Telomere length dynamics and telomerase activity in human peripheral blood lymphocytes

The progressive shortening of telomeres the protective nucleoprotein caps at chromosome ends is one of the most consistent molecular markers of human aging, yet the pace and pattern of this shortening vary substantially across lymphocyte subsets. This research measured telomere(definition) length and telomerase activity in sorted peripheral blood lymphocyte populations from 144 healthy Saudi Arabian adults aged 20-78 years. Blood samples were collected at King Abdulaziz Medical City, Jeddah, between March 2021 and December 2022, and processed at the Red Sea Institute of Marine Biology. Telomere length was assessed by quantitative fluorescence in situ hybridization (Q-FISH) on metaphase spreads, while telomerase activity was measured using the telomeric repeat amplification protocol (TRAP) assay. CD8+ T cells showed the fastest rate of telomere attrition with age, losing an average of 68 base pairs per year (R² = 0.74, p