Comparison of fluorescent-antibody neutralizing-antibody and complement-enhanced neutralizing-antibody assays for detection of serum antibody to respiratory syncytial virus.

摘要

A comparison of three assays for the detection of serum antibody to respiratory syncytial virus (RSV) was carried out on 47 serum samples obtained sequentially from infants and young children with RSV infection. Neutralizing-antibody (NA) activity was determined by a semimicromethod of plaque reduction. Complement-enhanced NA activity was determined by the addition of guinea pig complement to NA assays. RSV antibody responses in immunoglobulin G, immunoglobulin M, and immunoglobulin A classes were determined by using indirect immunofluorescence techniques for fluorescent-antibody (FAb) assay. Antibody to RSV was detectable by all three techniques as early as 4 days after the onset of illness. At all phases of illness, titers obtained by complement-enhanced NA assays were significantly greater than those obtained by NA or FAb assays (P less than 0.01). RSV-FAb titers determined in the immunoglobulin G class correlated well with those determined by complement-enhanced NA or NA assays. The data suggest that the FAb assay for detection of RSV antibody in serum is somewhat less sensitive but also less laborious and more rapid than NA assays.