['Antinuclear antibodies (ANA) are a common feature of autoimmune diseases such as rheumatoid arthritis (RA). Herein, we investigate the relationship between ANA and polymorphism in the tumour necrosis factor receptor (TNFR) genes.', 'Serum titers of ANA at diagnosis were measured in 267 patients with RA and a single nucleotide polymorphism (SNP) in each of the TNFR-I (36A/G) and TNFR-II (676T/G) genes was genotyped by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis. Circulating levels of soluble TNFR (sTNFR) and TNF-α were also measured in some patients.', 'Our initial analyses revealed the presence of ANA was associated with the TNFR-I 36A/G SNP, with a trend of increasing ANA frequency with G allele dosage (p=0.004). ANA status was also associated with lower sTNFR-I levels and a raised sTNFR-II/sTNFR-I ratio. The TNFR-II 676T/G SNP and circulating levels of sTNFR-II and TNF-α were not associated with ANA status. In an adjusted multivariate regression model the TNFR-I 36 GG genotype (OR 7.8, p=0.008) and levels of sTNFR-I (p=0.018) were independently associated with ANA status.'] Are antinuclear antibodies associated with tumor necrosis factor receptor I gene polymorphism in patients with rheumatoid arthritis?