Anti-inflammatory cytokines in cystic fibrosis lung disease.

Lung inflammation plays a pivotal role in the pathogenesis of airway disease in cystic fibrosis (CF). An imbalance between pro- and anti-inflammatory mediators has been observed and a deficiency in the anti-inflammatory response has been proposed, but this concept remains controversial. In the present study, the concentrations of two anti-inflammatory mediators, lipoxin A (LxA4) and Clara cell protein 10 (CC-10), were assessed in bronchoalveolar lavage fluid (BALF) of CF patients with a wide range of endobronchial inflammation and disease controls with neutrophilic inflammation unrelated to CF. No differences were observed in LxA4 BALF concentrations between CF patients and controls with a similar degree of neutrophilic airway inflammation. Concentrations were also similar in CF patients with mild versus more severe airway inflammation. In contrast, CC-10 concentrations were lower in CF patients, but this decrease was limited to patients with more intense airway inflammation. The present data do not support the concept of a primary defect in anti-inflammatory mediators in cystic fibrosis lung disease. Although Clara cell protein concentrations were found to be reduced, these alterations appear to be secondary to neutrophilic airway inflammation rather than due to a primary deficiency.

Protein oxidation by chronic pulmonary diseases in children.

The oxidation of proteins may play an important role in the pathogenesis of chronic inflammatory lung diseases, and may contribute to lung damage. However, the extent of oxidation and the distribution among proteins are not known for most pediatric lung diseases. In this work, protein oxidation was assessed as protein carbonyls. Bronchoalveolar lavages (BAL) from children with chronic lung diseases were investigated by dot-blot assay for content and for pattern of distribution of oxidized proteins by two-dimensional (2D) electrophoresis and Western blotting. Significantly higher levels of protein oxidation than in healthy controls were determined in groups of patients with interstitial lung disease, gastro-esophageal reflux disease, and pulmonary alveolar proteinosis. The proteins most sensitive to oxidation were serum albumin, surfactant protein A, and alpha1-antitrypsin. Our data show increased oxidative stress in lungs of children with chronic pulmonary diseases, with significant interindividual variations. The extent of protein oxidation was proportional to the count of neutrophilic granulocytes in BAL fluid. These findings strongly support the concept that an abundance of reactive oxygen species produced during neutrophilic inflammation may be a deleterious factor, leading to pulmonary damage in these patients.

Inhaled glutathione decreases PGE2 and increases lymphocytes in cystic fibrosis lungs.

Reduced glutathione (GSH), a major antioxidant and modulator of cell proliferation, is decreased in the bronchoalveolar lavage fluid (BALF) of cystic fibrosis (CF) patients. We previously have shown that GSH inhalation in CF patients significantly increased GSH levels in BALF and improved lung function (M. Griese et al., 2004, Am. J. Respir. Crit. Care Med.169, 822-828). GSH depletion in vitro enhances susceptibility to oxidative stress, increases inflammatory cytokine release, and impairs T cell responses. We therefore hypothesized that an increase in GSH in BALF reduces oxidative stress, decreases inflammation, and modulates T cell responses in lungs of CF patients. BALF from 17 CF patients (median FEV1 67% (43-105%) of predicted) was assessed before and after GSH inhalation for total protein, markers of oxidative stress (8-isoprostane, myeloperoxidase, and ascorbic and uric acid), pattern of protein oxidation, prostaglandin E2 (PGE2), and proinflammatory cytokines. BALF cells were differentiated using cytospin slides, and lymphocytes were further analyzed by flow cytometry. Inhalation of GSH decreased BALF levels of PGE2 and increased CD4+ and CD8+ lymphocytes in BALF significantly but had no effect on markers of oxidative stress. BALF lymphocytes correlated positively with lung function, whereas levels of PGE2 showed an inverse correlation. The patients with the greatest improvement in lung function after GSH treatment also had the largest decline in PGE2 levels. We conclude that GSH inhalation in CF patients increases lymphocytes and suppresses PGE2 in the bronchoalveolar space. Thus, GSH primarily affected the pulmonary immune response rather than the oxidative status in CF patients. The effect of GSH inhalation on PGE2 levels and lymphocytes in CF warrants further investigation.