Comparison of four HTLV-I and HTLV-I plus II ELISAs

Background: Various countries require blood donor screening using assays ap plying specific HTLV-I and HTLV-II antigens. We evaluated the sensitivity a nd specificity of 4 anti-HTLV-I + II ELISAs (Abbott, Murex, Organon Teknika and Ortho). Methods: Panel A consisted of HTLV-I-positive individuals (n = 41), panel B of Mixed Titer Performance Panel 204 (Boston Biomedica Inc. p anels C and D of dilution series from HTLV-I-positive (n = 30) and HTLV-II- positive (n = 20) individuals and panel E of sera from first-time blood don ors (n = 1,055). Results: In HTLV-I- and -II-positive samples, a sensitivit y of 100% could be observed in all 4 ELISAs. In diluted HTLV-I- and -II-pos itive samples, probit analysis revealed that the Murex assay had the highes t analytical sensitivity, followed by the ELISAs from Ortho, Abbott and Org anon Teknika. In specimens from first-time donors, a specificity of 100% wa s observed in ELISAs from Murex, Organon Teknika and Ortho, and of 99.7% in the assay from Abbott. Conclusion: The 4 anti-HTLV-I + II ELISAs studied w ere appropriate as screening tests.