In this study we investigated if smoking subjects with a normal or slightly decreased lung function differ in the lymphocyte pattern compared to never-smokers. In a group of 'healthy' smokers (n = 58) and never-smokers (n = 34) 60 years old, we investigated the lymphocyte pattern in both BAL (n = 30 and n = 18 respectively), bronchial epithelium and lamina propria (n = 14 and n = 10 respectively) and blood. We found that all subjects, despite smoking history, had a higher number of CD8+ cells per mm2 in the epithelium compared to the lamina propria in the bronchial biopsies. In smokers, these CD8+ cells were significantly negatively correlated to FEV1 (r = -0.56, P = 0.04). In smokers, the number of CD8+ lymphocytes was higher and the T cell activation markers (CD57+ and CD28+) were lower in BAL, than in never-smokers. This last finding was also seen in blood for CD3+ 57+. We conclude, that in 'healthy' smokers the lymphocyte patterns are different compared to never-smokers, to some extent in BAL. There is also a relation between lymphocytes in the bronchial mucosa and lung function. This has previously been shown in patients with chronic obstructive pulmonary disease (COPD) and chronic bronchitis but not in asymptomatic smokers.
Subject classification (UKÄ)
- Respiratory Medicine and Allergy