Summary Chronic obstructive pulmonary disease is a highly prevalent, complex disease, usually caused by cigarette smoke. It causes serious morbidity and mortality and costs the global community billions of dollars per year. While chronic inflammation, extracellular matrix destruction and increased airway epithelial cell apoptosis are reported in chronic obstructive pulmonary disease, the understanding of the basic pathogenesis of the disease is limited and there are no effective treatments. We hypothesized that the accumulation of apoptotic airway epithelial cells chronic obstructive pulmonary disease in could be due to defective phagocytic clearance by alveolar macrophages. There have been no previous studies of the phagocytic capacity of alveolar macrophages in chronic obstructive pulmonary disease using physiologically relevant apoptotic airway epithelial cells as phagocytic targets. We developed a phagocytosis assay whereby cultured 16HBE airway epithelial cells were induced to apoptosis with ultraviolet radiation and stained with mitotracker green. Alveolar macrophages from bronchoalveolar lavage from eight control and six chronic obstructive pulmonary disease subjects were analysed following 1.5 h incubation with apoptotic airway epithelial cells, then staining with macrophage marker anti CD33. CD33+/mitotracker green + events (i.e., alveolar macrophages which had phagocytosed apoptotic airway epithelial cells) were analysed using flow cytometry. Phagocytosis of polystyrene microbeads was investigated in parallel. A significantly reduced proportion of alveolar macrophages from chronic obstructive pulmonary disease subjects ingested apoptotic airway epithelial cells compared with controls (11.6 ± 4.1% for chronic obstructive pulmonary disease versus 25.6 ± 9.2% for control group). Importantly, the deficiency was not observed using polystyrene beads, suggesting that the failure to resolve epithelial damage in chronic obstructive pulmonary disease may result, at least partially, from specific defects in phagocytic ability of alveolar macrophages to ingest apoptotic airway epithelial cells.

Budesonide/formoterol single inhaler therapy has the potential to provide a complete asthma management approach with one inhaler, demonstrating a high level of efficacy in patients with moderate to severe asthma.

Chronic obstructive pulmonary disease (COPD) is associated with inflammation of airway epithelium, including an increase in the number of intraepithelial T cells. Increased apoptosis of these T cells has been reported in the airways in COPD, and although this process is critical for clearing excess activated T cells, excessive rates of apoptosis may result in unbalanced cellular homeostasis, defective clearance of apoptotic material by monocytes/macrophages, secondary necrosis, and prolongation of the inflammatory response. Lymphocytes are known to traffic between the airway and the peripheral circulation, thus we hypothesized that in COPD, circulating T cells may show an increased propensity to undergo apoptosis. We analyzed phytohemagglutinin (PHA)-stimulated peripheral blood T cells from COPD patients and controls for apoptosis using flow cytometry and staining with annexin V and 7-aminoactinomycin D. As several pathways are involved in induction of apoptosis of T cells, including transforming growth factor (TGF)-beta/TGF receptor (TGFR), TNF-alpha/TNFR1, and Fas/Fas ligand, these mediators were also investigated in peripheral blood samples from these subject groups. Significantly increased apoptosis of PHA-stimulated T cells was observed in COPD (annexin positive 75.0 +/- 14.7% SD vs. control 50.2 +/- 21.8% SD, P = 0.006), along with upregulation of TNF-alpha/TNFR1, Fas, and TGFR. Monocyte production of TGF-beta was also increased. In conclusion we have demonstrated the novel finding of increased apoptosis of stimulated T cells in COPD and have also shown that the increased T-cell death may be associated with upregulation of apoptotic pathways, TGF-beta, TNF-alpha, and Fas in the peripheral blood in COPD.

An association has been reported between chronic infection with Chlamydia pneumoniae and the severity of asthma, and uncontrolled observations have suggested that treatment with antibiotics active against C. pneumoniae leads to an improvement in asthma control. We studied the effect of roxithromycin in subjects with asthma and immunoglobulin G (IgG) antibodies to C. pneumoniae > or = 1:64 and/or IgA antibodies > or = 1:16. A total of 232 subjects, from Australia, New Zealand, Italy, or Argentina, were randomized to 6 wk of treatment with roxithromycin 150 mg twice a day or placebo. At the end of 6 wk, the increase from baseline in evening peak expiratory flow (PEF) was 15 L/min with roxithromycin and 3 L/min with placebo (p = 0.02). With morning PEF, the increase was 14 L/min with roxithromycin and 8 L/min with placebo (NS). In the Australasian population, the increase in morning PEF was 18 L/min and 4 L/min, respectively (p = 0.04). At 3 mo and 6 mo after the end of treatment, differences between the two groups were smaller and not significant. Six weeks of treatment with roxithromycin led to improvements in asthma control but the benefit was not sustained. Further studies are necessary to determine whether the lack of sustained benefit is due to failure to eradicate C. pneumoniae.