Respiratory syncytial virus and allergic conjunctivitis.

The pathogenesis of allergic conjunctivitis is largely conjectural. We investigated the possible involvement of respiratory syncytial virus (RSV), a ubiquitous respiratory pathogen, in the development of allergic conjunctivitis through immune mechanisms. Brush cytology technique was used to obtain conjunctival cells from 30 patients with allergic conjunctivitis and 20 controls. Samples were assayed for the presence of RSV sequences with the reverse transcription polymerase chain reaction (RT-PCR) and the nested polymerase chain reaction (nested PCR). In order to further investigate the relation of RSV and allergic conjunctivitis, we performed an animal study. BALB/c mice were either infected with live RSV or sham infected intranasally. The mice were exposed to ovalbumin (OVA) with alum adjuvant. At differing intervals, levels of OVA concentration in serum and IgG-anti-OVA antibody were measured by ELISA and IgE-anti OVA antibody in serum was assessed by passive cutaneous anaphylaxis. RSV sequences were detected in 7 (23%) of 30 patient samples and 1 (5%) of 20 control samples. IgG and IgE antibody responses to OVA in serum were demonstrable only in RSV-infected mice immunized with OVA and alum. Our results proved that PCR could detect RSV sequences in conjunctival samples. RSV may be a significant pathogenic factor in allergic conjunctivitis.