Association of defective monocyte chemotaxis with recurrent acute exacerbations in chronic obstructive lung disease

Since mononuclear phagocytes are crucial in resisting microbial challenge in the lung, selected functions of blood monocytes were studied in 27 patients with chronic bronchitis (19 with hypersecretory symptoms and many acute infectious exacerbations and eight with obstructive symptoms without recurrent infections), and compared with 82 healthy controls. While monocytes from patients with solely obstructive symptoms had a normal migratory function, both spontaneous and chemotactic migration were depressed in the patients with hypersecretory symptoms. Phagocytic activity of the blood monocytes was equally depressed in both subgroups. Intracellular killing of Candida albicans was normal in all patients when compared with smoking control subjects. Chemotactic responsiveness was thus decreased only in patients with hypersecretory symptoms, suggesting that a defect in monocyte migration in these patients might contribute to the high incidence of acute bronchial exacerbations.