Effects of a Low Versus Moderate-High Intense Exercise Program on Innate Immune Recovery, Fitness, and Quality of...

Pediatric cancer patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) are severely immunosuppressed leading to a high risk for life-threatening infections. This trial investigates the effects of exercise during allo-HSCT on immune cell recovery and patient-related outcomes (DRKS00019865).

Twenty-two pediatric cancer patients (≥4 years) undergoing allo-HSCT were randomized into an intervention group with moderate to high intensity training (IG^high) and an intervention group with low intensity training (IG^low). Supervised and individualized exercise sessions were scheduled three to five times per week during hospitalization. The primary outcome was the quantity of NK cells 30 days after HSCT. Further, feasibility and safety of the intervention, physical fitness, fatigue, quality of life (QoL), transplant-related metrics, and clinical data were assessed.

At Day +30, the median NK cell count was more than twice as high in the IG^high compared to the IG^low (n.s., 208.45/µL vs. 99.12/µL). Subset analysis revealed that CD16⁺ CD56^dim NK cells and NKp44⁺ CD56^dim NK cells were higher in the IG^high on Day +30 (p = 0.043 and p = 0.061, respectively). In contrast, the IG^low exhibited higher levels of NKp44^- circulating innate lymphoid cells (cILC3) on Day +15 (p = 0.045). As expected, the IG^high showed significant increases in leg strength compared to the IG^low. All participants experienced a decline in QoL and fatigue.

This pilot study implied a trend toward improved immune recovery with moderate to vigorous exercise. Importantly, both programs were safe and feasible. The higher intensity intervention showed significant benefits on leg strength and specific innate immune cell populations, but these findings must be considered preliminary in the context of the exploratory nature of the study.