Bronchoalveolar lavage in pulmonary fibrosis: comparison of cells obtained with lung biopsy and clinical features

Abstract

Bronchoalveolar lavage, open lung biopsy, and cell extraction from the biopsy material have been studied in 21 symptomatic patients with progressive pulmonary fibrosis (18 with cryptogenic fibrosing alveolitis, fulfilling also the criteria for “usual interstitial pneumonia” (UIP), and three with rapidly progressive disease probably related to asbestos exposure). The total and differential cell counts between the three different samples have been compared as well as the influence on them of smoking and their correlation with steroid responsiveness and later progress. There was no correlation between semiquantitative scores of cell types observed within alveolar spaces and in alveolar walls and the differential or total cell counts obtained from extraction or lung lavage samples. There was, however, some correlation between differential counts obtained from lung lavage and extractions (neutrophils p<0·02, eosinophils p<0·07, lymphocytes p<0·08) suggesting that lung lavage reflects the cellularity of the peripheral parts of the lung in patients without overt bronchial disease. Steroid responsiveness related to the percentage of lymphocytes found in extraction samples (p<0·01) and was associated with a complementary fall in the percentage of macrophages (p<0·02). There was no relationship between steroid response and the numbers of neutrophils or eosinophils in extracted samples. There was a trend towards increased numbers of lymphocytes in the lung wash in those patients responding to steroids. Those cases showing more rapid progression before starting treatment tended to have higher percentages of lymphocytes, neutrophils, or eosinophils in the lung lavage than more slowly deteriorating cases (p<0·01). Follow-up studies showed that three cases having predominant lymphocytes in the lung lavage continued to do well while nine cases with predominant neutrophils or eosinophils or both showed a less satisfactory response to steroids and often deteriorated. Differential cell counts from biopsy extractions and lung lavage may give information additional to conventional light microscopy on the likelihood of steroid responsiveness as well as providing some measure of the activity of disease.