Programmed death-1 gene polymorphisms in patients with systemic lupus erythematosus in Taiwan.

To investigate the role of programmed cell death-1 (PD-1) gene polymorphisms in the development of systemic lupus erythematosus (SLE) in Taiwan, 109 patients with SLE and 100 healthy controls were enrolled in this study. The PD-1 gene polymorphisms were determined by the method of polymerase chain reaction/restriction fragment length polymorphism. This study showed that the genotype distributions of PD-1 7209 C/T polymorphisms were significantly different between the patients with SLE and controls (P=0.002, Pc=0.018). The frequencies of the PD-1 7209 C/C genotype and PD-1 7209 C allele were significantly higher in the patients with SLE than those of the controls (P=0.001, OR=2.6, 95% CI=1.5-4.6, and P=0.002, OR=2.1, 95% CI=1.3-3.4, Pc=0.018, respectively). Moreover, the association of PD-1 7209 C with susceptibility to SLE was independent of the PD-1 ligand. This study also showed that the PD-1-536 A 7146 G 7209 C 7499 G haplotype was associated with the development of SLE in Taiwan.