Changes in sputum T-lymphocyte subpopulations at the onset of severe exacerbations of chronic obstructive pulmonary disease

CD8+ve T-cell responses play a primary role in chronic obstructive pulmonary disease (COPD), but there is little information regarding COPD exacerbations. Sputum induction is a relatively non-invasive and safe method to study airway inflammation. The aim of the study was to investigate changes in airway T-lymphocyte subpopulations at the onset of severe COPD exacerbations via analysis of sputum. Induced sputum samples were collected from 12 COPD patients aged (mean+/-sd) 69+/-7 years, ex-smokers (68+/-23 pack-years), mean FEV1 (%predicted) 40+/-14 at the onset of an acute severe exacerbation requiring hospital admission and 16 weeks after remission of the exacerbation. Inflammatory cells and T-lymphocyte subpopulations (CD4, CD8, Tc1, Tc2) were measured using chemical and double immunocytochemical methods. Increased percentages of sputum neutrophils (P=0.002) and decreased CD4/CD8 and CD8-IFNgamma/CD8-IL4+ve (Tc1/Tc2) cell ratios (P=0.03, P=0.02, respectively) were found at the onset of exacerbation compared to stable state. We conclude that a CD8+ve type-2-mediated immune response is induced at the onset of severe COPD exacerbation.     

CD8+T细胞在慢性阻塞性肺疾病发病机制中的作用

研究表明CD8^＋T细胞在吸烟导致的慢性阻塞性肺疾病（COPD）发病的各个环都起着非常重要的作用。本文就CD8^＋T细胞在COPD发病机制中的研究进展作一简要综述。     

Th17与CD8+T细胞在慢性阻塞性肺疾病中的作用

慢性阻塞性肺疾病(COPD)是由吸烟诱导的,影响肺实质及气道的慢性炎性疾病.Th17细胞能分泌多种细胞因子促进中性粒细胞聚集活化,并增加CD8+T细胞数量,在COPD发病机制中发挥重要作用.在不同炎性微环境中,Thl7细胞与CD8+T细胞共同参与COPD发病,连接COPD的先天免疫反应及后天免疫反应.     

CD8+ve cells in the lungs of smokers with chronic obstructive pulmonary disease.

Previous studies have shown an increased number of inflammatory cells and, in particular, CD8+ve cells in the airways of smokers with chronic obstructive pulmonary disease (COPD). In this study we investigated whether a similar inflammatory process is also present in the lungs, and particularly in lung parenchyma and pulmonary arteries. We examined surgical specimens from three groups of subjects undergoing lung resection for localized pulmonary lesions: nonsmokers (n = 8), asymptomatic smokers with normal lung function (n = 6), and smokers with COPD (n = 10). Alveolar walls and pulmonary arteries were examined with immunohistochemical methods to identify neutrophils, eosinophils, mast cells, macrophages, and CD4+ve and CD8+ve cells. Smokers with COPD had an increased number of CD8+ve cells in both lung parenchyma (p < 0.05) and pulmonary arteries (p < 0.001) as compared with nonsmokers. CD8+ve cells were also increased in pulmonary arteries of smokers with COPD as compared with smokers with normal lung function (p < 0.01). Other inflammatory cells were no different among the three groups. The number of CD8+ve cells in both lung parenchyma and pulmonary arteries was significantly correlated with the degree of airflow limitation in smokers. These results show that an inflammatory process similar to that present in the conducting airways is also present in lung parenchyma and pulmonary arteries of smokers with COPD.     

Induced sputum and other outcome measures in chronic obstructive pulmonary disease: safety and repeatability

