Correlation analyses between age and indices in routine blood laboratory tests suggest potential aging biomarkers

Background: Aging, especially its related immune senescence, is an important risk factor for many diseases, including neurodegenerative diseases, cardiovascular diseases and tumors. One major hurdle to study aging is the lack of a comprehensive set of biomarkers to evaluate and predict the progress of aging. The biomarkers for immune senescence are crucial for effective vaccination and optimal immunotherapy. Methods: In this study, to identify potential biomarkers linked to aging from routine blood laboratory tests, we analyzed the correlations between aging and indices in peripheral blood cell population, cytokines, Complete Blood Count and Blood Chemistry panel. Furthermore, we analyzed the differences of immune cells and inflammatory cytokines among different age groups. In addition, differential gene expression was evaluated by using whole transcriptome data of 258 samples, which was subsequently used for pathway analysis. Results: Our results showed significant correlations between some of the indices with aging, and some were also associated with genders and ethnics. Transitional B Cells were negatively correlated with aging, and several cytokines, including CCL22, CXCL9, IL21, IL23A and IL31, were related to aging as well. In addition, we found several genes associated with aging, including SERPINA1 , ORM2 , MS4A1 , ETS1 , CD27 and IL7R . Conclusions: Our study demonstrated that changes of a couple of indices from routine blood laboratory tests and gene expression had correlation to aging, and these could potentially be used as biomarkers of aging.