Biomedical subjects

P Speckin

Publications and source records attributed to P Speckin.

2 recordsLinked to original sources

PubMed1998

Changes in sputum composition during sputum induction in healthy and asthmatic subjects.

BACKGROUND: Induced sputum is increasingly used to characterize the cellular and biochemical composition of the airways. OBJECTIVE: We studied whether the composition of induced sputum is different between samples obtained sequentially during one sputum induction. METHODS: Subjects with mild asthma (n=7) or healthy subjects (n=6) produced sputum during and after three consecutive 10 min periods of hypertonic saline inhalation. Samples were analysed separately for the three periods. To determine the reproducibility of the cellular composition, sputum induction was repeated on another two days. RESULTS: The mean percentage of neutrophils decreased significantly (P<0.01) during sputum induction in asthmatic (36.9, 29.8, 16.3%) and healthy subjects (43.6, 17.2, 18.0%). Correspondingly, percentages of macrophages increased and percentages of eosinophils were 4.9, 3.5, and 3.7% in the asthmatic and 0.6, 0.7, and 0.5% in the healthy subjects, without significant change over the three periods; mean eosinophil numbers were significantly higher in the subjects with asthma (P< 0.05). Reproducibility of percentage cell counts did not markedly depend on sampling periods in terms of coefficients of variation. The concentration of eosinophil cationic protein decreased in both groups during sputum induction (P<0.01), geometric mean values being 579, 143, 57.4 microg L(-1) in the asthmatic and 130, 47.3, 28.4 microg L(-1) in the healthy subjects. Similar changes were seen for lactate dehydrogenase. CONCLUSION: The separate analysis of induced sputum from three consecutive sampling periods of a single induction procedure demonstrated significant changes in their cellular and biochemical composition, both in healthy and mild asthmatic subjects.

Administration, Inhalation↗

PubMed1998

Changes in sputum composition between two inductions performed on consecutive days.

BACKGROUND: Sputnum induction is a non-invasive method for obtaining cellular and biochemical material from the airways and appears to be particularly suited for repeated testing. However, it has not been clarified whether repeated inductions lead to a change in sputum composition. The aim of this study was to compare induced sputum results between two inductions performed 24 hours apart. METHODS: Ten subjects with mild asthma and 19 healthy subjects were included. Sputum was obtained during three consecutive 10 minute periods of hypertonic saline inhalation. Samples were analysed separately for the three inhalation periods. Corresponding pooled values were computed, taking into account total cell numbers of each inhalation period. RESULTS: In the three consecutive inhalation periods mean (SE) percentages of neutrophils increased from 29.2 (4.2)%, 22.0 (4.6)% and 14.5 (2.9)% on day 1 to 43.1 (5.3)%, 34.8 (5.5)% and 25.7 (5.3)% on day 2 in healthy subjects and from 21.3 (4.3)%, 24.1 (5.9)% and 15.9 (3.7)% to 35.9 (6.9)%, 30.7 (7.1)% and 31.8 (6.5)% in asthmatic subjects. This parallel shift corresponded to a mean (95% CI) increase in the pooled percentages of neutrophils of 17.4 (11.6) to 23.3)% in healthy and 14.6 (1.2 to 28.0)% in asthmatic subjects. In contrast to neutrophils, the percentage of macrophages decreased from day 1 to day 2, while eosinophil and lymphocyte percentages did not change significantly. CONCLUSION: These results suggest that the induction procedure itself causes a change in the composition of sputum detectable after 24 hours. This effect has to be taken into account when repeated sputum induction is performed.

Adult↗