TNF-α-308 polymorphism determines clinical manifestations and therapeutic response of ankylosing spondylitis in Han Chinese.

BACKGROUND AND OBJECTIVE:There is ongoing debate as to whether tumor necrosis factor alpha (TNF-α)-308 is associated with ankylosing spondylitis (AS). The aim of the present study was to determine whether TNF-α-308 is involved into genetic susceptibility, clinical features and therapeutic response of AS in Han Chinese. METHODS:Two hundred and sixty AS patients with 260 ethnically matched healthy blood donors were enrolled into the present study. TNF-α-308 promoter polymorphism was identified using polymerase chain reaction amplification with restriction fragment length polymorphism assay. RESULTS:Population genetic analysis showed that the prevalence of allele A and G/A genotype was equally infrequent in both AS patients (3.85% and 7.69%) and healthy subjects (4.23% and 8.46%). Compared with the carriers of G/G genotype, remarkably elevated erythrocyte sedimentation rate and serum C-reactive protein were observed in AS patients with G/A variant (87.06±49.40 vs. 55.53±42.99mm/h, P=.0126; 54.95±27.77 vs. 34.36±36.13mg/dl, P=.0116, respectively), and they always presented with inflammatory spinal pain (70.00% vs. 43.33%, P=0.0214) and suffered relatively mild sacroiliitis (65.00% vs. 41.67%, P=0.0431). The allele G and G/G genotype were more frequent in good responders to anti-TNF-α treatment (96.55% vs. 73.53%, P=.0032; 93.10% vs. 47.06%, P=.0015), whereas there was no obvious superiority of them in predicting therapeutic response of conventional medications for AS. CONCLUSIONS:Our data suggest that TNF-α-308 polymorphism may influence the clinical features rather than susceptibility to AS in our Han Chinese.