Effects of aging on immune function and inflammatory biomarkers

To explore the clinical significance of multimodal plasma biomarkers and the alterations in their interrelationships within the immune microenvironment during aging.

A total of 83 elderly participants were included, all of whom were free from serious illnesses, fever, mental disorders, and severe hearing, speech, or comprehension impairments in the past two weeks. Based on the definition of "elder" by the World Health Organization (WHO) and the United Nations (UN), participants in this study were divided into three groups: the "Light-Old" (LO group, under 70 years), the "Moderate-Old" (MO group, 70-79 years), and the "Heavy-Old" (HO group, 80 years and above). This stratification aimed to explore the effect of different aging degrees. The samples were analyzed for coagulation markers, nerve damage markers, and metabolic markers. Basic demographic data, including height, weight, age, and gender, were also recorded.

Statistical analysis revealed significant differences among the 3 age groups in phosphorylated tau (P-Tau181, F=5.214, P=0.007) and white blood cells (WBC, F=3.278, P=0.044). Furthermore, interleukin-6, thrombin-antithrombin complex, thrombomodulin (TM), plasminogen-plasmin α1 complex (PIC), WBC, blood glucose (GLU), and P-Tau181 all showed an increasing trend with age. Gender-based analysis revealed significant differences in high-density lipoprotein (t=5.738, P<0.001), total cholesterol (t=2.530, P=0.013), and GLU (t=2.840, P=0.006). Spearman correlation analysis indicated a strong positive correlation between PIC and TM (correlation coefficient =0.65).

Aging significantly influences the clinical relevance of biomarkers, particularly for coagulation, inflammatory, and immune mechanisms. The reference ranges for various biomarkers in the elderly should be further refined to reflect their unique physiologic conditions.