The forced expiratory volume in 1 sec (FEV1) is the most established outcome measure in chronic obstructive pulmonary disease (COPD). However, changes in FEV1 in response to treatment are small in relation to the repeatability of the measurement and there is increasing interest in other measures including markers of lower airway inflammation in induced sputum, assessment of symptoms and health status using visual analogue scores, and questionnaires. Little is known about the repeatability of these measures or the safety of sputum induction in COPD.We have assessed the safety of sputum induction in 61 subjects with moderate and severe COPD who participated in a placebo-controlled cross-over study The within-subject repeatability of sputum markers of airway inflammation, health status using the chronic respiratory disease questionnaire (CRQ) and symptom visual analogue scores (VAS) were estimated from the data obtained from before and after 2 weeks of treatment with placebo. Sputum induction was performed on 122 occasions and was successful resulting in a cytospin adequate to assess a differential cell count in 95% of inductions. The group mean (SEM) FEV1 was 1.09 (0.05)[41.6 (2.9)% predicted] and the mean (SEM) fall in FEV1 after sputum induction was 120 ml (6) and % fall 10.9% (0.55%). Seven inductions were stopped due to a fall in FEV1 >20% and at a further 13 visits the full sputum induction protocol was not completed due to development of symptoms. The reproducibility of measurements, calculated by the intra-class correlation coefficient, was relatively high for all indices measured (0.4-0.95) with the exception ofthe proportion of lymphocytes (0.15) and epithelial cells (0.3). The ICC for symptom scores and the CRQ domains ranged between 0.87 and 0.96. In conclusion, sputum induction is safe and the cell and fluid phase mediators repeatable in the investigation of airway inflammation in patients with COPD. VAS symptom scores and the CRQ are reproducible outcome measures in COPD.     

Safety of sputum induction in moderate-to-severe chronic obstructive pulmonary disease

This retrospective study was designed to evaluate the safety and efficacy of a bronchoprotective sputum induction protocol in moderate to severe chronic obstructive pulmonary disease (COPD). Forty-two adults with COPD (FEV1 = 51.7 +/- 3.2% predicted (mean +/- SEM)) under went sputum induction using a protocol designed to minimize hypertonic saline-induced bronchoconstriction. Hypertonic (3%) saline was used for subjects with FEV1 > or = 50%, and normal (0.9%) saline was used for subjects with FEV1 < 50%. Primary outcomes were change in peak flow, FEV1 and oxygen saturation. Mean decline in peak flow during sputum induction was 13.2 +/- 2.1%. FEV1 fell by 11.4 +/- 2.3%, an absolute fall of 0.14 +/- 0.031. Oxygen saturation did not change. A fall in peak flow of > or = 20% reliably predicted a fall in FEV1 of > or = 20%. Thirty-five of 42 subjects (83.3%) produced an acceptable sputum sample. Sputum eosinophil and neutrophil percentages were 2.8 +/- 0.9 and 73.0 +/- 3.0%, respectively, and were not correlated with changes in peak flow, FEV1 or oxygen saturation. A protocol for sputum induction which restricts the use of hypertonic saline based on lung function is both safe and effective in subjects with moderate to severe COPD.     

Safety of sputum induction in chronic obstructive pulmonary disease.

The aim of the present study was to evaluate the safety of sputum induction in patients with varying severity of chronic obstructive pulmonary disease. The subjects were 28 smokers with baseline forced expiratory volume in one second (FEV1) of (mean and range) 1.8 (0.8-2.9) L that is 53 (28-69)% of the predicted and reversibility of 2.5 (-7.4-9.9)%. Sputum was induced after premedication with 200 microg salbutamol at increasing concentrations (0.9, 3, 4, and 5%) of hypertonic saline nebulized by an ultrasonic nebulizer. The procedure was well tolerated, and none of the patients reported major side-effects. However, the mean change from prebronchodilator FEV1 during induction was -8.5 (-23-11)%, p=0.001, and from postbronchodilator FEV1 -10.7 (-25-5)%, p<0.0001. Three (11%) of the patients had a fall in FEV1 from the prebronchodilator baseline of >20%, and a further 10 (36%) had a fall of 10-20%. Patients with greater reversibility in airway obstruction seemed to get the best benefit from the bronchodilator pretreatment, since there was an inverse relationship between reversibility in FEV1 and fall in FEV1 during induction (r=-0.4, p=0.03). It is concluded that sputum induction by hypertonic saline inhalation can cause meaningful bronchoconstriction in patients with chronic obstructive pulmonary disease, despite pretreatment with an inhaled beta2-agonist. The results highlight the importance of monitoring spirometry during sputum induction to detect bronchoconstriction.     

