PT  - JOURNAL ARTICLE
AU  - Andersson, Anders
AU  - Bossios, Apostolos
AU  - Malmhäll, Carina
AU  - Sjöstrand, Margareta
AU  - Houltz, Birgitta
AU  - Qvarfordt, Ingemar
AU  - Lindén, Anders
TI  - The impact of long-term tobacco smoking on circulating IL-16<sup>+</sup> NK cells
DP  - 2012 Sep 01
TA  - European Respiratory Journal
PG  - P786
VI  - 40
IP  - Suppl 56
4099  - https://publications.ersnet.org//content/40/Suppl_56/P786.short
4100  - https://publications.ersnet.org//content/40/Suppl_56/P786.full
SO  - Eur Respir J2012 Sep 01; 40
AB  - Natural killer (NK) cells constitute a first line of anti-viral host defence and tobacco smoke may cause reduced cytotoxicity. Among the cytokines expressed in NK cells, interleukin-16 (IL-16) is of interest since it is known that the extracellular concentrations of this CD4 cell chemoattractant are increased in the airways of long-term smokers. Here, we investigated whether long-term smoking alters the number and IL-16 content of circulating NK cells.Never-smokers (NS) and asymptomatic smokers (AS) with a normal ventilatory capacity plus a normal diffusion capacity for carbon monoxide (DLCO) were included. We also examined smokers with COPD (GOLD stages 2 & 3) with reduced DLCO (>2SD from the predicted mean). In each subject, a peripheral, venous blood sample was taken during clinically stable conditions for flow cytometry analysis of intracellular IL-16 in NK cells (IL-16+ NK cells; IL-16+CD3-CD16+CD56+). The relative and absolute number of NK cells (CD3-CD16+CD56+) was determined.Smokers (AS and COPD) exhibited a lower relative number of IL-16+ NK cells compared to NS (Mann-Whitney U test, p<0.05). In line with this, the absolute number of IL-16+ NK cells tended to be lower in smokers as well, although this trend was not statistically significant. Among smokers, there was a negative and statistically significant correlation for both the absolute and relative numbers of NK cells, on the one hand, and tobacco load (ie. pack-years; Spearmen Rank Corr. test; p<0.05; rho=-0.056 for both correlations) on the other.Our study indicates that long-term smoking exerts a negative impact on circulating NK cells, in terms of number and IL-16 content. Hypothetically, this impact may impair anti-viral host-defence.