Immune Cell Differences Must Be Considered in Epigenetic Age
Epigenetic age is commonly assessed through blood samples, focusing on the epigenetic markers of immune cells. However, mainstream epigenetic clocks may provide different ages for various immune cell populations, leading to variability in assessing the same individual. Understanding which cell populations contribute most to epigenetic age could impact interventions aimed at slowing or reversing aging. Despite the recognized challenge in current epigenetic clocks, consensus on how to address this issue remains elusive.
Aging is a significant risk factor for human disorders, and DNA methylation clocks are valuable tools for estimating biological age and predicting health outcomes. Recent DNA methylation clocks focus on methylation data from blood DNA. However, the influence of immune cell composition on epigenetic age acceleration (EAA) is not fully understood, as only some clocks consider cell type composition when analyzing EAA.
Our research investigates the impact of 12 immune cell types on EAA, as predicted by six widely-used DNA methylation clocks in a dataset of over 10,000 blood samples. We found significant associations between immune cell composition and EAA across all clocks tested. Certain cell types showed substantial associations with EAA, with memory lymphocyte subtypes linked to increased EAA and naïve lymphocyte subtypes linked to decreased EAA. These findings underscore the importance of considering immune cell composition in EAA studies.
Our study provides valuable insights into the contributions of immune cell types to EAA in blood samples, highlighting the need to account for immune cell composition in EAA studies. Understanding the relationship between EAA and immune profiles is crucial for interpreting epigenetic age in the context of aging and disease research.
Link: https://doi.org/10.1111/acel.14071
