TNF-α -857 and -1031 polymorphisms predict good therapeutic response to TNF-α blockers in Chinese Han patients with ankylosing spondylitis

Abstract

Aim: To evaluate whether polymorphisms at -857, -1031, -308 and -238 positions of the TNF-α gene influence response to TNF-α-blocker therapy in Chinese Han patients with ankylosing spondylitis. Patients & methods: A total of 106 patients with ankylosing spondylitis were recruited and genotyped for -857, -1031, -308 and -238 TNF-α gene polymorphisms. In total, 32 received infliximab and 74 received a recombinant human TNF-α receptor II–IgG Fc fusion protein (rhTNFR–Fc). At the end of 12 weeks, patients were assessed using the Assessment of SpondyloArthritis International Society (ASAS) 20, 40, 50 and 70 criteria. Results: Polymorphisms at -308 and -238 did not affect therapeutic response. The -857 C/C genotype (p = 0.0021) responded better to therapy. The -1031 T/T genotype (p = 0.0004) showed better outcome. Conclusion: In Chinese Han ankylosing spondylitis patients, polymorphisms at the -308 and -238 positions of the TNF-α gene are unable to predict TNF-α-blocker response; however, -857 C/C and -1031 T/T genotypes have the ability to predict good response. Original submitted 13 June 2012; Revision submitted 6 August 2012