BLOOD EOSINOPHIL AND MONOCYTE COUNTS ARE RELATED TO SMOKING AND LUNG-FUNCTION

The aim of this study was to investigate the predictive value of perip heral eosinophil and monocyte blood counts regarding lung function in smokers and non-smokers, and to investigate the influence of smoking o n these cell counts. Forced expiratory volume in 1s (FEV1) measurement s and blood samples were collected from 298 non-atopic smokers and 136 never-smokers. Blood samples were repeated in 160 smokers after cessa tion of smoking (quitters) and 30 continuing smokers, 2, 6, 12 and 26 weeks after smoking cessation. Monocyte (P<0.05) but not eosinophil bl ood counts were higher in never-smokers compared to smokers. In never- smokers, blood eosinophil counts and monocyte counts correlated invers ely (P<0.05) and directly (P<0.01), respectively, with standardized FE V1 residuals (FEVR). In smokers, blood eosinophil (P<0.05) and monocyt e (P<0.05) counts correlated directly with FEVR independent of smoking history. After smoking cessation, monocyte blood counts (P<0.05) incr eased. Both eosinophil and monocyte blood counts showed a greater incr ease in quitters with decreased lung function (P<0.05). Former heavy s mokers had higher blood eosinophil (P<0.05) but lower monocyte (P<0.05 ) count increase than had former light smokers. These data suggest tha t smoking influences eosinophil and monocyte blood counts and that thi s is associated with a small negative effect on lung function. Eosinop hil blood counts had an opposite relation to lung function in smokers and non-smokers. Further research should include investigations of rel ations between smoking and stimulatory factors for recruitment and act ivity of eosinophils and monocytes.