Characterization of airway inflammation after repeated exposures to occupational agents (original) (raw)

Changes in sputum cell counts after exposure to occupational agents: What do they mean?

Journal of Allergy and Clinical Immunology - J ALLERG CLIN IMMUNOL, 2001

= 10). Induced sputum and methacholine challenges were performed at the end of the control day and again at the end of the last day of exposure; the last day of exposure was always performed in the laboratory. Results: There was an increase in median sputum eosinophil and neutrophil numbers in subjects with positive SIC responses. Cell counts remained unchanged after exposure in asthmatic subjects without OA. A combination of a greater than 0.26 10 6 /mL increase in sputum eosinophil numbers and a decrease in the concentration of methacholine inducing a 20% fall in FEV 1 of at least 1.8-fold compared with baseline values predicted a 20% fall in FEV 1 in 96% (95% CI, 70%-99%) of patients. Conclusion: Exposure to occupational agents per se does not induce airway inflammation. Changes in both sputum eosinophil counts and methacholine responsiveness are satisfactory predictors of a significant bronchial responsiveness to occupational agents

The use of induced sputum to investigate airway inflammation

Thorax, 1997

Clinicians have been interested in the macroscopic and protocol , based on that described by Pin et al 7 using a relatively low output ultrasonic nebuliser (output 0.9 ml/ microscopic appearance of sputum in asthma since the last half of the 19th century when Charcot-Leyden crystals, min, particle size 5.6 m), results in successful sputum induction in 76% of normal and asthmatic subjects who Curschmann's spirals, and their association with sputum eosinophilia was first recognised in patients with asthma. 1 cannot produce sputum spontaneously. Cell counts and biochemical content of induced and spontaneous sputum Forty years ago Morrow Brown suggested that the microscopic examination of sputum might be clinically useful are similar with the exception of fibrinogen which is present in higher concentrations in spontaneous sputum. 11 With by showing that the presence of eosinophils in a crude Leishman stained sputum smear identified patients whose salbutamol premedication and careful monitoring of forced expiratory volume in one second (FEV 1 ) during sputum wheeze was responsive to corticosteroids. 2 Recently, with the recognition that even mild asthma is associated with induction in mild asthma significant bronchoconstriction rarely occurs, 7 but it is more common in patients with evidence of airway mucosal inflammation in bronchial biopsy specimens and bronchoalveolar lavage fluid, 3 4 there more severe or uncontrolled asthma. 12 In a recent study a third of sputum inductions in patients with asthma has been renewed interest in the use of sputum to assess airway inflammation non-invasively.

Induced sputum to assess airway inflammation: a study of reproducibility

Clinical & Experimental Allergy, 1997

Background Infiltration of the airways mucosa with activated inflammatory cells appears to be a major factor in the pathogenesis of asthma and other airway diseases. Examination of sputum provides a direct method to investigate airway inflammation non-invasively. Objectives The aim of the present study was to evaluate the reproducibility of cell counts on cytospins and fluid phase (eosinophil cationic protein, ECP) measurements in a selected portion of induced sputum. We aimed to confirm the validity of the tecnique by comparing measurements between stable asthmatics, allergic rhinithis and healthy subjects. Methods Sputum was induced with hypertonic saline (4.5%) twice within one week in 53 stable asthmatics, 16 subjects with seasonal rhinitis {out of the pollen season), and 19 healthy subjects. Reproducibility was examined within sample (two different plugs of the same sample) between sample (two specimens of induced sputum obtained within one week) and between examiners on stable subjects taking into account sample size, number of examinations per patients and Confidence Interval (CI) of the estimates. Results We have found that the method is highly reproducible within sample and between examiners for all types of cells and fluid phase measurements of ECP. It is reproducible between sample for eosinophils, macrophages, neutrophils and ECP, but not for lymphocytes and weakly for epithelial cells. Sputum from asthmatics, in comparison with the sputum of healthy subjects and subjects with rhinitis had higher eosinophils (asthmatics: 12.2% ±12.9, rhinitis: 0.4 ± 0.8, normals: 0.4±0.7(%) and ECP (asthmatics: 827 ± 491 figfL, rhinitis: 127 ± 82 normals: 157 ± 203). No significant differences were found between healthy subjects and subjects with rhinitis. Eosinophil counts were inversely correlated with F^V, {r=-0.37) expressed as percentage of predicted, but not significantly correlated with PC20 methacholine {r=-0.28) or blood eosinophils (r-0.26). Conclusions The importance of this study is the confirmation, within important statistical guidelines for a study of reproducibility, that the methods examined are reproducible and valid.

