A 6-year experience of Zephyr endobronchial valves for severe emphysema in an Australian single-centre cohort.

BACKGROUND: Endobronchial valve (EBV) insertion for lung volume reduction is a management option for patients with severe emphysema. One-way valves cause lobar deflation and improve lung function, exercise capacity and quality of life. AIMS: To retrospectively analyse and compare the outcomes of the first 57 patients treated with EBVs between 2015 and 2021 at the Royal Adelaide Hospital to international standards. METHODS: Clinical outcomes of forced expiratory volume in 1 s (FEV1), residual volume (RV), treated lobe volume reduction (TLVR) and 6-min walk distance (6MWD) at 3, 6 and 12 months after valve insertion were reviewed against established minimally clinically important differences (MCIDs). Complications and subjective breathlessness measured by Borg scores were also reviewed. RESULTS: Fifty-seven patients were included. At 12 months, 77.2% achieved TLVR. FEV1 improved by 170 mL (95% confidence interval (CI): 100-250, P < 0.001), 80 mL (95% CI: 10-150, P = 0.019) and 40 mL (95% CI: -60 to 130, P 0.66) at 3, 6 and 12 months respectively. RV improved by -610 mL (95% CI: -330 to -900, P < 0.0001) at 3 months, -640 mL (95% CI: -360 to -920, P < 0.0001) at 6 months and -360 mL (95% CI: -60 to -680, P = 0.017) at 12 months. 6MWD improved by 57.34 m (95% CI: 36.23-78.45, P < 0.0001) and 44.93 m (95% CI: 7.19-82.67, P = 0.02) at 3 and 6 months. Borg score improved by -0.53 (95% CI: 0.11 to -1.2, P = 0.11) and -0.49 (95% CI: 0.17 to -1.15, P = 0.16) at 3 and 6 months. Complication rates aligned with international standards with mucous/infection (26.3%) and pneumothorax (17.5%) as the most common. Subgroup analysis signalled improved outcomes in patients with heterogeneous emphysema. CONCLUSION: Our study represents the first publicly funded Australian analysis of EBVs. The results align with international prospective trials demonstrating improved lung function and exercise capacity. Australians with severe emphysema and gas trapping should be referred to a multidisciplinary centre for consideration of EBVs.

COPD is associated with increased pro-inflammatory CD28null CD8 T and NKT-like cells in the small airways.

We previously showed increased steroid-resistant CD28null CD8+ senescent lymphocyte subsets in the peripheral blood from patients with chronic obstructive pulmonary disease (COPD). These cells expressed decreased levels of the glucocorticoid receptor (GCR), suggesting their contribution to the steroid-resistant property of these cells. COPD is a disease of the small airways (SA). We, therefore, hypothesized that there would be a further increase in these steroid-resistant lymphocytes in the lung, particularly in the SA. We further hypothesized that the pro-inflammatory/cytotoxic potential of these cells could be negated using prednisolone with low-dose cyclosporin A. Blood, bronchoalveolar lavage, large proximal, and small distal airway brushings were collected from 11 patients with COPD and 10 healthy aged-matched controls. The cytotoxic mediator granzyme b, pro-inflammatory cytokines IFNγ/TNFα, and GCR were determined in lymphocytes subsets before and after their exposure to 1µM prednisolone and/or 2.5 ng/mL cyclosporin A. Particularly in the SA, COPD subjects showed an increased percentage of CD28null CD8 T-cells and NKT-like cells, with increased expression of granzyme b, IFNγ and TNFα and a loss of GCR, compared with controls. Significant negative correlations between SA GCR expression and IFNγ/TNFα production by T and NKT-like cells (eg, T-cell IFNγ R = -0.834, P = 0.031) and with FEV1 (R = -0.890) were shown. Cyclosporine A and prednisolone synergistically increased GCR expression and inhibited pro-inflammatory cytokine production by CD28null CD8- T and NKT-like cells. COPD is associated with increased pro-inflammatory CD28null CD8+ T and NKT-like cells in the SA. Treatments that increase GCR in these lymphocyte subsets may improve the efficacy of clinical treatment.

Pulmonary Disease Is Associated With Human T-Cell Leukemia Virus Type 1c Infection: A Cross-sectional Survey in Remote Aboriginal Communities.

