Respiratory syncytial virus detection by immunofluorescence in nasal secretions with monoclonal antibodies against selected surface and internal proteins

Specimens containing respiratory tract epithelial cells from infants and children with acute respiratory disease were evaluated by using an indirect immunofluorescence technique with two specific respiratory syncytial virus monoclonal antibodies. One (RS/HN 13-1) was directed against a cell surface viral antigen, and the other (RS/HN 25-2) was directed against viral antigen present in large cytoplasmic inclusions. The same results on presence or absence of respiratory syncytial virus were obtained by cell culture and immunofluorescence in 93% of 252 patients tested adequately by both methods. The sensitivity of indirect immunofluorescence was approximately equal to that of cell culture. A total of 84 specimens were positive for RSV by immunofluorescence; 82 of them were positive with both monoclones, and the remaining 2 were positive only with the monoclone directed against the internal protein. The fluorescence pattern of the latter monoclone was unique and easily recognized. Indirect immunofluorescence testing with monoclonal antibodies to respiratory syncytial virus proved to be a very useful diagnostic technique, and results could be obtained within 4 h of specimen collection.