Journal of

A B S T R A C T
Background and Objectives
This study aimed to evaluate the impact of a single session of high-intensity interval training (HIIT) on hematopoietic stem cell (HSC) mobilization and on the expression of genes regulating HSC homing (SCF and CXCL12) in autologous stem cell transplantation candidates.
Materials and Methods
This study is a quasi-experimental applied research in which 20 patients with Hodgkin’s or non-Hodgkin’s lymphoma were matched based on age, sex, body mass index, and physical fitness status and allocated into two control (n=10) and HIIT (n=10) groups. The HIIT group completed a protocol of 12×1-minute intervals at 100% VO₂peak, six hours after receiving the last dose of granulocyte colony-stimulating factor (G-CSF). The control group remained seated without performing any exercise. Peripheral Blood sampling was performed in both groups before and immediately after the intervention, and apheresis samples were also taken immediately after the intervention. Peripheral blood samples were analyzed for white blood cells (WBCs), CD34+ cells, and subpopulations CD34+/CD38− and CD34+/CD110+ without significant time delay in less than 24 hours with proper storage conditions at 4 degrees, by flow cytometry, and for SCF and CXCL12 gene expression by qRT-PCR. Apheresis products were also examined.
Results
After HIIT, the mean CD34+ cell count increased from 40.86±12.89 to 58.21±16.15 and white blood cell (WBC) count increased from 35.35±3.87 to 41.61±5.1, while the changes in the control group were small. HIIT training significantly increased the number of WBC, CD34+ cells and CD34+/CD110+ subset in peripheral blood with a significant effect size (p< 0.05) (d~1-1.4). However, this increase was not observed in apheresis yield. Also, no significant changes were observed in the expression of SCF and CXCL-12 genes after training and no significant correlation was observed between the expression of these genes and stem cell count.
Conclusions  
HIIT may serve as a transient, noninvasive adjunct to enhance HSC mobilization in peripheral blood following G-CSF administration. Nevertheless, its effects are temporary and do not augment apheresis yield, suggesting that the timing of exercise relative to apheresis is critical. The molecular mechanisms underlying HSC mobilization appear to operate independently of changes in SCF and CXCL12 expression.