Comparison of two commercially available anti-HIV ELISAs: Abbott HTLV III EIA and Du Pont HTLV III-ELISA

Serum specimens were tested for HIV antibodies by two commercially available ELISAs (Abbott HTLV III EIA and Du Pont HTLV III-ELISA). The specificity and sensitivity of these assays were determined by comparison with indirect immunofluorescence and Western blot analysis. Specificity ranged from 94.3% in the Abbott assay to 97.9% in the Du Pont-ELISA. The sensitivity was 100% in the Abbott-ELISA and 99% in the Du Pont test. With both tests, false-positive results occurred predominantly in sera from patients with immunological disorders (kidney transplant recipients, lymphoma, Stevens-Johnson syndrome, etc.), whereas symptomatic AIDS-patients, patients with ARC, and persons with a defined risk for HIV infection could be diagnosed unequivocally. Specificity and sensitivity of anti-HIV ELISAs seemed to depend not only on definition of the cutoff value but also on other factors, such as antigen preparation and inactivation measures. Testing of ELISA-reactive sera by confirmatory tests remains necessary.