ABSTRACT
Objective To explore the correlation between the expression of serum specific antibody IgM,IgG and IgA in the respiratory syncytial virus (RSV) in hospitalized children,and the antibody indexes with early auxiliary diagnostic signifi cance were screened.Methods Using fluorescent quantitative polymerase chain reaction (FQ-PCR) to screen 50 cases of throat swabs which RSV RNA were positive in hospitalized children from 2015 to 2017 and using enzyme linked immunosorbent assay (ELISA) detected specific antibodies IgM,IgG and lgA in the children's serum.Meanwhile 95 cases of children's serum specimens without respiratory symptoms were taken as the control group.The results were analyzed by chi-square test.Results In the 50 cases of serum from children who's RSV RNA were positive from throat swabs,the positive rates of IgM,IgG,IgA and the three forms coming together were 24.00％,60.00％00,22.00％ and 16.00％ respectively.And the difference was statistically significant (x2 =28.19,P＜0.01).About the serums which were the same gender child patient in the experimental group and the control group,the positive rates of IgM,IgG and IgA had significant differences (x2 =9.16,P＜0.01).There was no significant difference in the positive rate of each antibody in the same experimental group or control group or control group (x2 =0.10,P＞0.05).IgM,IgG and IgA were not detected in acute laryngotracheal bronchitis.Only 1 case with IgG was detected in the acute upper respiratory infection.It was the highest that the detection rates of IgG in bronchial pneumonia and acute bronchitis were 41.38％ and 23.53％,and IgA was not been detected alone.In the group of ＜6 months,IgM and IgA were not detected within 7 days and 21 days.In the group of 1～5 years old,the positive rate of IgM within 7 days was 50％,which was the highest in all groups.And IgM,IgG and IgA could be detected in 21 days also.The positive rates of IgG and IgA in the age group of 5～10 years old were 100％ and 66.67％ respectively.Conclusion Specific antibodies of RSV-IgM,IgG and IgA cannot be used as a diadynamic criteria alone in early RSV infection.The spe cific antibody was not affected by gender.Upper respiratory tract infection RSV was difficult to produce IgM,IgG and IgA.The younger the child,was the slower the IgM and IgA were produced.At the same time,IgG was able to vertical transmis sion and it had no protective effect on body.That RSV could infect the body and cause clinical respiratory symptoms would be related with immunity.Finally,IgA was the earliest specific antibody and could not be alone.