关键词: 闭塞性细支气管炎, 重症肺炎, CD4细胞, CD8细胞, NK细胞

Abstract: Objective：To investigate the significance of lymphocyte subsets changes in peripheral blood for early identification of children with post-infectious bronchiolitis obliterans(BO).
Methods：Forty-eight children admitted to Hunan Children's Hospital from June 2016 to June 2018, who were diagnosed with severe pneumonia at the initial stage of admission, were selected;the 24 cases of BO confirmed after adenovirus infection were in the observation group, and 24 children with severe pneumonia that did not progress to BO in the same period were selected as the control group.The lymphocyte subsets in both groups were determined by flow cytometry upon admission diagnosis of severe pneumonia.
Results：There was no significant difference in the number or ratio of total T lymphocytes and total B lymphocytes between the two groups(P<0.05).The number and ratio of CD4 cells in the observation group were significantly lower than those in the control group, and the difference was statistically significant(P<0.05).There was no statistically significant difference in the number of CD8 cells between the two groups(P<0.05), but the ratio of CD8 cells in the observation group was higher than that in the control group(P<0.05).The number and ratio of natural killer (NK) cells in the observation group were lower than those in the control group, and the difference was statistically significant(P<0.05).The difference in CD4/CD8 ratio between the two groups was statistically significant(P<0.05).
Conclusion：The number and ratio of CD4 and NK cells in children with severe pneumonia of secondary postinfectious BO may be used as indicators for early identification of BO.

Key words: Bronchiolitis obliterans, Severe pneumonia, CD4 cells, CD8 cells, NK cells