Leukocyte counts in hypertonic saline-induced sputum in subjects with occupational asthma

Respiratory Medicine, 1998

We measured markers of eosinophilic inflammation in the blood and in the sputum induced by hypertonic saline (HS) inhalation of 24 subjects with occupational asthma who were still exposed to high molecular weight compounds (HMWCs, n=8) or to low molecular weight compounds (LMWCs, n=16); all subjects were symptomatic and showed bronchial hyperresponsiveness to methacholine at the time of study. Sputum cell counts were also measured in 14 normal subjects and in 24 subjects with non-occupational asthma with asthma severity similar to that of occupational asthmatics. Both occupational and non-occupational asthmatic subjects showed higher neutrophil percentages in HS-induced sputum than normal subjects, asthmatics with LMWC-induced asthma showing the highest values. Eosinophil percentages in HS-induced sputum were higher in non-occupational asthmatics and in asthmatics with HMWCinduced asthma than in normal subjects and in subjects with occupational asthma due to LMWCs. No difference in bronchial responsiveness, peak expiratory flow variability and serum eosinophil cationic protein (ECP) levels were observed among the different asthma groups. Although sputum eosinophil percentages significantly correlated with blood eosinophil percentages, sputum allowed the detection of a higher number of subjects with eosinophilic inflammation than blood. Serum ECP levels were normal in most asthmatic subjects. A significant correlation between sputum eosinophil percentages and bronchial hyperresponsiveness to HS was observed. Despite a similar degree of functional abnormalities, subjects with asthma due to LMWCs and still exposed to the occupational sensitizer showed a lower degree of eosinophilic inflammation and a higher degree of neutrophilic inflammation in the airways than subjects with occupational asthma due to HMWCs or non-occupational asthmatics. Furthermore, sputum eosinophil counts detect, better than blood indices, the degree of airway inflammation in both occupational and non-occupational asthma.

Induced sputum in children: feasibility, repeatability, and relation of findings to asthma severity

Thorax, 2000

The collection of induced sputum provides a non-invasive method of investigating airway inflammation. Few studies have been performed in children, so a study was undertaken to determine the feasibility of sputum induction, the repeatability of eosinophil counts and sputum eosinophil cationic protein (ECP) levels, and the relation of these to current asthma severity. For comparison, serum ECP levels were also measured. In a cross sectional study of children aged 5-15 years, 27 healthy children and 60 with asthma underwent sputum induction using inhaled nebulised hypertonic saline. The whole sputum sample was used for analysis. Ten children with stable asthma repeated the procedure within 10 days. A satisfactory sample (>500 non-squamous cells) was obtained in 61% of children with asthma and in 60% of healthy controls. The limits of agreement within subjects ranged from a 0.68 to 2.8 fold difference for eosinophil differential counts and from 0.38 to 4.4 fold for sputum ECP. Despit...

Comparison between eosinophilic markers in induced sputum and blood in asthmatic patients

Clinical <html_ent glyph="@amp;" ascii="&"/> Experimental Allergy, 1998

Background The usefulness and safety of the analysis of blood inflammatory markers in asthma are widely recognized. Recently, the analysis of induced sputum has been proposed as a safe, non-invasive tool in the study of airway inflammation in asthma. Objective Our aim was to test whether sputum analysis is more useful than blood analysis in the evaluation of airway inflammation in untreated and treated asthmatic patients. Methods Twelve untreated patients with mild to moderate asthma underwent a methacholine challenge test, sputum induction and blood sampling. A group of 14 normal subjects was also evaluated for baseline comparison. The same evaluation was repeated after 3 months of budesonide treatment. Before and after treatment, we tested the relationship of eosinophilic markers in induced sputum and blood with clinical and functional data. We also compared eosinophilic markers in induced sputum with the same markers in blood. Results Untreated patients showed a significant relationship between sputum eosinophils and symptom score, and between sputum eosinophilic cationic protein and symptom score, FEV 1 and PD 20 FEV 1. No relationship between blood eosinophilic markers and clinical or functional data was observed. In budesonide-treated patients, both sputum and blood eosinophils were significantly lower than in untreated patients, but eosinophil decrease was greater in sputum than in blood. Sputum eosinophilic proteins were also significantly lower in treated patients, whereas serum eosinophilic proteins were low at baseline and remained unchanged after treatment. Sputum eosinophilic markers were lower in normal subjects than in both untreated and treated patients, while blood eosinophils, but not serum eosinophilic cationic protein, were lower in normals than in untreated patients. Conclusions The analysis of induced sputum is more useful than the analysis of blood in the evaluation of asthma severity and of the effect of glucocorticoid treatment in patients with mild to moderate asthma.

Induced sputum is a reproducible method to assess airway inflammation in asthma

Mediators of Inflammation, 2002

To evaluate the reproducibility of induced sputum analysis, and to estimate the sample size required to obtained reliable results, sputum was induced by hypertonic saline inhalation in 29 asthmatic subjects on two different days. The whole sample method was used for analysis, and inflammatory cells were counted on cytospin slides. Reproducibility, expressed by intra-class correlation coefficients, was good for macrophages (+0.80), neutrophils (+0.85), and eosinophils (+0.87), but not for lymphocytes (+0.15). Detectable differences were 5.5% for macrophages, 0.6% for lymphocytes, 5.2% for neutrophils, and 3.0% for eosinophils. We conclude that analysis of induced sputum is a reproducible method to study airway inflammation in asthma. Sample sizes greater than ours give little improvement in the detectable difference of eosinophil percentages.