The "destructive index" in nonemphysematous and emphysematous lungs. Morphologic observations and correlation with function

We examined the relationship of the newly described "Destructive Index" (DI) to emphysema using nine nonemphysematous and 13 emphysematous lungs obtained at autopsy. The amount of emphysema was assessed by the panel method (emphysema grade, EG) and measurement of the mean linear intercept (Lm). The DI depends on three components--alveolar wall/duct disruption, DId; alveolar fibrosis, DIf; and classic emphysema, DIe. DIf was a minor component in our series. The mean DI was 5.8 +/- 2.5, 10.9 +/- 3.9, and 55.7 +/- 7.0% (+/- 1 SEM) in the nonemphysematous (panel grade EG = 0), mild (0 less than EG less than or equal to 25), and moderate to severe (30 less than or equal to EG less than or equal to 60) emphysematous lungs, respectively. The increase in the DI in mild emphysema did not reach significant levels (p less than 0.2). The mean DId was 5.6 +/- 2.5, 10.0 +/- 4.0, and 12.8 +/- 3.9% in the above categories, and the DId in mild emphysema did not differ significantly from that of the nonemphysematous lungs. Lm showed a similar trend and alveolar disruption did not precede airspace enlargement, rather both changes appeared to advance in parallel. The DI correlated closely with EG (r = 0.83, p less than 0.01), but this was due to the component of DIe. The DIe increased steeply in the lungs with EG greater than or equal to 30.(ABSTRACT TRUNCATED AT 250 WORDS)