Sensitivities of radioimmunoprecipitation assay and PCR for detection of human T-lymphotropic type II infection.

Five hundred forty-eight uncoagulated blood specimens from intravenous drug users infected with human T-lymphotropic virus type II (HTLV-II) were used to evaluate the sensitivities of the radioimmunoprecipitation assay (RIPA) and PCR for detecting HTLV-II-infected people. The sensitivities of both RIPA and PCR were found to be dependent on the HTLV-II antibody titer, as determined by the immunofluorescence assay. Neither of these recommended confirmatory methods was as sensitive for detecting weakly reactive HTLV-II specimens as the immunofluorescence assay, Western blotting (immunoblotting), or a modified licensed enzyme immunoassay. Use of RIPA and PCR to determine the reliabilities of other tests may sometimes give erroneous results.