Comparison of HTLV-1/2 screening assays: an optimal efficiency of the current HTLV-1/2 diagnosis

BERINI C, PASCUCCIO S, GENDLER S, EIRIN ME, SALOMON H, BIGLIONE M.

Hakone, Japan

Congreso; 13th International Conference on Human Retrovirology: HTLV and related retroviruses; 2007

The International Retrovirology Association

Background: In 2005, HTLV screening became mandatory in BB of Argentina. The aim of this study was to compare the performance of 4 commercial assays commonly used at the initial diagnosis. Methods: 142 HTLV-1 and -2 seropositive and 336 seronegative samples from high-risk populations and BD were analyzed by 4 different commercial tests (3 ELISAs: BioKit, Vironostika and Murex, and PA test, Fujirebio). Reactive samples were analyzed by WB (HTLV-1/2 Genelabs). N-PCR results were used as the reference standards. Results: The sensitivity for HTLV-I was 100.0% for Biokit, 98.8% for Murex and Fujirebio, and 97.7% for Vironostika. Regarding HTLV-II, the sensitivity were 98.2% for Fujirebio, 96.4% for Biokit and 94.6% for Vironostika and Murex. The more sensitive and specific test for HTLV-1/2 infection was Murex (97.2%, 99.7%), followed by BioKit (98.6%, 97.0%), Fujirebio (98.6%, 95.8%), and Vironostika (96.5%, 92.9%). The test agreement (kappa) with the n-PCR results was 0.97 for Murex, 0.94 for Biokit, 0.92 for Fujirebio, and 0.86 for Vironostika. Conclusions: Vironostika, the only assay approved by the FDA, reported the lowest performance while Murex was the most efficient assay. A combination of highly sensitive and specific tests would considerably reduce the quantity of seroindeterminate results by WB and therefore reduce the need of a PCR. These results should be considered for choosing the better screening assays in order to obtain an optimal efficiency of the current HTLV-1/2 infection and diminish the final cost for HTLV-1/2 diagnosis.