ENDOBRONCHIAL BIOPSY AND BRONCHOALVEOLAR LAVAGE IN STABLE LUNG-TRANSPLANT RECIPIENTS AND CHRONIC REJECTION

We have obtained endobronchial biopsies (EBB), bronchoalveolar lavage (BAL), and transbronchial biopsies (TBB) in 17 stable lung transplant recipients (sLTR), 8 subjects with physiologic evidence of chronic rej ection (BOS), and 9 normal subjects. A striking finding was the marked neutrophilia in BAL samples from patients with BOS, in the carefully screened absence of infection. A statistically higher neutrophil count was also present in the sLTR group relative to the normal group. Medi an BAL neutrophil count in BOS was 100 x 10(3)/ml, range 13-1,661 10(3 )/ml (p < 0.001 relative to normal subjects and sLTR). Median BAL neut rophil count in sLTR was 7 x 10(3)/ml, range 1-81 10(3)/ml (p < 0.01 r elative to normal subjects). Normal subjects had a median BAL neutroph il count of 3 x 103/ml, range 1-7 10(3)/ml. There was evidence of a pr edominance of CD8 lymphocytes in BAL from sLTR and BOS with a lower CD 4/CD8 ratio in both compared to normal subjects (p < 0.05). EBB mononu clear cell counts, class II major histocompatibility complex expressio n, and T-cell activation markers were normal in BOS, in contrast to th e sLTR group. Our data may be consistent with BOS, representing a rela tive resolution of an active mononuclear cell chronic inflammation, pe rhaps at the expense of airway fibrosis. The relevance of the BAL neut rophilia and its role in BOS pathogenesis need further longitudinal in vestigation.