TNF and TNF receptor polymorphisms in Korean Behcet’s disease patients

Abstract

Behcet’s disease (BD) is an autoimmune disease characterized by recurrent oral ulcers, genital ulcers, erythema nodosum, and uveitis. Genetic factors are considered important in its pathogenesis. The serum level of tumor necrosis factor (TNF) is elevated in patients with active BD, and its production is elevated in monocytes and in the γδ T cells of BD patients. A dramatic response to anti-TNF-α antibody treatment further supports the role of TNF in BD. In this study, we investigated genetic polymorphisms of TNFα −308 G/A, TNFβ +252 G/A, and TNFR2 196 R/M in 94 Korean BD patients and age- and sex-matched healthy controls to investigate the role of TNF and TNF receptor polymorphisms in BD. The polymerase chain reaction–restriction fragment length polymorphism was used to identify the TNF-α promoter (G = TNFA1, A = TNFA2) and TNF-β intron polymorphisms (G = TNFB1, A = TNFB2), and polymerase chain reaction–singly-strand conformation polymorphism was used to identify TNFR2 196R/M polymorphism (T = TNFR2M, G = TNFR2R). No differences were found in the TNF-α, TNF-β or TNFR2 polymorphisms of the patients and the healthy controls. The allele frequencies of TNFA1/A2 were 0.94/0.06 in patients and 0.96/0.04 in healthy controls ( p = 0.36, OR = 0.65, 95% CI = 0.26-1.63), for TNFB1/TNFB2 these were 0.42/0.58 in patients and 0.44/0.56 in controls ( p = 0.68, OR = 0.91, 95% CI = 0.61–1.38), and for TNFR2R/TNFR2M 0.23/0.77 in patients and 0.21/0.79 in controls ( p = 0.62, OR = 1.13, 95% CI = 0.69–1.84). In conclusion, this study found no differences of TNFα -308 G/A, TNFβ +252 G/A or of the TNFR2 196R/M polymorphisms in Korean BD patients versus healthy controls. These findings suggest that the role of TNF in BD is not genetically determined, but can be functionally explained.