Blunted gamma delta T-lymphocyte response in chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) is characterised by an excessive inflammatory response to inhaled particles, mostly tobacco smoking. Although inflammation is present in all smokers, only a percentage of them develop COPD. T-lymphocytes are important effector and regulatory cells that participate actively in the inflammatory response of COPD. They comprise the T-cell receptor (TCR)-alpha beta (CD4+ and CD8+) and TCR-gamma delta T-lymphocytes. The latter represent a small percentage of the total T-cell population, but play a key role in tissue repair and mucosal homeostasis. To investigate TCR-alpha beta (CD4+ and CD8+) and TCR-gamma delta T-lymphocytes in COPD, the present authors determined, by flow cytometry, the distribution of both subpopulations in peripheral blood and bronchoalveolar lavage (BAL) samples obtained from patients with COPD, smokers with normal lung function and never-smokers. The present study found that: 1) the distribution of CD4+ and CD8+ lymphocytes in blood and BAL was similar in all three groups; 2) compared with nonsmokers, gamma delta T-lymphocytes were significantly increased in smokers with preserved lung function; and 3) this response was blunted in patients with COPD. These results highlight a novel, potentially relevant, pathogenic mechanism in chronic obstructive pulmonary disease.     

白介素8与慢性阻塞性肺疾病

慢性阻塞性肺疾病(chronic obstructive pulmonary disease,COPD)是呼吸系统的常见病、多发病,COPD患病人数多、病死率高,近年来发病率呈明显上升的趋势.COPD的确切发病机制尚不完全清楚,目前认为炎症是COPD发生发展的主要机制.白介素8(IL-8)是主要的炎症介质之一,在COPD患者多种因素可以导致其明显增高,IL-8有强力的中性粒细胞、T细胞及嗜碱粒细胞趋化作用,并可激活中性粒细胞,产生中性粒细胞反应,破坏肺泡,产生多种炎症效应.对IL-8的干预可能影响COPD的炎症过程.     

淋巴细胞趋化因子在慢性阻塞性肺疾病患者外周血中的表达及其对CD4+CD8+T细胞亚群的影响

目的 探讨淋巴细胞趋化因子(lymphotactin,XCL1)对COPD患者外周血CD4+ T、CD8+T细胞亚群及有关炎症因子的影响及机制.方法 随机选取1 3例COPD患者(急性加重期和稳定期)和13名健康人,分离外周血T淋巴细胞进行培养,经淋巴细胞趋化因子干预后,用流式细胞仪分别检测外周血中CD4+T、CD8+T细胞亚群变化及其表面Fas、FasL表达,并用酶联免疫吸附试验(enzymelinked immunosorbent assay,ELISA)分别检测血清及细胞培养上清液中的XCL1、IL-2表达水平.结果 AECOPD及稳定期患者外周血中的XCL1的表达均高于健康对照组(P＜0.05),AECOPD组又高于稳定期组患者(P＜0.05).COPD患者(包括急性发作期与稳定期)T细胞培养液中,XCL1干预组与未干预组相比,XCL1、CD4+-Fas、CD4+-FasL、CD8+-Fas、CD8+-FasL表达增高(P＜0.05),CD4+/CD8+降低(P＜0.05),而IL-2表达减少(P＜0.05).且XCL1的表达与CD4+-Fas、CD4+ FasL、CD8+-Fas、CD8+-FasL的表达呈正相关,与IL-2的表达及CD4+/CD8+呈负相关.结论 XCL1参与了COPD的炎症过程,其参与炎症反应的机制可能是通过促进Fas、FasL的表达,导致CD4+T、CD8+ T细胞的凋亡增加,CD4+ T/CD8+T比值下降,造成CD4+/℃D8 +比例失衡,XCL1还可引起IL-2水平降低,间接导致机体免疫功能紊乱或低下,可能是导致COPD炎症持续存在的重要机制.     

Predictors of positive sputum cultures in exacerbations of chronic obstructive pulmonary disease

