Evaluation of an enzyme-linked immunosorbent assay that measures rhinovirus-specific antibodies in human sera and nasal secretions.

Rhinovirus-specific antibodies have traditionally been detected by their ability to neutralise the homologous rhinovirus serotype in tissue culture. Recently, however, we have described an enzyme-linked immunosorbent assay that detects rhinovirus-specific antibodies in sera and nasal secretions [Barclay and Al-Nakib, 1987]. Here we describe an evaluation of the ELISA in a study involving 71 adult volunteers inoculated intranasally with human rhinovirus type 2 (HRV-2). Pre- and post-inoculation serum samples and pre-inoculation nasal washings were tested for the presence of HRV-2-specific antibodies by ELISA. Such antibodies were associated with protection against infection when present locally in nasal secretions, but when also present in the serum they were associated with protection against both infection and the development of illness. The antibody concentrations showed strong correlation with each other and with that of antibodies detected by the neutralisation test. Following HRV-2 infection, rises in HRV-2-specific IgA in sera detected by ELISA occurred more frequently than rises in neutralising antibody. These results suggest that the ELISA is a sensitive and reliable indicator of recent infection, as well as a predictor of homologous immune status.