Shorter Donor Leukocyte Telomere Length is Associated with Poor Peripheral Blood Stem Cell Mobilization Induced by Granulocyte Colony-Stimulating Factor

Background/purpose Insufficient numbers of peripheral blood stem cells (PBSC) after granulocyte colony-stimulating factor (G-CSF) mobilization occurs in a significant proportion of PBSC collections, often from older age donors. Telomere length (TL) is often used as an indicator of an individual's biological age. This study aimed to investigate the relationship between donors' leukocyte TL and the outcome of G–CSF–induced PBSC mobilization in healthy unrelated donors. Methods Donors’ leukocyte TLs and the outcome of G–CSF–induced PBSC mobilization, as assessed by pre-harvest CD34+ cell counts, were analyzed in 39 healthy PBSC donors. TL in a non-mobilized general population (n = 90) was included as a control group. G-CSF mobilization effect was categorized into three groups according to pre-harvest CD34+ cell count: poor (≤25/μL, PMD), intermediate (between 25 and 180/μL), and good (≥180/μl, GMD). Results Leukocyte TL of PBSC donors correlated well with pre-harvest CD34+ cell counts (r = 0.645, p < 0.001). Leukocyte TLs of PMDs (n = 8) were significantly shorter than those of GMDs (n = 9) and non-mobilization controls (p < 0.05). Moreover, all PMD TLs were below the 50th percentile, and 62.5% of PMDs had TLs below the 10th percentile of age-matched control participants. In contrast, no GMD TLs were below the 10th percentile; in fact, 33.3% (3/9) of them were above the 90th percentile. Conclusion Our results indicate that shorter donor leukocyte TL is associated with poor G–CSF–induced PBSC mobilization. TL, which represents a donor's biological age, could be a potential predictor for mobilization outcome.