Background and objective: Although sputum culture in patients with an acute exacerbation of COPD is of uncertain value, it is routinely done. The ability to clinically identify patients likely or unlikely to yield bacterial sputum isolates would potentially reduce unnecessary tests. The objective of this study was to identify the clinical predictors of positive sputum cultures in this patient population. Methods: Consecutive patients with a COPD exacerbation requiring an emergency visit were prospectively enrolled. Quantitative sputum culture was performed on‐site. Data on current smoking, sputum purulence, FEV₁, Medical Research Council chronic dyspnoea scale, BMI, severe exacerbations in the preceding year requiring hospitalization, PaO₂, PaCO₂, Acute Physiology and Chronic Health Evaluation (APACHE) II score, and oral and inhaled steroid use were recorded. Results: Of the 94 patients enrolled, sputum from 36 yielded bacterial pathogens. These patients were characterized by a higher frequency of purulent sputum, lower FEV₁, BMI and PaO_2, higher APACHE II score and more frequent use of inhaled steroids (P < 0.05). On multivariate regression, purulent sputum, FEV₁ and BMI were independent determinants of a positive sputum culture. Using receiver‐operator‐optimized thresholds for these variables (purulent sputum, FEV₁ < 35% predicted and BMI ≤ 22 kg/m²), we proposed a regression coefficient‐weighted prediction model that accurately determined the likelihood of sputum bacterial isolation. Conclusions: A prediction model based on the variables of purulent sputum, FEV₁ and BMI predicted sputum culture result with about 90% accuracy. Pending further validation, this model may save valuable healthcare resources.     

The cellular composition of induced sputum in chronic obstructive pulmonary disease.

Asthma and chronic obstructive pulmonary disease are characterized by airway inflammation, which can be assessed by bronchoscopic techniques as well as by the analysis of induced sputum. A method to induce sputum with inhaled hypertonic saline was adapted for use in 21 chronic obstructive pulmonary disease (COPD) patients (mean baseline forced expiratory volume in one second (FEV1) 1.60 L, or 54% predicted) and in 16 healthy volunteers. The success rate and safety of the method, were investigated along with the reproducibility of cell counts and differences in cell counts between both groups. All subjects produced adequate samples and the procedure did not alter spirometric values. A marked sputum neutrophilia was noted in patients with COPD (74.9+/-4.7%), whereas mainly macrophages were seen in healthy volunteers (74.0+/-4.0%). Reliability of the cell counts was high, both within investigators (r=0.99 neutrophils, r=0.99 macrophages) and between investigators (r=0.95 neutrophils, r=0.77 macrophages). In patients with COPD, an inverse correlation was noted between percentage of neutrophils and FEV1 (r(s)=-0.48, p<0.05). Immunostaining revealed a large proportion of activated macrophages in both groups. It was concluded that induction of sputum is a safe and reproducible method to study the composition of airway secretions in patients with chronic obstructive pulmonary disease.     

诱导痰嗜酸粒细胞检测在支气管哮喘-慢性阻塞性肺疾病重叠综合征中的应用

目的：本研究旨在探讨支气管哮喘(简称哮喘)-慢性阻塞性肺疾病重叠综合征(ACOS)患者诱导痰嗜酸粒细胞水平及其与吸入糖皮质激素(inhaled corticosteroid,ICS)治疗效果的关系,为 ACOS 的诊断及治疗提供依据。方法选择2012年6月至2014年6月广东省江门市中心医院诊治的稳定期 ACOS 患者60例(ACOS 组),同期在广东省江门市中心医院诊治的无合并哮喘的稳定期 COPD 患者60例(单纯 COPD 组)。所有受试者均接受单纯 ICS 治疗,治疗前后进行肺通气功能检查,支气管舒张试验,动脉血气分析,血嗜酸粒细胞计数及诱导痰中炎性细胞的分析。结果外周血嗜酸粒细胞计数和诱导痰嗜酸粒细胞计数 ACOS 组均显著高于单纯 COPD 组。ROC 曲线分析显示以2.5%为截点,诱导痰嗜酸粒细胞计数诊断 ACOS 的敏感性为82.4%,特异性为84.8%。ICS 治疗后的 FEV1值增幅 ACOS 组亦显著高于单纯 COPD 组。ACOS 组 ICS 治疗后的 FEV1值增幅与诱导痰嗜酸粒细胞计数呈显著正相关。结论诱导痰嗜酸粒细胞检测可以作为 ACOS 和 COPD 鉴别诊断的指标之一,且能较好的预测 ACOS 对 ICS 治疗的反应性。     

