RT Journal Article
SR Electronic
T1 Autoimmunity and tuberculosis. Opposite association with TNF polymorphism.
JF The Journal of Rheumatology
JO J Rheumatol
FD The Journal of Rheumatology
SP 219
OP 224
VO 32
IS 2
A1 Paula A Correa
A1 Luis M Gomez
A1 Jose Cadena
A1 Juan-Manuel Anaya
YR 2005
UL http://www.jrheum.org/content/32/2/219.abstract
AB OBJECTIVE: To examine the influence of the -308 and -238 single nucleotide polymorphisms (SNP) of tumor necrosis factor-a gene (TNF) on patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), primary Sjogren's syndrome (SS), and tuberculosis (TB). METHODS: Genomic DNA from patients with RA (n = 165), SLE (n = 100), primary SS (n = 67), and TB (n = 135) and ethnically matched controls (n = 430) was genotyped for TNF -308 and -238 SNP by PCR-RFLP. RESULTS: TNF -308A allele was associated with RA (odds ratio, OR 1.8, p = 0.002), SLE (OR 2.6, p < 0.0001), and primary SS (OR 2.9, p < 0.0001). TNF -308G was associated with TB (OR 1.8, p = 0.02). The -308 GG genotype was protective for autoimmunity (p < 0.003). TNF -238A allele was protective for autoimmunity but represented a susceptibility factor for TB (OR 2.2, p < 0.0001). Haplotype -308A-238G was a protective factor against TB, whereas it carried susceptibility for RA, SLE, and primary SS (p < 0.0001). CONCLUSION: The results show an opposite association of TNF polymorphism with autoimmunity and TB, and suggest the existence of heterozygote advantage, sustaining the hypothesis that autoimmune diseases are a consequence of natural selection for enhanced TB resistance. Data also provide genetic evidence supporting the common variants/multiple disease hypothesis, which emphasizes that many disease genes may not be disease-specific, and that similar immunogenetic mechanisms underlie autoimmune diseases.