Stressin and natural killer cell activity in professional soldiers.

Chronic stress causes multiple biochemical and physiological changes in the human organism. Recently we have identified stressin, a human serum glycoprotein that was significantly increased in sera of prisoners released from Serbian concentration camps. To eliminate malnutrition and maltreatment as possible causes for the increased stressin concentration, we have analyzed stressin in sera of 40 professional soldiers after involvement in major military activity and compared it to stressin in sera of 20 control individuals. As expected, the sera of professional soldiers contained more than 2.2 times higher concentrations of stressin than control sera. It is interesting that, contrary to expectations, the natural killer cell activity of professional soldiers was normal or even increased. We hypothesize that this might be an effect of winning the war that could have, at least temporarily, erased the immunosuppressive effects of stress.