R. Meehan et al., THE ROLE OF PSYCHONEUROENDOCRINE FACTORS ON SPACEFLIGHT-INDUCED IMMUNOLOGICAL ALTERATIONS, Journal of leukocyte biology, 54(3), 1993, pp. 236-244
This paper summarizes previous in-flight infections and novel conditio
ns of spaceflight that may suppress immune function. Granulocytosis, m
onocytosis, and lymphopenia are routinely observed following short dur
ation orbital flights. Subtle changes within the monocyte and T cell p
opulations can also be noted by flow cytometric analysis. The similari
ty between the immunological changes observed after spaceflight and ot
her diverse environmental stressors suggest that most of these alterat
ions may be neuroendocrine-mediated. Available data support the hypoth
esis that spaceflight and other environmental stressors modulate norma
l immune regulation via stress hormones, other than exclusively glucoc
orticoids. It will be essential to simultaneously collect in-flight en
docrine, immunologic, and infectious illness data to determine the cli
nical significance of these results. Additional research that delineat
es the neuroendocrine mechanisms of stress-induced changes in normal i
mmune regulation will allow clinicians in the future to initiate proph
ylactic immunomodulator therapy to restore immune competence altered b
y the stress of long-duration spaceflight and therefore reduce morbidi
ty from infectious illness, autoimmune disease, or malignancy.