In vivo testing confirms a blunting of the human cell-mediated immune mechanism during space flight

• Published in: Journal of leukocyte biology Vol. 51; no. 2; pp. 129 - 132
• Main Authors: Taylor, G. R., Janney, R. P.
• Format: Journal Article
• Language: English
• Published: Legacy CDMS Society for Leukocyte Biology 01.02.1992; Federation of American Societies for Experimental Biology
• Subjects: Aerospace Medicine; Applied physiology; Biological and medical sciences; delayed‐type hypersensitivity; Human physiology applied to population studies and life conditions. Human ecophysiology; Humans; Hypersensitivity, Delayed; Immunity, Cellular; immunosuppression; Leukocyte Count; Medical sciences; Multitest CMI; skin testing; space flight; Space life sciences; Time Factors; Transports. Aerospace. Diving. Altitude; Human; In vivo; Immune response; Immunomodulation; Delayed hypersensitivity; Cellular immunity; Space flight; Skin test; NASA Center JSC; NASA Discipline Regulatory Physiology
• ISSN: 0741-5400; 1938-3673
• DOI: 10.1002/jlb.51.2.129

The cell-mediated immune (CMI) mechanism was evaluated in 10 space shuttle astronauts by measuring their delayed-type hypersensitivity response to seven common recall antigens. The Multitest CMI test system was used to administer antigens of tetanus, diphtheria, Streptococcus, Proteus, old tuberculin, Candida, and Trichophyton to the forearm 46 h before nominal mission termination; readings were conducted 2 h after landing. The mean number of reactions was reduced from 4.5 preflight to 3.0 inflight, and the mean reaction score was reduced from 21.4 to 13.7 mm inflight. The data presented suggest that the CMI system is still being degraded by space flight conditions on day 4 and that between day 5 and day 10, the depression maximizes and the system begins to adjust to the new conditions. The relation of these in vivo findings to previously reported in vitro results is discussed.