The Bronchoalveolar Lavage Fluid of Cystic Fibrosis Lung Transplant Recipients Demonstrates Increased Interleukin-8 and Elastase and Decreased IL-10

Cystic fibrosis (CF) patients continue to have reservoirs of Pseudomonas aeruginosa infection in their sinuses and trachea after transplantation, and studies indicate that nontransplanted CF patients have high bronchoalveolar lavage (BAL) levels of proinflammatory factors, interleukin-8 (IL-8), and elastase and decreased airway lavage levels of IL-10. The aims of our study were to measure the IL-8 and IL-10 levels and elastase activity in the BAL of lung transplant patients, with correlation to microbiologic and pathologic findings, and to identify any differences in the findings between CF and non-CF patients. Fifty serial BAL samples were collected from 38 lung transplant recipients over 8 months. The BAL supernatant fluid was cultured for bacterial, viral, and fungal organisms. Histologic tissue analysis was performed as indicated. The fluid IL-10 and IL-8 levels were measured in duplicate using ELISA techniques. Elastase activity was measured using a colorimetric assay system. The mean IL-8, IL-10, and elastase levels for the group studied were 1894 pg/ml, 394 pg/ml, and 4.2 U/ml, respectively. The CF patients had significantly higher levels of IL-8, with a mean value of 4093 pg/ml (p < 0.02), and lower IL-10, mean 217 pg/ml (n = 9). Elastase activity correlated strongly with IL-8 level (p < 0.04). Pseudomonas growth was associated with higher elastase and IL-8 concentrations (p < 0.02). There was no association between allograft rejection and the markers studied. CF transplanted patients have higher airway lavage concentrations of IL-8 and elastase correlated to the presence of Pseudomonas in the lower airway. They also have lower BAL levels of anti-inflammatory cytokine IL-10.