Cellular and molecular characteristics of inflammation in chronic bronchitis

Methods To examine the inflammatory process in chronic bronchitis, we evaluated the cell and cytokine profile in bronchoalveolar lavage fluid from 12 chronic bronchitis patients who smoked, six chronic bronchitis patients who did not smoke, 10 subjects control subjects without pulmonary diseases who smoked and eight control subjects who did not smoke. Results Chronic bronchitis patients who smoked had increased numbers of macrophages, neutrophils, eosinophils, mast cells and activated CD8+ T lymphocytes and predominantly expressed interleukin-8, tumour necrosis factor alpha and interleukin-2 genes and proteins. The number of macrophages and neutrophils and the expression of interleukin 8 were also increased in control subjects who smoked compared with healthy subjects who did not smoke. Chronic bronchitis patients who did not smoke had increased numbers of eosinophils, mast cells and activated CD4+ T lymphocytes and predominantly expressed interleukin-5 and granulocyte–macrophage colony-stimulating factor genes and proteins. Conclusion Thus, the cellular and molecular characteristics of the inflammatory process in chronic bronchitis patients who smoke and do not smoke are different, suggesting a different pathogenesis of the disease.