BACKGROUND: The human T-cell leukemia virus type 1 (HTLV-1) subtype c is endemic to central Australia. We report the first large-scale, community-based, health survey of HTLV-1 and its disease associations in this setting. METHODS: Aboriginal community residents aged >2 years in 7 remote communities were invited to do a health survey that included a questionnaire, spirometry, and clinical examination by a physician blinded to HTLV-1 status, clinical records, and spirometry results. Blood was drawn for HTLV-1 serology and proviral load (PVL). Pulmonary disease was assessed clinically and spirometrically and, where records were available, radiologically after the clinical assessment. Associations between specific diseases and HTLV-1 status were determined using logistic regression, adjusting for available confounders. RESULTS: Overall, 579 residents (164 children aged 3-17 years; 415 adults) were examined (37.7% of the estimated resident population). HTLV-1 prevalences for children and adults were 6.1% and 39.3%, respectively. No associations were found between HTLV-1 and any assessed clinical condition among children. Chronic pulmonary disease and gait abnormalities were more common among adults with HTLV-1 infection. Adjusted odds ratios among participants with PVL ≥1000 per 105 peripheral blood leukocytes were 7.08 (95% confidence interval [CI], 2.67-18.74; P < .001), 9.81 (95% CI, 3.52-27.35; P < .001), and 14.4 (95% CI, 4.99-41.69; P < .001) for clinically defined chronic pulmonary disease, moderate-severe expiratory airflow limitation, and radiologically determined bronchiectasis/bronchiolitis, respectively, and 5.21 (95% CI, 1.50-18.07; P = .009) for gait abnormalities. CONCLUSIONS: In the first study of HTLV-1 disease associations based on community recruitment and blinded assessment, HTLV-1 infection was strongly associated with pulmonary disease and gait abnormalities.

Human T-cell leukaemia virus type 1 associated pulmonary disease: clinical and pathological features of an under-recognised complication of HTLV-1 infection.

The lung is one of several organs that can be affected by HTLV-1 mediated inflammation. Pulmonary inflammation associated with HTLV-1 infection involves the interstitium, airways and alveoli, resulting in several clinical entities including interstitial pneumonias, bronchiolitis and alveolitis, depending on which structures are most affected. Augmentation of the inflammatory effects of HTLV-1 infected lymphocytes by recruitment of other inflammatory cells in a positive feedback loop is likely to underlie the pathogenesis of HTLV-1 associated pulmonary disease, as has been proposed for HTLV-1 associated myelopathy. In contrast to the conclusions of early case series, HTLV-1 associated pulmonary disease can be associated with significant parenchymal damage, which may progress to bronchiectasis where this involves the airways. Based on our current understanding of HTLV-1 associated pulmonary disease, diagnostic criteria are proposed.

Use of Ventilation-Perfusion Single-Photon Emission Computed Tomography to Select the Target Lobe for Endobronchial Valve Lung Volume Reduction.

BACKGROUND: Quantitative planar ventilation-perfusion (VQ) has a complementary role in target lobe selection for endobronchial valve lung volume reduction (EBV-LVR), especially in homogenous disease. We investigated a novel method of lung lobar quantitation using VQ single-photon emission computed tomography (SPECT) with computed tomography (CT) to generate a parameter called the ventilation-perfusion differential index (VQDI). AIM: The aim of this study was to validate VQDI as a parameter for target lobe selection in EBV-LVR against the gold standard test of quantitative computed tomography (qCT). METHODS: This study was a prospective, multi-centre, single-blinded, observational study of EBV-LVR patients. Baseline and 3-month post intervention VQ SPECT and qCT were performed. The target lobe was chosen using qCT and planar VQ report (CTTL) whilst blinded to VQDI. Post EBV-LVR, our nuclear physician, blinded to CTTL, selected a target lobe using deidentified VQDI (VQDITL). Inter-rater agreement between CTTL and VQDITL was calculated by Kappa statistic. Treatment outcomes were analysed with a linear mixed-effects model. RESULTS: There was a high concordance between CTTL and VQDITL in 16 patients (89%, Kappa statistic = 0.85). Post EBV-LVR, our subjects showed significant changes in FEV1 (mean difference [MD] +150 mL, p < 0.001), target lobe volume reduction (MD -973 mL, p < 0.001), residual volume (MD -800 mL, p < 0.001), and St. George's Respiratory Questionnaire score (MD -11, p = 0.001). Improvements in 6-minute walk distances did not reach statistical significance. CONCLUSION: In this study of treatment responders, EBV-LVR target lobe selection using VQDI concurs with qCT and thus supports its value for this purpose. It complements qCT and may potentially be of synergistic value especially in homogenous emphysema.

