Medically reviewed by Dr. Brian Koffman
The Bottom Line:
Exercise increases the number of immune cells in the blood and increases the ability of rituximab to kill CLL cells.
Who Performed the Research and Where Was it Presented:
Dr. Harrison Collier-Bain from the University of Bath and colleagues presented the results at the American Society for Hematology (ASH) Annual Meeting 2023.
Background:
In the scientific literature, it is well established that a single bout of exercise can increase the number of immune cells in the bloodstream, particularly natural killer cells. Natural killer cells are a type of immune cell necessary for an antibody-dependent cellular cytotoxicity (ADCC) process. In ADCC, a target cell is coated with antibodies; the natural killer cells recognize and bind to the antibodies, and then they release substances that kill the target cell. Rituximab is a monoclonal antibody that recognizes the CD20 protein on the surface of B cells and works through this mechanism. Rituximab binds to the CD20 protein on the surface of chronic lymphocytic leukemia (CLL) and small lymphocytic lymphoma (SLL) cells. Natural killer cells then bind to the rituximab-CD20 complex on the surface of the CLL cells and release compounds to kill the cells. For this study, researchers wanted to know if exercise could enhance the efficacy of rituximab through this mechanism.
Methods and Participants:
Patients with treatment-naïve CLL cycled at moderate intensity for 30 minutes and had blood samples taken before and after exercising. Researchers isolated natural killer cells and CLL cells from the blood samples. The natural killer cells and CLL cells were incubated together in the lab with or without the addition of rituximab.
Results:
- This pilot study enrolled 20 treatment-naïve patients with CLL with a mean age of 62 years.
- The single exercise session significantly increased natural killer cells in the blood by over 300%.
- When the cells were studied in the lab, rituximab-mediated breakdown of CLL cells increased by 129% following exercise.
- Exercise also increased the number of CD20-expressing CLL cells in the blood, which were likely mobilized from different body tissues.
Conclusions:
A single exercise session increased the ability of rituximab to kill CLL cells through ADCC in the lab. Exercise also transiently increased the number of natural killer and CLL cells in the blood, making it more likely that these cells would interact in the presence of rituximab. Future research is planned to see if exercise improves clinical responses in patients with CLL being treated with anti-CD20 monoclonal antibodies (rituximab, obinutuzumab).
Links and Resources:
Watch the interview on the abstract here:
You can read the actual ASH abstract here: A Single Bout of Exercise Enhances the Efficacy of Rituximab Against Autologous Chronic Lymphocytic Leukaemia B Cells Ex Vivo By Transiently Increasing Natural Killer Cell Frequency in Blood, and Simultaneously Mobilises CD5 +CD19 +CD20 + B Cells into Blood.
Take care of yourself first.
Ann Liu, PhD
