The development of respiratory syncytial virus-specific immune complexes in nasopharyngeal secretions following natural infection

Sequential samples of nasopharyngeal secretions (NPS) from 61 infants and children with respiratory syncytial virus (RSV) infection were examined for the presence of RSV-specific immune complexes in order to determine their possible role in recovery from or pathogenesis of RSV infection. Immune complexes in NPS were identified by the Raji cell assay using indirect immunofluorescence and RSV antigen in these complexes was also detected by indirect immunofluorescence. RSV-specific immune complexes were detected in 56% of subjects tested, being present as early as 3-6 days after the onset of illness and persisting for up to 36 days after the onset of illness. The appearance of immune complexes was temporally associated with the disappearance of RSV antigen from airway epithelial cells, suggesting a role for immune complexes in eradication of infection. RSV-specific immune complexes were identified with approximately equal frequency in patients with all forms of illness due to RSV, an observation which tends to rule out a role for immune complexes in the pathogenesis of RSV disease.