Respiratory surveillance for coal mine dust and artificial stone exposed workers in Australia and New Zealand: A position statement from the Thoracic Society of Australia and New Zealand.

Coal mine lung dust disease (CMDLD) and artificial stone (AS) silicosis are preventable diseases which have occurred in serious outbreaks in Australia recently. This has prompted a TSANZ review of Australia's approach to respiratory periodic health surveillance. While regulating respirable dust exposure remains the foundation of primary and secondary prevention, identification of workers with early disease assists with control of further exposure, and with the aims of preserving lung function and decreasing respiratory morbidity in those affected. Prompt detection of an abnormality also allows for ongoing respiratory specialist clinical management. This review outlines a medical framework for improvements in respiratory surveillance to detect CMDLD and AS silicosis in Australia. This includes appropriate referral, improved data collection and interpretation, enhanced surveillance, the establishment of a nationwide Occupational Lung Disease Registry and an independent advisory group. These measures are designed to improve health outcomes for workers in the coal mining, AS and other dust-exposed and mining industries.

Radial Endobronchial Ultrasound Greyscale Texture Analysis Using Whole-Lesion Analysis Can Characterise Benign and Malignant Lesions without Region-of-Interest Selection Bias.

BACKGROUND: Radial-probe endobronchial ultrasound (RP-EBUS) is predominantly used clinically for the localisation of peripheral pulmonary lesions prior to biopsy. However, the RP-EBUS image itself contains information that can characterise the aetiology of lesions. OBJECTIVES: The aim of this study was to show the utility of RP-EBUS image analysis using unconstrained regions of interest (ROIs) that utilise more image information and eliminate ROI selection bias. METHODS: We developed custom software to analyse RP-EBUS images digitally captured during clinical procedures. Unconstrained ROIs were mapped onto lesions. We computed first-order greyscale image statistics of minimum, maximum, mean, standard deviation and range of pixel intensities, and entropy. We also computed second-order greyscale texture features of contrast, correlation, energy and homogeneity. The results of image analysis were compared to gold-standard tissue diagnosis. Features from expert- and non-expert-defined ROIs were also compared. RESULTS: Eighty-five images were analysed (38 benign and 47 malignant). Five greyscale features were significantly different between benign and malignant lesions. Benign lesions had higher mean (p < 0.01) and maximal (p < 0.001) intensity, greater range (p < 0.001) of pixel intensities and greater entropy (p < 0.01). The highest positive predictive values were associated with maximal (87.8%) and range of pixel (83.8%) intensities. There were no significant differences between expert- and non-expert-defined ROIs. CONCLUSION: RP-EBUS image analysis using unconstrained ROIs eliminates ROI selection bias and can characterise benign and malignant lesions with an accuracy of up to 85%.

Airway epithelial cells exposed to wildfire smoke extract exhibit dysregulated autophagy and barrier dysfunction consistent with COPD.

