Specific enzyme immunoassay for the detection of antibody to HTLV-III using rheumatoid factor-coated plates.

A 1-step method was developed to detect IgG antibody to human T-cell lymphotropic virus type III (HTLV-III). The supernatant of T-lymphocyte cultures infected with HTLV-III was incubated for several days with peroxidase-labelled anti-HTLV-III F(ab')2 antibody fragments. During this incubation period an enzyme-labelled immune complex (ELIC) was formed which could be stored at -20 degrees C. For the detection of anti-HTLV-III antibody only a single incubation step was required: ELIC and serum specimens were mixed in the wells of a microtitre plate coated with rheumatoid factor (RF). In the presence of HTLV-III specific antibody additional immune complexes form which are selectively bound to the immobilized RF. Compared with other routine procedures the test was able to detect antibody to HTLV-III with improved sensitivity and specificity.