Diagnóstico serológico de HTLV-1/2: combinación de técnicas de tamizaje para definir el estatus serológico en donantes de sangre

ResumenCon el objetivo de reducir el número de resultados falsos reactivos al determinar los anticuerpos contra HTLV-1/2, se evaluaron algoritmos alternativos. De 20 210 muestras estudiadas, el 0,37 % (74/20 210) fueron reactivas por ELISA Murex Abbott. De estas, 23 se confirmaron positivas por inmunofluorescencia indirecta y 51 fueron negativas; valor predictivo positivo (VPP) 31,08 %. Al combinar ELISA Murex con aglutinación de partículas de gelatina (AP) y con ELISA MP, se obtuvieron los siguientes resultados: 26/74 resultaron reactivas por Murex y AP, VPP 88,5 %, y 32/74 reactivas con Murex y ELISA MP, VPP 71,8 %. Del análisis de la curva ROC se determinó que para un valor de RP de 4,74 por Murex, la sensibilidad, la especificidad, el VPP y el VPN son 100 %, 98,04 %, 95,8 % y 100 %, respectivamente. Proponemos que las muestras reactivas por ELISA Murex con RP ≤ 4,74 sean retesteadas por duplicado por AP, y que las que resulten concordantemente no reactivas sean definidas como negativas para HTLV-1/2.

Alternative algorithms were evaluated in order to reduce the number of false reactive results for antibodies against HTLV-1/2. From 20,210 samples tested, 0.37% (74/20,210) was reactive by ELISA Murex. Of these, 23 were confirmed as positive by the indirect immunofluorescence assay whereas 51 were negative, being the positive predictive value (PPV) 31.08%. From a combination of the ELISA Murex assay with the particle agglutination assay (PA) and ELISA MP, the following results were obtained: 26/74 were reactive by ELISA Murex and PA, PPV 88.5% and 32/74 were reactive by ELISA Murex and ELISA MP, PPV 71.8%. The ROC curve analysis determined that for an RP 4.74, the values for sensitivity, specificity, PPV and NPV by ELISA Murex were 100%, 98.04%, 95.8% and 100%, respectively. We propose that reactive samples by ELISA Murex with an RP ≤ 4.74 should be retested in duplicate by PA, and the resulting concordantly nonreactive samples should be defined as negative for HTLV-1/2.