Quantitative assessment of elastic fibers in chronic obstructive pulmonary disease.

Objective: To quantify elastic fibers (EFs) and smooth muscle (SM) cells, as well as CD4+ and CD8+ T lymphocytes, in stable chronic obstructive pulmonary disease (COPD).

Methods: Surgical specimens were obtained from 15 COPD patients, 18 smokers without airflow limitation, and 14 nonsmokers. Histological and immunohistochemical methods were employed in order to quantify EFs, SM cells, CD4+ T cells, and CD8+ T cells.

Results: There was no significant difference in EF numbers among the three groups (p > 0.05). The number of EFs per unit area of lung tissue (mm(2)) and the percentage of EFs in the lung tissue were similar among the three groups. The numbers of SM cells were found to be higher in the COPD patients than in the smokers (p = 0.003) or in the nonsmokers (p = 0.009). There was a tendency toward an increase in CD8+ T-cell counts in the COPD patients. In specimens collected from the COPD patients, CD4+ T-cell counts were lower than in those collected from the smokers (p = 0.015) or from the nonsmokers (p = 0.003). There was a weak correlation between CD4+ T-cell count and the ratio of forced expiratory volume in one second to forced vital capacity (r(2) = 0.003).

Conclusions: The EF counts were similar among the three groups. Hypertrophy/hyperplasia of airway wall SM cells was found in the COPD patients and in the smokers, indicating that airway remodeling occurs in smokers. The CD4/CD8 ratio was lower in the COPD patients.