Lack of type II cells and emphysema in human lungs.

Ten surgically removed human lungs or lobes were studied, to assess the relationship between the abundance of type II alveolar epithelial cells and the degree of emphysema. Type II cell abundance (total number as well as percentage of the total parenchymal cell population) was determined in sections of randomly selected tissue samples of these lungs or lobes by using a type II cell specific antibody specific anti-lavage serum (SALS-Hu), which recognizes surfactant-associated proteins. In these tissue samples we also determined the degree of emphysema with the aid of a number of morphometric parameters, destructive index (DI), mean linear intercept (Lm in mm), and the number of normal alveolar attachments on (pre)terminal bronchioles (normal AA.mm.1). We subsequently calculated the Spearman rank correlation coefficients (rs) between the abundance of type II cells and parameters for emphysema. We found a significant negative correlation between the percentage of type II cells and DI at tissue sample level (rs = 0.55; p = 0.02). We also calculated correlation coefficients between the abundance of type II cells and the degree of small airways disease in (pre)terminal and respiratory bronchioles (SADscore), lung function, age and smoking habits. The results suggest a role for type II cells in the pathogenesis of emphysema.