A new study found that living in space may take a toll on humans' immune systems.
Almost nothing is known about the persistence of changes in the immune systems of astronauts during long-term space flights. For the said research, the scientists aimed to examine the changes that will transpire in the immune systems of astronauts, who are set to participate in a space mission aboard the International Space Station (ISS) that will last for six months.
The researchers conducted the study by extracting blood samples prior, during and post the space mission of 23 astronauts. The specimens collected during the flight were immediately returned back to Earth after 48 hours for analysis. The diagnostic tests performed include T-cell function, peripheral distribution of white blood cells (WBC), immunity to specific viruses and mitogen-stimulated cytokine production profiles.
The findings of the study, published in the journal NPJ Microgravity, show that the WBC count, which is the protective component of the immune system against infections and diseases, are elevated. The function of the T-cells, which a type of WBC, were found to have decreased throughout the 6-month mission. Other study results also exhibited various alterations during and after the flight.
Staying in space somehow diminishes the function of the immune system, says Brian Crucian from NASA Johnson Space Center, where he works as an immunologist. This then makes the body susceptible to allergies, infections and hypersensitivities. Examples of possible conditions that may typically be associated with the alterations of the immune system include impaired wound healing, autoimmune system problems and reactivation of previous viruses such as herpes.
The reason for the study results have not been clearly determined and that it is quite challenging to identify a specific, primary cause. Nonetheless, the study stated possible factors that may trigger the immune system functionality to change; these include impaired sleeping patterns, confinement and physiological stresses - all of which are linked to space flight missions. The combination of these factors, among many others may be working together to alter the immune system.
In the end, the authors concluded that immune modification may continue to occur during long-term space flights. If these events will not be countered by appropriate interventions, these may increase the risk of space crew members to develop clinical problems, especially during deep space missions.
Although the results of the study will not halt future space missions, these may still serve as essential reminders that should be considered when planning spaceflights, alongside other protective measures being deliberated prior to missions.
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