Cell mediated immunity in Antarctic wintering personnel; 1984-1992.

Cell-mediated immune responses were studied in 12 Antarctic and sub-Antarctic wintering groups at quarterly intervals over the period 1984-1992, using the cutaneous CMI Multitest. These populations are among the most isolated on earth. While the sub-Antarctic population at Macquarie Island had levels of responsiveness and hypoergy (9%) comparable to healthy populations in temperate zones, the Antarctic Continental group showed a level of hypoergy of 36%. There was no seasonal variation in the pattern of responses. It is concluded that the extreme and isolated environment and stress factors are responsible for the decreased immunological responsiveness but the mechanisms are presently unclear. On review, one factor appears to be perceived anxiety. The high rate of hypoergy in Antarctica, where medical care is limited, may have health implications. These groups provide an excellent analogue for immunological investigations in longer term space flight.