BACKGROUND: Individuals with respiratory disease are being increasingly exposed to wildfire smoke as populations encroach further into forested regions and climate change continues to bring higher temperatures with lower rainfall. Frequent exposures have significant potential to accelerate conditions such as chronic obstructive pulmonary disease (COPD) which is characterised by an exaggerated inflammatory response to environmental stimuli. Here we employ models of human airway epithelium exposed to wildfire smoke-extract (WFSE) to examine modulation in airway epithelial cell (AEC) survival, fragility and barrier function. METHODS: Submerged cultures of small airway epithelial cells (SAEC) and differentiated air-liquid interface (ALI) cultures of primary bronchial AEC (bAEC) were treated for 1-24 h with 1-10% WFSE generated from plant species found in the Australian bushland. Autophagy (LC3-II and Sequestosome), apoptosis (Poly-(ADP)-Ribose Polymerase (PARP) cleavage) and tight junction proteins were measured using western blot. Barrier function was assessed via permeability of fluorescein tracers and measuring trans-epithelial electrical resistance. The production of IL-6 was assessed using ELISA. RESULTS: Primary epithelial models exposed to WFSE exhibited a significant blockade in autophagy as evidenced by an increase in LC3-II coupled with a concomitant elevation in Sequestosome abundance. These exposures also induced significant PARP cleavage indicative of apoptotic changes. ALI cultures of bAEC treated with 5% WFSE demonstrated barrier dysfunction with significant increases in paracellular molecular permeability and ionic conductance, and a reduction in the abundance of the tight junction proteins ZO-1 and Claudin-1. These cultures also exhibited increased IL-6 secretion consistent with the aberrant and pro-inflammatory repair response observed in the COPD airways. Further, blocks in autophagy and barrier disruption were significantly elevated in response to WFSE in comparison to similar exposures with cigarette smoke-extract. CONCLUSION: WFSE inhibits autophagic flux and induces barrier dysfunction in the airway epithelium. As autophagy is a central regulator of cellular repair, viability, and inflammation, targeting the block in autophagic flux may ameliorate the consequences of wildfire smoke-exposure for individuals with pre-existing respiratory conditions.

The uncoupling of autophagy and zinc homeostasis in airway epithelial cells as a fundamental contributor to COPD.

The proper regulation of zinc (Zn) trafficking proteins and the cellular distribution of Zn are critical for the maintenance of autophagic processes. However, there have been no studies that have examined Zn dyshomeostasis and the disease-related modulation of autophagy observed in the airways afflicted with chronic obstructive pulmonary disease (COPD). We hypothesized that dysregulated autophagy in airway epithelial cells (AECs) is related to Zn dysregulation in cigarette smoke (CS)-induced COPD. We applied a human ex vivo air-liquid interface model, a murine model of smoke exposure, and human lung tissues and investigated Zn, ZIP1, and ZIP2 Zn-influx proteins, autophagy [microtubule-associated 1A/1B-light chain-3 (LC3), Beclin-1], autophagic flux (Sequestosome), apoptosis [Bcl2; X-linked inhibitor of apoptosis (XIAP), poly (ADP)-ribose polymerase (PARP)], and inflammation [thymic stromal lymphopoietin (TSLP), regulated on activation, normal T cell expressed and secreted (RANTES), and IL-1ß]. Lung tissues from CS-exposed mice exhibit reduced free-Zn in AECs, with elevated ZIP1 and diminished ZIP2 expression. Interestingly, increased LC3 colocalized with ZIP1, suggesting an autophagic requirement for free-Zn to support its catabolic function. In human AECs, autophagy was initiated but was unable to efficiently degrade cellular debris, as evidenced by stable Beclin-1 and increased LC3-II, but with a concomitant elevation in Sequestosome. Autophagic dysfunction due to CS exposure coupled with Zn depletion also induced apoptosis, with the reduction of antiapoptotic and antiautophagic proteins Bcl2 and XIAP and PARP cleavage. This was accompanied by an increase in RANTES and TSLP, an activator of adaptive immunity. We conclude that the uncoupling of Zn trafficking and autophagy in AECs constitutes a fundamental disease-related mechanism for COPD pathogenesis and could provide a new therapeutic target.

Nonantibiotic macrolides restore airway macrophage phagocytic function with potential anti-inflammatory effects in chronic lung diseases.

