Exploring Hematology in Space: Blood Behavior and Health Risks

### Exploring Hematology in Space: Blood Behavior and Health Risks

**Milan, Italy – June 14, 2025** – As commercial space travel gains momentum, understanding the effects of low gravity on human physiology, particularly hematology, becomes increasingly critical. Recent discussions at the 2025 European Hematology Association (EHA) Congress highlighted significant alterations in blood cell behavior during spaceflight, with implications for astronaut health and future commercial travelers.

Dr. Joseph Borg, a researcher at NASA GeneLab and the University of Malta, emphasized that space presents unique challenges for medical science. "Space has a lot to offer, even in the context of medical and health sciences," said Borg, who collaborates with Space Applications Services to send experiments, including blood samples, to space for analysis. This research is essential as commercial flights into space are projected to increase significantly over the next decade.

#### Understanding Hemoglobin Function in Space

Astronauts often develop anemia during extended missions, but the mechanisms behind this phenomenon remain largely unexplored. According to Borg, NASA's twin astronaut study, which examined physiological differences between an astronaut in space and his twin on Earth, revealed important insights. Preliminary findings indicate that gene expression regulating hemoglobin shifts significantly in space, with a repression of adult globin genes and an increase in fetal globin production. Borg stated, "This shift in erythropoiesis suggests a primitive-type response characterized by overexpressing embryonic and fetal globins" (Borg, et al., 2024).

#### Coagulation Disorders and Low Gravity Risks

Dr. Roopen Arya of King’s College London elaborated on the increased risk of coagulation disorders arising from low gravity conditions, which can lead to conditions like venous thromboembolism. Arya referred to a 2019 report detailing an astronaut's internal jugular vein thrombosis as a catalyst for heightened focus on preventive measures during space flights. "Understanding the mechanisms behind these coagulation disorders is essential, especially as the demographic of space travelers broadens to include older individuals with pre-existing health conditions," Arya stated. He advocates for personalized medical approaches to mitigate these risks, noting that protocols must account for the unique challenges posed by space travel (Marshall-Goebel et al., 2019).

#### Immune Responses in Space

In addition to hematological changes, space travel affects immune function. Dr. Judith-Irina Buchheim from Ludwig-Maximilians-Universität in Munich discussed how astronauts often experience immune-related health issues, including skin infections and reactivation of dormant viruses. Her research indicates a rise in both pro- and anti-inflammatory cytokines, leading to what she terms "transient signs of inflammaging," a combination of inflammation and immune aging. Buchheim noted that these immune shifts only partially resolve upon return to Earth, emphasizing the need for functional immune testing prior to space missions to tailor countermeasures effectively (Buchheim et al., 2019).

### Implications for Future Space Exploration

The insights gained from these studies underscore the necessity for continued research into the health impacts of space travel, particularly as missions extend to destinations like the Moon and Mars. With commercial space tourism on the rise, the health profiles of travelers will likely differ from those of conventional astronauts, necessitating adaptive medical protocols.

"As we look towards long-term missions, we must be prepared to address a myriad of health challenges, from muscle atrophy to exposure to space radiation," Buchheim urged, calling for a collaborative approach to developing research projects that can further elucidate these complex issues.

The ongoing research in space hematology not only enhances our understanding of human biology in extreme conditions but also sets the groundwork for safer and more effective health measures for future space voyagers. As the field of space medicine continues to evolve, the integration of personalized medicine may offer promising avenues for ensuring the health and safety of astronauts and commercial travelers alike.

### References 1. Borg, J., Loy, C., Kim, J., et al. (2024). Spatiotemporal expression and control of haemoglobin in space. *Nature Communications*, 15(1), 4927. doi:10.1038/s41467-024-49289-8. 2. Marshall-Goebel, K., Laurie, S.S., Alferova, I.V., et al. (2019). Assessment of jugular venous blood flow stasis and thrombosis during spaceflight. *JAMA Network Open*, 2(11): e1915011. doi:10.1001/jamanetworkopen.2019.15011. 3. Buchheim, J.I., Matzel, S., Rykova, M., et al. (2019). Stress related shift toward inflammaging in cosmonauts after long-duration space flight. *Frontiers in Physiology*, 10: 85. doi:10.3389/fphys.2019.00085.