Raymond J. Sapsford

Relation of sputum inflammatory markers to symptoms and lung function changes in COPD exacerbations

BACKGROUND Although it is presumed that exacerbations of chronic obstructive pulmonary disease (COPD) are associated with increased airway inflammation, there is little information available on inflammatory markers during an exacerbation and the relationship with severity or time course of recovery. A study was undertaken to investigate the sputum cell and cytokine characteristics of COPD when stable and during an exacerbation. METHODS Induced sputum samples from 57 patients with moderate to severe COPD were analysed (44 samples were taken during a stable period and 37 during an exacerbation). The patients recorded daily symptoms on diary cards. Cell counts and sputum levels of interleukin (IL)-6 and IL-8 were measured. RESULTS Patients with ⩾3 exacerbations/year had higher median stable sputum levels of IL-6 (110 (95% CI 11 to 215) pg/ml) and IL-8 (6694 (95% CI 3120 to 11995) pg/ml) than those with ⩽2 exacerbations/year (22 (95% CI 12 to 93) and 1628 (95% CI 607 to 4812) pg/ml, respectively). Median IL-6 levels were increased during exacerbations compared with stable conditions. The levels of IL-6 during exacerbations were related to the presence of a cold and to the total cell count and eosinophil and lymphocyte numbers, while IL-8 was positively correlated with all sputum cell counts. Sputum cell counts and cytokine levels during an exacerbation did not predict the size and duration of lung function changes in the exacerbation. CONCLUSIONS Patients with more frequent exacerbations have higher baseline sputum cytokine levels, which may predict the frequency of future exacerbations.

Inflammatory changes, recovery and recurrence at COPD exacerbation

Chronic obstructive pulmonary disease (COPD) exacerbations are associated with increased airway and systemic inflammation, though relationships between exacerbation recovery, recurrent exacerbation and inflammation have not been previously reported. In the present study, inflammatory changes at COPD exacerbations were related to clinical nonrecovery and recurrent exacerbations within 50 days. Serum interleukin (IL)-6, C-reactive protein (CRP), sputum IL-6 and IL-8 were measured in 73 COPD patients when stable, at exacerbation and at 7, 14 and 35 days post-exacerbation. In 23% of patients, symptoms did not recover to baseline by day 35. These patients had persistently higher levels of serum CRP during the recovery period. A total of 22% of the patients who had recurrent exacerbations within 50 days had significantly higher levels of serum CRP at day 14, compared with those without recurrences: 8.8 mg·L−1 versus 3.4 mg·L−1. Frequent exacerbators had a smaller reduction in systemic inflammation between exacerbation onset and day 35 compared with infrequent exacerbators. Nonrecovery of symptoms at chronic obstructive pulmonary disease exacerbation is associated with persistently heightened systemic inflammation. The time course of systemic inflammation following exacerbation is different between frequent and infrequent exacerbators. A high serum C-reactive protein concentration 14 days after an index exacerbation may be used as a predictor of recurrent exacerbations within 50 days.

Sputum and plasma endothelin-1 levels in exacerbations of chronic obstructive pulmonary disease

BACKGROUND Endothelin (ET)-l is a bronchoconstrictor peptide produced in the airways. It has been implicated in the pathogenesis of asthma and virally mediated airway inflammation and may play a role in exacerbations of chronic obstructive pulmonary disease (COPD). METHODS Seventy one patients with COPD were followed prospectively and sampled for plasma and sputum ET-1 levels when stable and during an exacerbation. Sputum was also examined for cytokines, human rhinovirus, and Chlamydia pneumoniae. RESULTS Plasma ET-1 levels were available for 67 patients with stable COPD (mean (SD) 0.58 (0.31) pg/ml); 28 pairs of stable-exacerbation plasma samples had a mean stable ET-1 level of 0.54 (0.30) pg/ml rising to 0.67 (0.35) pg/ml at exacerbation (mean difference 0.13, 95% confidence interval (CI) 0.04 to 0.21, p = 0.004). Plasma ET-1 levels in the 67 patients with stable COPD were inversely correlated with baseline forced expiratory volume in one second (FEV1;r = –0.29, p = 0.022) and forced vital capacity (FVC; r = –0.38, p = 0.002). The change in plasma ET-1 levels during an exacerbation correlated with the change in oxygen saturation (Sao 2;r = –0.41, p = 0.036). In 14 stable-exacerbation pairs of sputum samples median stable ET-1 levels were 5.37 (0.97–21.95) pg/ml rising to 34.68 (13.77–51.95) pg/ml during an exacerbation (mean difference 25.14, 95% CI 3.77 to 46.51, p = 0.028). This increase in sputum ET-1 levels correlated with the increase in plasma ET-1 levels (r = 0.917, p = 0.001) and sputum interleukin (IL)-6 levels (r = 0.718, p = 0.013). CONCLUSIONS Sputum levels of ET-1 rise in COPD patients during an exacerbation and this is reflected by a smaller rise in plasma ET-1 levels. ET-1 may have a role in mediating airway inflammatory changes during exacerbations of COPD.