We reported defective efferocytosis associated with cigarette smoking and/or airway inflammation in chronic lung diseases, including chronic obstructive pulmonary disease, severe asthma, and childhood bronchiectasis. We also showed defects in phagocytosis of nontypeable Haemophilus influenzae (NTHi), a common colonizer of the lower airway in these diseases. These defects could be substantially overcome with low-dose azithromycin; however, chronic use may induce bacterial resistance. The aim of the present study was therefore to investigate two novel macrolides-2'-desoxy-9-(S)-erythromycylamine (GS-459755) and azithromycin-based 2'-desoxy molecule (GS-560660)-with significantly diminished antibiotic activity against Staphylococcus aureus, Streptococcus pneumonia, Moraxella catarrhalis, and H. influenzae We tested their effects on efferocytosis, phagocytosis of NTHi, cell viability, receptors involved in recognition of apoptotic cells and/or NTHi (flow cytometry), secreted and cleaved intracellular IL-1ß (cytometric bead array, immunofluorescence/confocal microscopy), and nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) using primary alveolar macrophages and THP-1 macrophages ± 10% cigarette smoke extract. Dose-response experiments showed optimal prophagocytic effects of GS-459755 and GS-560660 at concentrations of 0.5-1 µg/ml compared with our findings with azithromycin. Both macrolides significantly improved phagocytosis of apoptotic cells and NTHi (e.g., increases in efferocytosis and phagocytosis of NTHi: GS-459755, 23 and 22.5%, P = 0.043; GS-560660, 23.5 and 22%, P = 0.043, respectively). Macrophage viability remained >85% following 24 h exposure to either macrolide at concentrations up to 20 µg/ml. Secreted and intracellular-cleaved IL-1ß was decreased with both macrolides with no significant changes in recognition molecules c-mer proto-oncogene tyrosine kinase; scavenger receptor class A, member 1; Toll-like receptor 2/4; or CD36. Particulate cytoplasmic immunofluorescence of NLRP3 inflammasome was also reduced significantly. We conclude that GS-459755 and GS-560660 may be useful for reducing airway inflammation in chronic lung diseases without inducing bacterial resistance.

Reduced DNA methylation of sphingosine-1 phosphate receptor 5 in alveolar macrophages in COPD: A potential link to failed efferocytosis.

BACKGROUND AND OBJECTIVE: We previously showed that alveolar macrophages from COPD patients are defective in their ability to phagocytose apoptotic cells ('efferocytosis') and that this defect is potentially linked to the sphingosine-1 phosphate (S1P) system, in particular the sphingosine-1 phosphate receptor 5 (S1PR5). In alveolar macrophages from COPD patients, S1PR5 mRNA expression levels increased and were correlated with both lung function and efferocytosis. However, it us unknown whether these changes are under epigenetic control via DNA methylation or whether DNA methylation directly modulates macrophage function. METHODS: Bisulfite sequencing was used to assess DNA methylation levels at CpG islands associated with genes encoding selected S1P system components, including sphingosine kinase 1 (SPHK1), S1PR1 and S1PR5, in alveolar macrophages from 20 COPD patients, 7 healthy smokers and 10 healthy non/ex-smokers) by methyl quantitative real-time PCR (methyl qPCR). The effect of the DNA methyltransferase inhibitor, 5-azacytidine on the efferocytosis capacity of THP-1 macrophages was assessed using flow cytometry. RESULTS: Among the S1P system genes examined, S1PR5 was the single target that showed significant changes in DNA methylation between patient groups. Alveolar macrophages isolated from COPD patients showed lower methylation levels in the same region compared to macrophages from non/ex-smokers. in vitro studies using THP-1 macrophages showed that DNA demethylation with 5-azacytidine increased the efferocytosis capacity and dose-dependently rescued the cells from the cigarette smoke-induced defect in efferocytosis. CONCLUSION: Macrophage function can be modulated epigenetically. Reduced methylation may underlie the increased expression of the S1PR5 gene in alveolar macrophages and associated defective efferocytosis in COPD.

Climate and season: the effects on ophthalmic diseases.

Seasonal changes and climate have a significant impact on human health. Diseases influenced by temperature and climate conditions are likely to undergo dynamic pattern shifts with consequent impact on human health. A number of infectious and non-infectious ophthalmic diseases are influenced by temperature and seasonality. Awareness of this is important from public and global health perspective in addition to resource allocation strategies. We examine the evidence for a seasonal pattern to ophthalmic diseases and assess the possible impact of climate change.

Steroid resistance in COPD is associated with impaired molecular chaperone Hsp90 expression by pro-inflammatory lymphocytes.