AECOPD外周血CD3＋、CD4＋、CD8＋及CD16＋56＋细胞表达变化及胸腺五肽的干预作用

目的 探讨慢性阻塞性肺疾病急性加重期（AECOPD）患者外周血CD3＋、CD4＋、CD8＋及CD16＋ 56＋细胞的表达变化及胸腺五肽的干预作用.方法 用流式细胞术分别检测AECOPD患者21例胸腺五肽干预治疗前、后和健康人对照组20例外周血CD3＋、CD4＋、CD8＋T细胞和CD16＋ 56＋ （NK）细胞的百分率,比较AECOPD患者与对照组、AECOPD患者胸腺五肽干预前、后淋巴细胞亚群的变化.结果 AECOPD患者与对照组比较,血清CD3＋、CD4＋、CD16＋ 56＋百分率、CD4＋/CD8＋明显降低,差异有统计学意义（P＜0.05）;胸腺五肽干预后与干预前比较,血清CD3＋、CD4＋、CD16＋ 56＋及CD4＋/CD8＋比值明显升高,差异有统计学意义（P＜0.05）.结论 AECOPD患者机体存在细胞免疫功能紊乱,胸腺五肽干预可提高患者免疫功能.     

Sequentially induced sputum in patients with asthma or chronic obstructive pulmonary disease.

It has been demonstrated that consecutive samples of induced sputum may differ with respect to cellular composition. The aim of this study was to compare two sequential sputum samples in patients with chronic obstructive pulmonary disease (COPD) and asthma with different severity. Two sputum inductions were performed 30 min apart and processed separately in healthy subjects (n=11), patients with moderate to severe COPD (n=10), asthmatics treated with beta2-agonists alone (group 1, n=11), inhaled steroids (group 2, n=12) or systemic steroids (group 3, n=7). In healthy subjects and asthma group 2, percentages of neutrophils decreased significantly between the two sputum inductions but did not change in COPD and asthma group 3. Percentages of eosinophils did not change significantly in any group of patients. Concentrations of interleukin (IL)-8 decreased significantly in the control group and asthma groups 1 and 2 but not in asthma group 3 and the COPD group. These data demonstrate differences in sputum composition between two consecutive samples which were most pronounced in healthy subjects. Therefore, pooling of sputum samples may affect the results, particularly in healthy subjects, in contrast to subjects with more severe asthma or chronic obstructive pulmonary disease. These findings may be suggestive of differences in the distribution of inflammation along the airways between distinct airway diseases.     

Association between cytokines in induced sputum and severity of chronic obstructive pulmonary disease

Cytokines are known to be increased in induced sputum in chronic obstructive pulmonary disease (COPD). In this study, the relationship between the levels of interleukin-6 (IL-6), interleukin-8 (IL-8), and tumour necrosis factor-alpha (TNF-alpha) in induced sputum of patients with exacerbation of COPD, and the severity of the disease, pulmonary function tests (PFT), arterial blood gases (ABG) were studied. Twenty-four patients with exacerbation of COPD were included in the study. The patients were grouped according to their PFT into two as: Group 1 (FEV1 below 50% of the predicted value, severe-very severe COPD, n=12) and, Group 2 (FEV1 above 50% of the predicted value, mild-moderate COPD, n=12). The levels of IL-6, IL-8 and TNF-alpha in induced sputum of the subjects were measured. The mean levels of IL-6, IL-8 and TNF-alpha in induced sputum were found to be higher in Group 1 (severe-very severe COPD) than in Group 2 (mild-moderate COPD). The differences in IL-6 and IL-8 levels between groups were statistically significant (P<0.05). A significant correlation was observed between the IL-6 value and FEV(1) (r=-0.435, P=0.034), FEV1/FVC (r=-0.446, P=0.029), PaO2 (r=-0.711, P=0.000), SaO2 (r=-0.444, P=0.030) and disease duration (r=0.427, P=0.037), respectively. Also, the level of IL-8 in induced sputum was inversely correlated with FEV1 (r=-0.562, P=0.004), PaO2 (r=-0.540, P=0.006) and SaO2 (r=-0.435, P=0.034). However, all three cytokines were positively correlated with the smoking load (r=0.653, P=0.001; r=0.439, P=0.032; r=0.649, P=0.001). We conclude, therefore, that in exacerbated COPD cases with greater degrees of obstruction of the airways have higher levels of cytokines in induced sputum. This can be interpreted to mean that these cytokines are related to the clinical parameters like the ABG and PFT and seem to be the determinant of the severity of the disease.