Format

Send to

Choose Destination
Clin Exp Allergy. 1997 Jul;27(7):769-79.

Comparison of inflammatory cell counts in asthma: induced sputum vs bronchoalveolar lavage and bronchial biopsies.

Author information

1
Department of Pulmonology, Leiden University Medical Centre, The Netherlands.

Abstract

BACKGROUND:

Induced sputum potentially allows monitoring of airway inflammation in patients with asthma in a non-invasive way. However, the relationship between the cellular content in sputum and airway tissue has not been fully clarified.

OBJECTIVE:

We compared the cellular compositions of hypertonic saline-induced sputum, bronchoalveolar lavage fluid (BAL) and bronchial biopsies in 18 clinically stable patients with mild to moderate atopic asthma (baseline FEV1: range 61-114%pred, PC20 methacholine: 0.04-4.7 mg/mL). They were treated with inhaled short-acting bronchodilators on demand, with (n = 8) or without (n = 10) regular inhaled steroids.

METHODS:

Each patient underwent sputum induction and fiberoptic bronchoscopy on separate days in random order. Differential cell counts of induced sputum, bronchoalveolar lavage and bronchial wash were determined on May-Gr├╝nwald-Giemsa stained cytospins. Flow cytometry was performed on sputum and BAL samples. Immunohistochemical techniques were used to stain inflammatory cells in 6 microm cryostat sections of bronchial biopsies.

RESULTS:

Sputum cell differentials were not different between the patients with and without inhaled steroids, and showed a median value of 19.4% squamous cells, with 1.0% eosinophils, 3.3% lymphocytes, 28.7% neutrophils, 49.4% macrophages and 6.9% cylindric epithelial cells (in percentage non-squamous cells). The percentage eosinophils in sputum was significantly correlated with their percentage in bronchial wash (Rs = 0.52, P = 0.03) and in BAL (Rs = 0.55, P= 0.02), whilst there was a trend towards such a correlation between the number of eosinophils/mL sputum and the number of EG2+ eosinophils/mm2 lamina propria in bronchial biopsies (Rs = 0.44, P = 0.07). In addition, the percentage of CD4+ lymphocytes correlated between sputum and BAL (Rs = 0.55, P = 0.03).

CONCLUSION:

We conclude that the eosinophil counts in hypertonic saline-induced sputum from patients with asthma are related to those in bronchial wash and BAL and, to a lesser extent, with the counts in bronchial biopsies. This suggests that induced sputum can be used to monitor the presence and severity of airway inflammation in asthma.

PMID:
9249269
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Wiley
Loading ...
Support Center