Immune Cell Type-Specific DNA Methylation Regions Associate With 24-Hour Blood Pressure Regulation in Black People

DNA methylation and immune cells have been linked to blood pressure (BP) regulation and the development of hypertension. However, the immune cell profiles and the cell type-specific DNA methylation associated with BPs remain unclear.

This study evaluates the 19 cell type deconvolution algorithms using reduced representation bisulfite sequencing data, comparing them to in silico mixtures derived from whole-genome bisulfite sequencing. The top-performing algorithm, Epigenetic Dissection of Intra-Sample Heterogeneity (EpiDISH)-Robust Partial Correlations, was applied to 281 Black inpatients with 24-hour BP monitoring. The immune cell profiles and cell type-specific DNA methylation regions associated with these BP phenotypes were further investigated using regression analysis.

In patients with hypertension, B-cell and CD4 effector memory T-cell abundances were significantly elevated. Monocyte and CD8 effector memory T-cell fractions positively correlated with nighttime BP, and CD3 T cells were inversely associated with office BP. These associations remained robust after covariate adjustments and were partially validated in the Medical Information Mart for Intensive Care-IV cohort. For the first time, we identified several cell type-specific DNA methylation regions as being associated with BP phenotypes and patterns across 13 immune cells, with approximately one third predominantly found in effector CD8 T cells.

These findings provide novel insights into the epigenetically regulated immune mechanisms underlying BP regulation and identify potential targets for hypertension management.