The assessment of crew immunocompetence was required for the determination of space flight infectious disease risk. This is of significant importance for longer duration missions and particularly, orbital station environments.
Data was collected from 54 crewmembers during six shuttle flights. White blood cells were collected after removal of the serum for use in the nominal Medical Operations physical. These cells were resuspended in isotonic saline and divided into two aliquots. One sample was used for flow cytometric analysis to determine cellular subpopulations and the other was further processed for functional assay of different immune cells (neutrophils, monocytes, and T-cells).
Flow cytometric analysis indicates that crewmembers exhibited a statistically significant decrease in total T cells with alterations in specific T cell subsets. In addition, a statistically significant increase in B cells as well as variable alterations in circulating monocytes was observed.
Neutrophil Functional Testing
Neutrophils exhibited a variable effect following space flight in response to a chemotactic factor.