Specific IgG antibodies against F and G glycoproteins of respiratory syncytial virus (RSV) in asthmatic children after infection with the virus

Abstract

Objective To determine the level of serum specific IgG antibodies against F and G glycoproteins of respiratory syncytial virus ( RSV) and the relationship between the level of these antibodies and the status of RSV infection. Methods Indirect enzyme-linked immunosorbent assay (ELISA) was used to detect the IgG responses to RSV, F and G glycoproteins in paired sera of 66 asthmatic children under 6 years of age. RSV F and G glycoprotein antigens were produced by expression of recombinant vaccinia virus. Results (1) RSV was verified in 35% of asthmatic children. (2) The mean levels of IgG F and G antibodies in acute sera were lower in those who subsequently became infected than in those who did not become infected. (3) The mean level of serum IgG antibody to F protein before infection was higher in those who had mild attack of asthma. (4) Titers of antibodis against both F and G glycoproteins significantly increased after RSV infection, but the IgG response was similar among different age groups; there were no significant differences between the IgG responses to F and G protein. Conclusion The level of serum IgG antibodies against F and G protein would protect asthmatic patients against RSV infection, and could also reflect the severity of asthma attacks. Key words: Asthma; Respiratory syncytial virus infection; Membrane glycoproteins; G-proteins; IgG