Association of the programmed cell death 1 (PDCD1) gene polymorphism with ankylosing spondylitis in the Korean population

Abstract

The PD-1 (programmed death 1) molecule is a negative regulator of T cells. PDCD1 (programmed cell death 1) has been reported to have a genetic association in systemic lupus erythematosus and rheumatoid arthritis in Caucasians. However, there are no reports on the association between this gene and ankylosing spondylitis (AS). The present study investigated the association of the PD-1 polymorphisms and the haplotypes with AS in a Korean population sample. In a case-control association study, two single-nucleotide polymorphisms, PD-1.5 C/T and PD-1.9 T/C, were genotyped in 95 AS patients and 130 healthy controls. The T allele of the PD-1.9 polymorphism was more frequent in the Korean male population with AS than in the Korean male controls (21.0% versus 6.9%, odds ratio 1.89, 95% confidence interval 1.483 to 2.408). The frequency of the CT haplotype (PD-1.5 C/T and PD-1.9 T/C) was higher in the AS patients (19%) than the controls (5.4%) (odds ratio 1.83, 95% confidence interval 1.559 to 2.521). The PD-1 polymorphism was demonstrated in Korean AS patients. The results suggest a genetic association between the PD-1 polymorphism and susceptibility to AS.

Figure 1

Gel electrophoresis patterns of PD-1.5 and PD-1.9. (a) The amplified fragments of PD-1.5 were digested with Alu I: the polymerase chain reaction (PCR) product size was 333 base pairs (bp), which was digested to 264 and 69 bp. If the product was digested, the allele was identified as T; if not, it was identified as C. (b) The amplified fragments of PD-1.9 were digested with Bpu 10I: the PCR product size was 408 bp, which was digested to 260 and 145 bp. If the product was digested, the allele was identified as C; if not, it was identified as T.