Cohen Frances, Kemeny Margaret E, Zegans Leonard S, Johnson Paul, Kearney Kathleen A, Stites Daniel P
Health Psychology Program, Department of Psychiatry, University of California San Francisco School of Medicine, 3333 California Street, Suite 465, San Francisco CA 94143-0848, USA.
Psychosom Med. 2007 Apr;69(3):225-34. doi: 10.1097/PSY.0b013e31803139a6. Epub 2007 Mar 30.
To examine the effect of unemployment on natural killer cell cytotoxicity (NKCC) and, in a subsample of persons who become re-employed, to determine if, after termination of the stressor, immune values recover to levels similar to matched controls.
One hundred unemployed and 100 matched employed healthy men and women, aged 29 to 45 years, were followed for 4 months with monthly blood samples taken to measure NKCC, the ability of NK cells to kill target cells. Twenty-five participants obtained employment before the end of the study, leaving 75 unemployed (and 75 employed) participants in the main sample. For unemployed participants who obtained employment before the end of the study, subsample analyses compared NKCC levels before and after obtaining a new job.
The persistently unemployed sample had significantly lower NKCC levels for all three effector:target ratios (100:1, p = .0004; 50:1, p = .002; and 25:1, p = .02) when compared with the matched employed sample. There were no significant gender effects. In the subsample analyses, NKCC was significantly higher after the participants became employed, compared with their unemployed period, with substantial "recovery" of immune function (44%-72%) compared with values from the steadily employed group.
Chronic stress is associated with persistent NKCC impairment. When the chronic stressor is terminated, however, the immune cell functional capacity quickly begins to recover. We believe this is the first study in humans to document immune function recovery after the definable end of a chronic stressor.
研究失业对自然杀伤细胞细胞毒性(NKCC)的影响,并在重新就业的子样本中,确定应激源终止后,免疫指标是否恢复到与匹配对照组相似的水平。
对100名失业和100名匹配的在职健康男女进行为期4个月的跟踪研究,每月采集血样以测量NKCC,即NK细胞杀伤靶细胞的能力。25名参与者在研究结束前获得了工作,主样本中剩下75名失业(和75名在职)参与者。对于在研究结束前获得工作的失业参与者,子样本分析比较了获得新工作前后的NKCC水平。
与匹配的在职样本相比,持续失业样本在所有三种效应细胞与靶细胞比例下(100:1,p = .0004;50:1,p = .002;25:1,p = .02)的NKCC水平均显著降低。不存在显著的性别效应。在子样本分析中,参与者就业后NKCC显著高于失业期间,与稳定就业组的值相比,免疫功能有大幅“恢复”(44%-72%)。
慢性应激与NKCC持续受损有关。然而,当慢性应激源终止时,免疫细胞功能能力迅速开始恢复。我们认为这是第一项在人类中记录慢性应激源明确结束后免疫功能恢复的研究。