Association of Cigarette Smoking with Decreased Numbers of Circulating Natural Killer Cells

Abstract

To investigate the relationship between cigarette smoking and the level of circulating natural killer (NK) cells, we studied 282 subjects from a population-based, stratified random sample of healthy persons. NK cells were enumerated by flow cytometry using the monoclonal antibody anti-Leu 11A. Cigarette smokers had a significantly lower proportion of NK cells than did subjects who had never smoked (5.5 +/- 0.3% versus 7.4 +/- 0.4% of lymphoid cells; p = 0.0002). NK cells were also decreased among ex-smokers (5.6 +/- 0.4%; p = 0.002), including subjects who had not smoked for more than 20 yr. The white blood cell and lymphocyte counts were increased in smokers compared with those in never smokers (p less than 0.0001). In contrast to NK cells, the smoking-related changes in leukocyte count were not present in ex-smokers, even those who had stopped smoking within the past year. Multivariate analysis confirmed that both current and past smokers had significant decreases in both the number and proportion of NK cells after controlling for age, sex, and lymphocyte count. These data indicate that cigarette smoking is associated with a decrease in the number and proportion of circulating NK cells, and that this effect is present many years after smoking cessation. This quantitative NK cell deficit may contribute to the elevated risk of malignancy in this population.

Enhancement of a Sense of Coherence and Natural Killer Cell Activity which Occurred in Subjects who Improved their Exercise Habits through Health Education in the Workplace

“…Furthermore, we have found a greater increase in NKCA in ex-smokers after health education than that in current smokers, although age distribution in the two groups was different. Tollerud and his associates 32) report that NK cells were also decreased among ex-smokers, including subjects who had not smoked for more than 20 yr. Many researches have demonstrated that smoking behavior contradicted with exercise habits [33][34][35] .…”

Colorectal cancer occurs earlier in those exposed to tobacco smoke: implications for screening

“…Animal experiments have shown that lower NK cell activity is associated with higher cancer incidence, while studies on NK cell activity on humans have found significantly lower NK activity among smokers compared to non-smokers (Ferson et al 1979;Ginns et al 1985;Phillips et al 1985;Talmadge et al 1980). Another study found that smoking decreased both the quantity and function of NK cells, and the quantity and function remained impaired after smoking cessation, while other white blood cell functions returned to normal (Tollerud et al 1989). Other research has linked lower initial NK cell activity to colorectal cancer recurrence and an advanced colorectal cancer stage at diagnosis (Tartter et al 1987).…”

An Occupational Health Study of Emergency Physicians in Japan: Health Assessment by Immune Variables (CD4, CD8, CD56, and NK Cell Activity) at the Beginning of Work

“…As for life style, it was reported that reduction of NK cell functions was associated with cigarette smoking [34][35][36][37][38] , shortened daily sleep 17) , disturbed sleep [39][40][41] , circadian rhythm (high activity in the morning and low activity at night) [42][43][44][45] , and excessive physical exercise 46,47) . Conversely, healthy life styles (i.e., good sleep, adequate physical exercise, and so on) were associated with increases of NK cell functions [48][49][50] .…”