Bacterial infections after lung transplantation cause airway epithelial injury and are associated with an increased risk of developing bronchiolitis obliterans syndrome. The damaged epithelium is a source of alarmins that activate the innate immune system, yet their ability to activate fibroblasts in the development of bronchiolitis obliterans syndrome has not been evaluated. Two epithelial alarmins were measured longitudinally in bronchoalveolar lavages from lung transplant recipients who developed bronchiolitis obliterans syndrome and were compared to stable controls. In addition, conditioned media from human airway epithelial cells infected with Pseudomonas aeruginosa was applied to lung fibroblasts and inflammatory responses were determined. Interleukin‐1 alpha (IL‐1α) was increased in bronchoalveolar lavage of lung transplant recipients growing P. aeruginosa (11.5 [5.4–21.8] vs. 2.8 [0.9–9.4] pg/mL, p < 0.01) and was significantly elevated within 3 months of developing bronchiolitis obliterans syndrome (8.3 [1.4–25.1] vs. 3.6 [0.6–17.1] pg/mL, p < 0.01), whereas high mobility group protein B1 remained unchanged. IL‐1α positively correlated with elevated bronchoalveolar lavage IL‐8 levels (r2 = 0.6095, p < 0.0001) and neutrophil percentage (r2 = 0.25, p = 0.01). Conditioned media from P. aeruginosa infected epithelial cells induced a potent pro‐inflammatory phenotype in fibroblasts via an IL‐1α/IL‐1R‐dependent signaling pathway. In conclusion, we propose that IL‐1α may be a novel therapeutic target to limit Pseudomonas associated allograft injury after lung transplantation.

IntroductionBronchiectasis (BR) in a pulmonary disease thought to involve a characteristic dilation of the bronchi resulting from a cycle of airway infection and inflammation. This inflammation is believed to be driven by neutrophils, which are present in the BR lung in high number. Vascular endothelial growth factor (VEGF) is a pro-angiogenic cytokine that may be upregulated in BR and could contribute towards creating a pro-angiogenic airway environment by supporting neutrophil migration into the airway tissue, however this has yet to be shown.Aims1) Examine the BR airway for any indications of increased angiogenesis, 2) Assess the ability of neutrophils to secrete VEGF upon stimulation in vitro, 3) Evaluate sera/sputa samples VEGF concentration to determine if VEGF could act as a biomarker for BR severity.MethodsHealthy volunteer (HV) and BR endobronchial biopsies were stained with a HRP conjugated anti-CD31 antibody, allowing blood vessels to be counted in a blinded manner. Peripheral blood neutrophils isolated from HV were stimulated (e.g. with TNF-α or bacterial PAMPs) for 4 hours, VEGF levels in supernatants were then quantified using ELISA. A VEGF ELISA was also used to determine VEGF concentration in sera and sputa samples from BR patients (n = 115), categorised by bronchiectasis severity index (BSI) scores and sera samples from HV controls (n = 26)ResultsEndobronchial biopsies from BR airways had a significantly (p < 0.05) higher number of blood vessels per mm of basement membrane than HV samples (18 and 9 blood vessels/mm basement membrane respectively). Stimulation of HV neutrophils with a variety of molecules (PMA, fMLP, LPS, TNF-α etc.) resulted in a significant increase in VEGF secretion compared to unstimulated (p < 0.05). Although elevated VEGF was found in some patient samples there was no significant correlation between sera/sputa VEGF and individual patient BSI scores.ConclusionThe increased presence of vascular tissue seen in BR could indicate a pro-angiogenic airway environment in BR. The in vitro data collected also show that a variety of stimulants can initiate secretion of VEGF by neutrophils. However, our data does not suggest that VEGF levels in sera or sputa can be used to predict disease severity.

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Results Healthy individuals andpatients with cystic fibrosis had robust antigen-specific memory CD4 + T cell responses to Pseudomonas aeruginosa that not only contained a Th1 and Th17 component but also Th22 cells. In contrast to previous descriptions of human Th22 cells, these Pseudomonal-specific Th22 cells lacked the skin homing markers CCR4 or CCR10, although they did express the chemokine receptor CCR6 that would direct migration to damaged epithelial surfaces. Furthermore, IL-22 production was evident in the lungs of CF patients colonised with PA. Healthy individuals and patients with cystic fibrosis had similar levels of Th22 and Th1 cells, but the patient group had significantly fewer Th17 cells in peripheral blood. Conclusions MemoryTh22 cells specific to Pseudomonas aeruginosa are induced in both healthy individuals and patients with CF, with IL-22 secretion being demonstrated in the CF lung. These Th22 cells do not express tissue specificity for gut or skin sites and we thus hypothesise may have a role in respiratory defense. Along with Th17 cells, they may play an important role in the pathogenesis of pulmonary infection with this microbe in patients with cystic fibrosis.

or sensitised patients would benefit from antifungal treatment. To aid treatment decisions and to monitor response more accurate methods to detect Aspergillus in sputum are needed. This study aimed to identify CF patients with Aspergillus colonisation, using real time PCR, and examine the relationship of colonisation to markers of sensitisation. Methods 108 adult CF patients provided a sputum sample and a blood sample. Serological tests included total IgE, specific A. fumigatus IgE and specific A. fumigatus IgG performed by Phadia ImmunoCAP Ò assay, and A. fumigatus precipitins by counter immunoelectrophoresis. Sputum was homogenised with sputasol and sonication. 10 ml was cultured on sabouraud agar (Oxoid, UK)