Comparison of spontaneous and induced sputum for investigation of airway inflammation in chronic obstructive pulmonary disease

BACKGROUND Although sputum induction is used as a technique to investigate lower airway inflammation in asthmatic subjects, advantages over spontaneous sputum in patients with chronic obstructive pulmonary disease (COPD) have not been investigated. METHODS Samples of spontaneous sputum and sputum induced with 3% hypertonic saline for 14 minutes were collected from 27 patients with chronic obstructive pulmonary disease (COPD) who usually produced spontaneous sputum. Spirometric indices and oxygen saturation (Sao 2) were measured at seven minute intervals. The spontaneous, seven and 14 minute sputum samples were analysed for total and differential cell counts, cell viability, and interleukin 8 levels. RESULTS Analysis of the sputum revealed that median cell viability was higher in the seven minute (62.8%; p = 0.004) and 14 minute (65%; p = 0.001) induced sputum samples than in spontaneous sputum (41.2%). There was no significant difference in total and differential cell counts or in interleukin 8 levels between spontaneous and induced sputum. During the sputum induction procedure the mean (SD) fall in forced expiratory volume in one second (FEV1) was 0.098 (0.111) l (p < 0.001) and in forced vital capacity (FVC) was 0.247 (0.233) l (p < 0.001). There was a small but significant fall in Sao 2 during sputum induction (p = 0.03). CONCLUSIONS Induced sputum contains a higher proportion of viable cells than spontaneous sputum. There are no significant differences between the sputum samples obtained at seven minutes and at 14 minutes of hypertonic saline nebulisation. Sputum induction is safe and well tolerated in patients with COPD.

Human rhinovirus infection during naturally occurring COPD exacerbations

Human rhinovirus (HRV) infection is an important trigger of exacerbations of chronic obstructive pulmonary disease (COPD) but its role in determining exacerbation frequency phenotype or the time-course of HRV infection in naturally occurring exacerbations is unknown. Sputum samples from 77 patients were analysed by real-time quantitative PCR for both HRV (388 samples), and Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis (89 samples). Patients recorded worsening of respiratory symptoms on daily diary cards, from which exacerbations were identified. HRV prevalence and load at exacerbation presentation were significantly higher than in the stable state (prevalence 53.3% versus 17.2%, respectively; p<0.001) but 0% by day 35 post-exacerbation. HRV load was higher in patients with cold symptoms (p=0.046) or sore throats (p=0.006) than those without. 73% of bacterium-negative but HRV-positive exacerbations were bacterium-positive by day 14. Patients with HRV detected at exacerbation had a higher exacerbation frequency (interquartile range) of 3.01 (2.02–5.30) per year compared with patients without HRV (2.51 (2.00–3.51)) (p=0.038). HRV prevalence and load increased at COPD exacerbation, and resolved during recovery. Frequent exacerbators were more likely to experience HRV infection. Secondary bacterial infection is common after HRV infection, and provides a possible mechanism for exacerbation recurrence and a potential target for novel therapies. Increased HRV prevalence and load are aetiological factors in natural COPD exacerbations and frequent exacerbations http://ow.ly/tlscz

Airway epithelial inflammatory responses and clinical parameters in COPD

This study examined inflammatory responses from primary cultured human bronchial epithelial cells in chronic obstructive pulmonary disease (COPD) and the clinical factors modulating them. Epithelial cells from bronchoscopic biopsies from 14 patients with COPD ((mean±sd) age 74.6±5.7 yrs, forced expiratory volume in one second (FEV1) 1.21±0.36 L, FEV1 % predicted 51.1±15.8%, 51.5±24.0 pack-yrs of smoking, inhaled steroid dosage 1237.5±671.0 µg·day−1, Medical Research Council (MRC) dyspnoea score 3.18±1.33) and eight current/exsmokers with normal pulmonary function (age 60.4±13.5 yrs, FEV1 2.66±1.27 L, FEV1 % pred 89.6±17.7%, 49±44 pack-yrs of smoking, MRC dyspnoea score 1±0) were grown in primary culture and exposed to 50 ng·mL−1 tumour necrosis factor‐α. Stimulated COPD cells produced significantly more interleukin (IL)‐6 at 24 and 48 h, and IL‐8 at 6 and 24 h than unstimulated COPD cells. This response was not seen in cells from current/exsmokers. IL‐6 and IL‐8 production was lower in COPD patients taking inhaled steroids. Following an inflammatory stimulus, bronchial epithelial cells in chronic obstructive pulmonary disease show a significant cytokine response not seen in smokers with normal pulmonary function and this may be modified by inhaled steroid therapy.

