BRONCHIOLITIS OBLITERANS SYNDROME IN LUNG-TRANSPLANT RECIPIENTS IS ASSOCIATED WITH INCREASED NEUTROPHIL ACTIVITY AND DECREASED ANTIOXIDANT STATUS IN THE LUNG

Long-term survival of lung transplant recipients is limited by the adv ent of obliterative bronchiolitis and irreversible airways obstruction , e,g, bronchiolitis obliterans syndrome (BOS). This study investigate d whether infammatory cells and their activation markers were increase d in bronchoalveolar lavage (BAL) and transbronchial biopsies (TBE) fr om patients with BOS, Levels of antioxidants in BAL fluid were also as sessed. BAL fluid and TRB from six single-lung, two bilateral-lung, an d five heart-lung transplanted patients with diagnosis of BOS were com pared with 13 transplant recipients without BOS, BAL fluid levels of m yeloperoxidase (MPO), eosinophil cationic protein (ECP) and interleuki n (IL)-8 were used as markers for the activation and attraction of neu trophils and eosinophils, respectively. Immunohistochemical staining o f TBB with monoclonal antibodies to MPO and ECP (EG2) was performed, S ignificantly increased BAL, percentages of neutrophils and levels of M PO were found ill patients with EOS. The findings correlated well with the degree of monoclonal staining for MPO in TBB. BAL levels of ECP a nd IL-8 mere significantly increased in BOS patients, BAL concentratio ns of the water-soluble antioxidants ascorbate, urate and glutathione were generally lower in BOS patients. The results indicate that neutro phil infiltration and activation, as well as oxidative stress, may pla y a role in the development and/or progression of bronchiolitis oblite rans syndrome, Markers for neutrophil activation could have a potentia l role in monitoring disease activity in patients with this syndrome.