Differences in the distribution of CD4+ and CD8+ T cells in emphysematous lungs

Recent studies have shown that T cells are the predominant cells infiltrating the alveolar wall of patients with emphysema. Since CD4+ and CD8+ cells have dissimilar function, they may have different distributions in emphysematous lungs.

The aim of this study was to investigate whether CD4+ and CD8+ are differently distributed in the lungs of patients with emphysema.

We evaluated CD4+ and CD8+ cell infiltration in lung tissue sections obtained from smokers with pulmonary emphysema who had undergone lung volume reduction surgery (n = 10). Paraffin-embedded lung tissue sections were immunostained using antibodies against CD4+ or CD8+, and distributions of CD4+ and CD8+ cells were evaluated using a morphometric analysis. We determined the degree of emphysema using the area fraction of the alveolar wall (A(A,aw)) and examined its relation to the number of cells per unit area of the alveolar wall (NA).

The majority of CD4+ cells were located in the lung parenchyma of severe emphysematous lesions characterized by the lowest alveolar wall fraction (A(A,aw)). In contrast, more CD8+ cells were located in mild emphysematous lesions than in severe lesions.

These results suggest that CD4+ and CD8+ cells are differently distributed according to the severity of emphysema. CD4+ T cells are located preferentially in severe emphysematous lesions whereas CD8+ T cells occur preferentially in mild emphysematous lesions.