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

BERINI C; PASCUSCCIO S; GENDLER S; EIRIN ME; SALOMON H; BIGLIONE M

Hakone, Japan

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

Background: Screening assays for HTLV-1/2 are widely used in routine testing of blood donors (BD). In December 2004, HTLV-1/2 screening became mandatory in blood banks of Argentina. Data about the efficiency of some screening tests is available. The aim of this study was to compare the performance of four commercial screening assays that are commonly used at the initial diagnosis of HTLV-1/2 infection in blood banks in Argentina. 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.) Nested-PCR results were used as the reference standards. Results: The more sensitive and specific test for HTLV-1/2 infection was Murex (99.3%, 99.7%), followed by BioKit (97.9%, 97.3%), Fujirebio (97.9%, 96.1%), and Vironostika (85.3%, 92.8%). The test agreement (kappa) between screening tests and nested-PCR results was 0.97 for Murex, 0.94 for BioKit, 0.92 for Fujirebio, and 0.86 for Vironostika. Conclusions: Murex resulted the most sensitive and specific assay and Vironostika reported the lowest performance being this the only one approved by the Food and Drug Administration. A combination of highly sensitive and specific ELISAs would considerably reduce the quantity of seroindeterminate results by WB and therefore reduce the need of a PCR to ultimate the diagnosis. 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.