Evaluation of PD-1 Gene Expression Profile and Methylation of the Regulatory Regions in Patients with Ankylosing Spondylitis.

The low level of PD-1 gene expression is implicated in the pathogenesis of AS. However, in both groups, the methylation level of the intron 1 CpG islands of the PD-1 gene suggests that other regulatory mechanisms are more relevant to PD-1 gene expression than methylation in the intron.