Preliminary Study On Clinical Features Of Bronchiolitis In Children Infected With Human Rhinovirus And Wheezing-related Cellular Immune Function

Objective:To investigate the prevalence,epidemiology and clinical features of human rhinovirus(HRV)in children with bronchiolitis,and to conduct a preliminary study on the changes of cellular immune function in children with wheezing.Methods:1.Clinical data of children with bronchiolitis,selected from the department of respiration of Children’s Hospital of Soochow University from January to December 2017 were collected for retrospective analysis.Gender,age,specimen collection time,clinical manifestations,signs,previous medical history and length of hospital stay were collected.Meanwhile,nasopharyngeal secretions were collected and divided into three parts.The first part was detected by real-time fluorescence RT-PCR for human rhinovirus(HRV)and human metapneumovirus(HMPV);the second used real-time fluorescence PCR to detect human boka virus(HBoV);the third was used for immunofluorescence detection of respiratory syncytial virus(RSV),parainfluenza virus 1,2,3(Pinfl,2,3),adenovirus(ADV)and influenza virus A,B(InfA,B).The prevalence,epidemiology and clinical features of HRV in children with bronchiolitis were analyzed.2.Peripheral venous blood was collected from 36 hospitalized children with bronchiolitis with wheezing(13 HRV-positive and 23 RSV-positive)from August to December,2018.Flow cytometry was employed to analyze the proportion of Thl(CD4+IFN-γ+),Th2(CD4+IL-4+),Treg(CD4+CD25+CD127-/low)and Th17(CD4+IL-17A+)in peripheral venous blood.The proportion of PMN-MDSCs(CD11b+CD14-CD15+)and M-MDSCs(CDllb+CD14+CD15-HLA-DR-/low)in peripheral blood mononuclear cells(PBMCs)was also analyzed by flow cytometry.Results:1.In the 367 children with bronchiolitis,the total virus detection rate was 58.6%(215/367),of which the HRV detection rate was 22.1%(81/367),next to RSV(29.2%,107/367).There was no significant difference in HRV detection rate between male and female children(χ2=0.320,P=0.572).The HRV positive detection rate increased with age,from 13.3%of children aged 0-6 months to 40.0%of children aged>24 months,and the difference between groups was statistically significant(χ2=18.429,P=0.001).HRV infection was detected in four seasons,with the highest detection rate in summer and the lowest in winter(x2=26.532,P<0.001).In the clinical signs,100%of the children with HRV-positive bronchiolitis were accompanied by wheezing sound(P<0.001),while the moist rale in RSV-infected children were significantly higher than HRV-infected children(P=0.001).In addition,The rate of wheezing history in HRV-positive children with bronchiolitis was significantly higher than that in RSV-positive children(P<0.001).2.The proportion of Th1 and Th2 cells in CD4+T cells of HRV-infected children with bronchiolitis was slightly higher than that of RSV infection,and the difference was not statistically significant(P=0.392 and 0.214,respectively).The Thl/Th2 ratio in HRV infection group was lower than that in RSV infection group,but the difference was not statistically significant(P=0.449).3.The proportion of Th17 cells in HRV-infected children with bronchiolitis was slightly higher than that in RSV-infected children,and the difference was not statistically significant(P=0.183).The proportion of Treg cells was 1.50%(0.75%,2.55%)in HRV-infected children with bronchiolitis,which was significantly lower than that of RSV infection 2.40%(2.10%,3.50%)(P=0.030).For Treg/Th17 ratio,HRV infection group was significantly lower than RSV infection group(P=0.022).4.The proportion of PMN-MDSCs in HRV-infected children with bronchiolitis was significantly higher than that of MDSCs,with results of 2.368%(0.834%,8.476%)and 0.331%(0.610%,1.198%)(P=0.002);However,there was no statistically significant difference between the PMN-MDSCs and MDSCs in RSV-infected children with bronchiolitis(P=0.258).The proportion of PMN-MDSCs in peripheral blood mononuclear cells(PBMCs)was significantly higher than that in RSV infection group(P=0.011),while the proportion of M-MDSCs in peripheral blood mononuclear cells(PBMCs)in HRV infection group was significantly lower than that in RSV infection group(P=0.034).Conclusion:1.HRV is one of the main pathogens in hospitalized children with bronchiolitis.There is no significant gender difference in HRV infection,which usually occurs in spring and summer,and is the rarest in winter.In children with bronchiolitis,the older the age,the higher the likelihood of HRV infection.Compared with RSV infection,children with HRV-infected bronchiolitis had higher wheezing performance and a history of wheezing,while wet vowels were relatively low.2.Children with HRV-infected bronchiolitis with wheezing performance showed relatively higher proportion of Th1 cells and Th2 cells,and relatively lower Th1/Th2 ratio,a lower proportion of Treg cells and Treg/Th 17 ratio,higher PMN-MDSCs and lower M-MDSCs,combined with HRV children having a higher wheezing incidence and wheezing history,these cellular immune changes may be HRV-infected bronchiolitis,wheezing children are prone to repeated wheezing and progression to asthma,and also a potential mechanism for asthma that is more likely to occur than RSV infection...