CD4 and susceptibility to pneumonia measurement: Results showed that the number of Th17 cells (CD3+CD8−IL-17+) in the asthma attack group (2.13 ± 1.78%) was significantly more than that in the asthma remission group (1.67 ± 0.40%), pneumonia group (1.56 ± 0.42%), and control group (1.53 ± 0.56%), whereas the number of Treg cells (CD4+CD25high+CD127low) in the asthma attack group (3.29 ± 1.23%) was significantly less when compared to that in the three remaining groups (5.66 ± 1.65%, 5.86 ± 1.93%, and 6.47 ± 2.87% for the asthma remission, pneumonia, and control groups, respectively, Fig. 1b–d).