RT Journal Article SR Electronic T1 Induced sputum, bronchoalveolar lavage and blood from mild asthmatics: inflammatory cells, lymphocyte subsets and soluble markers compared JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 828 OP 834 DO 10.1183/09031936.98.11040828 VO 11 IS 4 A1 E Pizzichini A1 MM Pizzichini A1 JC Kidney A1 A Efthimiadis A1 P Hussack A1 T Popov A1 G Cox A1 J Dolovich A1 P O'Byrne A1 FE Hargreave YR 1998 UL http://erj.ersjournals.com/content/11/4/828.abstract AB Airway inflammation in asthma can be measured directly by invasive bronchoalveolar lavage (BAL), directly and relatively noninvasively by induced sputum and indirectly from peripheral blood. We compared cellular and fluid phase indices of inflammation in induced sputum, BAL and blood from 11 adults with mild stable asthma. On one day, induced sputum selected from saliva was collected and on the next, blood and BAL. Median results of sputum compared with BAL showed a higher number of nonsquamous cells (53 versus 0.8 x 10(6) cells x mL(-1), p=0.003), more neutrophils (34.3 versus 1.0%, p<0.001), CD4+ and CD19+ T-cells (76.5 versus 54.7%, p=0.01 and 5.2 versus 1.1%, p=0.03, respectively), fewer macrophages (603 versus 95.0%, p=0.002) and markedly higher levels of eosinophil cationic protein (ECP) (264 versus 2.0 microg x L(-1), p<0.001), tryptase (17.6 versus 2.2 UI x L(-1), p<0.001) and fibrinogen (1,400 versus 150 microg x L(-1), p=0.001). Sputum and BAL neutrophils and CD4+ T-cells were strongly correlated. Sputum and BAL differed from blood by having higher proportions of T-cells (94.9 and 98.9% versus 87.7%, p=0.002) and lower proportions of CD19+ T-lymphocytes (p=0.04 and 0.006). Sputum also differed from blood by having higher proportions of CD4+ T-cells (76.5 versus 51.4%, p=0.001), lower proportions of CD8+ cells (24.0 versus 403%, p=0.04) and a higher CD4+/CD8+ ratio (3.3 versus 1.4, p=0.01). We conclude that in mild asthmatics, sputum, bronchoalveolar lavage and blood measure different compartments of inflammation. Induced selected sputum has the advantage over bronchoalveolar lavage of higher density of cell recovery and stronger signal for fluid-phase markers.