Spirometric Abnormalities in Young Smokers Correlate with Increased Chemiluminescence Responses of Activated Blood Phagocytes

Abstract Spirometric values determined from the flow-volume loops of 60 healthy young smokers (mean age, 28 ± 0.6 yr) were correlated with measurements of the release of extracellular and intracellular reactive oxidants (RO) as determined by luminol-enhanced chemiluminescence (LECL) from peripheral blood activated with the synthetic chemotactic tripeptide FMLP combined with cytochalasin B (CB). Fractionation and reconstitution experiments revealed that LECL originated predominantly from polymorphonuclear leukocytes (PMNL). Circulating total leukocyte counts and serum thiocyanate levels were also determined. The data were analyzed using Spearman's correlation coefficient and by multiple regression analysis. Cigarette smoking was associated with elevated intracellular and especially extracellular LECL responses, the latter being strongly correlated (p 0.0001) with cigarettes smoked per day, serum thiocyanate levels, circulating leukocytes, and PMNL counts. Abnormalities of the spirometric parameters FEV1/FVC1 FEF50/FVC, FEF25, FEF25–75, and FEF75–85 correlated best with extracellular LECL (p 0.0002 to p 0.0001), but also with packyears (p 0.006 to p 0.0001), cigarettes smoked per day (p 0.008 to p 0.0002), thiocyanate levels (p 0.04 to p 0.002) and leukocyte counts (p 0.03 to p 0.002). According to stepwise multiple regression analysis of the data the combination of the independent variables extracellular LECL, pack-years, and numbers of circulating PMNL accounts for 35.6% of the variation in lung function in the group of cigarette smokers, with LECL being the most important contributor (26%). Our findings indicate that cigarette smoking can increase the intracellular level of RO and their extracellular release from FMLP/CB-stimulated PMNL and that this increased LECL appears to be associated with the impairment of flow volume parameters.