Use of induced sputum cell counts to investigate airway inflammation in asthma.

Pin, Isabelle; Gibson, Peter G.; Kolendowicz, R.; Girgis-Gabardo, Adele; Denburg, Judah A.; Fe, Hargreave; Dolovich, J.

doi:10.1136/thx.47.1.25

Cited by 851 publications

(716 citation statements)

References 20 publications

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“…The original studies introducing the sputum induction method reported few side-effects and no fall in FEV1 [15,16]. Studies concentrating upon safety aspects of sputum induction have found it safe even in patients with severe asthma [6±9] and in COPD [1±4].…”

Section: Discussionmentioning

confidence: 99%

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Safety of sputum induction in chronic obstructive pulmonary disease

Rytilä¹,

Lindqvist²,

Laitinen³

2000

Eur Respir J

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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 mg 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 sideeffects. 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 b 2 -agonist. The results highlight the importance of monitoring spirometry during sputum induction to detect bronchoconstriction. Eur Respir J 2000; 15: 1116±1119. The study was supported by Astra Charnwood, UK and P. Rytila È was supported by a grant from the Ida Montin Foundation, Finland.Sputum induction by inhalation of hypertonic saline has been used as a direct and relatively noninvasive method to investigate airway inflammation. It has been applied in patients with asthma and chronic obstructive pulmonary disease (COPD) [1±4]. Sputum-induction methodology may offer important benefits in diagnosing patients with airflow obstruction and in comparing treatment strategies.Although no standardized method for the induction of sputum has been agreed upon, recently a consensus on the use of sputum induction in asthma has appeared [5]. The challenge procedure should be performed in a standardized manner, because hypertonic saline can cause asthmatics to suffer from airway constriction. This procedure includes spirometry before and during the induction as well as pretreatment with a short-acting b 2 -agonist.Some studies assess the safety of sputum induction in patients with asthma [6±8], but information on patients with COPD is scarce [3,4]. The aim of the present study was to evaluate the safety and success of sputum induction in patients with varying severity of COPD [9]. Materials and methods SubjectsThe authors studied 28 patients with at least a 2-yr clinical diagnosis of symptomatic COPD [10] and a smoking history of 20±103 pack-yrs (table 1). Two (7%) of them were exsmokers, all others were current smokers. Patients had to fulfil the following criteria: 1) prebronchod...

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Section: Discussionmentioning

confidence: 99%

“…min -1 , particle-size 4.5 mm). The original paper on asthmatics by PIN et al [15] used a relatively low-output ultrasonic nebulizer (output 0.9 mL . min -1 , particle-size 5.6 mm), with which significant bronchoconstriction rarely occurred.…”

Section: Discussionmentioning

confidence: 99%

Safety of sputum induction in chronic obstructive pulmonary disease

Rytilä¹,

Lindqvist²,

Laitinen³

2000

Eur Respir J

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“…Eur Respir J 2000; 16: 324±329. The method of induced sputum is widely used as a noninvasive procedure for obtaining biological samples from the airways [1,2] in order to determine their cellular and biochemical composition in relation to airway diseases [3,4]. As sputum cells are embedded in airway secretions, the material has to be liquified in order to prepare singlecell suspensions for flow cytometry.…”

mentioning

confidence: 99%

Flow cytometric analysis of the effect of dithiothreitol on leukocyte surface markers

