ABSTRACT
PURPOSE: The aim of this study was to investigate the profile of bronchoalveolar lavage cell differentials and to compare the cell differentials between 3 different post-infectious BO (bronchiolitis obliterans)(Adenovirus BO, Mycoplasma BO, Measles BO) who showed a different clinical severity of illness. METHODS: Using a bronchoalveolar lavage (BAL) with flexible bronchoscopy procedure, this study investigated the cellular profiles of BAL fluid in children with BO caused by adenovirus (adenovirus BO, n=8), Mycoplasma(Mycoplasma BO, n=6) and measles (measles BO, n=6). These results were compared with clinical severity of illness score. Comparisons between all the groups were first made using the Kruskal-Wallis test. In case of significant difference, individual groups were compared by using the Mann-Whitney U test. RESULTS: The total cell number was higher in the adenovirus BO group than the Mycoplasma BO or the measles BO group, but the difference did not reach statistical significance. Neutrophil percentage was higher in the adenovirus BO group [72.5% (39.3-95.5); P<0.05], with no difference found between the Mycoplasma BO group [36.5%(8.8-60.4)] and the measles BO group [29.5%(20.8-58.1)]. The percentage of macrophages was lower in the adenovirus BO group [18%(4.5-42.0); P<0.05] than in Mycoplasma BO group [57.0%(38.5-76.0)] or measles BO group [54.5%(39.8-74.3)] in conjunction with a marked increase in the percentage of neutrophils. The high severity score children (65.0%, P<0.05) showed higher % nerutrophils than those of the low severity score children (29.0%). CONCLUSION: These results indicate that clinical severity of BO is associated with neutrophil proportion and suggest that neutrophils are playing an important role in the pathogenesis of the post infectious BO.