Differences in interleukin-8 and tumor necrosis factor-alpha in induced sputum from patients with chronic obstructive pulmonary disease or asthma.

Commercially available immune assays are being used with increasing frequency in the study of lung inflammation. However, their performance in complex biological fluids is rarely assessed. The authors wished to assess their reliability to determine whether the results obtained in sputum samples can be easily interpreted.The reproducibility of several such assays was therefore determined together with their ability to recover known amounts of pure reagent. Sputum sol phase was obtained from several patients with chronic lung disease and used together with the reagents in a series of "spiking" and dilutional experiments.Results confirmed that the enzyme assay for myeloperoxidase and the immune assays for interleukin-8, leukotriene B 4 and secretory leukoproteinase inhibitor were all reproducible (intra-assay coefficient of variation 3.8±7.7%). Furthermore, each of these assays gave >85% recovery of a "spike" with pure reagent. However, the immune assay for myeloperoxidase (although reproducible) gave poor recovery and was dependent on the degree of sample dilution and elastase content.These studies confirm that the reliabilities of fluid phase measurements should be assessed before being widely applied to complex biological samples. Eur Respir J 2000; 15: 778±781.

Section: Resultsmentioning

confidence: 90%

mentioning

confidence: 99%

Validation of assays for inflammatory mediators in sputum

Stockley¹,

Bayley²

2000

“…Lower airway IL-8 levels have been shown to increase with experimental rhinovirus type 16 infection in normal and asthmatic patients in some studies [29], but not in others [28]. However, COPD patients already have upregulated airway IL-8 levels when stable, possibly due to their high sputum neutrophil load [30], and so a further increase in IL-8 concentration at COPD exacerbation would be unlikely. Using a transformed epithelial cell line, rhinovirus has been shown to attach to airway epithelium [31] and to increase IL-6 production from epithelial cells through a nuclear factor-kB-dependent transcription pathway [32].…”

Section: Discussionmentioning

confidence: 99%

Detection of rhinovirus in induced sputum at exacerbation of chronic obstructive pulmonary disease

Seemungal

Harper-Owen²,

Bhowmik³

et al. 2000

309

208

Common colds are associated with exacerbations of chronic obstructive pulmonary disease (COPD). However, the role of the common cold virus (human rhinovirus) in the production of symptoms and lower airway inflammation at COPD exacerbation is unknown.Thirty three patients with moderate-to-severe COPD were seen at baseline, when the number of chest infections in the previous year was noted, and acutely at COPD exacerbation. Within 48 h after the onset of the exacerbation and at baseline, nasal aspirates and induced sputum were taken for rhinovirus reverse transcriptase polymerase chain reaction (RT-PCR) analysis and determination of cytokine levels. Symptoms, recorded on diary cards, were noted and forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) measured.At exacerbation, mean FEV1 and FVC fell significantly from baseline (p<0.001). Ten of 43 exacerbations were associated with rhinovirus infection, detected in induced sputum. In four of these, nasophageal samples contained no detectable rhinovirus. All baseline samples were negative for rhinovirus. The simultaneous presence of increased nasal discharge/nasal congestion (in 26 of the 43 exacerbations) and increased sputum (29 exacerbations) was strongly associated with the presence of rhinovirus (odds ratio 6.15; p=0.036). Total symptom scores were greater for rhinovirus as compared to nonrhinovirus exacerbations (p=0.039). Median baseline sputum interleukin-6 levels rose from 90.2 to 140.3 pg . mL -1 at exacerbation (p=0.005); the change was greater in the presence of rhinovirus infection (p=0.008).Rhinovirus infection can be detected at chronic obstructive pulmonary disease exacerbation. This is associated with elevation of lower airway interleukin-6 levels, which may mediate lower airway symptom expression during chronic obstructive pulmonary disease exacerbations. Eur Respir J 2000; 16: 677±683.

“…It induces chronic inflammatory changes associated with an increase in a variety of defence mechanisms including antioxidants levels [141]. TNF-a is an important inflammatory mediator in COPD and ARDS and is present in increased amounts in the bronchoalveolar lavage fluid (BALF) and sputum of COPD patients [142]. Recently, various investigators [86,143] have shown rapid depletion of intracellular GSH by TNF-a exposure in epithelial and endothelial cells in vitro, due to oxidation of GSH to GSSG.…”

Section: Effect Of Pro-and Anti-inflammatory Mediatorsmentioning

confidence: 99%

Oxidative stress and regulation of glutathione in lung inflammation

Rahman¹,

MacNee²

2000

808

555

Inflammatory lung diseases are characterized by chronic inflammation and oxidant/antioxidant imbalance, a major cause of cell damage. The development of an oxidant/antioxidant imbalance in lung inflammation may activate redox‐sensitive transcription factors such as nuclear factor‐κB, and activator protein‐1 (AP‐1), which regulate the genes for pro‐inflammatory mediators and protective antioxidant genes. Glutathione (GSH), a ubiquitous tripeptide thiol, is a vital intra‐ and extracellular protective antioxidant against oxidative/nitrosative stresses, which plays a key role in the control of pro‐inflammatory processes in the lungs. Recent findings have suggested that GSH is important in immune modulation, remodelling of the extracellular matrix, apoptosis and mitochondrial respiration. The rate‐limiting enzyme in GSH synthesis is γ‐glutamylcysteine synthetase (γ‐GCS). The human γ‐GCS heavy and light subunits are regulated by AP‐1 and antioxidant response elements and are modulated by oxidants, phenolic antioxidants, growth factors, and inflammatory and anti‐inflammatory agents in lung cells. Alterations in alveolar and lung GSH metabolism are widely recognized as a central feature of many inflammatory lung diseases such as idiopathic pulmonary fibrosis, acute respiratory distress syndrome, cystic fibrosis and asthma. The imbalance and/or genetic variation in antioxidant γ‐GCS and pro‐inflammatory versus antioxidant genes in response to oxidative stress and inflammation in some individuals may render them more susceptible to lung inflammation. Knowledge of the mechanisms of GSH regulation and balance between the release and expression of pro‐ and anti‐inflammatory mediators could lead to the development of novel therapies based on the pharmacological manipulation of the production as well as gene transfer of this important antioxidant in lung inflammation and injury. This review describes the redox control and involvement of nuclear factor‐κB and activator protein‐1 in the regulation of cellular glutathione and γ‐glutamylcysteine synthetase under conditions of oxidative stress and inflammation, the role of glutathione in oxidant‐mediated susceptibility/tolerance, γ‐glutamylcysteine synthetase genetic susceptibility and the potential therapeutic role of glutathione and its precursors in protecting against lung oxidant stress, inflammation and injury.