Excessive neutrophil elastase in bronchoalveolar lavage fluid in subclinical emphysema

Aya Yoshioka, Tomoko Betsuyaku, Masaharu Nishimura, Kenji Miyamoto, Takahito Kondo, Yoshikazu Kawakami

Research output: Contribution to journalArticlepeer-review

60 Citations (Scopus)


In an attempt to further evaluate the role of neutrophil elastase (NE) in the development of emphysema, we examined the immunologic quantity of NE bound to α1-protease inhibitor (PI), the NE inhibitory activity, and the molecular pattern of α1-PI in unconcentrated bronchoalveolar lavage fluid (BALF) supernatant from 36 community-based older volunteers. They were classified into three groups: 10 current smokers with low attenuation areas (LAAs) on the lung computed tomography (CT) scans who were considered to have subclinical emphysema, 13 current smokers who had a comparable smoking history but no LAA, and 13 noncurrent smokers without LAA. The concentration of NE-α1-PI complex was significantly increased in the subjects with subclinical emphysema when compared not only with the noncurrent smokers (0.52 ± 0.10 versus 0.21 ± 0.03 SEM μg/mg albumin, p < 0.01) but also with the LAA(-) current smokers (0.52 ± 0.10 versus 0.23 ± 0.07 SEM μg/mg albumin, p < 0.01). NE inhibitory activity measured by a spectrophotometric method using methoxysuccinyl-alanyl-alanyl-prolyl-valyl-paranitroanilide did not show any significant difference between the two groups of current smokers. There was no difference in the pattern or density of native and proteolysed α1-PI bands between the three groups by Western blotting. We conclude that NE-α1-PI complex in BALF is a factor that may differentiate smokers who are potentially developing emphysema from those who are not.

Original languageEnglish
Pages (from-to)2127-2132
Number of pages6
JournalAmerican journal of respiratory and critical care medicine
Issue number6 I
Publication statusPublished - 1995 Dec
Externally publishedYes

ASJC Scopus subject areas

  • Pulmonary and Respiratory Medicine
  • Critical Care and Intensive Care Medicine


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