C. Lensmar et al., LEUKOCYTE COUNTS AND MACROPHAGE PHENOTYPES IN INDUCED SPUTUM AND BRONCHOALVEOLAR LAVAGE FLUID FROM NORMAL SUBJECTS, The European respiratory journal, 12(3), 1998, pp. 595-600
It is unclear whether leukocytes in induced sputum (TS) and bronchoalv
eolar lavage (BAL) represent the same cell populations. To compare leu
kocyte counts and macrophage phenotypes and investigate any measurable
dithiothreitol (DTT)-mediated effect on macrophage immunocytochemical
staining results, IS and BAL samples from nine healthy smokers and se
ven nonsmokers were examined. BAL and IS samples were processed and ce
ll viability and cell counts were assessed. The macrophages were chara
cterized by seven monoclonal antibodies (RFD1, RFD7, CD11b, CD54, CD68
, CD71 and HLA-DR) using an indirect immunoalkaline phosphatase method
, Intraindividual comparison of IS and BAL showed that IS samples from
smokers and nonsmokers contained a lower total cell count (p<0.01 smo
kers, p<0.05 nonsmokers), a lower percentage of macrophages (both p<0.
05) and a higher percentage of neutrophils (both p<0.05) than BAL samp
les. In addition, nonsmokers sputum samples contained a lower proporti
on of lymphocytes (p<0.05) than BAL, The macrophage expression of RFD7
and CD71 was higher in smokers sputum samples (both p<0.05) than in B
AL, while nonsmokers sputum macrophages showed a higher expression of
CD54 and CD71 (both p<0.05) than BAL macrophages. DTT-incubated BAL sa
mples showed no difference in macrophage antigen expression from BAL s
amples not exposed to DTT. In conclusion, the relative proportions of
leukocytes and the macrophage phenotypes differed between induced sput
um and bronchoalveolar lavage suggesting that the methods provide samp
les from different lung compartments, inhabited by cells with differen
t phenotypes.