotype; D006720:Homozygote; D006801:Humans; D008233:Lymphotoxin-alpha / Q000235:genetics*; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic; D012595:Scleroderma, Systemic / Q000235:genetics* / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*
D008233:Lymphotoxin-alpha; D014409:Tumor Necrosis Factor-alpha