It is not known whether cytokine levels in sputum may be used as outcome measures after parenteral antibiotic therapy in cystic fibrosis (CF) patients. Here, we assessed the effects of antibiotic therapy on cytokine levels in sputum and serum obtained from young CF patients. Thirty-two CF patients (14 females; mean age, 18.6 years; range, 11.4-35.7 years), consecutively admitted at the CF Center of Milan for parenteral antibiotic therapy during pulmonary exacerbation, were enrolled in the study. Before and after 21 days (range, 5-41) of intravenous antibiotic treatment, all patients underwent routine laboratory determinations (including white blood cell (WBC) count and C-reactive protein (CRP)), a chest X-ray, pulmonary function tests (forced expiratory volume in 1 sec (FEV1) and forced vital capacity (FVC) as % predicted), and sputum cultures. Interleukin (IL)-6, IL-8, IL-10, and tumor necrosis factor (TNF)-alpha levels in serum and sputum samples were determined by means of immunometric assays. After therapy, FEV1 and FVC significantly improved (median increase of 7.5% and 8.5% predicted, respectively), while CRP and WBC count were significantly decreased (median values from 14 to 5.5 mg/dl and from 8,350 to 7,400 n/mm3, respectively). While levels of IL-6 and IL-10 in sputum were generally undetectable, IL-8 and TNF-alpha were always measurable, and IL-8 levels significantly decreased after antibiotic treatment (median values from 7,165 to 5,415 pg/ml). Following antibiotic therapy, IL-8 and TNF-alpha levels in sputum were inversely related with both FEV(1) and FVC. In conclusion, TNF-alpha and IL-8 levels in sputum of young CF patients with pulmonary exacerbation were always detectable and may be useful, noninvasive outcome measures to assess response to therapy in CF patients.

The pathological hallmark of cystic fibrosis (CF) chronic inflammatory response is the massive neutrophil influx into the airways. This dysregulated neutrophil emigration may be caused by the abnormal secretion of chemoattractants by respiratory epithelial cells and polarised lymphocyte T-helper response. Neutrophils from CF patients have a different response to inflammatory mediators than neutrophils from normal subjects, indicating that they are primed in vivo before entering the CF airways. CF neutrophils secrete more myeloperoxidase and elastase, mobilise less opsonin receptors and release less L-selectin than non-CF neutrophils. Moreover, they show altered cytokine production and a dysregulated chemotaxis response. Laboratory studies now suggest that CFTR is involved in regulating some neutrophil functions and indicate that altered properties of CF neutrophils may depend on genetic factors. Current gene therapy approaches are targeted to the respiratory epithelium, but many hurdles oppose an efficient and efficacious CFTR gene transfer. The possibility of CFTR gene therapy-based approach targeting CF neutrophils at the hematopoietic stem cell level is discussed.

To investigate the regeneration process of a well-differentiated and functional human airway epithelium, we adapted an in vivo xenograft model in which adult human nasal epithelial cells adhere and progressively repopulate denuded rat tracheae grafted in nude mice. The proliferating activity, the degree of differentiation, and the barrier integrity of the repopulated epithelium were studied during the regeneration process at optical and ultrastructural levels with immunocytochemistry and a permeability tracer. Three days after implantation in nude mice, tracheal xenografts were partially repopulated with a flattened nonciliated and poorly differentiated leaky epithelium. By the end of the first week after the graft, cell proliferation produced on the entire surface of the rat trachea an epithelium that was stratified into multiple layers and tightly sealed. During successive weeks, cell proliferation dramatically decreased. Moreover, the epithelium became progressively columnar, secretory, ciliated, and transiently leaky. At 4-5 wk, a fully differentiated pseudostratified functional epithelial barrier impermeable to a low-molecular-weight tracer was reconstituted. The regeneration of a well-differentiated and functional human airway epithelium in rat tracheae grafted in nude mice includes several steps that mimic the regeneration dynamics of airway epithelium after injury.

CF respiratory epithelial cells exhibit a basal dysregulated production of IL-8 that partially correlates to enhanced NF-kappaB activity. Our data corroborate the hypothesis of a basal exaggerated inflammatory response in the CF respiratory epithelium.

Our results demonstrate that albumin increases PEI gene transfer efficiency in confluent and polarised respiratory epithelial cells and can allow CFTR gene expression in the appropriate cellular compartment. PEI-HSA complexes display a higher efficiency than PEI also in the presence of CF sputum, indicating that albumin-containing polyplexes may help overcome barriers imposed by CF airway secretions.

NCT00637910.

No abstract

Taken together, these results show that GAGs are involved in VSV-G LV transduction of airway epithelial cells.