Methods: Sera collected from asthmatic or non-asthmatic subjects from Costa Rica, Virginia, and northern Sweden were assayed for specific antibodies to RV capsid proteins. Specific IgE and IgG4 antibodies to RV-16 VP1 were measured by ImmunoCAP using biotinylated antigen coupled to a streptavidin immunosorbent. Serum IgG antibodies were adsorbed onto recombinant Protein G-Sepharose and incubated with radiolabeled RV-16 VP1 or RV-3 VP2. The radioactivity of bound antigen was measured using a gamma counter.
Results: IgG antibodies to RV-16 VP1 were higher in titer and prevalence compared to serum levels of IgG to RV-3 VP2 among subjects from Virginia. Specific IgE and IgG4 antibodies to RV-16 VP1 were detected in low quantities in subjects from Costa Rica and Virginia. Though not associated with atopy in Virginia or asthma in northern Sweden, asthmatic children from Costa Rica had higher levels of IgG antibodies to RV-16 VP1 compared to controls in that country. Furthermore, IgG antibodies to RV-16 VP1 were higher in Costa Rican children who were positive for RV-A by PCR compared to those positive to RV-C.
Conclusions: These data suggest the antibody response against RV is dominated by IgG1.