C-Reactive Protein in Bronchoalveolar Lavage Fluid is Associated With Markers of Airway Inflammation After Lung Transplantation

Abstract Background C-reactive protein (CRP), an acute-phase marker of systemic inflammation, may also be a local regulator of the pulmonary immune system. Its role in lung transplantation (LT), however, is unclear. We hypothesized that CRP in bronchoalveolar lavage (BAL) fluid might be associated with airway inflammation or remodeling. Therefore, it could play a role in the development of bronchiolitis obliterans syndrome (BOS). Patients and Methods A total of 100 LT recipients who had undergone transplantation between August 2001 and August 2005 were included in the current cross-sectional study. Patients who were evaluated at 90 days after LT were categorized as either stable (n = 36), colonized (n = 25), or suffering from infection (n = 16) or acute rejection (n = 23). BAL CRP, cell differentials, and interleukin (IL), IL8, transforming growth factor β (TGFβ), and vascular endothelial growth factor (VEGF) protein levels, as well as blood leukocytosis, plasma CRP, and forced expiratory value in 1 second (FEV1 ; % predicted) were compared between groups. We analyzed the correlation of BAL CRP with inflammatory or remodeling markers and FEV1. Results Compared with stable LT recipients, BAL CRP was significantly increased in patients with infection or acute rejection ( P < .0001), but not in those with colonization. Generally, BAL CRP levels positively correlated with BAL total cell count, neutrophilia, and IL8 levels, as well as with plasma CRP levels ( P < .0001). An inverse correlation was observed with BAL macrophages ( P < .01), VEGF ( P < .0001), and FEV1 ( P < .0001). Only a trend for a positive, respectively inverse correlation was seen for BAL IL6 and TGFβ. Conclusions The current data corroborate a possible role for CRP in airway inflammation after LT. Its importance for BOS should therefore be further elucidated.