SEROLOGICAL SPECIATION OF HUMAN T-CELL LEUKEMIA-VIRUS INFECTIONS USING SYNTHETIC PEPTIDE ANTIGENS

In order to assess the specificity and sensitivity of two peptide-base d assays (Synth(TM) HTLV-I and HTLV-II enzyme-linked immunoassay [EIA] [UBI] and Select-HTLV(TM) EIA [IAF]) in discriminating between antibo dy to HTLV-I and HTLV-II infection, a panel of 186 well-characterised serum/plasma samples was tested by the two assays. The panel comprised 160 samples that by Western blot were confirmed to contain antibodies to HTLV-I/II and 26 samples that showed reactivity with gag but not e nv gene products. Both assays were found to be specific in that they d id not misclassify any of the 80 specimens from cases of tropical spas tic paraparesis or adult T-cell leukaemia/lymphoma, diseases believed to be HTLV-I associated, as anti-HTLV-II positive. Of the 160 specimen s confirmed as anti-HTLV-I/II positive by Western blot, 6.2% were nega tive or untypable in the Synth EIA compared with 13.7% in the Select E IA. Of the 26 Western blot indeterminate samples, 16 were negative by both assays. Five were typed as anti-HTLV-I by both assays and 5 as an ti HTLV-II by Select EIA only. The peptide based EIAs offer an economi cal and, in most cases, reliable means of discriminating between anti- HTLV-I and anti-HTLV-II. However, they should only be applied to sera that have been confirmed by Western blot or other methods as anti-HTLV -I/II positive. Even then they may fail to speciate sera from non-Japa nese, non-Afrocaribbean populations.