Whole-genome methylation profiling of peripheral blood mononuclear cell for acute exacerbations of chronic obstructive pulmonary disease treated with corticosteroid

OBJECTIVE: Although association studies in the general population may be relevant for determining susceptibility to chronic obstructive pulmonary disease (COPD), they may be less applicable for pharmacogenetics research in participants who have already acquired the disease. PATIENTS AND METHODS: A genome-wide methylation profiling (generated by HumanMethylation450 BeadChips study was performed on peripheral blood mononuclear cells of 24 patients with AECOPD (acute exacerbation COPD), with good and poor responsiveness to standard corticosteroid treatment. Pyrosequencing was used to replicate the selected CpG sites in 50 patients with AECOPD with standard corticosteroid treatment. RESULTS: The results showed the patients with AECOPD with good and poor response to standard corticosteroid treatment have a distinct DNA methylation pattern. A total of 23 CpG loci located in 19 known gene regions, including gene-body and promoter, appeared to be significantly differentially methylated. Replication by pyrosequencing revealed that one CpG site in PSMD8 showed the same trend of differential methylation and reached to statistical significance as the microarray result. CONCLUSION: Our preliminary findings provide evidence for molecular heterogeneity in patients with AECOPD, which may contribute to significant differences in their response to COPD treatment.