Detection of RS-virus IgG-subclass-specific antibodies: variation according to age in infants and small children and diagnostic value in RS-virus-infected small infants.
The variation according to age of RS-virus IgG-subclass specific antibodies was investigated by ELISA in 140 acute phase sera from 140 infants and children 1-47 mo of age who were hospitalized with acute respiratory disease. Sixty-nine of these serum samples were obtained from patients with RS-virus infections. Mean OD values of IgG-1 antibodies decreased corresponding to the decrease in maternal antibodies. In patients with RS-virus infections, the mean IgG-1 OD values increased in children who were 3 yr old, but in patients without RS-virus infections this increase was observed in children at 1 yr of age. RS-virus IgG-3 antibodies were detected only in children 1-3 yrs of age, and only in 18% of samples from children without RS-virus infections. The concept of the transient nature of RS-virus IgG-3 antibodies as compared with RS-virus IgG-1 antibodies is supported by these results. RS-virus subclass specific antibodies were studied in paired serum samples from 12 infants 1-5 mo of age with acute lower RS-virus disease. IgG-1 antibodies developed in six infants, but only in one of six infants aged 1-3 mo. IgG-3 antibodies developed in nine infants, including four of six infants who were 1-3 mo old. These results suggest that in small infants with RS-virus infections the detection of IgG-3 antibodies is of higher diagnostic value than the detection of IgG-1 antibodies.
D000208:Acute Disease; D000328:Adult; D000367:Age Factors; D000914:Antibodies, Viral / Q000032:analysis*; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis*; D007223:Infant; D007231:Infant, Newborn; D012136:Respiratory Syncytial Viruses / Q000276:immunology*; D012141:Respiratory Tract Infections / Q000276:immunology*; D010253:Respirovirus Infections / Q000175:diagnosis / Q000276:immunology*
D000914:Antibodies, Viral; D007074:Immunoglobulin G