Airway neutrophilia in stable and bronchiolitis obliterans syndrome patients following lung transplantation

Background-The bronchiolitis obliterans syndrome (BOS) remains the major co nstraint on the Pong term success of lung transplantation. Neutrophils have been associated with fibrosing lung conditions and have been noted to be i ncreased in the bronchoalveolar lavage (BAL) fluid of patients with BOS. Methods-This study was undertaken to examine neutrophil accumulation in the BAL fluid, airway wall and lung parenchyma, as well as levels of interleuk in (IL)-8 in the BAL fluid, in normal controls and lung transplant recipien ts with and without BOS. Bronchoscopic examination included endobronchial b iopsy (EBB), BAL fluid, and transbronchial biopsy (TBB) sampling. Tissue ne utrophils were identified by neutrophil elastase staining on 3 pm paraffin biopsy sections and quantified by computerised image analyser. IL-8 levels were measured in unconcentrated BAL fluid by ELISA. Results-Compared with controls, airway wall neutrophilia was increased in b oth stable lung transplant recipients and those with BOS (p < 0.05). BAL ne utrophils and IL-8 levels were also increased in both groups of transplant recipients compared with controls (p < 0.01), the levels being significantl y higher in the BOS group (p < 0.01). Neutrophil numbers in the lung parenc hyma were not significantly different between the two groups of lung transp lant recipients. Conclusion-Increased levels of neutrophils are present in the airway wall a nd BAL fluid of lung transplant recipients with and without BOS. BAL fluid levels of IL-8 are also increased, raising the possibility that neutrophils and/or IL-8 may play a part in the pathogenesis of BOS following lung tran splantation.