Tumor Necrosis Factor-α Promoter Polymorphisms in Mexican Patients With Spondyloarthritis

Abstract

To evaluate the role of tumor necrosis factor–α (TNF-α) gene as susceptibility marker for spondyloarthritis (SpA), two polymorphisms (−238 and −308 positions) were analyzed in 229 patients with SpA (113 with ankylosing spondylitis [AS], 92 with undifferentiated SpA [U-SpA], 24 with reactive arthritis), and 169 ethnically matched healthy control subjects. The HLA-B alleles were detected by PCR-SSP technique and the TNF-α polymorphism by PCR-RFLP. In comparison with healthy control subjects, the frequencies of TNF-238 in SpA were similar. In contrast, the analysis of −308 polymorphism showed increased frequencies of the T2(A) allele in the whole SpA group ( p < 0.05, pC = NS, OR = 1.83) as well as the T2(A) allele ( pC < 0.05, OR = 2.4) and T1T2(AG) genotype ( p < 0.05, pC = NS, OR = 2.25) in U-SpA patients. Comparison of B27-negative patients and healthy control subjects yielded similar results. There was no significant correlation between TNF genotypes and clinical data. The present study demonstrates that TNF-α −308 polymorphism appears to be associated with the genetic susceptibility U-SpA. The association seems independent of the susceptibility conferred by the HLA-B27 in this group of patients.