Increased activation of blood neutrophils after cigarette smoking in young individuals susceptible to COPD

Susan JM Hoonhorst, Wim Timens, Leo Koenderman, Adèle T Lo Tam Loi, Jan-Willem J Lammers, H Marike Boezen, Antoon JM van Oosterhout, Dirkje S Postma, Nick HT ten Hacken

BackgroundCigarette smoking is the most important risk factor for Chronic Obstructive Pulmonary Disease (COPD). Only a subgroup of smokers develops COPD and it is unclear why these individuals are more susceptible to the detrimental effects of cigarette smoking. The risk to develop COPD is known to be higher in individuals with familial aggregation of COPD. This study aimed to investigate if acute systemic and local immune responses to cigarette smoke differentiate between individuals susceptible or non-susceptible to develop COPD, both at young (18-40 years) and old (40-75 years) age.MethodsAll participants smoked three cigarettes in one hour. Changes in inflammatory markers in peripheral blood (at 0 and 3 hours) and in bronchial biopsies (at 0 and 24 hours) were investigated. Acute effects of smoking were analyzed within and between susceptible and non-susceptible individuals, and by multiple regression analysis.ResultsYoung susceptible individuals showed significantly higher increases in the expression of Fc¿RII (CD32) in its active form on neutrophils after smoking (p¿=¿0.016 and 0.028 respectively), independently of age, smoking status and expression of the respective markers at baseline. Smoking had no significant effect on mediators in blood or inflammatory cell counts in bronchial biopsies. In the old group, acute effects of smoking were comparable between healthy controls and COPD patients.ConclusionsWe show for the first time that COPD susceptibility at young age associates with an increased systemic innate immune response to cigarette smoking. This suggests a role of systemic inflammation in the early induction phase of COPD.Trial registrationClinicaltrials.gov: NCT00807469.