BACKGROUND: Corticosteroid resistance is a major barrier to effective treatment of COPD. We have shown that the resistance is associated with decreased expression of glucocorticoid receptor (GCR) by senescent CD28nullCD8+ pro-inflammatory lymphocytes in peripheral blood of COPD patients. GCR must be bound to molecular chaperones heat shock proteins (Hsp) 70 and Hsp90 to acquire a high-affinity steroid binding conformation, and traffic to the nucleus. We hypothesized a loss of Hsp70/90 from these lymphocytes may further contribute to steroid resistance in COPD. METHODS: Blood was collected from COPD (n = 10) and aged-matched controls (n = 10). To assess response to steroids, cytotoxic mediators, intracellular pro-inflammatory cytokines, CD28, GCR, Hsp70 and Hsp90 were determined in T and NKT-like cells in the presence of ± 10 µM prednisolone and 2.5 ng/mL cyclosporine A (binds to GCR-Hsp70/90 complex) using flow cytometry, western blot and fluorescence microscopy. RESULTS: A loss of expression of Hsp90 and GCR from CD28null CD8+ T and NKT-like cells in COPD was noted (Hsp70 unchanged). Loss of Hsp90 expression correlated with the percentage of CD28null CD8+ T and NKT-like cells producing IFNγ or TNFα in all subjects (eg, COPD: R = -0.763, p = 0.007 for T-cell IFNγ). Up-regulation of Hsp90 and associated decrease in pro-inflammatory cytokine production was found in CD28nullCD8+ T and NKT-like cells in the presence of 10 µM prednisolone and 2.5 ng/mL cyclosporine A. CONCLUSIONS: Loss of Hsp90 from cytotoxic/pro-inflammatory CD28nullCD8+ T and NKT-like cells could contribute to steroid resistance in COPD. Combination prednisolone and low-dose cyclosporine A therapy inhibits these pro-inflammatory cells and may reduce systemic inflammation in COPD.

Pro-phagocytic Effects of Thymoquinone on Cigarette Smoke-exposed Macrophages Occur by Modulation of the Sphingosine-1-phosphate Signalling System.

Oxidative stress, inflammation, increased bronchial epithelial cell apoptosis, and deficient phagocytic clearance of these cells (efferocytosis) by the alveolar macrophages are present in chronic obstructive pulmonary disease (COPD) and in response to cigarette smoke. We previously showed that the macrophage dysfunction is associated with changes to the sphingosine-1-phosphate (S1P) signalling system. We hypothesized that the antioxidant/anti-inflammatory agent, thymoquinone, would improve macrophage phagocytosis via modulation of the S1P system and protect bronchial epithelial cells from cigarette smoke or lipopolysaccharide (LPS)-induced apoptosis. Phagocytosis was assessed using flow cytometry, S1P mediators by Real-Time PCR, and apoptosis of 16HBE bronchial epithelial cells using flow cytometry and immunohistochemistry. Cigarette smoke and LPS decreased phagocytosis and increased S1P receptor (S1PR)-5 mRNA in THP-1 macrophages. Thymoquinone enhanced efferocytic/phagocytic ability, antagonized the effects of cigarette smoke extract and LPS on phagocytosis and S1PR5, and protected bronchial epithelial cells from cigarette smoke-induced apoptosis. Thymoquinone is worth further investigating as a potential therapeutic strategy for smoking-related lung diseases.

Lymphocyte senescence in COPD is associated with decreased histone deacetylase 2 expression by pro-inflammatory lymphocytes.

BACKGROUND: Histone acetyltransferases (HAT) and histone deacetylases (HDAC) are enzymes that upregulate and down-regulate pro-inflammatory gene transcription respectively. HDAC2 is required by corticosteroids to switch off activated inflammatory genes and is reduced in lung macrophages in COPD. We have shown that COPD patients have increased steroid resistant CD28null (senescent) pro-inflammatory T and NKT-like peripheral blood cells (particularly CD8+ subsets) and we hypothesized that these changes would be associated with a loss of HDAC2 from these senescent pro-inflammatory lymphocytes. METHODS: Blood was collected from 10 COPD and 10 aged-matched controls. Intracellular pro-inflammatory cytokines, IFNγ and TNFα, and expression of CD28, HDAC2 and HAT, were determined in lymphocyte subsets in the presence of ± 5 mg/ml theophylline (HDAC2 activator), 10 µM prednisolone and 2.5 ng/ml cyclosporine A (immunosuppressant), using flow cytometry. RESULTS: There was a loss of HDAC2 from CD28null CD8+ T and NKT-like cells in COPD. There was a significant negative correlation between HDAC2 expression and the percentage of CD28null CD8+ T and NKT-like cells producing IFNγ or TNFα in all subjects (eg, COPD: R = -.763, p < 0.001 for T-cell IFNγ). There was a synergistic upregulation of HDAC2 and associated decrease in pro-inflammatory cytokine production in CD28nullCD8+ T and NKT-like cells in the presence of 5 mg/L theophylline + 10(-6) M prednisolone or 2.5 ng/mL cyclosporine A (CsA). CONCLUSIONS: Lymphocyte senescence in COPD is associated with loss of HDAC2 in CD28nullCD8+ T and NKT-like cells. Alternative treatment options such as combined theophylline with low-dose CsA, that inhibit these pro-inflammatory cells, may reduce systemic inflammation in COPD.

