Age‐related increase of CD45RO+ lymphocytes in physically active adults

The CD45RO phenotype of peripheral blood CD4 + and CD8 + lymphocytes were determined in physically active males (n=171) and females (n=70) ranging in age from 15-68 years. Direct immunofluorescence and dual color flow cytometry was performed for analysis. Absolute cell numbers (r=0.473) and percentages of CD4 + CD45RO + (r=0.648) within the CD4 + population, percentage of CD8 + CD45RO + cells within the CD8 + lymphocytes (r=0.498) and total lymphocyte number (r=-0.242) correlated significantly (p<0.001) with age. We conclude that the age-related increase of CD45RO + T cells indicates a gradual increase of activated T cells