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Rheumatology 2003; 42: 308-313
© 2003 British Society for Rheumatology
The -308 polymorphism in the tumour necrosis factor (TNF) gene promoter region and ex vivo lipopolysaccharide-induced TNF expression and cytotoxic activity in Chilean patients with rheumatoid arthritis
1 Disciplinary Program of Immunology, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, University of Chile,
2 Rheumatology Section, Department of Medicine, University of Chile Clinical Hospital and
3 School of Public Health, Faculty of Medicine, University of Chile, Santiago, Chile
Objective. To investigate the association of the -308 polymorphism in the promoter region of the tumour necrosis factor (TNF) gene with susceptibility to the development of RA. We also explored the expression and cytotoxicity of TNF in relation to the -308 polymorphism.
Methods. We recruited 92 RA patients and 42 healthy control subjects. Genotyping for the TNF promoter was performed by polymerase chain reaction–restriction fragment length polymorphism analysis. To study the overexpression of TNF we used a whole-blood culture system. TNF cytotoxicity was assessed in the L929 cell line.
Results. The TNF2 allele was found in 23% of RA patients and 10% of controls. Although both groups showed high variability in serum TNF concentration, in the lipopolysaccharide-induced TNF level and in the cytotoxicity of the cytokine in the L929 cell line, these differences were not associated with the -308 TNF polymorphism.
Conclusion. No associations were found between the -308 TNF promoter polymorphism, serum and ex vivo TNF levels and the cytotoxic activity of TNF in RA patients.
KEY WORDS: TNF, Polymorphism, Gene, Rheumatoid arthritis.
Correspondence to: J. C. Aguillón, Disciplinary Program of Immunology, ICBM, Faculty of Medicine, University of Chile, Independencia 1027, Santiago, Chile. E-mail: jaguillo{at}machi.med.uchile.cl