Association between PDCD1 gene polymorphisms and psoriasis susceptibility in the Chinese population

Background As an immune regulator expressed on the surface of activated T cells, programmed cell death 1 (PDCD1) plays an important role in psoriasis. However, whether PDCD1 genetic polymorphism is associated with psoriasis has yet to be explored. Objective To study the association between polymorphisms of the immune-related gene PDCD1 and psoriasis susceptibility in the Chinese population, to illustrate the genetic mechanism of psoriasis and provide new research ideas for the diagnosis and treatment of psoriasis (PS). Methods Overall, 128 psoriasis patients and 88 healthy controls were included in this study. Using polymerase chain reaction (PCR)-Sanger sequencing analysis, six PDCD1 single nucleotide polymorphisms (SNPs) were sequenced: PD1.1, PD1.3, PD1.4, PD1.5, PD1.6, and PD1.9. Results Among the six tested SNPs, PD1.6 showed a significant association with psoriasis in genotype and allele frequency distribution. The G allele of PD1.6 increased the risk of psoriasis (P = 0.03). In contrast, the other five SNPs failed to show association with psoriasis. Further analysis within the patient group showed that the frequency of the PD1.6 G allele was relatively high in severe psoriasis, but the difference was nonsignificant. Conclusion PDCD1 gene polymorphism is associated with psoriasis. The population carrying PD1.6 allele G are at a higher risk of developing psoriasis, though the severity of psoriasis does not correlate with PD1.6 polymorphism.