Comparison of detection of antibody to the acquired immune deficiency syndrome virus by enzyme immunoassay, immunofluorescence, and Western blot methods

There was 100% agreement between enzyme immunoassay (EIA) (Abbott Laboratories), Western blot, and indirect immunofluorescence (IF) when these three methods were used to measure antibody to the acquired immune deficiency syndrome (AIDS) virus in sera from 142 high-risk individuals, indicating that IF was a sensitive alternative method for detecting antibody to this agent. Thirty-two (64%) of 50 EIA-positive plasma specimens from a blood bank and 6 (21%) of 28 EIA-positive sera from alternative testing sites were negative by IF. In addition, two EIA-negative sera from the latter group were positive by IF. Western blotting agreed with IF on those 40 specimens which gave discrepant results by EIA and IF. The IF method was determined to be equal to Western blotting in sensitivity and specificity for detection of AIDS antibody, and it was found to be useful for confirming positive EIA results, especially in specimens from individuals in low-risk groups.