Cigarette smoke-induced lung emphysema: C57BL/6 versus BALB/c

Background: The most important cause for developing lung emphysema is cigarette smoke (CS). The alveoli are destroyed and, hence, the alveolar septa disappear. This process is irreversible. There is much discussion in the literature on whether lung emphysema is a Th1- or Th2-driven disease. Objective: A more Th1 mouse strain: the C57BL/6 was compared with a more Th2 mouse strain: the BALB/c in the development of CS-induced lung emphysema. Methods: Mice were exposed to CS or normal air (controls) for 12 weeks. Airway and blood cells, right ventricular hypertrophy, airway reactivity, lung cytokines, and lung emphysema were measured. Results: In the C57BL/6 mice, the CS induced lung emphysema that was associated with hypertrophy of the right heart ventricular. Airway hyperreactivity, broncho-alveolar cells, and the mean linear intercept (Lm) were increased. The fat percentage was decreased. In the BALB/c mice, only broncho alveolar cells and hypertrophy were increased. Conclusion: Based on the results, it is more likely that the development of lung emphysema is a more Th1 mediated disease since an increase in Lm was only observed in the C57BL/6 mice and not in the BALB/c mice.