Correlation between response to hepatitis B virus vaccine and cellular immunity and clinical characteristics in children with respiratory infection

Objective To analyze the correlation between response to hepatitis B virus (HBV) vaccine and cellular immunity and clinical characteristics in children with respiratory infection. Methods Nine hundred and sixty children in Department of Respiratory in Children′s Hospital of of Soochow University, who were over 7 months old and had full course of HBV vaccination between January and December 2015 were enrolled in this study.Peripheral blood (1-2 mL) was collected, and antigen-antibody of HBV was detected by using enzyme-linked immunosorbent assay and PCR included HBV surface antigen, hepatitis B antibody, HBV e antigen, HBV e antibody, HBV core antibody, and HBV nucleic acid.According to the results, these children were divided into 4 groups: non response group, low response group, normal response group and high response group according to their responses to HBV vaccine.Cellular immunity was detected by using flow cytometry and patients′ clinical data was collected. Results There was no statistical diffe-rences of CD3+ CD4+ , which were (3.43±0.28)%, (3.42±0.30)%, (3.43±0.36)% and (3.52±0.29)%, among the four groups (F=0.520, P=0.669). CD3+ CD8+ in non response group was (3.18±0.28)%, which was significantly higher than that in low response group, normal response group and high response group [(3.08±0.36)%, (3.05±0.34)%, (2.93±0.30)%] , the differences were significant (all P 0.05). CD3-CD19+and CD19+CD23+level were lowest in non response group[(3.00±0.57)%, (2.25±0.67)%] and highest in high response group [(3.33±0.45)%, (2.57±0.38)%], the differences were significant (all P 0.05). Proportion of severe pneumonia was significantly higher in non response group [6.1%(22/363cases)] and high response group [13.3% (2/15 cases)] compared to those in normal response group [2.6%(7/274cases)], the differences were statistically significant(χ2=4.417, P=0.036; χ2=5.476, P=0.019). The total white blood cell number was lowest in non response group (F=4.695, P=0.003). Platelet number was increased with higher degree of response to HBV (F=6.598, P<0.001). Conclusions Cellular immunity is lower in respiratory infection children with non response or low response to HBV vaccine.After they have respiratory infection, children with non response to HBV vaccine may have a longer course of disease and worse condition. Key words: Hepatitis B virus vaccine; Cellular immunity; Respiratory infection; Child