Lymphocyte senescence in COPD is associated with loss of glucocorticoid receptor expression by pro-inflammatory/cytotoxic lymphocytes.

BACKGROUND: Glucocorticoid (GC) resistance is a major barrier in COPD treatment. We have shown increased expression of the drug efflux pump, Pgp1 in cytotoxic/pro-inflammatory lymphocytes in COPD. Loss of lymphocyte co-stimulatory molecule CD28 (lymphocyte senescence) was associated with a further increase in their pro-inflammatory/cytotoxic potential and resistance to GC. We hypothesized that lymphocyte senescence and increased Pgp1 are also associated with down-regulation of the GC receptor (GCR). METHODS: Blood was collected from 10 COPD and 10 healthy aged-matched controls. Flow cytometry was applied to assess intracellular pro-inflammatory cytokines, CD28, Pgp1, GCR, steroid binding and relative cytoplasm/nuclear GCR by CD28+ and CD28null T, NKT-like cells. GCR localization was confirmed by fluorescent microscopy. RESULTS: COPD was associated with increased numbers of CD28nullCD8+ T and NKT-like cells. Loss of CD28 was associated with an increased percentage of T and NKT-like cells producing IFNγ or TNFα and associated with a loss of GCR and Dex-Fluor staining but unchanged Pgp1. There was a significant loss of GCR in CD8 + CD28null compared with CD8 + CD28+ T and NKT-like cells from both COPD and controls (eg, mean ± SEM 8 ± 3% GCR + CD8 + CD28null T-cells vs 49 ± 5% GCR + CD8 + CD28+ T-cells in COPD). There was a significant negative correlation between GCR expression and IFNγ and TNFα production by T and NKT-like cells(eg, COPD: T-cell IFNγ R = -.615; ) and with FEV1 in COPD (R = -.777). CONCLUSIONS: COPD is associated with loss of GCR in senescent CD28null and NKT-like cells suggesting alternative treatment options to GC are required to inhibit these pro-inflammatory/cytotoxic cells.

Increased CD8 T-cell granzyme B in COPD is suppressed by treatment with low-dose azithromycin.

BACKGROUND AND OBJECTIVE: Corticosteroid resistance in chronic obstructive pulmonary disease (COPD) is a major challenge. We have reported increased bronchial epithelial cell apoptosis and increased airway CD8 T-cell numbers in COPD. Apoptosis can be induced via the serine protease, granzyme B. However, glucocorticosteroids fail to adequately suppress granzyme B production by CD8 T cells. We previously showed that low-dose azithromycin reduced airways inflammation in COPD subjects and we hypothesized that it would also reduce granzyme B production by CD8 T cells. METHODS: We administered 250 mg azithromycin daily for 5 days then twice weekly (total 12 weeks) to 11 COPD subjects (five current smokers; six ex-smokers) and assessed granzyme B in the airway (bronchoalveolar lavage), intra-epithelial compartment and peripheral blood, collected before and following administration of azithromycin. To then dissect the effects of on CD4 and CD8 T-cell subsets, we applied an in vitro assay and physiologically relevant concentrations of azithromycin (and, for comparison, n-acetyl cysteine) and stimulation of peripheral blood mononuclear cells from five healthy subjects with CD3/CD28 T-cell expander. RESULTS: T-cell granzyme B production in both airway and intra-epithelial compartments was reduced in COPD patients following 12 weeks of azithromycin treatment, with no significant effect in blood. Both azithromycin and n-acetyl cysteine suppressed CD4 T-cell granzyme B production, but only azithromycin was effective at reducing CD8+ T-cell granzyme B production in vitro. CONCLUSIONS: We provide further evidence for the application of low-dose azithromycin as an attractive adjunct treatment option for controlling epithelial cell apoptosis, abnormal airway repair and chronic inflammation in COPD.