Biomarkers for Immunosenescence
The aging immune system exhibits a declining ability to destroy pathogens and dysfunctional, harmful cells. This is known as immunosenescence. There are ways to assess immune cell populations and their characteristics to measure the degree of immunosenescence, but this is comparatively costly and cannot be used on banked samples. Researchers here ask whether combinations of circulating proteins can instead be used to assess the degree of immunosenescence from a blood sample, and propose a few such biomarkers based on their analysis.
Inflammaging, the characteristics of immunosenescence, is characterized by continuous chronic inflammation that could not be resolved. It not only affects older people but can also occur in young individuals, especially those suffering from chronic inflammatory conditions such as autoimmune disease, malignancy, or chronic infection. This condition led to altered immune function and as consequent immune function is reduced. Detection of immunosenescence has been done by examining the immune risk profile (IRP), which uses flow cytometry. These tests are not always available in health facilities, especially in developing countries and require fresh whole blood samples. Therefore, it is necessary to find biomarkers that can be tested using stored serum to make it easier to refer to the examination.
Here we proposed an insight for soluble biomarkers which represented immune cells activities and exhaustion, namely sCD163, sCD28, sCD80, and sCTLA-4. Those markers were reported to be elevated in chronic diseases that caused early aging and easily detected from serum samples using ELISA method, unlike IRP. Therefore, we conclude that these soluble markers are beneficial to predict the pathological condition of immunosenescence.