The frequency of the TNF-alpha -1031C allele was significantly higher in Behcet's patients than in healthy controls (p = 0.015; chi(2) = 5.84; OR = 1.65; 95% CI = 1.08-2.54), whereas the frequencies of the TNF-alpha -308G and the TNF-beta +252G alleles were similar in the two compared groups.
However, polymorphic analyses of the TNFB gene and Tau-a microsatellite between the HLA-B and TNF genes indicate that the pathogenic gene of BD is not the HLA-B51 gene itself but another gene located around the HLA-B gene.
To address the possibility that a non-human leukocyte antigen (HLA) gene closely linked to the HLA-B gene, such as tumor necrosis factor (TNF)-alpha, TNF-beta, or ECl (the locus that determines the susceptibility to alloreactive natural killer [NK] cells), is involved in the susceptibility to Behçet's disease, NcoI and EcoRI restriction fragment length polymorphisms in the TNF-beta gene and the susceptibility to lysis by alloreactive NK cells were investigated in Behçet's patients.