Loppow¹,

Böttcher²,

Gercken³

et al. 2000

Eur Respir J

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Pretreatment with dithiothreitol (DTT) is necessary to dissolve mucus in samples of induced sputum prior to analysis. However, DTT may affect cell surface markers which are essential for lymphocyte subtyping. Therefore, the aim of this study was to evaluate the effect of DTT on an appropriate panel of surface markers. Peripheral blood leukocytes were used because these cells, in contrast to sputum cells, could be obtained without DTT treatment.Peripheral blood from healthy donors was incubated with either DTT according to standard sputum procedures or phosphate-buffered saline (PBS), washed and incubated with fluorochrome-labelled antibodies. After lysis of erythrocytes, analysis was performed using a calibrated flow cytometer. Leukocyte populations were identified by their light scattering properties. For analysis, fluorescence intensity was compared between DTT-and PBS-treated samples.After treatment with DTT, fluorescence intensity was significantly increased in CD16-positive granulocytes; it was reduced in CD2-positive lymphocytes, CD45-positive lymphocytes and CD14-positive monocytes (p#0.001). These changes occurred in all samples. The fluorescence intensity of CD3-, CD4-, CD8-, CD19-, CD56-and histocompatibility leukocyte antigen DR-positive lymphocytes was not altered by DTT. However, there were statistically significant (p<0.001), although small, changes in the percentages of leukocytes.The present data demonstrate that, although dithiothreitol as used in sputum analysis affects some surface markers of peripheral blood leukocytes, comparability between samples concerning lymphocyte surface markers is preserved. Therefore, it is suggested that treatment of sputum samples with dithiothreitol does not invalidate the immunocytochemical analysis of lymphocytes. Eur Respir J 2000; 16: 324±329. The method of induced sputum is widely used as a noninvasive procedure for obtaining biological samples from the airways [1,2] in order to determine their cellular and biochemical composition in relation to airway diseases [3,4]. As sputum cells are embedded in airway secretions, the material has to be liquified in order to prepare singlecell suspensions for flow cytometry. This can be achieved by incubation with the potent reducing agent dithiothreitol (DTT, 2,3-dihydroxybutane-1,4-dithiol) [5]. Therefore, DTT is widely used in sputum processing [6±9]. However, owing to its reducing properties, DTT could affect the three-dimensional structure of proteins, which is maintained by disulphide bonds, thereby leading to changes in the availability and integrity of epitopes which could hamper immunological detection procedures [10].Indeed, the data which are available indicate effects of DTT or dithioerythritol (DTE) on surface markers assessed by flow cytometry on eosinophils or neutrophils even if cell viability remains unchanged [11±13]. Data regarding markers that are essential for lymphocyte subtyping have been published in abstract form [14]. Recent data have shown improved cell and sputum supernatant inflamma...

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“…Basically two protocols describing the procedure of induction and subsequent processing of samples have been proposed [1,2]. These protocols have been modified in multiple respects subsequently, and the procedures used by different research groups vary considerably in detail.…”

Section: Induction and Processingmentioning

confidence: 99%

Noninvasive methods to measure airway inflammation: future considerations

et al. 2000

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This last contribution to the series focuses on open questions regarding: 1) methodological issues; and 2) the potential clinical application of the noninvasive methods such as induced sputum and the analysis of exhaled air for the assessment of airway inflammation. In addition their potential future role in occupational health and the early diagnosis of neoplastic lesions are briefly discussed. The future clinical application of noninvasive methods will depend on the progress made to improve their practicability, particularly in rendering them less time consuming and cheaper. To assess their clinical value, prospective studies are needed to establish whether patients actually benefit from the results obtained. This is also important to implement the methods into the healthcare system and to obtain adequate financial compensation. Therefore, it is necessary to know: 1) whether the assessment of airway inflam‐mation can aid in coming to an earlier and better defined diagnosis; 2) whether by repeated monitoring it is possible to avoid exacerbations through earlier interventions; and 3) whether the long‐term outcome of patients is improved through knowledge of the type and degree of airway inflammation that is taken into account in selecting the appropriate treatment. In the meantime a wealth of data has become available, both for induced sputum and the analysis of exhaled air, which give these methods the potential to be incorporated into future clinical practice. This, however, will, amongst the other issues, depend on favourable cost‐benefit ratios which should also be the subject of future prospective studies.

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Use of induced sputum cell counts to investigate airway inflammation in asthma.

Cited by 851 publications

References 20 publications

Safety of sputum induction in chronic obstructive pulmonary disease

Safety of sputum induction in chronic obstructive pulmonary disease

Flow cytometric analysis of the effect of dithiothreitol on leukocyte surface markers

Noninvasive methods to measure airway inflammation: future considerations

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