Dose response of continuous positive airway pressure on nasal symptoms, obstruction and inflammation in vivo and in vitro

Obstructive sleep apnoea is a common condition associated with cardiovascular risk. Continuous positive airway pressure (CPAP) is an effective treatment but is associated with nasal side-effects, which hinder compliance and may result from inflammation. We investigated whether CPAP was pro-inflammatory to human subjects in vivo, and to cultured bronchial epithelial cells in vitro. In vivo, we further investigated whether induction of nasal inflammation was associated with the development of systemic inflammation, nasal symptoms and changes in nasal mucociliary clearance. In vitro, CPAP resulted in cytokine release from cultured BEAS-2B cells in a time- and dose (pressure)-dependent manner. In vivo, CPAP resulted in dose-dependent upregulation of nasal inflammatory markers associated with the development of nasal symptoms, and reduced mucociliary clearance. CPAP also upregulated selected markers of systemic inflammation. CPAP results in dose-dependent release of inflammatory cytokines from human epithelial cells in vitro and in vivo. In vivo responses were associated with systemic inflammation, reductions in nasal mucociliary function and the development of nasal symptoms. This emphasises the need for novel strategies to reduce nasal inflammation and therefore aid compliance.

Intersession repeatability of a novel nasal lavage technique

This study describes a novel nasal lavage method using a pediatric tracheostomy tube and examines intersession repeatability for several clinically and technically relevant parameters. Fourteen healthy subjects were included in this study. Both nasal cavities were washed using a standard amount of saline solution (7 mL) via a pediatric tracheostomy tube, and the 2 samples were pooled for measurement of cytokine concentrations and cell count. Recovery volume was also recorded. For each subject, measurements were repeated on 5 consecutive days. Intersession repeatability of recovery volume, cell count, and cytokine concentrations interleukin (IL)-6 and IL-8 were expressed in terms of mean coefficient of variation, intraclass correlation coefficient, and interitem correlations. Intraclass correlation coefficients and interitem correlation coefficients indicated almost perfect agreement for cell count and IL-8 concentrations. Recovery volume and IL-6 concentrations were more variable. The mean coefficient of variation was low for cell count (2%), IL-8 concentration (3%), and recovery volume (3%), whereas the mean percentage recovery was high (87%). This newly developed nasal lavage technique is repeatable over successive sessions for cytokine concentrations and cell counts in nasal secretions of healthy subjects. This method might be valuable in the study of inflammatory conditions involving the upper respiratory tract.

Randomized Double-Blind Controlled Trial of Roflumilast at Acute Exacerbations of Chronic Obstructive Pulmonary Disease

the respective sites of disease to identify common pathways that can underpin dissection of the fundamental pathological process. This approach may elucidate the disease mechanisms in pulmonary TB, which continues to be poorly understood and for which standard treatment has remained unchanged for 40 years and vaccination for almost 100 years (9). Defining an autoimmune process that exacerbates pathology in TB would help inform emerging host-directed therapies, to limit the lung-tissue destruction that results in mortality and potentially to accelerate cure (10), as well as avoid vaccination strategies that may inadvertently exacerbate lung destruction and transmission. n

P116 Serum PARC (CCL18) and exacerbation frequency in COPD

Introduction Patients with Chronic Obstructive Pulmonary Disease (COPD) experience intermittent exacerbations. The frequency of exacerbations varies amongst patients but the ‘Frequent Exacerbator’ appears to be an independent disease phenotype. As frequent exacerbations are associated with more rapid lung function decline, a validated biomarker is needed to identify those susceptible, prompting rigorous medical treatment and aiding selective recruitment to clinical trials. Pulmonary and Activation-Regulated Chemokine (PARC/CCL18) is a plausible biomarker based on previous reports in other respiratory diseases, making it worthy of study in COPD. Methods PARC was measured using ELISA in serum samples from 115 patients enrolled in The London COPD cohort, including 44 paired samples taken at baseline and exacerbation (pre-treatment). PARC was assessed with relation to exacerbation frequency and other inflammatory markers. Results The study cohort comprised of 77 males, 34 current smokers, mean age 69.6 years (SD 9.1), FEV1 1.13 (0.47) l (45.3 (18.0)% predicted), baseline PARC concentration 124 ng/ml (40.4), median (IQR) exacerbation frequency 1.8/year (0.6–3.0). Higher PARC concentration was associated with more frequent exacerbations (r=0.22, p=0.035). PARC was not related to age, sex, BMI, disease severity (FEV1), or smoking pack years (all p>0.05). Significantly lower PARC concentrations were found in current smokers compared to ex-smokers, 112 ng/ml vs 130 ng/ml respectively (p=0.036). PARC did not change from baseline to exacerbation (131 ng/ml vs 125 ng/ml, p=0.256), and the correlation between PARC in the two states was highly significant (r=0.53, p<0.0001). PARC was related to baseline CRP (r=0.28, p=0.013) and blood eosinophil count (r=0.39, p=0.001), with no significant associations at exacerbation, and no relationship with neutrophils or total white blood cell count. Conclusion A relationship has been demonstrated between serum PARC concentration and exacerbation frequency in patients with COPD. Correlations between PARC, eosinophils and CRP indicate that this biomarker may identify a subset of patients with a particular inflammatory profile, suggesting specific treatment options. Further work should be carried out to explore the relevance of PARC as a biomarker in the COPD population.