NKT Cells in the Induced Sputum of Severe Asthmatics

Abstract

To determine whether there was a specific inflammatory process in severe asthmatics, the phenotypic characteristics of induced sputum immune cells were analysed among patients with severe asthma. Twenty-two induced sputa (10 severe asthmatics) were studied. Flow cytometric analysis was performed using immune cells of the sputum and monoclonal antibodies to CD3, CD4, CD8, CD56, CD25, and TCRγδ . The number of NKT (CD3 + CD 56+ ) cells was significantly higher in the sputum of severe asthmatics compared with mild asthmatic and healthy control groups ( p<.05 ). CD8+CD 56+ cells were the predominant subtype of the increased NKT cells in severe asthmatics. CD3 +CD56+Vα24 +, TCRγδ CD56+, and CD4+CD25+ T cells were significantly increased in severe asthmatic patients. These results suggest that the immunopathogenesis of severe asthmatics vary between severe and mild asthmatics, and that CD8+ CD 56+ NKT cells may play an important role in the immunopathogenesis of severe asthma.